/* =====================================================================
   IGCSE Past Papers — "Ballpoint" design system
   ---------------------------------------------------------------------
   Idea     bright exam paper, written on in blue ballpoint: the pen every
            candidate uses. Cobalt is the one signature colour; everything
            else is paper white and blue-black ink.
   Type     Manrope for display and interface (wide, open, friendly;
            display 500, tracking -3.5% to -4.5% at large sizes).
            JetBrains Mono only for paper references and codes.
   Motif    the answer box: a small square cell (logo, year coverage,
            list markers).
   Structure rules, not boxes. Heavy 2px ink rules open sections and
            year groups; 1px hairlines separate rows. Boxes only where a
            thing really is a surface (a window, a sheet, a dialog).
   Motion   buttons step on hover and press, underlines draw. No scroll
            reveals, no loops, no springs.
   ===================================================================== */

:root {
  color-scheme: light;

  /* Grounds */
  --bg: #f5f5f2;
  --surface: #ffffff;
  --surface-2: #ebebe6;
  --surface-3: #dcdcd5;

  /* Ink — three text roles */
  --ink: #0d1020;
  --ink-2: #3c4152;
  --ink-3: #5d6273;
  --line: rgba(13, 16, 32, .08);
  --line-2: rgba(13, 16, 32, .16);
  --rule: #0d1020;

  /* The signature: ballpoint cobalt */
  --accent: #1442ff;
  --accent-hover: #0b33d9;
  --accent-ink: #ffffff;
  --accent-soft: rgba(20, 66, 255, .08);
  --accent-line: rgba(20, 66, 255, .35);

  /* Brand band (always electric cobalt) and the dark ground */
  --band: #1442ff;
  --band-ink: #ffffff;
  --band-ink-2: rgba(255, 255, 255, .78);
  --dark: #0d1020;
  --dark-2: #171b2e;
  --dark-ink: #f5f5f2;
  --dark-ink-2: rgba(245, 245, 242, .7);
  --dark-line: rgba(245, 245, 242, .14);

  /* Status */
  --good: #13794a; --good-soft: rgba(19, 121, 74, .1);
  --warn: #8a5600; --warn-soft: rgba(176, 120, 10, .13);
  --bad: #c0262d;  --bad-soft: rgba(192, 38, 45, .09);
  --star: #b26f00;

  /* Subjects no longer carry their own colours: one accent, one system */
  --chemistry: var(--accent); --physics: var(--accent); --biology: var(--accent);
  --computer-science: var(--accent); --english: var(--accent); --add-math: var(--accent);

  /* Paper sheets stay paper in both themes */
  --sheet: #ffffff;
  --sheet-2: #f1f1ec;
  --sheet-ink: #0d1020;
  --sheet-ink-3: #6b7080;
  --sheet-line: rgba(13, 16, 32, .16);
  --pen: #1442ff;

  --viewer-bg: #e4e4de;
  --focus: #1442ff;

  --shadow-xs: 0 1px 2px rgba(13, 16, 32, .06);
  --shadow-sm: 0 1px 2px rgba(13, 16, 32, .06), 0 4px 12px -4px rgba(13, 16, 32, .1);
  --shadow: 0 2px 4px rgba(13, 16, 32, .06), 0 12px 32px -12px rgba(13, 16, 32, .22);
  --shadow-lg: 0 2px 4px rgba(13, 16, 32, .06), 0 28px 56px -18px rgba(13, 16, 32, .32);

  --font-display: "Manrope", system-ui, -apple-system, "Apple SD Gothic Neo", sans-serif;
  --font-body: "Manrope", system-ui, -apple-system, "Segoe UI", "Apple SD Gothic Neo", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  /* Radius: soft, never pills */
  --r-lg: 14px;
  --r: 10px;
  --r-sm: 8px;
  --r-xs: 6px;
  --r-xl: 16px;

  --tap: 40px;
  --topbar-h: 64px;
  --tabbar-h: 0px;
  --page: 1280px;
  --gut: 48px;

  --ease: cubic-bezier(.22, 1, .36, 1);
  --ease-out: var(--ease);
  --spring: var(--ease);
}

/* Big monitors: let the page grow so the composition keeps its MacBook proportions */
@media (min-width: 1680px) { :root { --page: 1440px; --gut: 64px; } }
@media (min-width: 2200px) { :root { --page: 1600px; } }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #0c0f18; --surface: #121625; --surface-2: #1a1f30; --surface-3: #252b40;
    --ink: #eef0f6; --ink-2: #b9bdcb; --ink-3: #8d93a5;
    --line: rgba(238, 240, 246, .07); --line-2: rgba(238, 240, 246, .14); --rule: #eef0f6;
    --accent: #4f86ff; --accent-hover: #74a0ff; --accent-ink: #0c0f18; --accent-soft: rgba(79, 134, 255, .12); --accent-line: rgba(79, 134, 255, .45);
    --dark: #05070d; --dark-2: #0e1220;
    --good: #5fd09a; --good-soft: rgba(95, 208, 154, .12); --warn: #f0b85a; --warn-soft: rgba(240, 184, 90, .12);
    --bad: #ff8a85; --bad-soft: rgba(255, 138, 133, .12); --star: #f0b84a;
    --sheet: #eef0f4; --sheet-2: #dfe2ea;
    --viewer-bg: #080a11; --focus: #74a0ff;
    --shadow-xs: 0 1px 2px rgba(0, 0, 0, .4);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4), 0 4px 12px -4px rgba(0, 0, 0, .5);
    --shadow: 0 2px 4px rgba(0, 0, 0, .4), 0 12px 32px -12px rgba(0, 0, 0, .7);
    --shadow-lg: 0 2px 4px rgba(0, 0, 0, .4), 0 28px 56px -18px rgba(0, 0, 0, .85);
  }
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0c0f18; --surface: #121625; --surface-2: #1a1f30; --surface-3: #252b40;
  --ink: #eef0f6; --ink-2: #b9bdcb; --ink-3: #8d93a5;
  --line: rgba(238, 240, 246, .07); --line-2: rgba(238, 240, 246, .14); --rule: #eef0f6;
  --accent: #4f86ff; --accent-hover: #74a0ff; --accent-ink: #0c0f18; --accent-soft: rgba(79, 134, 255, .12); --accent-line: rgba(79, 134, 255, .45);
  --dark: #05070d; --dark-2: #0e1220;
  --good: #5fd09a; --good-soft: rgba(95, 208, 154, .12); --warn: #f0b85a; --warn-soft: rgba(240, 184, 90, .12);
  --bad: #ff8a85; --bad-soft: rgba(255, 138, 133, .12); --star: #f0b84a;
  --sheet: #eef0f4; --sheet-2: #dfe2ea;
  --viewer-bg: #080a11; --focus: #74a0ff;
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, .4);
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, .4), 0 4px 12px -4px rgba(0, 0, 0, .5);
  --shadow: 0 2px 4px rgba(0, 0, 0, .4), 0 12px 32px -12px rgba(0, 0, 0, .7);
  --shadow-lg: 0 2px 4px rgba(0, 0, 0, .4), 0 28px 56px -18px rgba(0, 0, 0, .85);
}

/* ---------------------------------------------------------------------
   Base
   --------------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }
html { -webkit-text-size-adjust: 100%; scroll-padding-top: calc(var(--topbar-h) + 16px); }
html, body { margin: 0; }
body {
  min-height: 100vh; overflow-x: clip;
  background: var(--bg); color: var(--ink);
  font: 400 16px/1.6 var(--font-body);
  -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale;
  padding-bottom: var(--tabbar-h);
}
a { color: var(--accent); text-underline-offset: 3px; text-decoration-thickness: 1px; }
a:hover { color: var(--accent-hover); }
button, input, select { font: inherit; color: inherit; }
img, svg { display: block; }
svg { flex: none; }
:focus-visible { outline: 2px solid var(--focus); outline-offset: 3px; border-radius: 2px; }
::selection { background: color-mix(in srgb, var(--accent) 24%, transparent); }
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--ink-3); }
.sr-only { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }

.tone-chemistry, .tone-physics, .tone-biology, .tone-computer-science, .tone-english, .tone-add-math { --tone: var(--accent); }

.skip-link {
  position: absolute; left: 16px; top: -80px; z-index: 200; padding: 8px 16px; border-radius: var(--r-sm);
  background: var(--accent); color: var(--accent-ink); font-weight: 500; text-decoration: none;
}
.skip-link:focus { top: calc(env(safe-area-inset-top, 0px) + 12px); color: var(--accent-ink); }

/* ---------------------------------------------------------------------
   Top bar — full width, opaque, one hairline
   --------------------------------------------------------------------- */
.topbar {
  position: sticky; top: 0; z-index: 40; padding: env(safe-area-inset-top, 0px) var(--gut) 0;
  background: var(--bg); border-bottom: 1px solid var(--line-2);
}
.topbar-inner { max-width: var(--page); margin: 0 auto; height: var(--topbar-h); display: flex; align-items: center; gap: 40px; }
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); white-space: nowrap; }
.brand:hover { color: var(--ink); }
.brand-mark svg { width: 24px; height: 24px; }
.brand-text { font: 500 19px/1 var(--font-display); letter-spacing: -.025em; }
.brand-text em { font-style: normal; color: var(--ink-3); }

.nav { display: flex; gap: 28px; align-self: stretch; }
.nav a {
  position: relative; display: inline-flex; align-items: center; white-space: nowrap;
  color: var(--ink-2); text-decoration: none; font-weight: 500; font-size: 15px; transition: color .15s var(--ease);
}
.nav a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -1px; height: 2px; background: var(--accent);
  transform: scaleX(0); transform-origin: left; transition: transform .25s var(--ease);
}
.nav a:hover { color: var(--ink); }
.nav a:hover::after { transform: scaleX(.35); }
.nav a[aria-current] { color: var(--ink); }
.nav a[aria-current]::after { transform: scaleX(1); }

