/* ============================================================
   STUDYHUB — style.css  v4 (2026 liquid glass overhaul)
   Ultra liquid glass, deep parallax, stream animations,
   aurora backgrounds, morphing orbs, scroll magic
   ============================================================ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
img, svg { display: block; }
button { font-family: inherit; cursor: pointer; border: none; background: none; }
a { text-decoration: none; color: inherit; }

/* ── DESIGN TOKENS ─────────────────────────────────────────── */
:root {
  --font: 'Inter', system-ui, sans-serif;
  --mono: 'JetBrains Mono', monospace;
  --nav-h: 52px;
  --sidebar-w: 280px;
  --max-w: 1100px;
  --r: 18px;
  --r-sm: 11px;
  --r-xs: 6px;
  --ease: cubic-bezier(.4,0,.2,1);
  --spring: cubic-bezier(.34,1.56,.64,1);
  --bounce: cubic-bezier(.68,-0.55,.27,1.55);
  --dur: .18s;
  --kyb: #4f8ef7;
  --prg: #34d399;
  --ces: #fbbf24;
  --mat: #c084fc;
  --ang: #f87171;
  --code: #34d399;
  --layout-max: 1140px;
  --layout-pad: 72px;
  --layout-gap: 22px;
  --block-pad: 32px;
  /* Liquid glass tokens */
  --glass-blur: 28px;
  --glass-sat: 180%;
  --glass-border: rgba(255,255,255,.13);
  --glass-shine: rgba(255,255,255,.08);
  --glass-shadow: 0 8px 40px rgba(0,0,0,.28), 0 2px 8px rgba(0,0,0,.18);
  --glass-inner: inset 0 1px 0 rgba(255,255,255,.12), inset 0 -1px 0 rgba(0,0,0,.08);
}
html[data-density="compact"] { --layout-max:900px; --layout-pad:40px; --layout-gap:14px; --block-pad:20px; }
html[data-density="wide"]    { --layout-max:1380px; --layout-pad:88px; --layout-gap:30px; --block-pad:40px; }

/* ── THEMES ────────────────────────────────────────────────── */
:root, [data-theme="dark"] {
  --bg:      #09090f;
  --bg2:     #111118;
  --bg3:     #18181f;
  --border:  rgba(255,255,255,.07);
  --border2: rgba(255,255,255,.13);
  --text:    #eaeaf4;
  --text2:   #7878a0;
  --text3:   #3a3a58;
  --accent:  #6366f1;
  --accent2: #818cf8;
  --surface: rgba(255,255,255,.035);
  --surface2:rgba(255,255,255,.08);
  --glass:   rgba(10,10,18,.52);
  --glass2:  rgba(16,16,26,.9);
  --glow:    rgba(99,102,241,.18);
  --glow2:   rgba(139,92,246,.12);
  color-scheme: dark;
}
[data-theme="light"] {
  --bg:#f4f4fb; --bg2:#ebebf5; --bg3:#e0e0ee;
  --border:rgba(0,0,0,.07); --border2:rgba(0,0,0,.13);
  --text:#0e0e1e; --text2:#48487a; --text3:#8888b0;
  --accent:#4f46e5; --accent2:#6366f1;
  --surface:rgba(0,0,0,.03); --surface2:rgba(0,0,0,.07);
  --glass:rgba(244,244,251,.78); --glass2:rgba(235,235,245,.95);
  --glow:rgba(79,70,229,.1); --glow2:rgba(99,102,241,.07);
  color-scheme: light;
}
[data-theme="forest"] {
  --bg:#050d07; --bg2:#0a1a0c; --bg3:#102214;
  --border:rgba(255,255,255,.07); --border2:rgba(255,255,255,.12);
  --text:#e6f5ea; --text2:#5e9a6e; --text3:#2a4e34;
  --accent:#22c55e; --accent2:#4ade80;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.08);
  --glass:rgba(5,13,7,.58); --glass2:rgba(10,26,12,.9);
  --glow:rgba(34,197,94,.18); --glow2:rgba(74,222,128,.1);
  color-scheme:dark;
}
[data-theme="ocean"] {
  --bg:#030c14; --bg2:#061626; --bg3:#0b2036;
  --border:rgba(255,255,255,.07); --border2:rgba(255,255,255,.12);
  --text:#ddf2fe; --text2:#4e96c4; --text3:#1a4868;
  --accent:#0ea5e9; --accent2:#38bdf8;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.08);
  --glass:rgba(3,12,20,.58); --glass2:rgba(6,22,38,.9);
  --glow:rgba(14,165,233,.18); --glow2:rgba(56,189,248,.1);
  color-scheme:dark;
}
[data-theme="sunset"] {
  --bg:#100707; --bg2:#1c0d09; --bg3:#28130e;
  --border:rgba(255,255,255,.07); --border2:rgba(255,255,255,.12);
  --text:#fef2ec; --text2:#b86858; --text3:#58281e;
  --accent:#f97316; --accent2:#fb923c;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.08);
  --glass:rgba(16,7,7,.58); --glass2:rgba(28,13,9,.9);
  --glow:rgba(249,115,22,.18); --glow2:rgba(251,146,60,.1);
  color-scheme:dark;
}
[data-theme="rose"] {
  --bg:#fff4f6; --bg2:#ffe6ec; --bg3:#ffd4de;
  --border:rgba(0,0,0,.07); --border2:rgba(0,0,0,.13);
  --text:#180810; --text2:#782e4e; --text3:#be8ea8;
  --accent:#e11d48; --accent2:#f43f5e;
  --surface:rgba(0,0,0,.03); --surface2:rgba(0,0,0,.07);
  --glass:rgba(255,244,246,.8); --glass2:rgba(255,230,236,.95);
  --glow:rgba(225,29,72,.1); --glow2:rgba(244,63,94,.07);
  color-scheme:light;
}
[data-theme="midnight"] {
  --bg:#000000; --bg2:#0a0a0a; --bg3:#111111;
  --border:rgba(255,255,255,.06); --border2:rgba(255,255,255,.1);
  --text:#e8e8e8; --text2:#666666; --text3:#333333;
  --accent:#a855f7; --accent2:#c084fc;
  --surface:rgba(255,255,255,.03); --surface2:rgba(255,255,255,.07);
  --glass:rgba(0,0,0,.7); --glass2:rgba(10,10,10,.95);
  --glow:rgba(168,85,247,.15); --glow2:rgba(192,132,252,.08);
  color-scheme:dark;
}
[data-theme="slate"] {
  --bg:#0f172a; --bg2:#1e293b; --bg3:#334155;
  --border:rgba(255,255,255,.08); --border2:rgba(255,255,255,.14);
  --text:#f1f5f9; --text2:#94a3b8; --text3:#475569;
  --accent:#38bdf8; --accent2:#7dd3fc;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.09);
  --glass:rgba(15,23,42,.6); --glass2:rgba(30,41,59,.92);
  --glow:rgba(56,189,248,.15); --glow2:rgba(125,211,252,.08);
  color-scheme:dark;
}
[data-theme="noir"] {
  --bg:#ffffff; --bg2:#ffffff; --bg3:#f0f0f0;
  --border:rgba(0,0,0,.12); --border2:rgba(0,0,0,.2);
  --text:#000000; --text2:#000000; --text3:#888888;
  --accent:#000000; --accent2:#333333;
  --surface:rgba(0,0,0,.04); --surface2:rgba(0,0,0,.09);
  --glass:rgba(255,255,255,.85); --glass2:rgba(255,255,255,.97);
  --glow:rgba(0,0,0,.08); --glow2:rgba(0,0,0,.04);
  color-scheme:light;
}
[data-theme="chalk"] {
  --bg:#0a0a0a; --bg2:#111111; --bg3:#1a1a1a;
  --border:rgba(255,255,255,.1); --border2:rgba(255,255,255,.18);
  --text:#ffffff; --text2:#ffffff; --text3:#555555;
  --accent:#ffffff; --accent2:#cccccc;
  --surface:rgba(255,255,255,.05); --surface2:rgba(255,255,255,.1);
  --glass:rgba(10,10,10,.7); --glass2:rgba(15,15,15,.95);
  --glow:rgba(255,255,255,.08); --glow2:rgba(255,255,255,.04);
  color-scheme:dark;
}
[data-theme="amber"] {
  --bg:#0d0800; --bg2:#1a1000; --bg3:#261800;
  --border:rgba(255,255,255,.07); --border2:rgba(255,255,255,.12);
  --text:#fef9ec; --text2:#c49a3c; --text3:#5a3e10;
  --accent:#f59e0b; --accent2:#fbbf24;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.08);
  --glass:rgba(13,8,0,.6); --glass2:rgba(26,16,0,.92);
  --glow:rgba(245,158,11,.18); --glow2:rgba(251,191,36,.1);
  color-scheme:dark;
}
[data-theme="mint"] {
  --bg:#f0fdf8; --bg2:#e0faf2; --bg3:#ccf5e8;
  --border:rgba(0,0,0,.07); --border2:rgba(0,0,0,.12);
  --text:#052e1c; --text2:#2d7a56; --text3:#7abf9e;
  --accent:#059669; --accent2:#10b981;
  --surface:rgba(0,0,0,.03); --surface2:rgba(0,0,0,.07);
  --glass:rgba(240,253,248,.82); --glass2:rgba(224,250,242,.96);
  --glow:rgba(5,150,105,.1); --glow2:rgba(16,185,129,.07);
  color-scheme:light;
}
[data-theme="lavender"] {
  --bg:#f5f3ff; --bg2:#ede9fe; --bg3:#ddd6fe;
  --border:rgba(0,0,0,.07); --border2:rgba(0,0,0,.12);
  --text:#1e1040; --text2:#6d4fc2; --text3:#a78bfa;
  --accent:#7c3aed; --accent2:#8b5cf6;
  --surface:rgba(0,0,0,.03); --surface2:rgba(0,0,0,.07);
  --glass:rgba(245,243,255,.82); --glass2:rgba(237,233,254,.96);
  --glow:rgba(124,58,237,.1); --glow2:rgba(139,92,246,.07);
  color-scheme:light;
}
[data-theme="crimson"] {
  --bg:#0a0005; --bg2:#150008; --bg3:#20000e;
  --border:rgba(255,255,255,.07); --border2:rgba(255,255,255,.12);
  --text:#ffe8f0; --text2:#c0405a; --text3:#5a1020;
  --accent:#e11d48; --accent2:#fb7185;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.08);
  --glass:rgba(10,0,5,.6); --glass2:rgba(21,0,8,.92);
  --glow:rgba(225,29,72,.2); --glow2:rgba(251,113,133,.1);
  color-scheme:dark;
}
[data-theme="nordic"] {
  --bg:#1a1f2e; --bg2:#242938; --bg3:#2e3448;
  --border:rgba(255,255,255,.08); --border2:rgba(255,255,255,.14);
  --text:#d8dee9; --text2:#81a1c1; --text3:#4c566a;
  --accent:#88c0d0; --accent2:#8fbcbb;
  --surface:rgba(255,255,255,.04); --surface2:rgba(255,255,255,.09);
  --glass:rgba(26,31,46,.62); --glass2:rgba(36,41,56,.93);
  --glow:rgba(136,192,208,.15); --glow2:rgba(143,188,187,.08);
  color-scheme:dark;
}
[data-theme="peach"] {
  --bg:#fff8f4; --bg2:#ffeee4; --bg3:#ffe0cc;
  --border:rgba(0,0,0,.07); --border2:rgba(0,0,0,.12);
  --text:#2a1008; --text2:#a0522d; --text3:#d4956a;
  --accent:#ea580c; --accent2:#f97316;
  --surface:rgba(0,0,0,.03); --surface2:rgba(0,0,0,.07);
  --glass:rgba(255,248,244,.82); --glass2:rgba(255,238,228,.96);
  --glow:rgba(234,88,12,.1); --glow2:rgba(249,115,22,.07);
  color-scheme:light;
}
[data-theme="cyber"] {
  --bg:#000a08; --bg2:#001410; --bg3:#001e18;
  --border:rgba(0,255,180,.1); --border2:rgba(0,255,180,.18);
  --text:#ccffe8; --text2:#00c896; --text3:#005a40;
  --accent:#00ff9d; --accent2:#00e5a0;
  --surface:rgba(0,255,180,.04); --surface2:rgba(0,255,180,.09);
  --glass:rgba(0,10,8,.65); --glass2:rgba(0,20,16,.93);
  --glow:rgba(0,255,157,.2); --glow2:rgba(0,229,160,.1);
  color-scheme:dark;
}
[data-theme="sepia"] {
  --bg:#f8f0e3; --bg2:#ede0c8; --bg3:#e0cfa8;
  --border:rgba(0,0,0,.08); --border2:rgba(0,0,0,.14);
  --text:#2c1a08; --text2:#7a5c38; --text3:#b89a70;
  --accent:#92400e; --accent2:#b45309;
  --surface:rgba(0,0,0,.04); --surface2:rgba(0,0,0,.08);
  --glass:rgba(248,240,227,.82); --glass2:rgba(237,224,200,.96);
  --glow:rgba(146,64,14,.1); --glow2:rgba(180,83,9,.07);
  color-scheme:light;
}

