/* ============================================================
   PhyKit 0625 - Notion x Cambridge, glassmorphism, dark-first
   ============================================================ */
* { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --display: "Outfit", "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: ui-monospace, "Cascadia Code", "SF Mono", Consolas, monospace;
  --radius: 16px;
  --radius-sm: 11px;
  --sidebar-w: 300px;

  /* ---- CINEMATIC DARK: midnight + violet→teal neon (default) ---- */
  --page: #060713;             /* deep near-black indigo */
  --page-2: #0a0b1a;
  --surface: #0d0f20;
  --surface-2: #141633;
  --glass: rgba(18, 20, 42, 0.55);
  --glass-2: rgba(26, 28, 58, 0.6);
  --glass-brd: rgba(168, 130, 255, 0.16);
  --ink: #eef0ff;
  --ink-2: #9aa0cf;
  --ink-3: #646a9a;
  --hairline: rgba(168, 150, 255, 0.12);
  --grid: rgba(168, 150, 255, 0.06);
  --accent: #a855f7;           /* violet */
  --accent-2: #22d3ee;         /* cyan / teal */
  --brand: #a855f7;
  --emerald: #22d3ee;
  --accent-soft: rgba(168, 85, 247, 0.16);
  --good: #34d399;
  --warn: #fbbf24;
  --crit: #fb7185;
  --star: #fbbf24;
  --paper: #ffffff;            /* question sheets stay white — never themed */
  --shadow: 0 30px 80px rgba(0, 0, 0, 0.6);
  --glow: 0 0 44px rgba(168, 85, 247, 0.35);
  --grad: linear-gradient(120deg, #a855f7 0%, #6366f1 48%, #22d3ee 100%);
  --grad-blue: linear-gradient(120deg, #6366f1, #22d3ee);
  --grad-emerald: linear-gradient(120deg, #22d3ee, #34d399);
  --grad-violet: linear-gradient(120deg, #c084fc, #a855f7);
  --seq100:#e7ddff; --seq200:#c9b4fb; --seq300:#a988f4; --seq400:#8b5cf6;
  --seq500:#6d3fd8; --seq600:#4b2ba0; --seq700:#2c1a66;
  --ease: cubic-bezier(.22,.61,.36,1);
  --ease-out: cubic-bezier(.16,1,.3,1);
}
:root[data-theme="light"] {
  /* clean light variant of the same violet/teal identity */
  --page: #f3f2fb;
  --page-2: #f8f7fe;
  --surface: #ffffff;
  --surface-2: #f0eefb;
  --glass: rgba(255, 255, 255, 0.72);
  --glass-2: rgba(255, 255, 255, 0.85);
  --glass-brd: rgba(120, 80, 200, 0.14);
  --ink: #17132b;
  --ink-2: #5b5580;
  --ink-3: #938db8;
  --hairline: rgba(90, 60, 160, 0.12);
  --grid: rgba(90, 60, 160, 0.07);
  --accent: #7c3aed;
  --accent-2: #0891b2;
  --brand: #7c3aed;
  --accent-soft: rgba(124, 58, 237, 0.1);
  --good: #059669;
  --crit: #e11d48;
  --shadow: 0 22px 54px rgba(60, 40, 110, 0.14);
  --glow: 0 0 34px rgba(124, 58, 237, 0.2);
  --grad: linear-gradient(120deg, #7c3aed, #6366f1 50%, #0891b2);
  --grad-blue: linear-gradient(120deg, #6366f1, #0891b2);
  --grad-emerald: linear-gradient(120deg, #0891b2, #059669);
  --grad-violet: linear-gradient(120deg, #9333ea, #7c3aed);
}