.top-actions { display: flex; align-items: center; gap: 8px; margin-left: auto; }
.cmd-btn {
  display: inline-flex; align-items: center; gap: 8px; height: 40px; min-width: 260px; padding: 0 8px 0 12px;
  border-radius: var(--r-sm); border: 1px solid var(--line-2); background: var(--surface); color: var(--ink-3);
  cursor: pointer; font-size: 15px; transition: border-color .15s var(--ease), color .15s var(--ease);
}
.cmd-btn:hover { border-color: var(--ink); color: var(--ink-2); }
.cmd-btn .ic svg { width: 16px; height: 16px; }
.cmd-label { flex: 1; text-align: left; }
.net-pill { display: inline-flex; align-items: center; font-size: 13px; font-weight: 500; padding: 4px 8px; border-radius: var(--r-xs); background: var(--warn-soft); color: var(--warn); }
.icon-btn {
  display: inline-grid; place-items: center; width: 40px; height: 40px; border-radius: var(--r-sm);
  border: 1px solid transparent; background: transparent; color: var(--ink-2); cursor: pointer;
  transition: color .15s var(--ease), background .15s var(--ease), transform .15s var(--ease);
}
.icon-btn:hover { color: var(--ink); background: var(--surface-2); }
.icon-btn:active { transform: scale(.96); }
.icon-btn svg { width: 18px; height: 18px; }

kbd {
  display: inline-flex; align-items: center; justify-content: center; min-width: 22px; height: 22px; padding: 0 6px;
  font: 500 12px/1 var(--font-mono); color: var(--ink-3); background: var(--bg);
  border: 1px solid var(--line-2); border-bottom-width: 2px; border-radius: var(--r-xs);
}

/* Bottom tab bar (phones) */
.tabbar { display: none; }
@media (max-width: 760px) {
  :root { --tabbar-h: calc(64px + env(safe-area-inset-bottom, 0px)); --topbar-h: 56px; --gut: 16px; }
  .nav { display: none; }
  .cmd-btn { min-width: 0; width: 40px; padding: 0; justify-content: center; border-color: transparent; background: transparent; }
  .cmd-btn .cmd-label, .cmd-btn kbd { display: none; }
  .tabbar {
    display: grid; grid-template-columns: repeat(5, 1fr); position: fixed; z-index: 40; left: 0; right: 0; bottom: 0;
    padding: 4px 8px env(safe-area-inset-bottom, 0px); background: var(--bg); border-top: 1px solid var(--line-2);
  }
  .tabbar a {
    position: relative; display: grid; justify-items: center; align-content: center; gap: 4px; min-height: 56px;
    font-size: 13px; font-weight: 500; color: var(--ink-3); text-decoration: none; transition: color .15s var(--ease);
  }
  .tabbar a::before { content: ""; position: absolute; top: -5px; left: 28%; right: 28%; height: 2px; background: var(--accent); transform: scaleX(0); transition: transform .25s var(--ease); }
  .tabbar a[aria-current] { color: var(--ink); }
  .tabbar a[aria-current]::before { transform: scaleX(1); }
  .tabbar svg { width: 20px; height: 20px; }
}

/* ---------------------------------------------------------------------
   Controls
   --------------------------------------------------------------------- */
.input {
  min-height: var(--tap); padding: 0 12px; border-radius: var(--r-sm); border: 1px solid var(--line-2);
  background: var(--surface); color: var(--ink); min-width: 0; font-size: 16px;
  transition: border-color .15s var(--ease), box-shadow .15s var(--ease);
}
.input::placeholder { color: var(--ink-3); opacity: 1; }
.input:hover { border-color: color-mix(in srgb, var(--ink) 45%, transparent); }
.input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
input[type="search"]::-webkit-search-cancel-button { cursor: pointer; }

.btn {
  position: relative; display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  min-height: var(--tap); padding: 0 16px; border-radius: var(--r-sm); border: 1px solid var(--ink);
  background: transparent; color: var(--ink); cursor: pointer; text-decoration: none;
  font-size: 15px; font-weight: 500; white-space: nowrap;
  transition: background .15s var(--ease), border-color .15s var(--ease), color .15s var(--ease), transform .15s var(--ease);
}
.btn:hover { background: var(--ink); color: var(--bg); transform: translateY(-1px); }
.btn:active { transform: translateY(0) scale(.98); }
.btn:disabled { opacity: .5; cursor: default; transform: none; }
.btn:disabled:hover { background: transparent; color: var(--ink); }
.btn svg { width: 16px; height: 16px; }
.btn.primary { color: var(--accent-ink); border-color: var(--accent); background: var(--accent); }
.btn.primary:hover { color: var(--accent-ink); background: var(--accent-hover); border-color: var(--accent-hover); }
.btn.ghost { border-color: transparent; color: var(--ink-2); }
.btn.ghost:hover { background: var(--surface-2); color: var(--ink); }
.btn.good { color: var(--good); border-color: var(--good); background: var(--good-soft); cursor: default; transform: none; }
.btn.danger { color: var(--bad); border-color: color-mix(in srgb, var(--bad) 50%, transparent); }
.btn.ghost.danger { border-color: transparent; }
.btn.danger:hover { background: var(--bad-soft); color: var(--bad); }
.btn.danger.confirm, .btn.confirm { background: var(--bad); border-color: var(--bad); color: #fff; }
.btn.small { min-height: 32px; padding: 0 12px; font-size: 14px; }
.btn[aria-pressed="true"] .star, .star-on { color: var(--star); }
.btn[aria-pressed="true"]:not(.seg *) { background: var(--surface-2); }
.btn[aria-pressed="true"]:not(.seg *):hover { color: var(--ink); }

.link-btn { background: none; border: 0; padding: 4px 0; color: var(--accent); cursor: pointer; font-size: 14px; font-weight: 500; text-decoration: underline; text-decoration-color: var(--accent-line); text-underline-offset: 3px; }
.link-btn:hover { text-decoration-color: currentColor; }
.link-btn.confirm { color: var(--bad); }

/* Segmented control: square tabs on a hairline */
.seg { display: inline-flex; gap: 2px; padding: 3px; border-radius: var(--r); background: var(--surface-2); }
.seg button, .seg a {
  min-height: 34px; padding: 0 14px; border: 0; border-radius: var(--r-sm); background: transparent; color: var(--ink-2);
  font-weight: 500; cursor: pointer; display: inline-flex; align-items: center; gap: 6px; text-decoration: none; font-size: 14px;
  transition: color .15s var(--ease), background .15s var(--ease);
}
.seg button:hover, .seg a:hover { color: var(--ink); }
.seg [aria-pressed="true"], .seg [aria-current="true"] { background: var(--surface); color: var(--ink); box-shadow: var(--shadow-xs); }
.seg [aria-pressed="true"]:hover, .seg [aria-current="true"]:hover { background: var(--surface); color: var(--ink); }

/* Chips: soft filter keys, never pills */
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip {
  min-height: 34px; padding: 0 12px; border-radius: var(--r-sm); border: 1px solid transparent; background: var(--surface-2);
  color: var(--ink-2); font-size: 14px; font-weight: 500; cursor: pointer; font-variant-numeric: tabular-nums;
  transition: background .15s var(--ease), border-color .15s var(--ease), color .15s var(--ease), transform .15s var(--ease);
}
.chip:hover { border-color: var(--line-2); color: var(--ink); }
.chip:active { transform: scale(.97); }
.chip[aria-pressed="true"] { background: var(--accent-soft); border-color: transparent; color: var(--accent); }

.badge { display: inline-flex; align-items: center; gap: 4px; font-size: 13px; line-height: 1.2; padding: 0; color: var(--ink-3); white-space: nowrap; }
.badge svg { width: 12px; height: 12px; }
.badge.good, .badge.warn { padding: 3px 6px; border-radius: var(--r-xs); font-weight: 500; }
.badge.good { background: var(--good-soft); color: var(--good); }
.badge.warn { background: var(--warn-soft); color: var(--warn); }

.spinner { width: 22px; height: 22px; display: inline-block; border: 2px solid var(--line-2); border-top-color: var(--accent); border-radius: 50%; animation: spin .8s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ---------------------------------------------------------------------
   Page shell, type, structure
   --------------------------------------------------------------------- */
main { max-width: calc(var(--page) + 2 * var(--gut)); margin: 0 auto; padding: 40px var(--gut) 96px; outline: none; }
.boot { display: grid; place-items: center; gap: 12px; padding: 18vh 0; }
.loading-msg { color: var(--ink-3); margin: 0; }

h1, h2, h3 { margin: 0; text-wrap: balance; }
h1 {
  font: 500 clamp(38px, 4.4vw, 60px)/1.06 var(--font-display);
  letter-spacing: -.04em;
}
h2 { font: 500 clamp(26px, 2.5vw, 36px)/1.15 var(--font-display); letter-spacing: -.03em; }
h3 { font-size: 18px; font-weight: 500; }
.eyebrow { display: inline-flex; align-items: center; gap: 8px; font: 500 14px/1.3 var(--font-body); color: var(--ink-3); }
.crumbs { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; font-size: 14px; color: var(--ink-3); margin-bottom: 24px; }
.crumbs a { color: var(--ink-2); text-decoration: none; }
.crumbs a:hover { color: var(--accent); text-decoration: underline; }
.crumbs [aria-hidden] { opacity: .5; }

.section { margin-top: 96px; }
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 16px; margin-bottom: 24px; }
.section-head > div { display: grid; gap: 4px; }
.section-head h2 { display: flex; align-items: baseline; gap: 12px; }
.section-head a { font-size: 15px; font-weight: 500; text-decoration: none; }
.section-head a:hover { text-decoration: underline; }
.count-pill { font: 500 15px var(--font-body); color: var(--ink-3); font-variant-numeric: tabular-nums; }

.card { position: relative; background: var(--surface); border: 1px solid var(--line-2); border-radius: var(--r-lg); }

.page-head { display: grid; gap: 12px; margin-bottom: 48px; }
.page-head p { margin: 0; color: var(--ink-2); max-width: 62ch; }