/* ── FONT SIZES ─────────────────────────────────────────────── */
html { font-size: 14px; scroll-behavior: smooth; }
html[data-font-size="sm"] { font-size: 12px !important; }
html[data-font-size="md"] { font-size: 14px !important; }
html[data-font-size="lg"] { font-size: 16px !important; }
html[data-font-size="xl"] { font-size: 18px !important; }

/* ── BASE ───────────────────────────────────────────────────── */
body {
  font-family: var(--font);
  font-size: 1rem;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease);
}
::-webkit-scrollbar { width: 5px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border2); border-radius: 99px; }
::-webkit-scrollbar-thumb:hover { background: var(--text3); }

/* ── AURORA BACKGROUND ──────────────────────────────────────── */
body::before {
  content: '';
  position: fixed; inset: 0; z-index: -1;
  background:
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(99,102,241,.07) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 80%, rgba(139,92,246,.05) 0%, transparent 55%),
    radial-gradient(ellipse 50% 40% at 50% 50%, rgba(14,165,233,.04) 0%, transparent 50%);
  pointer-events: none;
  animation: auroraShift 20s ease-in-out infinite alternate;
}
@keyframes auroraShift {
  0%   { opacity: 1; transform: scale(1) rotate(0deg); }
  50%  { opacity: .7; transform: scale(1.05) rotate(1deg); }
  100% { opacity: 1; transform: scale(1) rotate(0deg); }
}
[data-theme="light"] body::before {
  background:
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(79,70,229,.05) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 80%, rgba(139,92,246,.04) 0%, transparent 55%);
}

/* ── NAVBAR ─────────────────────────────────────────────────── */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 200;
  height: var(--nav-h);
  background: var(--glass);
  backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-sat));
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(var(--glass-sat));
  border-bottom: 1px solid transparent;
  transition: background var(--dur), box-shadow var(--dur), border-color var(--dur);
}
.navbar::after {
  content: '';
  position: absolute; bottom: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(99,102,241,.3), rgba(139,92,246,.2), transparent);
  opacity: 0; transition: opacity .4s;
}
.navbar.scrolled::after { opacity: 1; }
.navbar.scrolled {
  background: var(--glass2);
  border-bottom-color: var(--glass-border);
  box-shadow: 0 1px 0 var(--border), 0 4px 32px rgba(0,0,0,.22);
}
.navbar-inner {
  max-width: 1400px; margin: 0 auto;
  height: var(--nav-h);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 18px; gap: 12px;
}
.nav-left { display: flex; align-items: center; gap: 10px; }
.nav-right { display: flex; align-items: center; gap: 2px; }
.hamburger {
  display: flex; flex-direction: column; gap: 4px;
  padding: 6px; border-radius: var(--r-sm);
  transition: background var(--dur);
}
.hamburger:hover { background: var(--surface2); }
.hamburger span { display: block; width: 17px; height: 1.5px; background: var(--text2); border-radius: 2px; transition: background var(--dur); }
.hamburger:hover span { background: var(--text); }
.nav-logo {
  display: flex; align-items: center;
  font-size: 0.95rem; font-weight: 700; color: var(--text);
  letter-spacing: -.4px; text-decoration: none;
}
.nav-logo em {
  font-style: normal; font-weight: 800;
  background: linear-gradient(90deg, var(--accent), #a78bfa, #60a5fa);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.nav-breadcrumb {
  display: flex; align-items: center; gap: 5px;
  font-size: 0.8rem; color: var(--text2);
  flex: 1; justify-content: center;
}
.nav-breadcrumb .crumb { color: var(--text2); }
.nav-breadcrumb .crumb.active { color: var(--text); font-weight: 500; }
.nav-breadcrumb .sep { color: var(--text3); }
.icon-btn {
  width: 32px; height: 32px; border-radius: var(--r-sm);
  display: flex; align-items: center; justify-content: center;
  color: var(--text2);
  transition: background var(--dur), color var(--dur), transform .15s var(--spring);
}
.icon-btn:hover { background: var(--surface2); color: var(--text); transform: scale(1.08); }

/* ── SEARCH BAR ─────────────────────────────────────────────── */
.search-bar {
  position: fixed; top: var(--nav-h); left: 0; right: 0; z-index: 190;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  transform: translateY(-110%); opacity: 0;
  transition: transform .25s var(--ease), opacity .25s var(--ease);
  pointer-events: none;
}
.search-bar.open { transform: translateY(0); opacity: 1; pointer-events: all; }
.search-inner {
  max-width: var(--layout-max); margin: 0 auto;
  display: flex; align-items: center; gap: 10px;
  padding: 10px 18px; color: var(--text2);
}
.search-inner input {
  flex: 1; background: none; border: none; outline: none;
  font-family: var(--font); font-size: 0.95rem; color: var(--text);
  color-scheme: inherit;
}
.search-inner input::placeholder { color: var(--text3); }
.search-inner kbd {
  font-family: var(--mono); font-size: 0.6rem;
  background: var(--surface2); border: 1px solid var(--border2);
  border-radius: 3px; padding: 2px 5px; color: var(--text3);
}
.search-close-btn {
  width: 26px; height: 26px; border-radius: 5px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.75rem; color: var(--text3);
  transition: background var(--dur), color var(--dur); flex-shrink: 0;
}
.search-close-btn:hover { background: var(--surface2); color: var(--text); }
.search-results {
  max-width: var(--layout-max); margin: 0 auto;
  padding: 0 18px 10px;
  display: flex; flex-direction: column; gap: 1px;
  max-height: 50vh; overflow-y: auto;
}
.search-result-item {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 10px; border-radius: var(--r-sm);
  cursor: pointer; transition: background var(--dur);
}
.search-result-item:hover { background: var(--surface2); }
.search-result-cat {
  font-size: 0.6rem; font-weight: 700; letter-spacing: 1px;
  text-transform: uppercase; padding: 2px 7px; border-radius: 99px;
}
.search-result-cat.kyb { background: rgba(79,142,247,.15); color: var(--kyb); }
.search-result-cat.prg { background: rgba(52,211,153,.15); color: var(--prg); }
.search-result-cat.ces { background: rgba(251,191,36,.15); color: var(--ces); }
.search-result-cat.mat { background: rgba(192,132,252,.15); color: var(--mat); }
.search-result-cat.ang { background: rgba(248,113,113,.15); color: var(--ang); }
.search-result-title { font-size: 0.875rem; color: var(--text); }
.search-empty { padding: 16px; text-align: center; color: var(--text3); font-size: 0.8rem; }

/* ── SIDEBAR ────────────────────────────────────────────────── */
.sidebar {
  position: fixed; top: 0; left: 0; bottom: 0; z-index: 300;
  width: var(--sidebar-w);
  background: var(--glass2);
  backdrop-filter: blur(32px) saturate(180%);
  -webkit-backdrop-filter: blur(32px) saturate(180%);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  transform: translateX(-100%);
  transition: transform .28s var(--ease);
}
.sidebar.open { transform: translateX(0); }
.sidebar-top {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 16px; border-bottom: 1px solid var(--border); flex-shrink: 0;
}
.sidebar-label { font-size: 0.6rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; color: var(--text3); }
.sidebar-close {
  width: 26px; height: 26px; border-radius: 5px;
  display: flex; align-items: center; justify-content: center;
  color: var(--text3); font-size: 0.8rem; transition: background var(--dur);
}
.sidebar-close:hover { background: var(--surface2); color: var(--text); }
#sidebarNav { flex: 1; overflow-y: auto; padding: 8px; }
.sb-cat { margin-bottom: 1px; }
.sb-cat-btn {
  width: 100%; display: flex; align-items: center; gap: 8px;
  padding: 7px 10px; border-radius: var(--r-sm);
  font-size: 0.8rem; font-weight: 600; color: var(--text2);
  transition: background var(--dur), color var(--dur); text-align: left;
}
.sb-cat-btn:hover { background: var(--surface2); color: var(--text); }
.sb-cat-chevron { margin-left: auto; font-size: 0.55rem; color: var(--text3); transition: transform var(--dur); }
.sb-cat.open .sb-cat-chevron { transform: rotate(90deg); }
.sb-items { display: none; padding: 2px 0 3px 20px; }
.sb-cat.open .sb-items { display: block; }
.sb-item {
  display: block; width: 100%;
  padding: 5px 10px; border-radius: var(--r-sm);
  font-size: 0.75rem; color: var(--text3); text-align: left;
  transition: background var(--dur), color var(--dur);
  border-left: 2px solid transparent;
}
.sb-item:hover { background: var(--surface); color: var(--text2); }
.sb-item.active { color: var(--accent); border-left-color: var(--accent); background: var(--surface); }
.backdrop {
  position: fixed; inset: 0; z-index: 250;
  background: rgba(0,0,0,.55);
  backdrop-filter: blur(4px);
  opacity: 0; pointer-events: none;
  transition: opacity .25s var(--ease);
}
.backdrop.show { opacity: 1; pointer-events: all; }

/* ── SETTINGS PANEL ─────────────────────────────────────────── */
.panel {
  position: fixed; top: calc(var(--nav-h) + 6px); right: 12px; z-index: 210;
  width: 300px;
  background: var(--glass2);
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid var(--border2);
  border-radius: var(--r);
  box-shadow: 0 12px 48px rgba(0,0,0,.3), inset 0 1px 0 rgba(255,255,255,.08);
  opacity: 0; pointer-events: none;
  transform: translateY(-10px) scale(.96);
  transition: opacity .2s var(--ease), transform .2s var(--spring);
}
.panel.open { opacity: 1; pointer-events: all; transform: none; }
.panel-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 12px 14px 8px;
  font-size: 0.6rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; color: var(--text3);
  border-bottom: 1px solid var(--border);
}
.panel-close {
  width: 22px; height: 22px; border-radius: 4px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.65rem; color: var(--text3); transition: background var(--dur);
}
.panel-close:hover { background: var(--surface2); color: var(--text); }
.panel-section { padding: 12px 14px; border-bottom: 1px solid var(--border); }
.panel-section:last-child { border-bottom: none; }
.panel-section label { display: block; font-size: 0.75rem; color: var(--text2); margin-bottom: 8px; }
.size-row { display: flex; gap: 5px; }
.size-btn {
  flex: 1; padding: 7px 4px; border-radius: var(--r-sm);
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text2); font-family: var(--font);
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  transition: background var(--dur), border-color var(--dur), color var(--dur);
}
.size-btn:nth-child(1) { font-size: 0.7rem; }
.size-btn:nth-child(2) { font-size: 0.85rem; }
.size-btn:nth-child(3) { font-size: 1rem; }
.size-btn:nth-child(4) { font-size: 1.2rem; }
.size-btn small { font-size: 0.55rem; color: var(--text3); }
.size-btn.active, .size-btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.size-btn.active small, .size-btn:hover small { color: rgba(255,255,255,.7); }
.density-btn {
  flex: 1; padding: 7px 4px; border-radius: var(--r-sm);
  background: var(--surface); border: 1px solid var(--border);
  color: var(--text2); font-family: var(--font);
  display: flex; flex-direction: column; align-items: center; gap: 2px; font-size: 1rem;
  transition: background var(--dur), border-color var(--dur), color var(--dur);
}
.density-btn small { font-size: 0.55rem; color: var(--text3); }
.density-btn.active, .density-btn:hover { background: var(--accent); border-color: var(--accent); color: #fff; }
.density-btn.active small, .density-btn:hover small { color: rgba(255,255,255,.7); }
.theme-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.theme-swatch {
  display: flex; flex-direction: column; align-items: center; gap: 5px;
  padding: 8px 5px; border-radius: var(--r-sm);
  border: 2px solid transparent; cursor: pointer;
  transition: border-color .18s, transform .18s var(--spring);
  background: var(--surface);
}
.theme-swatch:hover { transform: translateY(-2px); border-color: var(--border2); }
.theme-swatch.active { border-color: var(--accent); }
.swatch-dot { width: 28px; height: 28px; border-radius: 50%; box-shadow: 0 2px 8px rgba(0,0,0,.3); }
.swatch-label { font-size: 0.6rem; color: var(--text2); font-weight: 500; }