/* vendored fonts (offline): Outfit for display, Inter for body */
@font-face { font-family: "Outfit"; src: url("../fonts/outfit.woff2") format("woff2"); font-weight: 100 900; font-style: normal; font-display: swap; }
@font-face { font-family: "Inter"; src: url("../fonts/inter.woff2") format("woff2"); font-weight: 100 900; font-style: normal; font-display: swap; }

html { height: 100%; }
body {
  font-family: var(--font);
  background: var(--page);
  color: var(--ink);
  height: 100%;
  overflow: hidden;
  font-size: 14.5px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
::selection { background: var(--accent-soft); color: var(--ink); }
/* cinematic animated aurora — moving violet/teal light behind the canvas */
body::before {
  content: "";
  position: fixed; inset: -25%; z-index: -2;
  background:
    radial-gradient(38% 42% at 18% 12%, rgba(168, 85, 247, 0.30), transparent 62%),
    radial-gradient(34% 40% at 86% 8%, rgba(99, 102, 241, 0.26), transparent 60%),
    radial-gradient(42% 46% at 78% 92%, rgba(34, 211, 238, 0.20), transparent 62%),
    radial-gradient(40% 44% at 8% 88%, rgba(139, 92, 246, 0.18), transparent 60%),
    var(--page);
  filter: saturate(1.15);
  animation: auroraDrift 24s var(--ease) infinite alternate;
}
@keyframes auroraDrift {
  0%   { transform: translate3d(0,0,0) scale(1) rotate(0deg); }
  50%  { transform: translate3d(3%, 2%, 0) scale(1.08) rotate(1.5deg); }
  100% { transform: translate3d(-2%, -1.5%, 0) scale(1.04) rotate(-1deg); }
}
:root[data-theme="light"] body::before { opacity: .55; }
@media (prefers-reduced-motion: reduce) {
  body::before { animation: none; }
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .001ms !important; transition-duration: .001ms !important; }
}

#app { display: flex; height: 100vh; }

/* ---------------- sidebar ---------------- */
#sidebar {
  width: var(--sidebar-w);
  flex: 0 0 auto;
  display: flex; flex-direction: column;
  backdrop-filter: blur(18px);
  background: var(--glass);
  border-right: 1px solid var(--glass-brd);
}
.side-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 14px 12px;
  border-bottom: 1px solid var(--hairline);
}
.brand { display: flex; gap: 10px; align-items: center; }
.brand-mark { font-size: 24px; }
.brand-name { font-weight: 700; letter-spacing: .2px; font-size: 15.5px; }
.brand-name span { color: var(--accent); }
.brand-sub { font-size: 11px; color: var(--ink-3); }

#sideNav { flex: 1; overflow-y: auto; padding: 10px 8px 20px; }
.nav-static { margin-bottom: 10px; }
.nav-item {
  display: flex; align-items: center; gap: 8px;
  width: 100%;
  padding: 6px 10px;
  border: 0; background: none; color: var(--ink-2);
  font: inherit; font-size: 13.5px;
  border-radius: var(--radius-sm);
  cursor: pointer; text-align: left;
}
.nav-item:hover { background: var(--surface-2); color: var(--ink); }
.nav-item.active { background: var(--accent-soft); color: var(--ink); font-weight: 600; }
.nav-item .count { margin-left: auto; font-size: 11px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.nav-item .ico { width: 18px; text-align: center; }

.topic-block { margin: 2px 0; }
.topic-head {
  display: flex; align-items: center; gap: 6px;
  width: 100%;
  padding: 6px 8px;
  border: 0; background: none; color: var(--ink);
  font: inherit; font-size: 13.5px; font-weight: 600;
  border-radius: var(--radius-sm); cursor: pointer; text-align: left;
}
.topic-head:hover { background: var(--surface-2); }
.topic-head .tw { transition: transform .15s; color: var(--ink-3); font-size: 10px; width: 12px; }
.topic-block.open .tw { transform: rotate(90deg); }
.topic-head .tnum {
  font-size: 10.5px; font-weight: 700;
  color: var(--accent);
  background: var(--accent-soft);
  border-radius: 5px; padding: 1px 5px; min-width: 20px; text-align: center;
}
.topic-head .count { margin-left: auto; font-size: 11px; color: var(--ink-3); font-weight: 400; }
.topic-kids { display: none; padding-left: 20px; }
.topic-block.open .topic-kids { display: block; }
.sub-item {
  display: flex; align-items: baseline; gap: 7px;
  width: 100%; padding: 4px 9px;
  border: 0; background: none; color: var(--ink-2);
  font: inherit; font-size: 12.8px;
  border-radius: var(--radius-sm); cursor: pointer; text-align: left;
}
.sub-item:hover { background: var(--surface-2); color: var(--ink); }
.sub-item.active { background: var(--accent-soft); color: var(--ink); font-weight: 600; }
.sub-item .code { font-family: var(--mono); font-size: 11px; color: var(--accent); }
.sub-item .count { margin-left: auto; font-size: 10.5px; color: var(--ink-3); font-variant-numeric: tabular-nums; }