/* ---------------------------------------------------------------------
   Home — hero: words on paper at the left, a cobalt stage bleeding off
   the right edge, the live session window straddling the two
   --------------------------------------------------------------------- */
.hero {
  display: grid; grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); gap: 0 64px;
  margin-top: -40px; min-height: max(640px, calc(100svh - var(--topbar-h)));
}
.hero.no-stage { grid-template-columns: minmax(0, 1fr); }
.hero-copy { align-self: center; display: grid; justify-items: start; padding: 48px 0 56px; min-width: 0; }
.hero-fact { margin: 0; font: 500 14px/1.4 var(--font-body); color: var(--ink-3); font-variant-numeric: tabular-nums; }
.hero-fact b { font-weight: 500; color: var(--ink); }
.hero h1 { margin-top: 24px; font-size: clamp(46px, min(5.6vw, 10.5svh), 88px); line-height: 1.02; letter-spacing: -.045em; }
/* The signature: cobalt as ballpoint ink, a ring drawn round the words */
.inked { position: relative; white-space: nowrap; }
.ink-ring {
  position: absolute; left: -9%; top: 2%; width: 117%; height: 110%; overflow: visible; pointer-events: none;
  fill: none; stroke: var(--accent); stroke-width: 4; stroke-linecap: round;
  stroke-dasharray: 2400; stroke-dashoffset: 0; animation: ink-draw 1.1s .25s var(--ease) backwards;
}
@keyframes ink-draw { from { stroke-dashoffset: 2400; } }
.hero-lead { margin: 32px 0 0; max-width: 46ch; color: var(--ink-2); font-size: 19px; line-height: 1.55; }

.hero-search { position: relative; display: flex; align-items: center; gap: 8px; width: min(100%, 600px); }
.hero .hero-search { margin-top: 32px; padding: 4px; background: var(--surface); border: 1px solid var(--line-2); box-shadow: var(--shadow-sm); border-radius: var(--r-lg); transition: box-shadow .15s var(--ease); }
.hero .hero-search:focus-within { box-shadow: 0 0 0 4px var(--accent-soft); border-color: var(--accent); }
.hero-search .hs-ic { position: absolute; left: 20px; color: var(--ink-3); pointer-events: none; }
.hero-search .hs-ic svg { width: 18px; height: 18px; }
.hero-search .input { flex: 1 1 0; width: 100%; min-height: 52px; font-size: 17px; }
.hero .hero-search .input { border: 0; background: transparent; box-shadow: none; padding-left: 44px; min-height: 48px; }
.hero-search .btn { min-height: 48px; padding: 0 20px; font-size: 16px; border-radius: var(--r); }

.examples { display: flex; flex-wrap: wrap; gap: 4px 16px; align-items: baseline; margin-top: 16px; max-width: 600px; font-size: 14px; color: var(--ink-3); }
.chip.example {
  min-height: 28px; padding: 0; border: 0; background: none; border-radius: 0; color: var(--ink-2);
  font: 400 14px var(--font-mono); text-decoration: underline; text-decoration-color: var(--line-2); text-underline-offset: 5px;
  transition: color .15s var(--ease), text-decoration-color .15s var(--ease);
}
.chip.example:hover { color: var(--accent); text-decoration-color: var(--accent); }

.hero-stage {
  position: relative; min-width: 0;
  margin-right: calc(-1 * max(var(--gut), (100vw - var(--page)) / 2));
  background: var(--band) repeating-linear-gradient(to bottom, transparent 0 31px, rgba(255, 255, 255, .12) 31px 32px);
}
.stage-sheet { position: absolute; top: max(56px, calc(50% - 400px)); right: max(40px, calc((100vw - var(--page)) / 2 - 40px)); width: 250px; }
.stage-sheet .sheet-stack { width: 100%; }
.stage-sheet .sheet { box-shadow: 0 30px 50px -20px rgba(2, 8, 50, .6); }
.stage-window {
  position: absolute; left: -96px; bottom: max(56px, calc(50% - 420px)); width: min(640px, calc(100% + 56px)); z-index: 1;
  background: var(--surface); color: var(--ink); border-radius: var(--r-lg);
  box-shadow: 0 0 0 1px rgba(0, 0, 0, .1), 0 40px 70px -24px rgba(2, 8, 50, .55);
}
.sw-head { display: flex; align-items: center; gap: 16px; padding: 16px 20px; border-bottom: 1px solid var(--line-2); }
.sw-title { display: grid; gap: 2px; min-width: 0; }
.sw-code { font: 400 13px var(--font-mono); color: var(--ink-3); }
.sw-title b { font: 500 18px/1.25 var(--font-display); letter-spacing: -.02em; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.aw-open { margin-left: auto; display: inline-flex; align-items: center; gap: 6px; font-size: 14px; font-weight: 500; white-space: nowrap; text-decoration: none; }
.aw-open svg { width: 14px; height: 14px; transition: transform .15s var(--ease); }
.aw-open:hover svg { transform: translateX(2px); }
.sw-list { padding: 0 20px 4px; }
.aw-row { display: grid; grid-template-columns: 150px minmax(0, 1fr); gap: 16px; align-items: center; min-height: 52px; border-bottom: 1px solid var(--line); }
.aw-row:last-child { border-bottom: 0; }
.aw-row .t { display: block; font-weight: 500; font-size: 15px; }
.aw-row .s { display: block; font-size: 13px; color: var(--ink-3); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.aw-row .sets { gap: 6px 16px; }

/* The sheet: a question paper drawn in code, its mark scheme underneath */
.sheet-stack { position: relative; display: block; aspect-ratio: 210 / 285; text-decoration: none; color: var(--sheet-ink); }
.sheet-stack:hover { color: var(--sheet-ink); }
.sheet {
  position: absolute; inset: 0; display: flex; flex-direction: column; overflow: hidden; padding: 20px 18px 16px;
  border-radius: 2px; background: var(--sheet); color: var(--sheet-ink); box-shadow: var(--shadow); transition: transform .3s var(--ease);
}
.sheet-ms { background: var(--sheet-2); transform: translate(26px, 14px) rotate(4deg); }
.sheet-qp { transform: rotate(-1.5deg); }
.sheet-stack:hover .sheet-qp { transform: rotate(-1.5deg) translateY(-4px); }
.qp-top { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; padding-bottom: 8px; border-bottom: 2px solid var(--sheet-ink); }
.qp-sub { font: 500 11px/1.2 var(--font-body); }
.qp-code { font: 500 11px/1 var(--font-mono); }
.qp-title { position: relative; align-self: flex-start; margin-top: 14px; font: 500 19px/1 var(--font-display); letter-spacing: -.03em; }
.qp-pname { margin-top: 4px; font: 500 12px/1.3 var(--font-body); }
.qp-session { margin-top: 4px; font: 400 10px var(--font-mono); color: var(--sheet-ink-3); }
.qp-fields { display: grid; gap: 8px; margin-top: 16px; font-size: 8px; color: var(--sheet-ink-3); }
.qp-field { display: grid; grid-template-columns: 64px 1fr; align-items: end; gap: 6px; white-space: nowrap; }
.qp-field i { height: 1px; background: var(--sheet-line); }
.qp-boxes { display: flex; }
.qp-boxes i { width: 11px; height: 12px; border: 1px solid var(--sheet-line); margin-left: -1px; background: none; }
.qp-instr { display: grid; gap: 6px; margin-top: 16px; padding-top: 10px; border-top: 1px solid var(--sheet-line); }
.qp-instr b { font: 500 8px var(--font-body); }
.qp-instr i { height: 3px; border-radius: 1px; background: color-mix(in srgb, var(--sheet-ink) 12%, transparent); }
.qp-instr i:nth-child(3) { width: 86%; } .qp-instr i:nth-child(4) { width: 92%; } .qp-instr i:nth-child(5) { width: 60%; }
.qp-foot { margin-top: auto; display: flex; justify-content: space-between; align-items: end; gap: 8px; padding-top: 8px; border-top: 1px solid var(--sheet-line); font: 400 8px var(--font-mono); color: var(--sheet-ink-3); }
.qp-type { font: 500 8px var(--font-body); color: var(--sheet-ink); }
.pen-ring { position: absolute; left: -12px; top: -7px; width: calc(100% + 26px); height: calc(100% + 14px); color: var(--pen); pointer-events: none; overflow: visible; }
.pen-tick { position: absolute; right: 16px; top: 64px; width: 30px; height: 24px; color: var(--pen); }
.ms-head { display: flex; flex-direction: row-reverse; justify-content: space-between; padding-bottom: 8px; border-bottom: 2px solid var(--sheet-ink); font: 500 10px var(--font-body); }
.ms-head span:last-child { font-family: var(--font-mono); font-weight: 400; }
.ms-table { display: grid; grid-template-columns: 26px 1fr 18px; gap: 8px; margin-top: 12px; font: 400 8px var(--font-mono); color: var(--sheet-ink-3); align-items: center; }
.ms-table b { font-weight: 500; color: var(--sheet-ink); }
.ms-table i { height: 3px; border-radius: 1px; background: color-mix(in srgb, var(--sheet-ink) 12%, transparent); }

@media (max-width: 1180px) {
  .hero { gap: 0 48px; }
  .stage-window { left: -64px; width: calc(100% + 32px); }
  .stage-sheet { width: 200px; right: 24px; }
  .aw-row { grid-template-columns: 120px minmax(0, 1fr); }
  .aw-row .set:nth-child(n+3) { display: none; }
}
@media (max-width: 900px) {
  .hero { grid-template-columns: minmax(0, 1fr); min-height: 0; margin-top: -16px; }
  .hero-copy { padding: 32px 0 40px; }
  .hero-stage { margin-inline: calc(-1 * var(--gut)); padding: 40px var(--gut); }
  .stage-sheet { display: none; }
  .stage-window { position: relative; left: auto; bottom: auto; width: 100%; }
  .aw-row .set:nth-child(n+3) { display: inline-flex; }
}
@media (max-width: 640px) {
  .hero h1 { font-size: clamp(46px, 13.5vw, 60px); }
  .hero-lead { font-size: 16px; margin-top: 24px; }
  .hero .hero-search { margin-top: 24px; }
  .hero-search .btn span { display: none; }
  .hero-search .btn { padding: 0 16px; }
  .chip.example:nth-of-type(n+4) { display: none; }
  .hero-stage { padding: 24px 16px; }
  .sw-head { padding: 12px 16px; }
  .sw-list { padding: 0 16px 4px; }
  .aw-row { grid-template-columns: minmax(0, 1fr); gap: 8px; padding: 12px 0; }
  .aw-row .set:nth-child(n+3) { display: none; }
  .aw-open span { display: none; }
}