/* ── PAGES ──────────────────────────────────────────────────── */
#app { margin-top: var(--nav-h); }
.page { display: none; }
.page.active { display: block; animation: pageIn .32s var(--ease); }
@keyframes pageIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.section { padding: var(--layout-pad) 18px; }
.section-inner { max-width: var(--layout-max); margin: 0 auto; }
.section-label {
  font-size: 0.65rem; font-weight: 700; letter-spacing: 2.5px; text-transform: uppercase;
  color: var(--text3); margin-bottom: 24px;
  display: flex; align-items: center; gap: 10px;
}
.section-label::before { content: ''; width: 16px; height: 2px; background: var(--accent); border-radius: 2px; }
.section-label::after { content: ''; flex: 1; height: 1px; background: var(--border); }

/* Reveal animations — staggered — see bottom of file */

/* ── HERO ───────────────────────────────────────────────────── */
.hero {
  position: relative; min-height: 100vh;
  display: flex; align-items: center; justify-content: center;
  overflow: hidden;
}
.hero-canvas {
  position: absolute; inset: 0; width: 100%; height: 100%;
  pointer-events: none; z-index: 0; opacity: .65;
}

/* Floating orbs — bigger, more vivid */
.hero-orbs { position: absolute; inset: 0; pointer-events: none; z-index: 0; }
.hero-orb {
  position: absolute; border-radius: 50%;
  filter: blur(90px); opacity: 0;
  animation: orbFloat 12s ease-in-out infinite;
}
.hero-orb-1 {
  width: 700px; height: 700px; top: -15%; left: -12%;
  background: radial-gradient(circle, rgba(99,102,241,.28), transparent 70%);
  animation-delay: 0s; animation-duration: 14s; opacity: .75;
}
.hero-orb-2 {
  width: 550px; height: 550px; top: 15%; right: -8%;
  background: radial-gradient(circle, rgba(139,92,246,.22), transparent 70%);
  animation-delay: -4s; animation-duration: 18s; opacity: .65;
}
.hero-orb-3 {
  width: 400px; height: 400px; bottom: 0%; left: 25%;
  background: radial-gradient(circle, rgba(14,165,233,.18), transparent 70%);
  animation-delay: -8s; animation-duration: 16s; opacity: .55;
}
.hero-orb-4 {
  width: 320px; height: 320px; top: 50%; right: 15%;
  background: radial-gradient(circle, rgba(52,211,153,.15), transparent 70%);
  animation-delay: -2s; animation-duration: 20s; opacity: .45;
}
.hero-orb-5 {
  width: 280px; height: 280px; bottom: 20%; left: 5%;
  background: radial-gradient(circle, rgba(249,115,22,.12), transparent 70%);
  animation-delay: -6s; animation-duration: 22s; opacity: .4;
}
@keyframes orbFloat {
  0%,100% { transform: translate(0,0) scale(1); }
  25%      { transform: translate(25px,-30px) scale(1.06); }
  50%      { transform: translate(-15px,20px) scale(.94); }
  75%      { transform: translate(20px,10px) scale(1.03); }
}

/* Floating subject chips — enhanced liquid glass */
.hero-chips { position: absolute; inset: 0; pointer-events: none; z-index: 1; }
.hero-chip {
  position: absolute;
  left: var(--x); top: var(--y);
  transform: translate(-50%, -50%);
  font-size: 0.6rem; font-weight: 800; letter-spacing: 2px; text-transform: uppercase;
  font-family: var(--mono);
  padding: 6px 14px; border-radius: 99px;
  background: rgba(255,255,255,.06);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255,255,255,.16);
  color: var(--text2);
  box-shadow:
    0 4px 20px rgba(0,0,0,.25),
    inset 0 1px 0 rgba(255,255,255,.14),
    inset 0 -1px 0 rgba(0,0,0,.1);
  animation: chipFloat 8s ease-in-out infinite;
  animation-delay: var(--d);
  opacity: .65;
  transition: opacity .3s;
}
.hero-chip:hover { opacity: 1; }
@keyframes chipFloat {
  0%,100% { transform: translate(-50%,-50%) translateY(0) rotate(0deg); }
  33%      { transform: translate(-50%,-50%) translateY(-12px) rotate(1deg); }
  66%      { transform: translate(-50%,-50%) translateY(-5px) rotate(-0.5deg); }
}

.hero-content {
  position: relative; z-index: 2;
  text-align: center; padding: 32px 18px;
  max-width: 760px;
}
.hero-eyebrow {
  font-size: 0.65rem; font-weight: 700; letter-spacing: 3px; text-transform: uppercase;
  color: var(--text3); margin-bottom: 28px;
  display: inline-flex; align-items: center; gap: 10px;
}
.hero-eyebrow::before, .hero-eyebrow::after {
  content: ''; display: inline-block; width: 24px; height: 1px; background: var(--border2);
}
.hero-h1 {
  font-size: clamp(3.5rem, 13vw, 8.5rem);
  font-weight: 800; line-height: .88; letter-spacing: -5px;
  color: var(--text); margin-bottom: 24px;
}
.hero-h1 em {
  font-style: normal;
  background: linear-gradient(135deg, var(--accent) 0%, #a78bfa 45%, #60a5fa 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  filter: drop-shadow(0 0 40px rgba(99,102,241,.4));
}
.hero-desc {
  font-size: 1.05rem; color: var(--text2); margin-bottom: 40px; line-height: 1.65;
  min-height: 1.65em;
}
/* Typewriter cursor */
.hero-desc::after {
  content: '|';
  color: var(--accent);
  animation: blink .8s step-end infinite;
  margin-left: 1px;
}
.hero-desc.typed-done::after { display: none; }
@keyframes blink { 0%,100% { opacity: 1; } 50% { opacity: 0; } }

.hero-stats { display: flex; align-items: center; gap: 28px; justify-content: center; margin-bottom: 44px; }
.hero-stat { display: flex; flex-direction: column; align-items: center; gap: 3px; }
.hero-stat-val {
  font-size: 1.8rem; font-weight: 800; color: var(--text); line-height: 1;
  font-family: var(--mono);
  background: linear-gradient(135deg, var(--text), var(--text2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.hero-stat-label { font-size: 0.6rem; font-weight: 600; color: var(--text3); text-transform: uppercase; letter-spacing: 1.5px; }
.hero-stat-div { width: 1px; height: 36px; background: var(--border2); }
.hero-cta-row { display: flex; align-items: center; gap: 14px; justify-content: center; }
.hero-cta-btn {
  padding: 14px 36px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff; font-size: 0.9rem; font-weight: 600; font-family: var(--font);
  transition: transform .22s var(--spring), box-shadow .22s;
  border: none; position: relative; overflow: hidden;
  box-shadow: 0 4px 24px rgba(99,102,241,.4), inset 0 1px 0 rgba(255,255,255,.2);
}
.hero-cta-btn::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,.15), transparent);
  opacity: 0; transition: opacity .2s;
}
.hero-cta-btn:hover::before { opacity: 1; }
.hero-cta-btn:hover { transform: translateY(-4px) scale(1.02); box-shadow: 0 12px 40px rgba(99,102,241,.55); }
.hero-cta-ghost {
  padding: 14px 28px; border-radius: var(--r-sm);
  background: rgba(255,255,255,.06);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  color: var(--text2); font-size: 0.9rem; font-weight: 500; font-family: var(--font);
  border: 1px solid rgba(255,255,255,.14);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.1), 0 4px 16px rgba(0,0,0,.15);
  transition: background var(--dur), color var(--dur), border-color var(--dur), transform .22s var(--spring), box-shadow .22s;
}
.hero-cta-ghost:hover { background: rgba(255,255,255,.1); color: var(--text); border-color: rgba(99,102,241,.4); transform: translateY(-3px); box-shadow: 0 8px 28px rgba(99,102,241,.2), inset 0 1px 0 rgba(255,255,255,.15); }
.hero-scroll-hint {
  position: absolute; bottom: 28px; left: 50%; transform: translateX(-50%);
  display: flex; align-items: center; gap: 5px;
  font-size: 9px; color: var(--text3); letter-spacing: 1.5px; text-transform: uppercase;
  animation: scrollBounce 2.5s ease-in-out infinite;
}
@keyframes scrollBounce {
  0%,100% { transform: translateX(-50%) translateY(0); opacity: .4; }
  50% { transform: translateX(-50%) translateY(6px); opacity: .9; }
}

/* ── FEATURE STRIP ──────────────────────────────────────────── */
.feature-strip {
  padding: 0 18px;
  margin-bottom: 0;
}
.feature-strip-inner {
  max-width: var(--layout-max); margin: 0 auto;
  display: grid; grid-template-columns: repeat(4, 1fr);
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(28px) saturate(180%);
  -webkit-backdrop-filter: blur(28px) saturate(180%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r);
  box-shadow: var(--glass-shadow), var(--glass-inner);
  overflow: hidden;
  position: relative;
}
.feature-strip-inner::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.18), rgba(99,102,241,.3), rgba(255,255,255,.18), transparent);
}
.feature-item {
  display: flex; align-items: center; gap: 14px;
  padding: 22px 24px;
  transition: background var(--dur);
  position: relative;
}
.feature-item:hover { background: rgba(255,255,255,.04); }
.feature-sep { width: 1px; background: var(--border); flex-shrink: 0; }
.feature-icon {
  width: 40px; height: 40px; border-radius: var(--r-sm);
  background: rgba(99,102,241,.1); border: 1px solid rgba(99,102,241,.2);
  display: flex; align-items: center; justify-content: center;
  color: var(--accent2); flex-shrink: 0;
  box-shadow: 0 2px 10px rgba(99,102,241,.15), inset 0 1px 0 rgba(255,255,255,.1);
  transition: transform .2s var(--spring), box-shadow .2s;
}
.feature-item:hover .feature-icon { transform: scale(1.1) rotate(-3deg); box-shadow: 0 4px 18px rgba(99,102,241,.3); }
.feature-text { display: flex; flex-direction: column; gap: 2px; }
.feature-text strong { font-size: 0.8rem; font-weight: 700; color: var(--text); }
.feature-text span { font-size: 0.7rem; color: var(--text3); line-height: 1.4; }

/* ── COUNTDOWN ──────────────────────────────────────────────── */
.countdown-widget {
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid var(--glass-border);
  border-radius: var(--r);
  overflow: hidden;
  box-shadow: var(--glass-shadow), var(--glass-inner);
  position: relative;
}
.countdown-widget::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), rgba(99,102,241,.4), rgba(255,255,255,.2), transparent);
}
.cd-tabs {
  display: flex; overflow-x: auto; gap: 0;
  border-bottom: 1px solid var(--border);
  padding: 0 2px; scrollbar-width: none;
}
.cd-tabs::-webkit-scrollbar { display: none; }
.cd-tab {
  flex-shrink: 0; padding: 11px 16px;
  font-size: 0.75rem; font-weight: 500; color: var(--text3);
  border-bottom: 2px solid transparent;
  transition: color var(--dur), border-color var(--dur);
  cursor: pointer; white-space: nowrap;
  background: none; border-top: none; border-left: none; border-right: none;
  font-family: var(--font);
}
.cd-tab:hover { color: var(--text2); }
.cd-tab.active { color: var(--text); border-bottom-color: var(--accent); }
.cd-display {
  padding: 32px 40px;
  display: flex; align-items: center; gap: 40px;
  min-height: 170px;
}
.cd-big { display: flex; align-items: baseline; gap: 8px; flex-shrink: 0; }
.cd-number {
  font-size: clamp(56px, 8vw, 88px);
  font-weight: 800; font-family: var(--mono); line-height: 1;
  background: linear-gradient(135deg, var(--text) 0%, var(--text2) 100%);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.cd-number.urgent { background: linear-gradient(135deg, #ef4444, #f97316); -webkit-background-clip: text; background-clip: text; }
.cd-number.soon { background: linear-gradient(135deg, #f59e0b, #fbbf24); -webkit-background-clip: text; background-clip: text; }
.cd-number.ok { background: linear-gradient(135deg, #10b981, #34d399); -webkit-background-clip: text; background-clip: text; }
.cd-number.done { background: var(--text3); -webkit-background-clip: text; background-clip: text; font-size: 40px; }
.cd-unit { font-size: 0.9rem; color: var(--text3); font-weight: 500; }
.cd-info { flex: 1; }
.cd-exam-name { font-size: 1.25rem; font-weight: 700; color: var(--text); margin-bottom: 5px; }
.cd-exam-date { font-size: 0.8rem; color: var(--text2); font-family: var(--mono); margin-bottom: 12px; }
.cd-exam-type {
  display: inline-block; font-size: 0.6rem; font-weight: 700; letter-spacing: 1.5px;
  text-transform: uppercase; padding: 3px 10px; border-radius: 99px;
  background: var(--surface2); color: var(--text3); border: 1px solid var(--border);
}
.cd-progress-bar { margin-top: 18px; height: 4px; background: var(--surface2); border-radius: 99px; overflow: hidden; }
.cd-progress-fill { height: 100%; border-radius: 99px; transition: width 1s var(--ease); }