.side-foot { padding: 10px 14px; border-top: 1px solid var(--hairline); font-size: 12px; }
.side-foot a { color: var(--ink-3); text-decoration: none; }
.side-foot a:hover { color: var(--accent); }

/* ---------------- main ---------------- */
#main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

#topbar {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 20px 10px;
}
#menuBtn { display: none; }
.search-wrap {
  flex: 1; max-width: 640px; position: relative;
}
.search-ico { position: absolute; left: 12px; top: 50%; transform: translateY(-50%); color: var(--ink-3); font-size: 16px; }
#search {
  width: 100%;
  padding: 9px 14px 9px 34px;
  font: inherit; color: var(--ink);
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: 12px;
  backdrop-filter: blur(14px);
  outline: none;
}
#search:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.result-count { font-size: 12.5px; color: var(--ink-3); white-space: nowrap; }

#filterbar {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
  padding: 4px 20px 12px;
  border-bottom: 1px solid var(--hairline);
}
.f-select {
  font: inherit; font-size: 12.5px; color: var(--ink-2);
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: 9px;
  padding: 5px 8px;
  cursor: pointer;
}
.f-select:focus { outline: none; border-color: var(--accent); }
.f-chip {
  font: inherit; font-size: 12.5px;
  padding: 5px 12px;
  border-radius: 999px;
  border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-2);
  cursor: pointer;
}
.f-chip:hover { border-color: var(--accent); color: var(--ink); }
.f-chip.on { background: var(--accent-soft); border-color: var(--accent); color: var(--ink); font-weight: 600; }
.f-clear { margin-left: auto; font-size: 12px; color: var(--ink-3); background: none; border: 0; cursor: pointer; font-family: inherit; }
.f-clear:hover { color: var(--crit); }

#view { flex: 1; overflow-y: auto; padding: 18px 20px 60px; scroll-behavior: smooth; }

.view-head { margin-bottom: 4px; }
.view-head h1 { font-size: 21px; font-weight: 700; letter-spacing: -.2px; }
.view-head .crumb { font-size: 12px; color: var(--ink-3); margin-bottom: 2px; }
.view-head .crumb b { color: var(--accent); font-family: var(--mono); font-weight: 600; }
.obj-note {
  margin: 10px 0 4px;
  padding: 12px 16px;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
    font-size: 13px; color: var(--ink-2);
}
.obj-note summary { cursor: pointer; font-weight: 600; color: var(--ink); font-size: 13px; }
.obj-note ul { margin: 8px 0 2px 18px; }
.obj-note li { margin: 3px 0; }
.obj-note .sup-tag { color: var(--accent); font-weight: 700; font-size: 10.5px; margin-right: 5px; }

/* ---------------- question cards ---------------- */
.qgrid { display: flex; flex-direction: column; gap: 18px; margin-top: 14px; max-width: 1060px; }
.qcard {
  background: var(--surface);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.qcard-top {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap;
  padding: 10px 14px;
  border-bottom: 1px solid var(--hairline);
}
.qref { font-weight: 700; font-size: 13.5px; }
.chip {
  font-size: 11px; padding: 2px 9px;
  border-radius: 999px;
  background: var(--surface-2); color: var(--ink-2);
  border: 1px solid var(--hairline);
  white-space: nowrap;
}
.chip.code { font-family: var(--mono); color: var(--accent); background: var(--accent-soft); border-color: transparent; cursor: pointer; }
.chip.code:hover { text-decoration: underline; }
.chip.diff-Easy { color: var(--good); border-color: var(--good); background: transparent; }
.chip.diff-Medium { color: var(--warn); border-color: var(--warn); background: transparent; }
.chip.diff-Hard { color: var(--crit); border-color: var(--crit); background: transparent; }
.chip.flag { background: transparent; }
.stars { color: var(--star); font-size: 12px; letter-spacing: 1px; margin-left: auto; cursor: default; }