/* Subjects and years: one timetable, years labelled once, each cell a count */
.section-head .tt-key { display: inline-flex; align-items: center; gap: 8px; font-size: 14px; color: var(--ink-3); }
.tt-key i { width: 14px; height: 14px; border-radius: 2px; background: var(--accent); }
.tt-head, .subj { display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 7fr) 112px; gap: 0 40px; align-items: center; }
.tt-head { padding-bottom: 12px; border-bottom: 1px solid var(--line-2); font: 400 13px var(--font-mono); color: var(--ink-3); }
.tt-head .yc-row span { text-align: center; }
.subjects { list-style: none; margin: 0; padding: 0; }
.subj { padding: 22px 0; border-bottom: 1px solid var(--line); }
.subj-main { display: grid; gap: 2px; min-width: 0; }
.subj-code { font: 400 13px var(--font-mono); color: var(--ink-3); }
.subj-name {
  justify-self: start; color: var(--ink); text-decoration: none;
  font: 500 clamp(24px, 2.2vw, 32px)/1.2 var(--font-display); letter-spacing: -.03em;
  background: linear-gradient(var(--accent), var(--accent)) 0 100% / 0 2px no-repeat; padding-bottom: 2px;
  transition: background-size .25s var(--ease), color .15s var(--ease);
}
.subj-name:hover { color: var(--accent); background-size: 100% 2px; }
.subj-meta { margin-top: 2px; font-size: 14px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.subj-meta .sep { margin: 0 8px; opacity: .5; }
.yc-row { display: grid; grid-template-columns: repeat(var(--n), minmax(0, 1fr)); gap: 4px; min-width: 0; }
.yc { display: grid; place-items: center; height: 46px; border: 1px dashed var(--line-2); border-radius: var(--r-xs); }
a.yc {
  border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink); text-decoration: none;
  font: 600 13px var(--font-body); font-variant-numeric: tabular-nums;
  transition: transform .15s var(--ease), background .15s var(--ease), border-color .15s var(--ease);
}
a.yc:hover { background: var(--ink); border-color: var(--ink); color: var(--bg); transform: translateY(-2px); }
.yc-none { grid-column: 1 / -1; display: flex; align-items: center; height: 48px; padding: 0 16px; border: 1px dashed var(--line-2); border-radius: 2px; font: 400 13px var(--font-mono); color: var(--ink-3); }
.subj-links { display: flex; flex-direction: column; align-items: flex-end; gap: 4px; }
.subj-links a {
  display: inline-flex; align-items: center; gap: 6px; font-size: 15px; font-weight: 500; color: var(--ink); text-decoration: none;
  background: linear-gradient(currentColor, currentColor) 0 100% / 0 1px no-repeat; transition: background-size .2s var(--ease), color .15s var(--ease);
}
.subj-links a svg { width: 14px; height: 14px; transition: transform .15s var(--ease); }
.subj-links a:hover { color: var(--accent); background-size: 100% 1px; }
.subj-links a:hover svg { transform: translateX(2px); }
@media (max-width: 1024px) {
  .tt-head, .subj { grid-template-columns: minmax(0, 3fr) minmax(0, 7fr) 96px; gap: 0 24px; }
  .tt-head .yc-row span:nth-child(even) { visibility: hidden; }
}
@media (max-width: 700px) {
  .tt-head { grid-template-columns: minmax(0, 1fr); }
  .tt-head > span:not(.yc-row) { display: none; }
  .tt-head .yc-row { display: flex; justify-content: space-between; }
  .tt-head .yc-row span { visibility: hidden; display: none; }
  .tt-head .yc-row span:first-child, .tt-head .yc-row span:last-child { display: inline; visibility: visible; }
  .subj { grid-template-columns: minmax(0, 1fr); gap: 12px; padding: 20px 0; }
  .subj-links { flex-direction: row; align-items: center; gap: 24px; }
  .yc { height: 36px; }
}

/* Your desk: recent and favourite papers, ruled lists */
.two-col { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 48px; }
@media (max-width: 860px) { .two-col { grid-template-columns: minmax(0, 1fr); gap: 64px; } }
.desk .section-head { margin-bottom: 4px; }
.desk h2 { font-size: clamp(24px, 2.2vw, 30px); }
.list { overflow: hidden; }
.card.list { background: none; border: 0; border-radius: 0; }
.list-row {
  position: relative; display: grid; grid-template-columns: 10px minmax(0, 1fr) auto; gap: 16px; align-items: center;
  padding: 14px 0; min-height: 64px; border-bottom: 1px solid var(--line); text-decoration: none; color: var(--ink);
  transition: background .15s var(--ease), padding .15s var(--ease);
}
.list-row:hover { color: var(--ink); background: var(--surface-2); padding-inline: 8px; }
.list-row .dot { width: 10px; height: 10px; border-radius: 1px; background: var(--accent); }
.list-row .title { font-weight: 500; overflow-wrap: anywhere; display: block; font-size: 16px; }
.list-row .sub { font-size: 14px; color: var(--ink-3); display: block; }
.list-row .side { display: flex; gap: 8px; align-items: center; }
.list-row .go { color: var(--ink-3); transition: transform .15s var(--ease), color .15s var(--ease); }
.list-row .go svg { width: 16px; height: 16px; }
.list-row:hover .go { color: var(--accent); transform: translateX(2px); }

.empty { display: grid; justify-items: start; gap: 4px; padding: 24px 0; color: var(--ink-3); font-size: 15px; }
.empty .empty-ic { display: grid; place-items: center; width: 32px; height: 32px; margin-bottom: 8px; border: 1px dashed var(--line-2); border-radius: 2px; color: var(--ink-3); }
.empty .empty-ic svg { width: 16px; height: 16px; }
.empty strong { color: var(--ink); font-weight: 500; font-size: 16px; }
.empty .btn { margin-top: 12px; }
.card > .empty { padding: 32px 24px; }

/* Question bank band: dark ink, full bleed */
.qb-band {
  margin-top: 96px; margin-inline: calc(50% - 50vw); padding: 96px max(var(--gut), calc(50vw - var(--page) / 2));
  background: var(--dark); color: var(--dark-ink);
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 48px 96px; align-items: start;
}
.qb-band h2 { font-size: clamp(36px, 4.4vw, 64px); line-height: .98; color: var(--dark-ink); }
.qb-band p { margin: 24px 0 0; max-width: 46ch; color: var(--dark-ink-2); font-size: 18px; line-height: 1.55; }
.qb-band .btn-row { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; margin-top: 32px; }
.qb-band .btn.primary { background: var(--band); border-color: var(--band); color: #fff; }
.qb-band .btn.primary:hover { background: #3a61ff; border-color: #3a61ff; }
.qb-band .note { font-size: 14px; color: var(--dark-ink-2); }
.qb-subjects { list-style: none; margin: 0; padding: 0; }
.qb-subjects a {
  display: grid; grid-template-columns: 64px minmax(0, 1fr) auto; gap: 16px; align-items: center; min-height: 64px;
  border-bottom: 1px solid var(--dark-line); color: var(--dark-ink); text-decoration: none; transition: padding .15s var(--ease), color .15s var(--ease);
}
.qb-subjects a:hover { padding-inline: 8px; color: #fff; }
.qb-subjects .code { font: 400 14px var(--font-mono); color: var(--dark-ink-2); }
.qb-subjects .name { font: 500 19px/1.25 var(--font-display); letter-spacing: -.02em; }
.qb-subjects svg { width: 16px; height: 16px; color: var(--dark-ink-2); transition: transform .15s var(--ease); }
.qb-subjects a:hover svg { transform: translateX(3px); color: #fff; }
@media (max-width: 860px) { .qb-band { grid-template-columns: minmax(0, 1fr); padding-block: 64px; } }

/* About the documents */
.notice {
  margin-top: 64px; display: grid; grid-template-columns: minmax(0, 4fr) minmax(0, 8fr); gap: 16px 48px;
  color: var(--ink-3); font-size: 15px; background: none; border: 0; border-radius: 0;
}
.notice > .n-ic { display: none; }
.notice strong { color: var(--ink); font: 500 22px/1.25 var(--font-display); letter-spacing: -.02em; }
.notice > span { grid-column: 2; max-width: 70ch; }
.notice ul { grid-column: 2; margin: 8px 0 0; padding: 0; list-style: none; display: grid; grid-template-columns: repeat(auto-fill, minmax(min(100%, 300px), 1fr)); gap: 0 32px; }
.notice li a { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 10px 0; border-bottom: 1px solid var(--line); font-size: 14px; text-decoration: none; color: var(--ink-2); }
.notice li a:hover { color: var(--accent); }
.notice li a svg { width: 12px; height: 12px; opacity: .6; }
.notice:not(.compact) > strong { grid-row: 1 / 4; }
@media (max-width: 760px) { .notice { grid-template-columns: minmax(0, 1fr); } .notice > span, .notice ul { grid-column: 1; } .notice:not(.compact) > strong { grid-row: auto; } }
.notice.compact {
  margin: 0 0 24px; padding: 16px 20px; grid-template-columns: 20px minmax(0, 1fr); align-items: center; gap: 4px 12px;
  border-left: 3px solid var(--accent); background: var(--accent-soft); border-radius: 0 var(--r-sm) var(--r-sm) 0;
}
.notice.compact > .n-ic { display: grid; color: var(--accent); }
.notice.compact > .n-ic svg { width: 18px; height: 18px; }
.notice.compact strong { font: 500 16px var(--font-body); }
.notice.compact > span, .notice.compact ul { grid-column: 2; }

/* Legacy home rows (kept for the continue / QB rows if rendered elsewhere) */
.continue, .qb-entry { display: grid; grid-template-columns: 20px minmax(0, 1fr) auto; gap: 16px; align-items: center; padding: 20px; text-decoration: none; color: var(--ink); }
.cv-ic, .qb-entry-icon { color: var(--accent); }
.cv-ic svg, .qb-entry-icon svg { width: 20px; height: 20px; }
.cv-body { display: grid; gap: 2px; min-width: 0; }
.continue .t, .qb-entry .t { font-weight: 500; }
.continue .ref, .qb-entry .s, .continue .k { font-size: 14px; color: var(--ink-3); }
.continue .go, .qb-entry .go { display: inline-flex; align-items: center; gap: 6px; font-weight: 500; font-size: 15px; color: var(--accent); }
.continue .go svg, .qb-entry .go svg { width: 16px; height: 16px; }