/* ── TICKER ─────────────────────────────────────────────────── */
.ticker-wrap {
  overflow: hidden; padding: 14px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--surface);
  margin: 0 0 0 0;
}
.ticker-track {
  display: flex; gap: 0; white-space: nowrap;
  animation: tickerScroll 40s linear infinite;
}
.ticker-track:hover { animation-play-state: paused; }
.ticker-item {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 0 32px;
  font-size: 0.72rem; color: var(--text3); font-weight: 500;
  letter-spacing: .5px;
}
.ticker-dot { width: 4px; height: 4px; border-radius: 50%; background: var(--accent); opacity: .5; flex-shrink: 0; }
@keyframes tickerScroll {
  from { transform: translateX(0); }
  to   { transform: translateX(-50%); }
}

/* ── CATEGORY CARDS ─────────────────────────────────────────── */
.cat-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.cat-cards .cat-card:last-child:nth-child(3n+2) { grid-column: span 2; }
.cat-cards .cat-card:last-child:nth-child(3n+1) { grid-column: span 3; }
.cat-card {
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid rgba(255,255,255,.09);
  border-radius: var(--r);
  padding: 26px;
  cursor: pointer;
  transition: transform .28s var(--spring), border-color .28s, box-shadow .28s, background .28s;
  position: relative; overflow: hidden;
  box-shadow: 0 4px 24px rgba(0,0,0,.14), inset 0 1px 0 rgba(255,255,255,.08), inset 0 -1px 0 rgba(0,0,0,.06);
}
/* Top shine line */
.cat-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), transparent);
  opacity: 0; transition: opacity .3s;
  pointer-events: none;
}
/* Glow sweep on hover */
.cat-card::after {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse 60% 50% at 50% 0%, rgba(255,255,255,.06), transparent 70%);
  opacity: 0; transition: opacity .3s;
  pointer-events: none;
}
.cat-card:hover::before { opacity: 1; }
.cat-card:hover::after { opacity: 1; }
.cat-card:hover { transform: translateY(-6px) scale(1.01); border-color: rgba(255,255,255,.16); box-shadow: 0 20px 60px rgba(0,0,0,.22), inset 0 1px 0 rgba(255,255,255,.12); }
.cat-card.kyb:hover { border-color: rgba(79,142,247,.45); box-shadow: 0 20px 60px rgba(79,142,247,.15), inset 0 1px 0 rgba(79,142,247,.2); }
.cat-card.prg:hover { border-color: rgba(52,211,153,.45); box-shadow: 0 20px 60px rgba(52,211,153,.15), inset 0 1px 0 rgba(52,211,153,.2); }
.cat-card.ces:hover { border-color: rgba(251,191,36,.45); box-shadow: 0 20px 60px rgba(251,191,36,.15), inset 0 1px 0 rgba(251,191,36,.2); }
.cat-card.mat:hover { border-color: rgba(192,132,252,.45); box-shadow: 0 20px 60px rgba(192,132,252,.15), inset 0 1px 0 rgba(192,132,252,.2); }
.cat-card.ang:hover { border-color: rgba(248,113,113,.45); box-shadow: 0 20px 60px rgba(248,113,113,.15), inset 0 1px 0 rgba(248,113,113,.2); }
.cat-card-id {
  font-size: 0.6rem; font-weight: 800; letter-spacing: 2px;
  text-transform: uppercase; color: var(--accent); margin-bottom: 10px;
  font-family: var(--mono);
}
.cat-card.kyb .cat-card-id { color: var(--kyb); }
.cat-card.prg .cat-card-id { color: var(--prg); }
.cat-card.ces .cat-card-id { color: var(--ces); }
.cat-card.mat .cat-card-id { color: var(--mat); }
.cat-card.ang .cat-card-id { color: var(--ang); }
.cat-card-name { font-size: 0.95rem; font-weight: 700; margin-bottom: 5px; }
.cat-card-desc { font-size: 0.75rem; color: var(--text2); line-height: 1.5; margin-bottom: 18px; }
.cat-card-footer { display: flex; align-items: center; justify-content: space-between; }
.cat-card-count { font-size: 0.65rem; font-weight: 600; letter-spacing: 1px; text-transform: uppercase; color: var(--text3); }
.cat-card-arrow { font-size: 1rem; color: var(--text3); transition: transform .2s var(--spring), color .2s; }
.cat-card:hover .cat-card-arrow { transform: translateX(5px); color: var(--text2); }

/* ── PRACTICE SECTION ───────────────────────────────────────── */
.practice-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.practice-card {
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid rgba(255,255,255,.09);
  border-radius: var(--r); padding: 26px;
  transition: transform .28s var(--spring), border-color .28s, box-shadow .28s;
  position: relative; overflow: hidden;
  box-shadow: 0 4px 24px rgba(0,0,0,.14), inset 0 1px 0 rgba(255,255,255,.08), inset 0 -1px 0 rgba(0,0,0,.06);
}
.practice-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), transparent);
  opacity: 0; transition: opacity .3s;
  pointer-events: none;
}
.practice-card::after {
  content: ''; position: absolute; inset: 0;
  background: radial-gradient(ellipse 60% 50% at 50% 0%, rgba(255,255,255,.05), transparent 70%);
  opacity: 0; transition: opacity .3s;
  pointer-events: none;
}
.practice-card:hover::before { opacity: 1; }
.practice-card:hover::after { opacity: 1; }
.practice-card:hover { transform: translateY(-5px) scale(1.01); border-color: rgba(255,255,255,.16); box-shadow: 0 18px 50px rgba(0,0,0,.2), inset 0 1px 0 rgba(255,255,255,.12); }
.practice-card-title { font-size: 1.05rem; font-weight: 700; margin-bottom: 6px; }
.practice-card-desc { font-size: 0.78rem; color: var(--text2); line-height: 1.55; margin-bottom: 18px; }
.practice-card-footer { display: flex; align-items: center; gap: 8px; }
.practice-select {
  flex: 1; padding: 8px 28px 8px 10px; border-radius: var(--r-sm);
  background: var(--surface2); border: 1px solid var(--border2);
  color: var(--text); font-family: var(--font); font-size: 0.78rem;
  outline: none; cursor: pointer; appearance: none; -webkit-appearance: none;
  color-scheme: inherit;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='10' viewBox='0 0 24 24' fill='none' stroke='%238080a0' stroke-width='2' stroke-linecap='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 8px center;
  transition: border-color var(--dur), box-shadow var(--dur);
}
.practice-select:hover, .practice-select:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(99,102,241,.15); }
.practice-start-btn {
  padding: 8px 20px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff; font-size: 0.78rem; font-weight: 600; font-family: var(--font);
  transition: transform .18s var(--spring), box-shadow .18s;
  white-space: nowrap;
  box-shadow: 0 2px 12px rgba(99,102,241,.3);
}
.practice-start-btn:hover { transform: translateY(-2px) scale(1.04); box-shadow: 0 6px 20px rgba(99,102,241,.45); }

/* ── PAGE HERO (category / topic) ───────────────────────────── */
.page-hero {
  position: relative; padding: 52px 18px 30px;
  overflow: hidden; min-height: 170px;
  display: flex; align-items: flex-end;
  border-bottom: 1px solid var(--border);
}
.page-hero-bg {
  position: absolute; inset: 0; z-index: 0;
  transition: background .3s var(--ease);
}
.page-hero-bg.kyb { background: radial-gradient(ellipse 80% 100% at -5% 50%, rgba(79,142,247,.12) 0%, transparent 60%); }
.page-hero-bg.prg { background: radial-gradient(ellipse 80% 100% at -5% 50%, rgba(52,211,153,.12) 0%, transparent 60%); }
.page-hero-bg.ces { background: radial-gradient(ellipse 80% 100% at -5% 50%, rgba(251,191,36,.12) 0%, transparent 60%); }
.page-hero-bg.mat { background: radial-gradient(ellipse 80% 100% at -5% 50%, rgba(192,132,252,.12) 0%, transparent 60%); }
.page-hero-bg.ang { background: radial-gradient(ellipse 80% 100% at -5% 50%, rgba(248,113,113,.12) 0%, transparent 60%); }
.page-hero-orbs { position: absolute; inset: 0; pointer-events: none; overflow: hidden; }
.ph-orb { position: absolute; border-radius: 50%; filter: blur(55px); opacity: .3; }
.ph-orb-1 { width: 240px; height: 240px; top: -70px; right: 8%; background: radial-gradient(circle, rgba(99,102,241,.28), transparent 70%); }
.ph-orb-2 { width: 180px; height: 180px; bottom: -40px; right: 28%; background: radial-gradient(circle, rgba(139,92,246,.2), transparent 70%); }
.page-hero-content {
  position: relative; z-index: 1;
  max-width: var(--layout-max); margin: 0 auto; width: 100%;
}
.back-link {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 0.75rem; color: var(--text3);
  padding: 4px 12px; border-radius: 99px;
  background: var(--glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border);
  transition: background var(--dur), color var(--dur), transform .18s var(--spring);
  height: 28px; flex-shrink: 0;
}
.back-link:hover { background: var(--surface2); color: var(--text); transform: translateX(-3px); }
.topic-hero-row { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.page-hero-title {
  font-size: clamp(1.4rem, 4vw, 2.4rem);
  font-weight: 800; letter-spacing: -1px; line-height: 1.1; margin-bottom: 0;
}
.page-hero-desc { font-size: 0.8rem; color: var(--text2); margin-top: 6px; }
.topic-badge {
  display: inline-flex; align-items: center; gap: 5px;
  font-size: 0.6rem; font-weight: 700;
  letter-spacing: 1.5px; text-transform: uppercase;
  padding: 0 12px; border-radius: 99px; height: 28px;
}
.topic-badge.kyb { background: rgba(79,142,247,.12); color: var(--kyb); border: 1px solid rgba(79,142,247,.22); }
.topic-badge.prg { background: rgba(52,211,153,.12); color: var(--prg); border: 1px solid rgba(52,211,153,.22); }
.topic-badge.ces { background: rgba(251,191,36,.12); color: var(--ces); border: 1px solid rgba(251,191,36,.22); }
.topic-badge.mat { background: rgba(192,132,252,.12); color: var(--mat); border: 1px solid rgba(192,132,252,.22); }
.topic-badge.ang { background: rgba(248,113,113,.12); color: var(--ang); border: 1px solid rgba(248,113,113,.22); }

/* ── TOPIC LIST ─────────────────────────────────────────────── */
.topic-list { display: flex; flex-direction: column; gap: 2px; }
.topic-row {
  display: flex; align-items: center; gap: 14px;
  padding: 13px 16px; border-radius: var(--r-sm);
  cursor: pointer;
  background: var(--glass);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid transparent;
  transition: background var(--dur), border-color var(--dur), transform .18s var(--spring), box-shadow .18s;
}
.topic-row:hover { background: var(--surface2); border-color: var(--border); transform: translateX(5px); box-shadow: 0 2px 12px rgba(0,0,0,.1); }
.topic-row-num { font-size: 0.65rem; font-family: var(--mono); color: var(--text3); min-width: 24px; text-align: right; flex-shrink: 0; }
.topic-row-title { font-size: 0.875rem; color: var(--text); flex: 1; line-height: 1.4; }
.topic-row-arrow { color: var(--text3); font-size: 0.9rem; flex-shrink: 0; transition: transform .18s var(--spring), color .18s; }
.topic-row:hover .topic-row-arrow { transform: translateX(4px); color: var(--text2); }
.topic-divider { height: 1px; background: var(--border); margin: 2px 0; }