.qimg-wrap { background: var(--paper); padding: 14px 18px; }
.qimg-wrap img { width: 100%; height: auto; display: block; }

.qcard-actions {
  display: flex; gap: 8px; flex-wrap: wrap; align-items: center;
  padding: 10px 14px;
  border-top: 1px solid var(--hairline);
}
.btn {
  font: inherit; font-size: 12.5px; font-weight: 600;
  padding: 7px 13px;
  border-radius: 9px;
  border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-2);
  cursor: pointer;
  text-decoration: none;
  display: inline-flex; align-items: center; gap: 6px;
}
.btn:hover { border-color: var(--accent); color: var(--ink); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { filter: brightness(1.1); }

.answer-panel {
  display: none;
  padding: 12px 16px;
  border-top: 1px dashed var(--hairline);
  background: var(--surface);
  font-size: 13px;
}
.qcard.revealed .answer-panel { display: block; }
.ans-line { display: flex; align-items: center; gap: 10px; margin-bottom: 8px; }
.ans-letter {
  width: 34px; height: 34px; border-radius: 9px;
  background: var(--good); color: #fff;
  font-weight: 800; font-size: 17px;
  display: inline-flex; align-items: center; justify-content: center;
}
.ans-src { font-size: 11.5px; color: var(--ink-3); }
.ans-obj { color: var(--ink-2); }
.ans-obj b { color: var(--ink); }
.ans-obj ul { margin: 6px 0 0 18px; }
.ans-obj li { margin: 3px 0; }

.empty {
  margin: 60px auto; text-align: center; color: var(--ink-3);
  max-width: 380px;
}
.empty .big { font-size: 40px; margin-bottom: 10px; }

.load-more { text-align: center; padding: 18px; }

/* ---------------- modal (question detail) ---------------- */
.modal {
  position: fixed; inset: 0; z-index: 50;
  background: rgba(0, 0, 0, 0.55);
  backdrop-filter: blur(6px);
  display: flex; align-items: flex-start; justify-content: center;
  overflow-y: auto;
  padding: 4vh 16px 6vh;
}
.modal.hidden, .hidden { display: none; }
.modal-card {
  width: min(980px, 100%);
  background: var(--surface);
  border: 1px solid var(--glass-brd);
  border-radius: 18px;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.modal-head {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 14px 18px;
  border-bottom: 1px solid var(--hairline);
  position: sticky; top: 0;
  background: var(--surface);
  z-index: 2;
}
.modal-head .x { margin-left: auto; }
.related-h { padding: 16px 18px 4px; font-weight: 700; font-size: 14px; }
.related-sub { padding: 0 18px 8px; font-size: 12px; color: var(--ink-3); }
.rel-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 12px; padding: 8px 18px 20px; }
.rel-card {
  border: 1px solid var(--hairline); border-radius: 11px;
  overflow: hidden; cursor: pointer; background: var(--glass);
}
.rel-card:hover { border-color: var(--accent); }
.rel-card .rel-img { background: var(--paper); height: 130px; overflow: hidden; }
.rel-card img { width: 100%; display: block; }
.rel-meta { padding: 7px 10px; font-size: 11.5px; color: var(--ink-2); display: flex; gap: 6px; flex-wrap: wrap; }