/* ---------------------------------------------------------------------
   Subject page
   --------------------------------------------------------------------- */
.subject-head {
  display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: start;
  grid-template-areas: "main action" "stats stats" "tabs tabs";
  background: none; border: 0; border-radius: 0; padding: 0; margin-bottom: 0;
}
.sh-main { grid-area: main; min-width: 0; }
.sh-side { display: contents; }
.subject-head .code { display: block; font: 400 14px var(--font-mono); color: var(--ink-3); margin-bottom: 16px; }
.subject-head h1 { font-size: clamp(52px, 7vw, 104px); line-height: 1; letter-spacing: -.05em; }
.sh-side > .btn { grid-area: action; margin-top: 4px; }
/* Stats read as a sentence of facts under the name: figure first, a quiet label after */
.sh-stats { grid-area: stats; display: flex; flex-wrap: wrap; gap: 16px 56px; margin: 28px 0 0; }
.sh-stats div { display: grid; gap: 4px; }
.sh-stats dt { order: 2; font-size: 14px; color: var(--ink-3); }
.sh-stats dd { order: 1; margin: 0; font: 500 30px/1 var(--font-display); letter-spacing: -.035em; font-variant-numeric: tabular-nums; }
.sh-stats div:first-child dd { color: var(--accent); }

/* Tabs: soft segments, no rules */
.tabs { grid-area: tabs; display: flex; align-items: center; gap: 4px; margin-top: 48px; overflow-x: auto; scrollbar-width: none; }
.tabs a {
  display: inline-flex; align-items: center; gap: 8px; min-height: 44px; padding: 0 16px; border-radius: var(--r);
  white-space: nowrap; text-decoration: none; color: var(--ink-3); font-weight: 500; font-size: 16px;
  transition: color .15s var(--ease), background .15s var(--ease);
}
.tabs a:hover { color: var(--ink); background: var(--surface-2); }
.tabs a[aria-current="page"] { color: var(--ink); background: var(--surface-2); }
.tabs .count { font-size: 13px; font-weight: 500; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.tabs a[aria-current="page"] .count { color: var(--accent); }
.tabs a.tab-out { margin-left: auto; color: var(--accent); }
.tabs a.tab-out:hover { background: var(--accent-soft); color: var(--accent); }
.tabs a.tab-out svg { width: 16px; height: 16px; transition: transform .15s var(--ease); }
.tabs a.tab-out:hover svg { transform: translateX(3px); }
@media (max-width: 760px) {
  .subject-head { grid-template-columns: minmax(0, 1fr); grid-template-areas: "main" "stats" "action" "tabs"; }
  .sh-side > .btn { justify-self: start; margin-top: 24px; }
  .sh-stats { gap: 16px 32px; margin-top: 24px; }
  .sh-stats dd { font-size: 26px; }
  .tabs { margin-top: 32px; margin-inline: calc(-1 * var(--gut)); padding-inline: var(--gut); }
}

/* Filters: the year rail leads, the rest is one relaxed line */
.card.filterbar { background: none; border: 0; border-radius: 0; padding: 0; margin-top: 32px; display: grid; gap: 20px; }
.year-rail { display: flex; align-items: flex-end; gap: 4px; overflow-x: auto; scrollbar-width: none; padding: 12px 0 8px 16px; margin-left: -16px; }
.year-rail::-webkit-scrollbar { display: none; }
.chip.yr {
  flex: none; display: grid; justify-items: start; gap: 4px; min-height: 0; padding: 10px 18px; position: relative;
  border: 0; border-radius: var(--r); background: none; color: var(--ink-3); text-align: left;
}
.chip.yr:first-child { margin-right: 20px; }
.chip.yr .yr-y { position: relative; font: 500 26px/1 var(--font-display); letter-spacing: -.035em; color: inherit; font-variant-numeric: tabular-nums; transition: color .15s var(--ease); }
.chip.yr .yr-n { font-size: 13px; font-weight: 500; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.chip.yr:hover { color: var(--ink); background: var(--surface-2); border: 0; }
.chip.yr[aria-pressed="true"] { background: none; color: var(--ink); }
/* The selected year is circled in ballpoint, like an answer */
.chip.yr[aria-pressed="true"] .yr-y::after {
  content: ""; position: absolute; left: -14px; right: -16px; top: -10px; bottom: -10px; pointer-events: none;
  background: var(--accent); -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 120 60' preserveAspectRatio='none'%3E%3Cpath d='M16 46C2 30 20 7 64 5s54 10 51 27-30 23-60 22S3 44 8 27c3-8 12-14 24-18' fill='none' stroke='black' stroke-width='3' stroke-linecap='round'/%3E%3C/svg%3E") center / 100% 100% no-repeat; mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 120 60' preserveAspectRatio='none'%3E%3Cpath d='M16 46C2 30 20 7 64 5s54 10 51 27-30 23-60 22S3 44 8 27c3-8 12-14 24-18' fill='none' stroke='black' stroke-width='3' stroke-linecap='round'/%3E%3C/svg%3E") center / 100% 100% no-repeat;
}
.chip.yr[aria-pressed="true"] .yr-n { color: var(--accent); }

.filter-line { display: flex; flex-wrap: wrap; align-items: center; gap: 16px 40px; padding: 0; }
.filter-row { display: grid; grid-template-columns: 88px minmax(0, 1fr); gap: 12px; align-items: center; }
.filter-line .filter-row { display: flex; gap: 12px; }
.filter-row > .lbl { font-size: 14px; font-weight: 500; color: var(--ink-3); }
.filter-tools { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; justify-content: space-between; }
.filter-line .filter-tools { flex-basis: 100%; margin-left: 0; }
.card.filterbar > .filter-tools { padding: 0; }
.filterbar > .filter-row { padding: 0; }
.input.with-ic { padding-left: 40px; }
.field { position: relative; display: flex; flex: 1 1 240px; max-width: 340px; }
.field .input { width: 100%; padding-left: 40px; border-color: transparent; background: var(--surface-2); }
.field .input:hover { border-color: var(--line-2); }
.field .input:focus { background: var(--surface); border-color: var(--accent); }
.field .f-ic { position: absolute; left: 13px; top: 50%; transform: translateY(-50%); color: var(--ink-3); pointer-events: none; }
.field .f-ic svg { width: 16px; height: 16px; }
@media (max-width: 760px) {
  .filter-line { gap: 16px; }
  .filter-line .filter-row, .filter-row { display: grid; grid-template-columns: minmax(0, 1fr); gap: 8px; width: 100%; }
  .filter-row .chips { flex-wrap: nowrap; overflow-x: auto; margin: 0 calc(-1 * var(--gut)); padding: 2px var(--gut) 4px; scrollbar-width: none; }
  .filter-row .chips::-webkit-scrollbar { display: none; }
  .filter-row .chip { flex: none; }
  .filter-line .filter-tools { margin-left: 0; width: 100%; }
  .field { max-width: none; }
  .chip.yr { padding: 8px 14px; }
  .chip.yr .yr-y { font-size: 22px; }
}
.result-bar { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; justify-content: space-between; margin: 40px 0 0; }
.result-bar .count { font: 500 14px var(--font-body); color: var(--ink-3); font-variant-numeric: tabular-nums; }
.result-bar .tools { display: flex; gap: 4px; flex-wrap: wrap; }

/* Groups: years carried by type and space, not rules */
.groups { display: grid; gap: 0; }
.card.group { background: none; border: 0; border-radius: 0; overflow: visible; }
.card.group + .card.group { margin-top: 24px; }
.groups > .card:not(.group) { margin-top: 8px; }
.group > summary {
  list-style: none; cursor: pointer; display: grid; grid-template-columns: minmax(0, 1fr) auto 36px; gap: 16px; align-items: center;
  padding: 24px 0 16px; transition: color .15s var(--ease);
}
.group > summary::-webkit-details-marker { display: none; }
.group > summary .chev-wrap {
  grid-column: 3; grid-row: 1; justify-self: end; display: grid; place-items: center; width: 36px; height: 36px;
  border-radius: var(--r); background: var(--surface-2); color: var(--ink-2); transition: background .15s var(--ease), color .15s var(--ease);
}
.group > summary:hover .chev-wrap { background: var(--surface-3); color: var(--ink); }
.group > summary .chev { width: 16px; height: 16px; transform: rotate(90deg); transition: transform .25s var(--ease); }
.group[open] > summary .chev { transform: rotate(-90deg); }
.group > summary .gt {
  grid-column: 1; grid-row: 1; display: flex; flex-wrap: wrap; gap: 4px 16px; align-items: baseline; font-variant-numeric: tabular-nums;
  font: 500 24px/1.2 var(--font-display); letter-spacing: -.03em;
}
.group--year > summary .gt { font-size: clamp(36px, 3.8vw, 52px); letter-spacing: -.045em; line-height: 1; }
.group > summary:hover .gt { color: var(--accent); }
.group > summary .gt .num { font: 500 18px var(--font-body); color: var(--accent); letter-spacing: 0; font-variant-numeric: tabular-nums; }
.group > summary .gt-sub { font: 500 15px var(--font-body); letter-spacing: 0; color: var(--ink-3); }
.group > summary:hover .gt-sub { color: var(--ink-3); }
.group > summary .gm { grid-column: 2; grid-row: 1; display: flex; flex-wrap: wrap; gap: 8px; justify-content: flex-end; align-items: center; color: var(--ink-3); font-size: 14px; }
.group-body { padding: 0 0 16px; }
@media (max-width: 560px) {
  .group > summary { grid-template-columns: minmax(0, 1fr) 36px; }
  .group > summary .chev-wrap { grid-column: 2; }
  .group > summary .gm { grid-column: 1 / -1; grid-row: 2; justify-content: flex-start; }
}

.sub-group { margin-top: 8px; }
.sub-group > summary { list-style: none; cursor: pointer; display: flex; align-items: center; gap: 8px; min-height: 40px; font-size: 15px; font-weight: 500; color: var(--ink); }
.sub-group > summary::-webkit-details-marker { display: none; }
.sub-group > summary .chev { width: 14px; height: 14px; color: var(--ink-3); transition: transform .25s var(--ease); }
.sub-group[open] > summary .chev { transform: rotate(90deg); }
.sub-group > summary:hover { color: var(--accent); }