/* ── TOPIC PAGE LAYOUT ──────────────────────────────────────── */
.topic-layout {
  display: grid; grid-template-columns: 1fr 280px; gap: var(--layout-gap); align-items: start;
}
.topic-main { display: flex; flex-direction: column; gap: var(--layout-gap); min-width: 0; overflow: hidden; }
.content-block {
  background: var(--glass);
  backdrop-filter: blur(16px) saturate(150%);
  -webkit-backdrop-filter: blur(16px) saturate(150%);
  border: 1px solid var(--border);
  border-radius: var(--r); padding: var(--block-pad);
  animation: fadeUp .3s var(--ease) both;
  min-width: 0; overflow: hidden;
  box-shadow: 0 2px 20px rgba(0,0,0,.1), inset 0 1px 0 rgba(255,255,255,.04);
}
@keyframes fadeUp { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.content-block > h3:first-child {
  font-size: 0.6rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase;
  color: var(--text3); margin-bottom: 16px; padding-bottom: 10px;
  border-bottom: 1px solid var(--border); display: block;
}
.content-block > h3:first-child::before { display: none; }
.content-block h2 {
  font-size: 1.1rem; font-weight: 700; color: var(--text);
  margin: 24px 0 10px; padding-bottom: 8px; border-bottom: 1px solid var(--border);
  letter-spacing: -.3px;
}
.content-block h3 {
  font-size: 0.9rem; font-weight: 700; color: var(--text);
  margin: 18px 0 8px;
  display: flex; align-items: center; gap: 8px;
}
.content-block h3::before {
  content: ''; display: inline-block; width: 3px; height: 0.9rem;
  background: var(--accent); border-radius: 2px; flex-shrink: 0;
}
.content-block h4 {
  font-size: 0.82rem; font-weight: 600; color: var(--accent2);
  margin: 14px 0 4px; padding: 6px 10px;
  background: rgba(99,102,241,.07); border-left: 3px solid var(--accent2);
  border-radius: 0 4px 4px 0;
}
.content-block ul { padding-left: 0; list-style: none; margin: 8px 0 12px; display: flex; flex-direction: column; gap: 3px; }
.content-block li {
  font-size: 0.85rem; line-height: 1.7; color: var(--text);
  padding: 4px 10px 4px 24px; position: relative;
  border-radius: 5px; transition: background .12s;
}
.content-block li:hover { background: var(--surface); }
.content-block li::before {
  content: ''; position: absolute; left: 9px; top: 12px;
  width: 5px; height: 5px; border-radius: 50%;
  background: var(--accent); opacity: .6;
}
.content-block li.sub-item { padding-left: 38px; color: var(--text2); font-size: 0.78rem; }
.content-block li.sub-item::before { left: 22px; width: 3px; height: 3px; background: var(--text3); opacity: .6; }
.content-block ol { padding-left: 0; margin: 8px 0 12px; counter-reset: ol-c; list-style: none; display: flex; flex-direction: column; gap: 3px; }
.content-block ol li { counter-increment: ol-c; padding-left: 36px; }
.content-block ol li::before {
  content: counter(ol-c); position: absolute; left: 6px; top: 4px;
  width: 18px; height: 18px; border-radius: 50%;
  background: var(--accent); color: #fff;
  font-size: 10px; font-weight: 700;
  display: flex; align-items: center; justify-content: center; opacity: .8;
}
.content-block p { font-size: 0.85rem; line-height: 1.8; color: var(--text); margin-bottom: 8px; }
.content-block p:last-child { margin-bottom: 0; }
.content-block strong { color: var(--text); font-weight: 600; }
.content-block em { color: var(--accent2); font-style: normal; font-weight: 500; }
.content-block code {
  font-family: var(--mono); font-size: 0.75rem;
  background: rgba(99,102,241,.1); border: 1px solid rgba(99,102,241,.18);
  padding: 1px 5px; border-radius: 4px; color: var(--accent2);
}
.content-block blockquote {
  border-left: 3px solid var(--accent);
  padding: 12px 16px; margin: 12px 0;
  background: rgba(99,102,241,.05);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  font-size: 0.85rem; color: var(--text); font-style: normal; line-height: 1.75;
  white-space: pre-wrap;
}
.content-block hr { border: none; border-top: 1px solid var(--border); margin: 18px 0; }
.content-block dl {
  display: grid; grid-template-columns: minmax(auto, 120px) 1fr; gap: 2px 14px;
  margin: 10px 0; background: var(--surface); border-radius: var(--r-sm);
  padding: 12px 14px; border: 1px solid var(--border);
}
.content-block dt { font-size: 0.78rem; font-weight: 600; color: var(--text); padding: 3px 0; white-space: nowrap; }
.content-block dd { font-size: 0.78rem; color: var(--text); padding: 3px 0; line-height: 1.5; }
.extra-section { margin-top: 16px; padding-top: 16px; border-top: 1px solid var(--border); }
.extra-label { font-size: 0.6rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; color: var(--text3); margin-bottom: 10px; }
mark { background: rgba(99,102,241,.2); color: var(--text); border-radius: 2px; padding: 0 2px; }

/* ── ASIDE ──────────────────────────────────────────────────── */
.topic-aside { display: flex; flex-direction: column; gap: 12px; position: sticky; top: calc(var(--nav-h) + 14px); }
.aside-block {
  border-radius: var(--r); padding: 16px;
  animation: fadeUp .3s .1s var(--ease) both;
}
.aside-block.tips {
  background: rgba(99,102,241,.06);
  border: 1px solid rgba(99,102,241,.15);
}
.aside-block.notes { background: var(--glass); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border: 1px solid var(--border); }
.aside-title {
  font-size: 0.6rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase;
  color: var(--text3); margin-bottom: 10px;
  display: flex; align-items: center; gap: 6px;
}
.tips-list { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 7px; }
.tips-list li { font-size: 0.78rem; line-height: 1.6; color: var(--text2); padding-left: 14px; position: relative; }
.tips-list li::before { content: '✦'; position: absolute; left: 0; color: var(--accent); font-size: 7px; top: 4px; }
.notes-textarea {
  width: 100%; min-height: 90px;
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: var(--r-sm); padding: 10px 12px;
  color: var(--text); font-family: var(--font); font-size: 0.78rem;
  resize: vertical; outline: none; line-height: 1.65;
  transition: border-color var(--dur), box-shadow var(--dur);
  color-scheme: inherit;
}
.notes-textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 2px rgba(99,102,241,.15); }
.notes-textarea::placeholder { color: var(--text3); }
.notes-footer { display: flex; align-items: center; gap: 8px; margin-top: 8px; }
.notes-save-btn {
  padding: 6px 14px; border-radius: 99px;
  background: var(--accent); border: none; color: #fff;
  font-size: 0.72rem; font-weight: 600; font-family: var(--font);
  transition: transform .18s var(--spring), opacity .18s;
}
.notes-save-btn:hover { transform: translateY(-1px); opacity: .88; }
.notes-saved-msg { font-size: 0.65rem; color: #10b981; opacity: 0; transition: opacity .3s; }
.notes-saved-msg.show { opacity: 1; }
.notes-display { display: flex; flex-direction: column; gap: 6px; margin-bottom: 10px; }
.note-card {
  background: var(--surface2); border: 1px solid var(--border);
  border-radius: var(--r-sm); padding: 8px 10px;
  font-size: 0.78rem; color: var(--text2); line-height: 1.55;
}
.note-card-time { font-size: 0.6rem; color: var(--text3); margin-top: 4px; }
.notes-empty { font-size: 0.72rem; color: var(--text3); text-align: center; padding: 12px 0; }
.topic-nav-row { display: flex; gap: 8px; margin-top: 4px; }
.topic-nav-btn {
  flex: 1; padding: 10px 14px; border-radius: var(--r-sm);
  background: var(--glass); backdrop-filter: blur(10px); -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  color: var(--text2); font-size: 0.78rem; font-family: var(--font);
  transition: background var(--dur), border-color var(--dur), color var(--dur), transform .18s var(--spring);
}
.topic-nav-btn:hover:not(:disabled) { background: var(--surface2); border-color: var(--accent); color: var(--text); transform: translateY(-1px); }
.topic-nav-btn:disabled { opacity: .3; cursor: not-allowed; }
.kv-row { display: flex; gap: 6px; margin-bottom: 5px; font-size: 0.8rem; }
.kv-key { color: var(--text3); min-width: 80px; max-width: 130px; width: max-content; flex-shrink: 0; font-size: 0.75rem; }
.kv-val { color: var(--text); line-height: 1.5; flex: 1; min-width: 0; }

/* ── MD TABLE ───────────────────────────────────────────────── */
.md-table-wrap { overflow-x: auto; margin: 10px 0; border-radius: var(--r-sm); border: 1px solid var(--border); }
.md-table { width: 100%; border-collapse: collapse; font-size: 0.8rem; line-height: 1.5; }
.md-table thead tr { background: var(--surface2); border-bottom: 2px solid var(--border2); }
.md-table th { padding: 8px 12px; text-align: left; font-weight: 600; color: var(--text); white-space: nowrap; }
.md-table td { padding: 7px 12px; color: var(--text2); border-bottom: 1px solid var(--border); vertical-align: top; }
.md-table td.td-first { font-weight: 600; color: var(--text); white-space: nowrap; }
.md-table tbody tr:last-child td { border-bottom: none; }
.md-table tbody tr:hover { background: var(--surface); }

/* ── CODE BLOCKS ────────────────────────────────────────────── */
.content-block pre {
  background: #0d0d18;
  border: 1px solid #1e1e30;
  border-radius: var(--r-sm);
  padding: 0; overflow: hidden;
  margin: 14px 0; position: relative;
  box-shadow: 0 4px 20px rgba(0,0,0,.35);
  max-width: 100%;
}
.content-block pre::before {
  content: attr(data-lang);
  display: block;
  background: #161626;
  border-bottom: 1px solid #1e1e30;
  padding: 6px 14px;
  font-family: var(--mono); font-size: 0.6rem; font-weight: 700;
  letter-spacing: 1.5px; text-transform: uppercase;
  color: #5050a0;
  position: sticky; left: 0;
}
.content-block pre code {
  font-family: var(--mono); font-size: 0.78rem;
  background: none; border: none; padding: 14px 18px;
  color: #f8f8f2; line-height: 1.7;
  display: block; white-space: pre;
  overflow-x: auto; box-sizing: border-box;
}
.mk-keyword  { color: #f92672; }
.mk-string   { color: #e6db74; }
.mk-comment  { color: #75715e; font-style: italic; }
.mk-number   { color: #ae81ff; }
.mk-type     { color: #66d9e8; }
.mk-method   { color: #a6e22e; }
.mk-operator { color: #f92672; }
.mk-builtin  { color: #fd971f; }

/* ── GLOSSARY TOOLTIP ───────────────────────────────────────── */
.code-term {
  font-family: var(--mono); font-size: 0.75rem;
  background: rgba(99,102,241,.1); border: 1px solid rgba(99,102,241,.25);
  padding: 1px 6px; border-radius: 4px; color: var(--accent2);
  cursor: pointer; display: inline-block;
  transition: background .12s, border-color .12s;
  text-decoration: underline dotted rgba(99,102,241,.4);
  text-underline-offset: 2px;
}
.code-term:hover { background: rgba(99,102,241,.2); border-color: rgba(99,102,241,.5); }
#glossaryTooltip {
  position: absolute; z-index: 9999;
  width: min(300px, 90vw);
  background: var(--glass2);
  backdrop-filter: blur(28px) saturate(200%);
  -webkit-backdrop-filter: blur(28px) saturate(200%);
  border: 1px solid var(--border2);
  border-radius: var(--r);
  box-shadow: 0 16px 48px rgba(0,0,0,.35), inset 0 1px 0 rgba(255,255,255,.08);
  padding: 14px 16px;
  opacity: 0; pointer-events: none;
  transform: translateY(6px) scale(.97);
  transition: opacity .18s var(--ease), transform .18s var(--spring);
}
#glossaryTooltip.visible { opacity: 1; pointer-events: all; transform: none; }
.tooltip-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 8px; }
.tooltip-term {
  font-family: var(--mono); font-size: 0.75rem; font-weight: 700; color: var(--accent2);
  background: rgba(99,102,241,.1); border: 1px solid rgba(99,102,241,.2);
  padding: 2px 8px; border-radius: 99px;
}
.tooltip-close {
  width: 22px; height: 22px; border-radius: 4px;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.65rem; color: var(--text3);
  transition: background var(--dur), color var(--dur); flex-shrink: 0;
}
.tooltip-close:hover { background: var(--surface2); color: var(--text); }
.tooltip-def { font-size: 0.8rem; color: var(--text2); line-height: 1.65; }

/* ── GAME PAGES — ULTRA LIQUID GLASS + ANIMATED BG ─────────── */

/* Animated background canvas */
.game-bg-canvas {
  position: fixed; inset: 0; z-index: 0;
  pointer-events: none; opacity: 0;
  transition: opacity 1s var(--ease);
}
.game-bg-canvas.active { opacity: 1; }