/* ---------------- stats ---------------- */
.stats-wrap { max-width: 1060px; display: flex; flex-direction: column; gap: 18px; margin-top: 14px; }
.tile-row { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 12px; }
.tile {
  background: var(--glass); border: 1px solid var(--glass-brd);
  border-radius: var(--radius); padding: 14px 16px;
  }
.tile .t-label { font-size: 11.5px; color: var(--ink-3); text-transform: uppercase; letter-spacing: .6px; }
.tile .t-value { font-size: 26px; font-weight: 750; margin-top: 2px; }
.tile .t-sub { font-size: 12px; color: var(--ink-2); }

.panel {
  background: var(--glass); border: 1px solid var(--glass-brd);
  border-radius: var(--radius); padding: 16px 18px;
  }
.panel h3 { font-size: 14.5px; margin-bottom: 12px; }
.panel .note { font-size: 11.5px; color: var(--ink-3); margin-top: 10px; }

.hbar-row { display: grid; grid-template-columns: 210px 1fr 46px; gap: 10px; align-items: center; margin: 5px 0; font-size: 12.5px; }
.hbar-row .lbl { color: var(--ink-2); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; cursor: pointer; }
.hbar-row .lbl:hover { color: var(--accent); }
.hbar-track { height: 18px; border-radius: 4px 6px 6px 4px; position: relative; }
.hbar {
  height: 100%; border-radius: 3px 5px 5px 3px;
  background: var(--accent);
  min-width: 2px;
}
.hbar-row .val { font-variant-numeric: tabular-nums; color: var(--ink-2); text-align: right; }

.heat-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 6px; }
.heat-cell {
  border-radius: 8px; padding: 8px 9px; cursor: pointer;
  border: 1px solid transparent;
  min-height: 58px;
}
.heat-cell:hover { border-color: var(--ink); }
.heat-cell .hc-code { font-family: var(--mono); font-size: 10.5px; font-weight: 700; }
.heat-cell .hc-n { font-size: 16px; font-weight: 750; }
.heat-cell .hc-t { font-size: 9.8px; line-height: 1.25; opacity: .85; }
.heat-legend { display: flex; align-items: center; gap: 6px; margin-top: 10px; font-size: 11px; color: var(--ink-3); }
.heat-legend .swatch { width: 22px; height: 10px; border-radius: 3px; }

.vbars { display: flex; align-items: flex-end; gap: 10px; height: 170px; padding-top: 8px; }
.vbar-col { flex: 1; display: flex; flex-direction: column; align-items: center; gap: 6px; height: 100%; justify-content: flex-end; }
.vbar { width: 100%; max-width: 54px; background: var(--accent); border-radius: 4px 4px 2px 2px; min-height: 2px; }
.vbar-col .vlbl { font-size: 11.5px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.vbar-col .vval { font-size: 11px; color: var(--ink-2); font-variant-numeric: tabular-nums; }

.diff-row { display: flex; gap: 12px; }
.diff-box { flex: 1; border-radius: 10px; padding: 12px 14px; border: 1px solid var(--hairline); }
.diff-box .d-n { font-size: 22px; font-weight: 750; }
.diff-box .d-l { font-size: 12px; display: flex; gap: 6px; align-items: center; }
.dot { width: 9px; height: 9px; border-radius: 50%; display: inline-block; }

.rep-list { display: flex; flex-direction: column; gap: 8px; }
.rep-item {
  display: flex; align-items: center; gap: 10px;
  padding: 9px 12px; border: 1px solid var(--hairline); border-radius: 10px;
  cursor: pointer; font-size: 13px;
}
.rep-item:hover { border-color: var(--accent); }
.rep-item .stars { margin-left: 0; }
.rep-item .n { margin-left: auto; color: var(--ink-3); font-size: 12px; }

/* ---------------- tooltip ---------------- */
.tooltip {
  position: fixed; z-index: 90; pointer-events: none;
  background: var(--surface); color: var(--ink);
  border: 1px solid var(--glass-brd); border-radius: 9px;
  box-shadow: var(--shadow);
  padding: 7px 11px; font-size: 12px; max-width: 280px;
}