/* Topic and paper groups (everything but years): a soft outlined row that clearly answers the pointer */
.card.group:not(.group--year) {
  border: 1px solid var(--line-2); border-radius: var(--r-lg); background: transparent;
  transition: border-color .15s var(--ease), background .15s var(--ease);
}
.card.group:not(.group--year) + .card.group:not(.group--year) { margin-top: 8px; }
.card.group:not(.group--year) > summary { padding: 16px 16px 16px 24px; border-radius: inherit; }
.card.group:not(.group--year) > summary .gt { font-size: 21px; letter-spacing: -.025em; gap: 4px 14px; }
.card.group:not(.group--year) > summary .gt .num {
  display: inline-grid; place-items: center; min-width: 32px; height: 32px; padding: 0 8px; border-radius: var(--r-sm);
  background: var(--accent-soft); font-size: 15px; transform: translateY(-2px);
}
.card.group:not(.group--year):hover { border-color: var(--accent-line); background: var(--accent-soft); }
.card.group:not(.group--year):hover > summary .gt { color: var(--accent); }
.card.group:not(.group--year):hover > summary .chev-wrap { background: var(--accent); color: var(--accent-ink); }
.card.group:not(.group--year)[open] { border-color: var(--line-2); background: var(--surface); }
.card.group:not(.group--year)[open]:hover { border-color: var(--accent-line); }
.card.group:not(.group--year)[open] > summary { border-bottom: 1px solid var(--line); border-bottom-left-radius: 0; border-bottom-right-radius: 0; }
.card.group:not(.group--year)[open] > summary .chev-wrap { background: var(--accent-soft); color: var(--accent); }
.card.group:not(.group--year) > .group-body { padding: 8px 24px 12px; }
.card.group:not(.group--year) > summary:focus-visible { outline-offset: -2px; }
@media (max-width: 560px) {
  .card.group:not(.group--year) > summary { padding: 14px 14px 14px 16px; }
  .card.group:not(.group--year) > .group-body { padding: 4px 16px 8px; }
}

/* Rows (by paper, topical): breathing room instead of rules */
.item-row {
  display: grid; grid-template-columns: minmax(200px, 300px) minmax(0, 1fr); gap: 8px 24px; align-items: center;
  margin-inline: -12px; padding: 14px 12px; border-radius: var(--r); transition: background .15s var(--ease);
}
.item-row:hover { background: color-mix(in srgb, var(--surface-2) 70%, transparent); }
.item-row .il .t { font-weight: 500; display: block; font-size: 16px; font-variant-numeric: tabular-nums; }
.item-row .il .s { font-size: 14px; color: var(--ink-3); display: block; }
.item-row .il .n { font-weight: 500; color: var(--accent); margin-right: 8px; font-variant-numeric: tabular-nums; }
@media (max-width: 760px) { .item-row { grid-template-columns: minmax(0, 1fr); } }

/* Year matrix: papers down, sessions across; whitespace separates, a short accent dash names each session */
.yr-matrix { display: grid; }
.ym-head, .ym-row { display: grid; grid-template-columns: minmax(180px, 220px) repeat(var(--cols), minmax(0, 1fr)); column-gap: 32px; }
.ym-head { margin-bottom: 4px; }
.ym-sess { display: grid; gap: 2px; padding: 10px 0 12px; }
.ym-sess::before { content: ""; width: 20px; height: 3px; margin-bottom: 8px; border-radius: 2px; background: var(--accent); }
.ym-sess b { font-size: 15px; font-weight: 500; }
.ym-sess span { font-size: 13px; font-weight: 500; color: var(--ink-3); }
.ym-row { margin-inline: -16px; padding: 0 16px; border-radius: var(--r-lg); transition: background .15s var(--ease); }
.ym-row:hover { background: color-mix(in srgb, var(--surface-2) 70%, transparent); }
.ym-row > .il { padding: 18px 0; }
.ym-row .il .t { display: block; font: 500 17px/1.3 var(--font-body); letter-spacing: -.01em; }
.ym-row .il .s { display: block; margin-top: 2px; font-size: 14px; color: var(--ink-3); }
.ym-cell { padding: 16px 0; }
.ym-cell .sets { flex-direction: column; align-items: flex-start; gap: 8px; }
.ym-none { font-size: 14px; color: var(--ink-3); opacity: .6; }
@media (max-width: 760px) {
  .ym-head { display: none; }
  .ym-row { grid-template-columns: minmax(0, 1fr); padding-bottom: 12px; }
  .ym-row > .il { padding: 16px 0 6px; }
  .ym-cell { display: grid; grid-template-columns: 44px minmax(0, 1fr); align-items: start; padding: 6px 0; }
  .ym-cell::before { content: attr(data-label); padding-top: 7px; font-size: 13px; font-weight: 500; color: var(--ink-3); }
  .ym-cell .sets { flex-direction: row; flex-wrap: wrap; gap: 8px 20px; }
}

/* Variant sets and the QP / MS keys: QP leads (soft cobalt), MS follows (quiet) */
.sets { display: flex; flex-wrap: wrap; gap: 8px 24px; }
.set { display: inline-flex; align-items: center; gap: 6px; }
.set .sl { min-width: 2.2ch; margin-right: 6px; font: 500 14px var(--font-body); color: var(--ink-3); font-variant-numeric: tabular-nums; }
.set .sl.text { font-size: 13px; }
.dbtn {
  display: inline-flex; align-items: center; justify-content: center; gap: 4px; min-width: 44px; min-height: 32px; padding: 0 10px;
  border-radius: var(--r-sm); border: 0; background: var(--surface-2); color: var(--ink-2); text-decoration: none;
  font: 500 13px var(--font-body); letter-spacing: .01em;
  transition: background .15s var(--ease), color .15s var(--ease), transform .15s var(--ease);
}
.dbtn.type-qp { background: var(--accent-soft); color: var(--accent); }
.dbtn:hover { background: var(--accent); color: var(--accent-ink); transform: translateY(-1px); }
.dbtn:active { transform: translateY(0) scale(.97); }
.dbtn .ok { width: 12px; height: 12px; color: var(--good); }
.dbtn:hover .ok, .dbtn:hover .fav { color: inherit; }
.dbtn .ok svg, .dbtn .fav svg { width: 12px; height: 12px; }
.dbtn .fav { width: 12px; height: 12px; color: var(--star); }
@media (pointer: coarse) { .dbtn { min-height: 40px; min-width: 48px; } .chip { min-height: 40px; } }

/* ---------------------------------------------------------------------
   Search page
   --------------------------------------------------------------------- */
.search-panel { padding: 4px; border-color: var(--ink); border-radius: var(--r); }
.search-panel .hero-search { width: 100%; }
.search-panel .hero-search .input { border: 0; box-shadow: none; padding-left: 48px; background: transparent; font-size: 18px; }
.search-panel:focus-within { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-soft); }
.search-panel .hs-ic { left: 18px; }
.search-hint { margin: 16px 0 0; color: var(--ink-3); font-size: 14px; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.search-hint code { font: 400 13px var(--font-mono); padding: 2px 6px; border-radius: var(--r-xs); background: var(--surface); border: 1px solid var(--line-2); color: var(--ink-2); }

/* ---------------------------------------------------------------------
   Preview
   --------------------------------------------------------------------- */
.doc-head { display: grid; gap: 12px; margin-bottom: 32px; }
.doc-head .row1 { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; }
.cover-ref { font: 500 15px var(--font-mono); color: var(--accent); }
.doc-head h1 { font-size: clamp(38px, 4.4vw, 64px); line-height: 1.04; letter-spacing: -.045em; }
.doc-head .facts { display: flex; flex-wrap: wrap; gap: 8px 32px; margin-top: 8px; }
.fact { display: inline-flex; align-items: baseline; gap: 8px; font-size: 15px; color: var(--ink); }
.fact b { font: 500 13px var(--font-body); color: var(--ink-3); }

.card.actionbar {
  position: sticky; top: calc(var(--topbar-h) - 1px); z-index: 20;
  display: flex; flex-wrap: wrap; align-items: center; gap: 8px; padding: 8px 0; margin-bottom: 16px;
  background: var(--bg); border: 0; border-bottom: 1px solid var(--line-2); border-radius: 0;
}
.actionbar .spacer { flex: 1; }
@media (max-width: 760px) {
  .card.actionbar {
    position: fixed; left: 0; right: 0; top: auto; bottom: var(--tabbar-h); margin: 0; padding: 8px 16px;
    justify-content: space-between; border-top: 1px solid var(--line-2); border-bottom: 0;
  }
  .actionbar .label-text { display: none; }
  .actionbar .spacer, .actionbar .wide-only { display: none; }
  .actionbar .btn { padding: 0 12px; }
  .preview-page { padding-bottom: 72px; }
}
.extra-actions { display: flex; flex-wrap: wrap; gap: 8px 16px; align-items: center; margin: 0 0 16px; font-size: 14px; color: var(--ink-3); }