/* Ultra liquid glass card base */
.glass-card {
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid rgba(255,255,255,.13);
  border-radius: var(--r);
  box-shadow:
    0 12px 50px rgba(0,0,0,.32),
    inset 0 1px 0 rgba(255,255,255,.14),
    inset 0 -1px 0 rgba(0,0,0,.1),
    inset 1px 0 0 rgba(255,255,255,.06),
    inset -1px 0 0 rgba(255,255,255,.06);
  position: relative;
}
.glass-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.25), transparent);
  border-radius: var(--r) var(--r) 0 0;
}
[data-theme="light"] .glass-card {
  background: rgba(255,255,255,.65);
  border-color: rgba(255,255,255,.8);
  box-shadow: 0 12px 50px rgba(0,0,0,.12), inset 0 1px 0 rgba(255,255,255,.95);
}

/* Shimmer sweep animation */
@keyframes shimmer {
  from { background-position: -200% center; }
  to   { background-position: 200% center; }
}

/* Card enter animation */
@keyframes cardSlideIn {
  from { opacity: 0; transform: translateY(32px) scale(.95); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}
.card-enter { animation: cardSlideIn .45s var(--spring) both; }

@keyframes cardFlipIn {
  from { opacity: 0; transform: rotateX(-18deg) translateY(24px) scale(.97); }
  to   { opacity: 1; transform: rotateX(0) translateY(0) scale(1); }
}
.card-flip-enter { animation: cardFlipIn .4s var(--spring) both; }

/* Stream text — char by char with fade */
@keyframes streamChar {
  from { opacity: 0; transform: translateY(5px); }
  to   { opacity: 1; transform: translateY(0); }
}
.stream-char { display: inline; animation: streamChar .14s var(--ease) both; }

/* Hint pill */
.game-hint-pill {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 0.7rem; color: var(--text3); font-family: var(--mono);
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.1);
  padding: 5px 14px; border-radius: 99px; margin-bottom: 14px;
  cursor: pointer; transition: background var(--dur), color var(--dur), border-color var(--dur);
  box-shadow: inset 0 1px 0 rgba(255,255,255,.1);
}
.game-hint-pill:hover { background: rgba(255,255,255,.09); color: var(--text2); }
.game-hint-pill.revealed { color: var(--accent2); border-color: rgba(99,102,241,.35); background: rgba(99,102,241,.1); }
.game-hint-text {
  font-size: 0.78rem; color: var(--text2); line-height: 1.55;
  background: rgba(99,102,241,.07); border: 1px solid rgba(99,102,241,.18);
  border-radius: var(--r-sm); padding: 12px 16px; margin-bottom: 12px;
  display: none;
}
.game-hint-text.show { display: block; animation: cardSlideIn .3s var(--spring) both; }

/* Progress bar for games */
.game-progress-bar {
  height: 3px; background: rgba(255,255,255,.06); border-radius: 99px;
  margin-bottom: 24px; overflow: hidden;
}
.game-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent), #a78bfa, #60a5fa);
  border-radius: 99px;
  transition: width .5s var(--ease);
  box-shadow: 0 0 12px rgba(99,102,241,.5);
}

/* ── FLASHCARDS ─────────────────────────────────────────────── */
.practice-header {
  display: flex; align-items: center; gap: 14px; margin-bottom: 28px; flex-wrap: wrap;
  background: rgba(255,255,255,.03);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255,255,255,.08);
  border-radius: var(--r);
  padding: 16px 20px;
  box-shadow: 0 4px 24px rgba(0,0,0,.12), inset 0 1px 0 rgba(255,255,255,.07);
}
.practice-title { font-size: 1.1rem; font-weight: 700; flex: 1; }
.practice-progress { font-size: 0.75rem; color: var(--text3); font-family: var(--mono); }

.diff-badge {
  display: inline-flex; align-items: center; gap: 4px;
  font-size: 0.6rem; font-weight: 700; letter-spacing: 1px; text-transform: uppercase;
  padding: 3px 10px; border-radius: 99px;
}
.diff-badge.easy   { background: rgba(52,211,153,.12); color: #34d399; border: 1px solid rgba(52,211,153,.25); }
.diff-badge.medium { background: rgba(251,191,36,.12); color: #fbbf24; border: 1px solid rgba(251,191,36,.25); }
.diff-badge.hard   { background: rgba(248,113,113,.12); color: #f87171; border: 1px solid rgba(248,113,113,.25); }

.flashcard-wrap { max-width: 680px; margin: 0 auto; }
.flashcard { perspective: 1600px; cursor: pointer; margin-bottom: 18px; }
.flashcard-inner {
  position: relative; width: 100%; height: 340px;
  transform-style: preserve-3d;
  transition: transform .65s cubic-bezier(.4,0,.2,1);
  border-radius: var(--r);
  /* Tilt via CSS vars — set by JS on mousemove, doesn't conflict with flip */
  transform: rotateX(var(--tilt-x, 0deg)) rotateY(var(--tilt-y, 0deg));
}
.flashcard.flipped .flashcard-inner {
  transform: rotateX(var(--tilt-x, 0deg)) rotateY(calc(180deg + var(--tilt-y, 0deg)));
}
.flashcard-front, .flashcard-back {
  position: absolute; inset: 0;
  backface-visibility: hidden; -webkit-backface-visibility: hidden;
  border-radius: var(--r);
  padding: 36px 40px;
  box-shadow: 0 12px 50px rgba(0,0,0,.28), inset 0 1px 0 rgba(255,255,255,.14), inset 0 -1px 0 rgba(0,0,0,.08);
}
.flashcard-front {
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid rgba(255,255,255,.14);
  font-size: 1.2rem; font-weight: 600; color: var(--text); line-height: 1.4;
  text-align: center;
  display: flex; align-items: center; justify-content: center;
  transform: rotateY(0deg);
  position: relative; overflow: hidden;
}
.flashcard-front::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.3), transparent);
}
.flashcard-back {
  background: rgba(99,102,241,.06);
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid rgba(99,102,241,.22);
  transform: rotateY(180deg);
  font-size: 0.82rem; color: var(--text2); line-height: 1.7;
  overflow-y: auto; text-align: left;
  display: flex; align-items: flex-start; justify-content: flex-start;
  padding: 26px 30px;
  box-shadow: 0 12px 50px rgba(99,102,241,.15), inset 0 1px 0 rgba(99,102,241,.2);
}
.flashcard-hint { text-align: center; font-size: 0.7rem; color: var(--text3); margin-bottom: 18px; letter-spacing: .5px; }
.flashcard-controls { display: flex; gap: 10px; justify-content: center; }
.fc-btn {
  padding: 11px 24px; border-radius: var(--r-sm);
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.12);
  color: var(--text2); font-size: 0.78rem; font-family: var(--font);
  transition: background var(--dur), color var(--dur), transform .2s var(--spring), box-shadow .2s;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.08);
}
.fc-btn:hover { background: rgba(255,255,255,.1); color: var(--text); transform: translateY(-3px); box-shadow: 0 6px 20px rgba(0,0,0,.2), inset 0 1px 0 rgba(255,255,255,.12); }
.fc-flip {
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  border-color: transparent; color: #fff;
  box-shadow: 0 4px 20px rgba(99,102,241,.4), inset 0 1px 0 rgba(255,255,255,.2);
}
.fc-flip:hover { opacity: .92; transform: translateY(-3px) scale(1.04); color: #fff; box-shadow: 0 10px 30px rgba(99,102,241,.55); }
.fc-back-heading {
  font-size: 0.65rem; font-weight: 700; letter-spacing: 1.5px; text-transform: uppercase;
  color: var(--accent2); margin-bottom: 10px; padding-bottom: 6px;
  border-bottom: 1px solid rgba(99,102,241,.15);
}
.fc-back-list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: 5px; }
.fc-back-list li { font-size: 0.78rem; color: var(--text2); line-height: 1.55; padding-left: 14px; position: relative; }
.fc-back-list li::before { content: '▸'; position: absolute; left: 0; color: var(--accent); font-size: 0.65rem; top: 2px; }
.fc-back-def { text-align: center; width: 100%; }
.fc-back-term {
  display: inline-block; font-family: var(--mono); font-size: 0.85rem;
  font-weight: 700; color: var(--accent2);
  background: rgba(99,102,241,.12); border: 1px solid rgba(99,102,241,.25);
  padding: 2px 12px; border-radius: 99px; margin-bottom: 12px;
}
.fc-back-def p { font-size: 0.85rem; color: var(--text2); line-height: 1.65; }
.fc-front-text { font-size: 1.1rem; font-weight: 600; color: var(--text); text-align: center; line-height: 1.4; }

/* ── QUIZ ───────────────────────────────────────────────────── */
.quiz-wrap { max-width: 680px; margin: 0 auto; }
.quiz-question {
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(32px) saturate(200%);
  -webkit-backdrop-filter: blur(32px) saturate(200%);
  border: 1px solid rgba(255,255,255,.13);
  border-radius: var(--r); padding: 30px;
  margin-bottom: 18px;
  box-shadow: 0 12px 50px rgba(0,0,0,.28), inset 0 1px 0 rgba(255,255,255,.14), inset 0 -1px 0 rgba(0,0,0,.08);
  position: relative; overflow: hidden;
}
.quiz-question::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.25), transparent);
}
.quiz-q-label { font-size: 0.6rem; font-weight: 700; letter-spacing: 2px; text-transform: uppercase; color: var(--text3); margin-bottom: 12px; }
.quiz-q-text { font-size: 1rem; font-weight: 600; color: var(--text); line-height: 1.55; }
.quiz-options { display: flex; flex-direction: column; gap: 10px; margin-bottom: 16px; }
.quiz-option {
  padding: 14px 20px; border-radius: var(--r-sm);
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.09);
  color: var(--text2); font-size: 0.88rem; font-family: var(--font);
  text-align: left; cursor: pointer;
  transition: background .18s, border-color .18s, transform .18s var(--spring), box-shadow .18s, color .18s;
  box-shadow: 0 2px 10px rgba(0,0,0,.12), inset 0 1px 0 rgba(255,255,255,.07);
  position: relative; overflow: hidden;
}
.quiz-option::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(255,255,255,.04), transparent);
  opacity: 0; transition: opacity .2s;
}
.quiz-option:hover:not(:disabled) {
  background: rgba(99,102,241,.1);
  border-color: rgba(99,102,241,.38);
  color: var(--text);
  transform: translateX(6px);
  box-shadow: 0 6px 20px rgba(99,102,241,.18), inset 0 1px 0 rgba(99,102,241,.15);
}
.quiz-option:hover:not(:disabled)::before { opacity: 1; }
.quiz-option.correct {
  background: rgba(52,211,153,.1);
  border-color: rgba(52,211,153,.45);
  color: #34d399;
  box-shadow: 0 0 24px rgba(52,211,153,.2), inset 0 1px 0 rgba(52,211,153,.2);
}
.quiz-option.wrong {
  background: rgba(248,113,113,.08);
  border-color: rgba(248,113,113,.38);
  color: #f87171;
}
.quiz-option:disabled { cursor: not-allowed; }
.quiz-feedback {
  padding: 12px 16px; border-radius: var(--r-sm);
  font-size: 0.82rem; line-height: 1.55; margin-bottom: 14px; display: none;
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
}
.quiz-feedback.show { display: block; animation: cardSlideIn .28s var(--spring) both; }
.quiz-feedback.ok { background: rgba(52,211,153,.08); border: 1px solid rgba(52,211,153,.22); color: #34d399; }
.quiz-feedback.fail { background: rgba(248,113,113,.07); border: 1px solid rgba(248,113,113,.2); color: #f87171; }
.quiz-feedback em { font-style: normal; color: var(--text2); font-size: 0.78rem; display: block; margin-top: 4px; }
.quiz-feedback strong { color: var(--text); }
.quiz-next-btn {
  padding: 11px 26px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff; font-size: 0.85rem; font-weight: 600; font-family: var(--font);
  transition: transform .18s var(--spring), box-shadow .18s; display: none;
  box-shadow: 0 4px 16px rgba(99,102,241,.35);
}
.quiz-next-btn.show { display: inline-block; animation: cardSlideIn .28s var(--spring) both; }
.quiz-next-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(99,102,241,.5); }
.quiz-score-label { font-size: 0.95rem; color: var(--text2); margin-bottom: 28px; }
.quiz-restart-btn {
  padding: 12px 32px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff; font-size: 0.9rem; font-weight: 600; font-family: var(--font);
  transition: transform .18s var(--spring), box-shadow .18s;
  box-shadow: 0 4px 20px rgba(99,102,241,.35);
}
.quiz-restart-btn:hover { transform: translateY(-3px); box-shadow: 0 10px 32px rgba(99,102,241,.5); }