.viewers { display: grid; gap: 16px; grid-template-columns: minmax(0, 1fr); }
.viewers.split { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.viewer { background: var(--viewer-bg); border: 1px solid var(--line-2); border-radius: var(--r-lg); overflow: hidden; display: grid; grid-template-rows: auto 1fr; min-width: 0; }
.viewer-bar { display: flex; align-items: center; gap: 4px; padding: 6px 8px 6px 16px; background: var(--surface); border-bottom: 1px solid var(--line-2); font-size: 14px; flex-wrap: wrap; }
.viewer-bar .vt { font-weight: 500; display: inline-flex; align-items: center; gap: 8px; }
.viewer-bar .vt::before { content: ""; width: 10px; height: 10px; border-radius: 1px; border: 1.5px solid var(--line-2); }
.viewer.primary .viewer-bar .vt::before { background: var(--accent); border-color: var(--accent); }
.viewer-bar .vp { font-size: 13px; color: var(--ink-3); }
.viewer-bar .spacer { flex: 1; }
.viewer-bar .zv { font: 400 13px var(--font-mono); min-width: 52px; text-align: center; color: var(--ink-2); }
.viewer-bar .zoom { display: inline-flex; align-items: center; border: 1px solid var(--line-2); border-radius: var(--r-sm); }
.viewer-bar .zoom .btn { min-height: 30px; min-width: 30px; padding: 0 8px; border: 0; }
.pages { overflow: auto; padding: 24px; display: grid; justify-items: center; gap: 16px; align-content: start; height: calc(100vh - var(--topbar-h) - 180px); min-height: 440px; }
@media (max-width: 760px) { .pages { height: auto; min-height: 60vh; padding: 12px; } }
.page-slot { background: #fff; border-radius: 1px; box-shadow: 0 1px 2px rgba(0, 0, 0, .12), 0 12px 30px -12px rgba(0, 0, 0, .35); position: relative; }
.page-slot canvas { display: block; width: 100%; height: 100%; animation: fade .3s var(--ease); }
@keyframes fade { from { opacity: 0; } }
.pages iframe { width: 100%; height: 100%; min-height: 70vh; border: 0; background: #fff; }
.viewer-state { display: grid; place-items: center; align-content: center; gap: 16px; padding: 56px 20px; text-align: center; color: var(--ink-2); min-height: 340px; width: 100%; }
.viewer-state .msg { max-width: 48ch; color: var(--ink); }
.viewer-state > svg { width: 24px; height: 24px; color: var(--bad); }
.viewer-state .row { display: flex; gap: 8px; flex-wrap: wrap; justify-content: center; }
.progress { height: 4px; width: min(320px, 80%); background: var(--line); border-radius: 0; overflow: hidden; }
.progress > div { height: 100%; width: 0; background: var(--accent); transition: width .25s var(--ease); }
.kbd-legend { margin-top: 16px; font-size: 13px; color: var(--ink-3); display: flex; flex-wrap: wrap; gap: 8px 20px; }
.kbd-legend span { display: inline-flex; align-items: center; gap: 6px; }
@media (max-width: 760px) { .kbd-legend { display: none; } }

/* ---------------------------------------------------------------------
   Saved and library
   --------------------------------------------------------------------- */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 0; margin-bottom: 48px; }
.card.stat { display: grid; gap: 4px; padding: 20px 24px 20px 0; background: none; border: 0; border-radius: 0; border-right: 1px solid var(--line-2); }
.card.stat + .card.stat { padding-left: 24px; }
.card.stat:last-child { border-right: 0; }
.stat .ic { display: none; }
.stat .v { font: 500 40px/1 var(--font-display); letter-spacing: -.04em; font-variant-numeric: tabular-nums; }
.stat .l { font-size: 14px; color: var(--ink-3); }
.card.table-wrap { overflow-x: auto; background: none; border: 0; border-radius: 0; }
table { width: 100%; border-collapse: collapse; font-size: 15px; }
th, td { text-align: left; padding: 14px 16px 14px 0; border-bottom: 1px solid var(--line-2); vertical-align: middle; }
thead th { font: 500 13px var(--font-body); color: var(--ink-3); background: none; border-bottom: 1px solid var(--line-2); }
tbody tr { transition: background .15s var(--ease); }
tbody tr:hover { background: color-mix(in srgb, var(--surface-2) 55%, transparent); }
td.num { font: 400 14px var(--font-mono); white-space: nowrap; color: var(--ink-2); }
td .t { font-weight: 500; }
td .t a { color: var(--ink); text-decoration: none; }
td .t a:hover { color: var(--accent); text-decoration: underline; }
td .s { font-size: 13px; color: var(--ink-3); }
td.act { text-align: right; white-space: nowrap; padding-right: 0; }
@media (max-width: 640px) {
  table, thead, tbody, tr, td { display: block; }
  thead { display: none; }
  tbody tr { padding: 14px 0; border-bottom: 1px solid var(--line-2); display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 4px 12px; }
  td { padding: 0; border: 0; }
  td:first-child { grid-column: 1 / -1; }
  td.act { grid-column: 2; grid-row: 2 / span 3; align-self: center; }
  td.num { font-size: 13px; }
}

/* ---------------------------------------------------------------------
   Command palette
   --------------------------------------------------------------------- */
.palette {
  width: min(680px, calc(100% - 24px)); max-height: min(580px, calc(100vh - 120px)); margin: 12vh auto auto; padding: 0;
  border: 1px solid var(--ink); border-radius: var(--r-lg); color: var(--ink); background: var(--surface); box-shadow: var(--shadow-lg); overflow: hidden;
}
.palette[open] { animation: pal-in .18s var(--ease); }
.palette::backdrop { background: rgba(13, 16, 32, .5); animation: fade .18s var(--ease); }
@keyframes pal-in { from { opacity: 0; transform: translateY(-6px); } }
.pal-panel { display: grid; grid-template-rows: auto minmax(0, 1fr) auto; max-height: inherit; }
.pal-head { display: flex; align-items: center; gap: 12px; padding: 0 12px 0 20px; border-bottom: 1px solid var(--line-2); }
.pal-head .ic { color: var(--accent); }
.pal-head .ic svg { width: 18px; height: 18px; }
.pal-head input { flex: 1; min-width: 0; height: 60px; border: 0; background: transparent; font-size: 18px; outline: none; color: var(--ink); }
.pal-head input::placeholder { color: var(--ink-3); }
.pal-head input::-webkit-search-cancel-button { display: none; }
.pal-esc { font: 500 12px var(--font-mono); padding: 4px 8px; border-radius: var(--r-xs); border: 1px solid var(--line-2); background: var(--bg); color: var(--ink-3); cursor: pointer; }
.pal-list { overflow-y: auto; padding: 8px; overscroll-behavior: contain; }
.pal-group + .pal-group { margin-top: 8px; }
.pal-label { padding: 12px 12px 4px; font: 500 13px var(--font-body); color: var(--ink-3); }
.pal-item { display: grid; grid-template-columns: 36px minmax(0, 1fr) auto auto; gap: 12px; align-items: center; padding: 8px 12px; border-radius: var(--r-sm); text-decoration: none; color: var(--ink); scroll-margin: 8px; }
.pal-item[aria-selected="true"] { background: var(--accent-soft); color: var(--ink); box-shadow: inset 2px 0 0 var(--accent); }
.pal-item .pi-ic { display: grid; place-items: center; width: 36px; height: 36px; border-radius: var(--r-xs); color: var(--ink-2); background: var(--bg); border: 1px solid var(--line-2); }
.pal-item[aria-selected="true"] .pi-ic { color: var(--accent); border-color: var(--accent-line); }
.pal-item .pi-ic svg { width: 16px; height: 16px; }
.pi-type { font: 500 12px var(--font-mono); }
.pi-mark { font: 500 13px/1 var(--font-body); }
.pi-main { display: grid; min-width: 0; }
.pi-t { font-weight: 500; font-size: 15px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pi-s { font-size: 13px; color: var(--ink-3); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.pi-go { color: var(--accent); opacity: 0; }
.pi-go svg { width: 16px; height: 16px; }
.pal-item[aria-selected="true"] .pi-go { opacity: 1; }
.pal-list .empty { padding: 28px 16px; }
.pal-foot { display: flex; gap: 20px; padding: 8px 20px; border-top: 1px solid var(--line-2); font-size: 13px; color: var(--ink-3); background: var(--bg); }
.pal-foot span { display: inline-flex; align-items: center; gap: 6px; }
@media (max-width: 640px) {
  .palette { margin-top: calc(env(safe-area-inset-top, 0px) + 12px); max-height: calc(100vh - 24px); }
  .pal-foot { display: none; }
}

/* Toast */
.toast {
  position: fixed; left: 50%; bottom: calc(var(--tabbar-h) + 24px); z-index: 80; transform: translateX(-50%);
  display: inline-flex; align-items: center; gap: 10px; max-width: calc(100% - 32px);
  padding: 12px 16px; border-radius: var(--r-sm); font-size: 15px; font-weight: 500;
  color: var(--dark-ink); background: var(--dark); box-shadow: var(--shadow-lg); border-left: 3px solid var(--band);
  animation: toast-in .25s var(--ease);
}
@keyframes toast-in { from { opacity: 0; transform: translate(-50%, 8px); } }
@media (max-width: 760px) { .toast { bottom: calc(var(--tabbar-h) + 80px); } }

/* Not found */
.not-found { display: grid; justify-items: center; text-align: center; gap: 16px; padding: 12vh 16px; }
.not-found .big { font: 500 clamp(96px, 16vw, 180px)/.95 var(--font-display); letter-spacing: -.06em; color: var(--accent); }
.not-found p { margin: 0; color: var(--ink-3); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; animation: none !important; scroll-behavior: auto !important; }
}

/* =====================================================================
   Question Bank (multiple choice)
   ===================================================================== */
.card.qb-head { display: grid; gap: 16px; margin-bottom: 40px; padding: 0; background: none; border: 0; border-radius: 0; }
.qb-head h1 { margin-top: 8px; font-size: clamp(46px, 6vw, 88px); line-height: 1; letter-spacing: -.05em; }
.qb-head .top { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 24px; }
.qb-head a.chip { display: inline-flex; align-items: center; gap: 6px; text-decoration: none; }
.qb-head a.chip .mono { font-size: 12px; opacity: .7; }
@media (max-width: 640px) {
  .qb-head .top > div { min-width: 0; max-width: 100%; }
  .qb-head .chips { flex-wrap: nowrap; overflow-x: auto; padding-bottom: 4px; scrollbar-width: thin; }
  .qb-head .chip { flex: none; }
}
.qb-sub { margin: 0; color: var(--ink-2); }
.qb-grid { display: grid; grid-template-columns: minmax(0, 2fr) minmax(0, 1fr); gap: 48px; align-items: start; }
@media (max-width: 900px) { .qb-grid { grid-template-columns: minmax(0, 1fr); } }
.card.qb-panel { padding: 0; display: grid; gap: 16px; background: none; border: 0; border-radius: 0; }
.qb-panel h2 { font-size: 32px; }
.qb-panel .filter-row { padding-top: 12px; border-top: 1px solid var(--line); }
.qb-actions { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; padding-top: 8px; }
.qb-stats { display: flex; gap: 40px; }
.qb-stats .v { display: block; font: 500 48px/1 var(--font-display); letter-spacing: -.045em; font-variant-numeric: tabular-nums; }
.qb-stats .l { font-size: 14px; color: var(--ink-3); }
.qb-mine-links { display: flex; flex-wrap: wrap; gap: 8px; }
.qb-mine-links .btn svg { color: var(--star); }
.qb-panel .hint, .section .hint { margin: 0; font-size: 14px; color: var(--ink-3); }
.qb-panel .danger { justify-self: start; }

.qb-topics { display: grid; gap: 0; }
.card.qb-topic {
  display: grid; grid-template-columns: 48px minmax(0, 1fr) auto; gap: 16px; align-items: center;
  padding: 18px 0; text-decoration: none; color: var(--ink); background: none; border: 0; border-radius: 0; border-bottom: 1px solid var(--line-2);
  transition: padding .15s var(--ease), background .15s var(--ease);
}
.card.qb-topic:hover { color: var(--ink); background: var(--surface-2); padding-inline: 8px; }
.qb-topic .num { font: 500 16px var(--font-body); color: var(--accent); font-variant-numeric: tabular-nums; }
.qb-topic .t { display: block; font: 500 20px/1.25 var(--font-display); letter-spacing: -.02em; }
.qb-topic .s { display: block; margin-top: 4px; font-size: 14px; color: var(--ink-3); }
.qb-topic-side { font-size: 13px; color: var(--ink-3); white-space: nowrap; }
@media (max-width: 620px) { .card.qb-topic { grid-template-columns: 36px minmax(0, 1fr); } .qb-topic-side { grid-column: 2; } }

.card.qb-list { overflow: hidden; background: none; border: 0; border-radius: 0; }
.qb-row {
  display: grid; grid-template-columns: 32px minmax(0, 1fr) auto; gap: 12px; align-items: center; width: 100%;
  padding: 14px 0; min-height: 60px; border: 0; border-bottom: 1px solid var(--line-2); background: transparent;
  text-align: left; cursor: pointer; color: var(--ink); font: inherit; transition: background .15s var(--ease), padding .15s var(--ease);
}
.qb-row:hover { background: var(--surface-2); padding-inline: 8px; }
.qb-row-stem { display: block; overflow-wrap: anywhere; }
.qb-row-meta { display: block; font-size: 14px; color: var(--ink-3); }
.qb-row-side { display: flex; gap: 8px; align-items: center; justify-content: flex-end; flex-wrap: wrap; }
.qb-row-side .star-on svg { width: 16px; height: 16px; }
@media (max-width: 620px) { .qb-row { grid-template-columns: 32px minmax(0, 1fr); } .qb-row-side { grid-column: 2; justify-content: flex-start; } }
.qb-status { display: inline-grid; place-items: center; width: 24px; height: 24px; border-radius: 2px; font-weight: 500; font-size: 13px; }
.qb-status svg { width: 14px; height: 14px; }
.qb-status.ok { background: var(--good-soft); color: var(--good); }
.qb-status.bad { background: var(--bad-soft); color: var(--bad); }
.qb-status.none { border: 1px solid var(--line-2); color: var(--ink-3); }
.badge.qb-src-past { color: var(--accent); font-weight: 500; }
.badge.qb-marks { color: var(--ink-2); font: 500 13px var(--font-mono); }

.qb-state { padding: 32px 0; display: grid; justify-items: center; gap: 12px; text-align: center; color: var(--ink-2); }
.qb-state svg { width: 28px; height: 28px; color: var(--warn); }
.qb-error strong { color: var(--ink); max-width: 60ch; }
.qb-detail { font-size: 13px; color: var(--ink-3); overflow-wrap: anywhere; max-width: 70ch; }
.qb-indeterminate > div { width: 40%; animation: qb-slide 1.1s ease-in-out infinite; }
@keyframes qb-slide { from { transform: translateX(-100%); } to { transform: translateX(260%); } }
.qb-warn { margin: 12px 0; padding: 12px 16px; border-left: 3px solid var(--warn); background: var(--warn-soft); color: var(--warn); font-weight: 500; }
.qb-hidden { margin-top: 16px; font-size: 14px; color: var(--ink-3); }
.qb-hidden summary { cursor: pointer; }
.qb-hidden ul { margin: 8px 0 0; padding-left: 20px; }

/* Practice: the question sits on a sheet of paper */
.qb-practice { display: grid; gap: 24px; }
.qb-progress { display: grid; grid-template-columns: auto minmax(80px, 1fr) auto; gap: 16px; align-items: center; font-size: 14px; font-variant-numeric: tabular-nums; }
.qb-progress .progress { width: 100%; }
.card.qb-question { padding: 40px; display: grid; gap: 24px; border-color: var(--line-2); box-shadow: var(--shadow-sm); border-top: 3px solid var(--accent); }
@media (max-width: 600px) { .card.qb-question { padding: 24px 16px; } .qb-progress { grid-template-columns: 1fr auto; } .qb-progress .progress { grid-column: 1 / -1; grid-row: 2; } }
.qb-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 16px; }
.qb-stem { font-size: 21px; line-height: 1.5; max-width: 62ch; }
.qb-stem p { margin: 0 0 12px; }
.qb-stem p:last-child { margin-bottom: 0; }
.qb-figure { margin: 0; display: grid; gap: 8px; justify-items: start; }
.qb-figure figcaption { font-size: 14px; font-weight: 500; color: var(--ink-2); }
.qb-figure img { display: block; max-width: min(100%, 460px); height: auto; background: #fff; border: 1px solid var(--line-2); border-radius: var(--r-sm); padding: 8px; }
.qb-figure .table-wrap { border: 1px solid var(--line-2); border-radius: var(--r-sm); max-width: 100%; }
.qb-figure table { width: auto; min-width: 280px; }
.qb-figure th, .qb-figure td { padding: 8px 12px; }
.qb-figure th[scope="row"] { font-weight: 500; }
.qb-figure td, .qb-figure th { font-variant-numeric: tabular-nums; }
.qb-figure.broken { display: flex; gap: 12px; align-items: flex-start; padding: 12px 16px; border-left: 3px solid var(--warn); background: var(--warn-soft); color: var(--warn); }
.qb-figure.broken svg { width: 20px; height: 20px; flex: none; }
.qb-figure.broken .mono { display: block; font-size: 13px; overflow-wrap: anywhere; }

.qb-options { border: 0; margin: 0; padding: 0; display: grid; gap: 8px; min-width: 0; }
.qb-option {
  position: relative; display: grid; grid-template-columns: 40px minmax(0, 1fr) auto; gap: 12px; align-items: center;
  padding: 12px 16px; min-height: 60px; border: 1px solid var(--line-2); border-radius: var(--r-sm); background: var(--surface);
  cursor: pointer; transition: border-color .15s var(--ease), background .15s var(--ease), transform .15s var(--ease);
}
.qb-option input { position: absolute; opacity: 0; width: 1px; height: 1px; }
.qb-option:hover { border-color: var(--ink); transform: translateY(-1px); }
.qb-option:focus-within { outline: 2px solid var(--focus); outline-offset: 2px; }
.qb-options:disabled .qb-option { cursor: default; transform: none; }
.qb-options:disabled .qb-option:hover { border-color: var(--line-2); }
.qb-key { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 2px; border: 1.5px solid var(--line-2); font: 500 15px var(--font-mono); color: var(--ink-2); background: var(--surface); }
.qb-opt-text { font-size: 17px; line-height: 1.5; overflow-wrap: anywhere; }
.qb-opt-text img { display: block; max-width: 100%; margin-top: 8px; background: #fff; }
.qb-opt-note { display: inline-flex; align-items: center; gap: 4px; font-size: 14px; font-weight: 500; white-space: nowrap; }
.qb-opt-note svg { width: 14px; height: 14px; }
.qb-option.chosen { border-color: var(--accent); background: var(--accent-soft); }
.qb-option.chosen .qb-key { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.qb-option.correct, .qb-options:disabled .qb-option.correct:hover { border-color: var(--good); background: var(--good-soft); }
.qb-option.correct .qb-key { background: var(--good); border-color: var(--good); color: var(--surface); }
.qb-option.correct .qb-opt-note { color: var(--good); }
.qb-option.wrong, .qb-options:disabled .qb-option.wrong:hover { border-color: var(--bad); background: var(--bad-soft); }
.qb-option.wrong .qb-key { background: var(--bad); border-color: var(--bad); color: var(--surface); }
.qb-option.wrong .qb-opt-note { color: var(--bad); }
@media (max-width: 520px) { .qb-option { grid-template-columns: 36px minmax(0, 1fr); } .qb-opt-note { grid-column: 2; } }

.qb-feedback { padding: 16px 20px; border-left: 3px solid; outline: none; }
.qb-feedback.ok { border-color: var(--good); background: var(--good-soft); }
.qb-feedback.bad { border-color: var(--bad); background: var(--bad-soft); }
.qb-verdict { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin: 0; font-size: 18px; color: var(--ink); }
.qb-verdict svg { width: 20px; height: 20px; }
.qb-verdict.ok svg, .qb-verdict.ok .lead { color: var(--good); }
.qb-verdict.bad .x, .qb-verdict.bad .lead { color: var(--bad); }
.qb-panel .filter-row .seg { justify-self: start; }
.qb-explain { margin-top: 12px; color: var(--ink); }
.qb-explain h3 { font-size: 16px; margin-bottom: 4px; }
.qb-explain p { margin: 0 0 8px; max-width: 62ch; }
.qb-buttons { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.qb-buttons .spacer { flex: 1; }
@media (max-width: 520px) { .qb-buttons .spacer { flex-basis: 100%; height: 0; } .qb-buttons .btn { flex: 1 1 auto; } }
.card.qb-source { padding: 24px 0 0; display: grid; gap: 12px; background: none; border: 0; border-radius: 0; border-top: 1px solid var(--line-2); }
.qb-source h2 { font-size: 28px; }
.qb-source .kv { grid-template-columns: auto minmax(0, 1fr); display: grid; gap: 8px 16px; margin: 0; font-size: 15px; }
.qb-source .kv dt { font: 500 13px var(--font-body); color: var(--ink-3); padding-top: 2px; }
.qb-source .kv dd { margin: 0; }
.qb-links { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.card.qb-summary { padding: 32px; display: grid; gap: 12px; margin-bottom: 16px; border-top: 3px solid var(--accent); }
.qb-code pre { margin: 0; padding: 16px; border-radius: var(--r-sm); background: var(--bg); border: 1px solid var(--line-2); font: 15px/1.55 var(--font-mono); color: var(--ink); overflow-x: auto; max-width: 100%; tab-size: 4; }
.badge.qb-level { padding: 3px 6px; border-radius: var(--r-xs); font-weight: 500; background: var(--warn-soft); color: var(--warn); }