/* code output quiz */
.code-quiz-block {
  background: #0d0d18; border: 1px solid #1e1e30; border-radius: var(--r-sm);
  padding: 14px 16px; margin: 12px 0;
  font-family: var(--mono); font-size: 0.78rem; color: #f8f8f2;
  line-height: 1.65; overflow-x: auto; white-space: pre;
  position: relative;
}
.code-quiz-block::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, #f92672, #66d9e8, #a6e22e);
  border-radius: var(--r-sm) var(--r-sm) 0 0;
}

/* Fill input — see enhanced version above */
.fill-input-row { display: flex; gap: 8px; margin: 16px 0; }
.fill-submit-btn {
  padding: 11px 20px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff; font-size: 0.82rem; font-weight: 600;
  border: none; cursor: pointer;
  transition: transform .18s var(--spring), box-shadow .18s;
  white-space: nowrap;
  box-shadow: 0 4px 14px rgba(99,102,241,.3);
}
.fill-submit-btn:hover:not(:disabled) { transform: translateY(-1px); box-shadow: 0 6px 20px rgba(99,102,241,.45); }
.fill-submit-btn:disabled { opacity: .4; cursor: not-allowed; }
.fill-definition {
  font-size: 1rem; font-weight: 500; color: var(--text);
  line-height: 1.7; margin-top: 6px;
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border-radius: var(--r-sm); padding: 18px 22px;
  border: 1px solid rgba(255,255,255,.12);
  box-shadow: 0 4px 24px rgba(0,0,0,.16), inset 0 1px 0 rgba(255,255,255,.1);
  position: relative; overflow: hidden;
}
.fill-definition::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), transparent);
}
.fill-wrap { max-width: 660px; margin: 0 auto; }

/* ── DIFFICULTY SELECTOR ────────────────────────────────────── */
.diff-selector { display: flex; gap: 6px; align-items: center; flex-wrap: wrap; }
.diff-btn {
  padding: 4px 12px; border-radius: 99px;
  font-size: 0.65rem; font-weight: 700; letter-spacing: 1px; text-transform: uppercase;
  border: 1px solid var(--border); background: var(--glass);
  backdrop-filter: blur(8px); -webkit-backdrop-filter: blur(8px);
  color: var(--text3); font-family: var(--font);
  transition: background var(--dur), border-color var(--dur), color var(--dur);
  cursor: pointer;
}
.diff-btn:hover { background: var(--surface2); color: var(--text2); }
.diff-btn.active.easy   { background: rgba(52,211,153,.12); border-color: rgba(52,211,153,.3); color: #34d399; }
.diff-btn.active.medium { background: rgba(251,191,36,.12); border-color: rgba(251,191,36,.3); color: #fbbf24; }
.diff-btn.active.hard   { background: rgba(248,113,113,.12); border-color: rgba(248,113,113,.3); color: #f87171; }
.diff-btn.active.all    { background: rgba(99,102,241,.12); border-color: rgba(99,102,241,.3); color: var(--accent2); }

/* ── MATCHING GAME ──────────────────────────────────────────── */
.match-timer {
  font-family: var(--mono); font-size: 1rem; font-weight: 700;
  color: var(--accent2);
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  padding: 4px 16px; border-radius: 99px;
  border: 1px solid rgba(255,255,255,.12);
  box-shadow: 0 2px 12px rgba(0,0,0,.18), inset 0 1px 0 rgba(255,255,255,.1);
}
.match-score-row { margin-bottom: 20px; }
.match-score-label { font-size: 0.82rem; color: var(--text2); }
.match-score-label strong { color: var(--text); }
.match-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; max-width: 900px; margin: 0 auto; }
.match-col { display: flex; flex-direction: column; gap: 10px; }
.match-card {
  padding: 14px 18px; border-radius: var(--r-sm);
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(20px); -webkit-backdrop-filter: blur(20px);
  border: 1px solid rgba(255,255,255,.09);
  color: var(--text2); font-size: 0.82rem; font-family: var(--font);
  text-align: left; cursor: pointer; line-height: 1.5;
  transition: background .18s, border-color .18s, transform .18s var(--spring), box-shadow .18s;
  box-shadow: 0 3px 14px rgba(0,0,0,.16), inset 0 1px 0 rgba(255,255,255,.08);
  position: relative; overflow: hidden;
}
.match-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.15), transparent);
  opacity: 0; transition: opacity .2s;
}
.match-card:hover:not(.matched):not(.wrong) {
  background: rgba(99,102,241,.1);
  border-color: rgba(99,102,241,.35);
  transform: translateY(-3px) scale(1.01);
  box-shadow: 0 8px 24px rgba(99,102,241,.22), inset 0 1px 0 rgba(99,102,241,.15);
}
.match-card:hover:not(.matched):not(.wrong)::before { opacity: 1; }
.match-card.selected {
  background: rgba(99,102,241,.15);
  border-color: var(--accent);
  color: var(--text);
  box-shadow: 0 0 0 2px var(--accent), 0 8px 28px rgba(99,102,241,.3), inset 0 1px 0 rgba(99,102,241,.2);
  transform: translateY(-2px);
}
.match-card.matched {
  background: rgba(52,211,153,.08);
  border-color: rgba(52,211,153,.38);
  color: #34d399; cursor: default; opacity: .8;
  box-shadow: 0 0 20px rgba(52,211,153,.18), inset 0 1px 0 rgba(52,211,153,.15);
}
.match-card.wrong {
  background: rgba(248,113,113,.08);
  border-color: rgba(248,113,113,.35);
  color: #f87171;
  animation: shake .32s ease;
}
.match-card-term {
  font-family: var(--mono); font-size: 0.8rem; font-weight: 700;
  color: var(--text); text-align: center;
}
@keyframes shake { 0%,100% { transform: translateX(0); } 25% { transform: translateX(-7px); } 75% { transform: translateX(7px); } }
.match-complete-time { font-size: 0.9rem; color: var(--text2); margin-bottom: 24px; font-family: var(--mono); }

/* ── SCROLL REVEAL — enhanced stagger ──────────────────────── */
.reveal {
  opacity: 0;
  transform: translateY(40px);
  transition: opacity .75s var(--ease), transform .75s var(--ease);
}
.reveal.visible { opacity: 1; transform: none; }
.reveal.from-left  { transform: translateX(-40px); }
.reveal.from-right { transform: translateX(40px); }
.reveal.from-left.visible, .reveal.from-right.visible { transform: none; }
.reveal:nth-child(2) { transition-delay: .1s; }
.reveal:nth-child(3) { transition-delay: .2s; }
.reveal:nth-child(4) { transition-delay: .3s; }
.reveal:nth-child(5) { transition-delay: .4s; }

/* ── STATS SECTION ──────────────────────────────────────────── */
.stats-section {
  padding: var(--layout-pad) 18px;
}
.stats-grid {
  max-width: var(--layout-max); margin: 0 auto;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 16px;
}
.stat-card {
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid rgba(255,255,255,.09);
  border-radius: var(--r); padding: 28px 24px;
  text-align: center; position: relative; overflow: hidden;
  box-shadow: 0 4px 24px rgba(0,0,0,.14), inset 0 1px 0 rgba(255,255,255,.08);
  transition: transform .28s var(--spring), box-shadow .28s;
}
.stat-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 2px;
  background: linear-gradient(90deg, transparent, var(--stat-color, var(--accent)), transparent);
  opacity: .7;
}
.stat-card:hover { transform: translateY(-5px); box-shadow: 0 16px 48px rgba(0,0,0,.2), inset 0 1px 0 rgba(255,255,255,.12); }
.stat-card-val {
  font-size: 2.8rem; font-weight: 800; font-family: var(--mono); line-height: 1;
  background: linear-gradient(135deg, var(--stat-color, var(--accent)), var(--text));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 6px;
}
.stat-card-label { font-size: 0.72rem; color: var(--text3); font-weight: 600; text-transform: uppercase; letter-spacing: 1.5px; }
.stat-card-icon { font-size: 1.6rem; margin-bottom: 10px; }

/* ── TIPS SECTION ───────────────────────────────────────────── */
.tips-section { padding: var(--layout-pad) 18px; }
.tips-section-inner { max-width: var(--layout-max); margin: 0 auto; }
.tips-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 0; }
.tip-card {
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid rgba(255,255,255,.09);
  border-radius: var(--r); padding: 24px;
  position: relative; overflow: hidden;
  box-shadow: 0 4px 24px rgba(0,0,0,.12), inset 0 1px 0 rgba(255,255,255,.08);
  transition: transform .28s var(--spring), box-shadow .28s, border-color .28s;
}
.tip-card::before {
  content: '';
  position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.2), transparent);
}
.tip-card:hover { transform: translateY(-4px); border-color: rgba(255,255,255,.16); box-shadow: 0 16px 48px rgba(0,0,0,.18); }
.tip-card-icon { font-size: 1.8rem; margin-bottom: 12px; }
.tip-card-title { font-size: 0.88rem; font-weight: 700; color: var(--text); margin-bottom: 6px; }
.tip-card-text { font-size: 0.75rem; color: var(--text2); line-height: 1.6; }

/* ── PROGRESS TRACKER ───────────────────────────────────────── */
.progress-section { padding: var(--layout-pad) 18px; }
.progress-section-inner { max-width: var(--layout-max); margin: 0 auto; }
.progress-subjects { display: flex; flex-direction: column; gap: 14px; }
.progress-subject {
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border: 1px solid rgba(255,255,255,.09);
  border-radius: var(--r-sm); padding: 18px 22px;
  display: flex; align-items: center; gap: 18px;
  box-shadow: 0 2px 14px rgba(0,0,0,.1), inset 0 1px 0 rgba(255,255,255,.07);
  transition: transform .2s var(--spring), box-shadow .2s;
}
.progress-subject:hover { transform: translateX(4px); box-shadow: 0 4px 20px rgba(0,0,0,.15); }
.progress-subject-id {
  font-family: var(--mono); font-size: 0.65rem; font-weight: 800;
  letter-spacing: 1.5px; text-transform: uppercase;
  min-width: 44px; text-align: center;
}
.progress-subject-name { font-size: 0.82rem; font-weight: 600; color: var(--text); min-width: 160px; }
.progress-bar-wrap { flex: 1; height: 6px; background: rgba(255,255,255,.06); border-radius: 99px; overflow: hidden; }
.progress-bar-fill {
  height: 100%; border-radius: 99px;
  transition: width 1.4s cubic-bezier(.4,0,.2,1);
  box-shadow: 0 0 10px currentColor;
  position: relative;
}
.progress-bar-fill::after {
  content: '';
  position: absolute; top: 0; right: 0; bottom: 0; width: 40px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.35));
  border-radius: 99px;
  animation: progressShine 2s ease-in-out infinite;
}
@keyframes progressShine {
  0%, 100% { opacity: 0; }
  50% { opacity: 1; }
}
.progress-subject-pct { font-family: var(--mono); font-size: 0.72rem; color: var(--text3); min-width: 36px; text-align: right; }

/* ── QUOTE SECTION ──────────────────────────────────────────── */
.quote-section { padding: var(--layout-pad) 18px; }
.quote-inner {
  max-width: 800px; margin: 0 auto; text-align: center;
  background: rgba(255,255,255,.04);
  backdrop-filter: blur(28px) saturate(180%);
  -webkit-backdrop-filter: blur(28px) saturate(180%);
  border: 1px solid rgba(255,255,255,.1);
  border-radius: var(--r);
  padding: 48px 52px;
  box-shadow: 0 8px 40px rgba(0,0,0,.18), inset 0 1px 0 rgba(255,255,255,.1);
  position: relative; overflow: hidden;
  animation: quoteBorderPulse 6s ease-in-out infinite;
}
@keyframes quoteBorderPulse {
  0%, 100% { border-color: rgba(255,255,255,.1); box-shadow: 0 8px 40px rgba(0,0,0,.18), inset 0 1px 0 rgba(255,255,255,.1); }
  50% { border-color: rgba(99,102,241,.25); box-shadow: 0 8px 40px rgba(99,102,241,.12), 0 0 0 1px rgba(99,102,241,.1), inset 0 1px 0 rgba(255,255,255,.12); }
}
.quote-inner::before {
  content: '"';
  position: absolute; top: -20px; left: 24px;
  font-size: 12rem; font-weight: 900; line-height: 1;
  color: var(--accent); opacity: .06;
  font-family: Georgia, serif;
}
.quote-text {
  font-size: 1.15rem; font-weight: 500; color: var(--text); line-height: 1.7;
  margin-bottom: 20px; position: relative; z-index: 1;
  font-style: italic;
  transition: opacity .4s var(--ease);
}
.quote-author {
  font-size: 0.75rem; color: var(--text3); font-weight: 600; letter-spacing: 1px;
  text-transform: uppercase;
  transition: opacity .4s var(--ease);
}

/* ── FILL INPUT ENHANCED ────────────────────────────────────── */
.fill-input {
  flex: 1; padding: 12px 18px; border-radius: var(--r-sm);
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.12);
  color: var(--text); font-size: 0.9rem; font-family: var(--font);
  transition: border-color .18s, box-shadow .18s;
  outline: none;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.08), 0 2px 8px rgba(0,0,0,.1);
}
.fill-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(99,102,241,.2), inset 0 1px 0 rgba(255,255,255,.1); }
.fill-input.correct { border-color: #34d399; background: rgba(52,211,153,.07); color: #34d399; box-shadow: 0 0 16px rgba(52,211,153,.18); }
.fill-input.wrong { border-color: #f87171; background: rgba(248,113,113,.07); color: #f87171; }

/* ── GLASS INPUT (quiz written) ─────────────────────────────── */
.glass-input {
  flex: 1; padding: 12px 18px; border-radius: var(--r-sm);
  background: rgba(255,255,255,.05);
  backdrop-filter: blur(16px); -webkit-backdrop-filter: blur(16px);
  border: 1px solid rgba(255,255,255,.12);
  color: var(--text); font-size: 0.9rem; font-family: var(--font);
  transition: border-color .18s, box-shadow .18s;
  outline: none;
  box-shadow: inset 0 1px 0 rgba(255,255,255,.08);
}
.glass-input:focus { border-color: var(--accent); box-shadow: 0 0 0 3px rgba(99,102,241,.2); }
.glass-input.correct { border-color: #34d399; color: #34d399; }
.glass-input.wrong { border-color: #f87171; color: #f87171; }

/* ── GLASS OPT (quiz option variant) ───────────────────────── */
.glass-opt {
  background: rgba(255,255,255,.04) !important;
  backdrop-filter: blur(16px) !important;
  -webkit-backdrop-filter: blur(16px) !important;
}

/* ── SCORE SCREEN ───────────────────────────────────────────── */
.quiz-score {
  text-align: center; padding: 60px 20px;
  position: relative; overflow: hidden;
}
.quiz-score::before {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 60% 50% at 50% 30%, rgba(99,102,241,.08), transparent 70%);
}
.quiz-score-num {
  font-size: 5rem; font-weight: 800; font-family: var(--mono);
  background: linear-gradient(135deg, var(--accent), #a78bfa, #60a5fa);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  margin-bottom: 8px; position: relative;
  filter: drop-shadow(0 0 30px rgba(99,102,241,.3));
}
.quiz-score-label { font-size: 1rem; color: var(--text2); margin-bottom: 32px; position: relative; }
.quiz-restart-btn {
  padding: 13px 36px; border-radius: var(--r-sm);
  background: linear-gradient(135deg, var(--accent), #7c3aed);
  color: #fff; font-size: 0.9rem; font-weight: 600; font-family: var(--font);
  transition: transform .2s var(--spring), box-shadow .2s;
  box-shadow: 0 4px 24px rgba(99,102,241,.4), inset 0 1px 0 rgba(255,255,255,.2);
  position: relative;
}
.quiz-restart-btn:hover { transform: translateY(-4px) scale(1.02); box-shadow: 0 12px 36px rgba(99,102,241,.55); }

/* ── RESPONSIVE ─────────────────────────────────────────────── */
@media (max-width: 1024px) {
  .cat-cards { grid-template-columns: repeat(2, 1fr); }
  .topic-layout { grid-template-columns: 1fr 260px; }
  .feature-strip-inner { grid-template-columns: repeat(2, 1fr); }
  .feature-sep:nth-child(4) { display: none; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .tips-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 900px) {
  .cat-cards { grid-template-columns: repeat(2, 1fr); }
  .practice-grid { grid-template-columns: 1fr; }
  .topic-layout { grid-template-columns: 1fr; }
  .topic-aside { position: static; }
  .cd-display { flex-direction: column; gap: 18px; padding: 22px 20px; }
  .sidebar { width: 260px; }
  .feature-strip-inner { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 640px) {
  .section { padding: 32px 12px; }
  .section-inner { padding: 0; }
  .stats-section { padding: 28px 12px; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }
  .stat-card { padding: 20px 14px; }
  .stat-card-val { font-size: 2rem; }
  .tips-section { padding: 28px 12px; }
  .tips-grid { grid-template-columns: 1fr; gap: 10px; }
  .quote-section { padding: 28px 12px; }
  .quote-inner { padding: 32px 24px; }
  .quote-text { font-size: 0.95rem; }
  .progress-section { padding: 28px 12px; }
  .progress-subject { flex-wrap: wrap; gap: 8px; }
  .progress-subject-name { min-width: unset; }
  .section-inner { padding: 0; }
  .page-hero { padding: 38px 14px 20px; }
  .page-hero-title { font-size: 1.3rem; letter-spacing: -.5px; }
  .navbar-inner { padding: 0 12px; }
  .nav-breadcrumb { display: none; }
  .hero-scroll-hint { display: none; }
  .hero-h1 { letter-spacing: -2px; }
  .hero-stats { gap: 14px; }
  .hero-stat-val { font-size: 1.2rem; }
  .hero-desc { font-size: 0.85rem; }
  .hero-cta-row { flex-direction: column; gap: 8px; }
  .hero-cta-btn, .hero-cta-ghost { width: 100%; text-align: center; }
  .hero-chips { display: none; }
  .feature-strip-inner { grid-template-columns: 1fr; }
  .feature-sep { display: none; }
  .countdown-widget { border-radius: var(--r-sm); }
  .cd-tabs { overflow-x: auto; flex-wrap: nowrap; padding: 0; }
  .cd-tab { font-size: 0.7rem; padding: 9px 12px; white-space: nowrap; flex-shrink: 0; }
  .cd-display { flex-direction: column; align-items: flex-start; gap: 10px; padding: 18px 16px; min-height: unset; }
  .cd-number { font-size: 52px; }
  .cd-exam-name { font-size: 1rem; }
  .cat-cards { grid-template-columns: 1fr 1fr; gap: 10px; }
  .cat-card { padding: 16px; }
  .cat-card-desc { display: none; }
  .practice-grid { grid-template-columns: 1fr; gap: 10px; }
  .practice-card { padding: 16px; }
  .practice-card-footer { flex-direction: column; align-items: stretch; gap: 8px; }
  .practice-select { width: 100%; }
  .practice-start-btn { width: 100%; text-align: center; padding: 10px 18px; }
  .content-block dl { grid-template-columns: 1fr; gap: 0; }
  .content-block dt { white-space: normal; font-size: 0.72rem; color: var(--text3); padding: 8px 0 2px; border-top: 1px solid var(--border); margin-top: 4px; }
  .content-block dt:first-of-type { border-top: none; margin-top: 0; padding-top: 0; }
  .content-block dd { padding: 0 0 6px; font-size: 0.82rem; }
  .content-block { padding: 14px; }
  .topic-layout { grid-template-columns: 1fr; }
  .topic-aside { position: static; }
  .back-link { font-size: 0.7rem; padding: 3px 10px; height: 26px; }
  .topic-badge { font-size: 0.55rem; height: 26px; padding: 0 10px; }
  .sidebar { width: 100%; max-width: 100%; }
  .panel { width: min(300px, 92vw); }
  .flashcard-inner { height: 240px; }
  .flashcard-front { font-size: 0.95rem; }
  .flashcard-controls { flex-wrap: wrap; gap: 6px; }
  .fc-btn { flex: 1; min-width: 80px; font-size: 0.75rem; padding: 9px; }
  .quiz-options { gap: 7px; }
  .quiz-option { padding: 11px 14px; font-size: 0.84rem; }
  .quiz-q-text { font-size: 0.92rem; }
  .fill-input-row { flex-direction: column; }
  .fill-submit-btn { width: 100%; }
  .match-grid { grid-template-columns: 1fr 1fr; gap: 7px; }
  .match-card { font-size: 0.72rem; padding: 9px 11px; min-height: 54px; }
  .md-table { font-size: 0.72rem; }
  .md-table th, .md-table td { padding: 6px 8px; }
  .kv-row { flex-direction: column; gap: 1px; margin-bottom: 10px; }
  .kv-key { min-width: unset; max-width: unset; width: auto; font-size: 0.7rem; font-weight: 700; letter-spacing: 0.5px; text-transform: uppercase; }
  .kv-val { font-size: 0.82rem; }
}
@media (max-width: 400px) {
  .cat-cards { grid-template-columns: 1fr; }
  .hero-stats { flex-wrap: wrap; gap: 10px; }
  .cd-tab { font-size: 0.65rem; padding: 8px 10px; }
}

/* ── CURSOR GLOW TRAIL ──────────────────────────────────────── */
.cursor-glow {
  position: fixed; pointer-events: none; z-index: 9998;
  width: 320px; height: 320px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(99,102,241,.06) 0%, transparent 70%);
  transform: translate(-50%, -50%);
  transition: left .12s ease, top .12s ease;
  mix-blend-mode: screen;
}

/* ── FLOATING PARTICLES (homepage ambient) ──────────────────── */
.ambient-particle {
  position: fixed; pointer-events: none; z-index: 0;
  border-radius: 50%;
  background: var(--accent);
  opacity: 0;
  animation: particleDrift linear infinite;
}
@keyframes particleDrift {
  0%   { opacity: 0; transform: translateY(0) scale(0); }
  10%  { opacity: .35; transform: translateY(-10px) scale(1); }
  90%  { opacity: .2; }
  100% { opacity: 0; transform: translateY(-120px) scale(.3); }
}

/* ── ENHANCED STAT CARD GLOW ────────────────────────────────── */
.stat-card::after {
  content: '';
  position: absolute; inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 100%, rgba(var(--stat-rgb, 99,102,241),.08), transparent 70%);
  opacity: 0; transition: opacity .3s;
  border-radius: var(--r);
}
.stat-card:hover::after { opacity: 1; }

/* ── STREAM TEXT CURSOR ─────────────────────────────────────── */
.stream-cursor {
  display: inline-block; width: 2px; height: 1em;
  background: var(--accent); border-radius: 1px;
  vertical-align: text-bottom; margin-left: 2px;
  animation: blink .7s step-end infinite;
}

/* ── MATCH COMPLETE ENHANCED ────────────────────────────────── */
.match-complete {
  text-align: center; padding: 52px 20px; grid-column: 1 / -1;
  animation: cardSlideIn .5s var(--spring) both;
}
.match-complete-title {
  font-size: 2.2rem; font-weight: 800; margin-bottom: 8px;
  background: linear-gradient(135deg, var(--accent), #a78bfa, #60a5fa);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.match-complete-time { font-size: 0.9rem; color: var(--text2); margin-bottom: 24px; font-family: var(--mono); }

/* ── ENHANCED HERO EYEBROW PULSE ────────────────────────────── */
@keyframes eyebrowPulse {
  0%, 100% { opacity: .6; }
  50% { opacity: 1; }
}
.hero-eyebrow { animation: eyebrowPulse 3s ease-in-out infinite; }

/* ── SECTION LABEL ENHANCED ─────────────────────────────────── */
.section-label::before {
  background: linear-gradient(90deg, var(--accent), #a78bfa);
  animation: labelGlow 3s ease-in-out infinite alternate;
}
@keyframes labelGlow {
  from { box-shadow: 0 0 0 rgba(99,102,241,0); }
  to   { box-shadow: 0 0 8px rgba(99,102,241,.6); }
}

/* ── TIPS SECTION LABEL ─────────────────────────────────────── */
.tips-section .section-label { margin-bottom: 24px; }

/* ── PROGRESS SECTION LABEL ─────────────────────────────────── */
.progress-section .section-label { margin-bottom: 24px; }

/* ── RESPONSIVE ADDITIONS ───────────────────────────────────── */
@media (max-width: 1024px) {
  .practice-header { padding: 12px 16px; }
}
@media (max-width: 640px) {
  .practice-header { padding: 10px 14px; gap: 10px; }
  .match-complete-title { font-size: 1.6rem; }
}