.icon-btn {
  font: inherit; font-size: 16px;
  width: 34px; height: 34px;
  display: inline-flex; align-items: center; justify-content: center;
  border-radius: 9px; border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-2); cursor: pointer;
}
.icon-btn:hover { color: var(--ink); border-color: var(--accent); }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: var(--hairline); border-radius: 6px; }
::-webkit-scrollbar-track { background: transparent; }

/* ---------------- responsive ---------------- */
@media (max-width: 900px) {
  #sidebar {
    position: fixed; z-index: 40; height: 100%;
    transform: translateX(-100%); transition: transform .2s;
  }
  #sidebar.open { transform: none; }
  #menuBtn { display: inline-flex; }
  .hbar-row { grid-template-columns: 130px 1fr 40px; }
}
@media print {
  #sidebar, #topbar, #filterbar, .qcard-actions { display: none; }
}

/* ============================================================
   Assessment Generator additions
   ============================================================ */

/* fade/slide entrance for cards and panels */
@keyframes fadeUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
.qcard, .panel, .tile, .gen-panel, .lib-card, .b-section { animation: fadeUp .28s ease both; }
.btn, .chip, .f-chip, .nav-item, .sub-item, .count-chip { transition: background .15s, border-color .15s, color .15s, transform .1s; }
.btn:active, .count-chip:active { transform: scale(.96); }
@media (prefers-reduced-motion: reduce) { * { animation: none !important; transition: none !important; } }

/* ---- list + generator panel split ---- */
.list-split { display: flex; gap: 18px; align-items: flex-start; }
.list-area { flex: 1; min-width: 0; }

.gen-panel {
  /* sticky inside .list-split: follows the viewport while questions scroll,
     stops naturally at the end of its parent, never overlaps the footer.
     Self-scrolls when taller than the viewport. */
  position: sticky;
  top: 8px;
  width: 300px; flex: 0 0 auto;
  max-height: calc(100vh - 150px);
  overflow-y: auto;
  overscroll-behavior: contain;
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow);
  margin-top: 14px;
  scrollbar-width: thin;
}
.gen-panel.closed { width: 46px; background: var(--surface); }
.gen-panel.closed .gen-body { display: none; }
.gen-toggle {
  position: absolute; top: 8px; right: 8px;
  width: 30px; height: 30px;
  border-radius: 8px; border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-2);
  cursor: pointer; font-size: 13px;
}
.gen-toggle:hover { border-color: var(--accent); color: var(--ink); }
.gen-body { padding: 16px 16px 18px; }
.gen-body h2 { font-size: 15.5px; margin-bottom: 6px; }
.gen-scope { font-size: 12px; color: var(--ink-2); margin-bottom: 10px; }
.gen-pool { color: var(--ink-3); }
.gen-label { display: block; font-size: 11px; text-transform: uppercase; letter-spacing: .6px; color: var(--ink-3); margin: 13px 0 6px; }
.gen-counts { display: flex; flex-wrap: wrap; gap: 6px; }
.count-chip {
  font: inherit; font-size: 12.5px; font-weight: 600;
  padding: 5px 11px; border-radius: 8px;
  border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-2); cursor: pointer;
}
.count-chip:hover { border-color: var(--accent); color: var(--ink); }
.count-chip.on { background: var(--accent); border-color: var(--accent); color: #fff; }
.gen-input {
  width: 100%; margin-top: 8px;
  font: inherit; padding: 7px 10px;
  background: var(--surface); color: var(--ink);
  border: 1px solid var(--hairline); border-radius: 8px;
}
.gen-input:focus { outline: none; border-color: var(--accent); }
.gen-methods { display: flex; flex-direction: column; gap: 2px; }
.gen-radio {
  display: flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--ink-2);
  padding: 5px 8px; border-radius: 7px; cursor: pointer;
}
.gen-radio:hover { background: var(--surface-2); color: var(--ink); }
.gen-radio.on { background: var(--accent-soft); color: var(--ink); font-weight: 600; }
.gen-radio input { accent-color: var(--accent); }
.gen-check { display: flex; align-items: center; gap: 8px; font-size: 12.5px; color: var(--ink-2); padding: 3px 2px; cursor: pointer; }
.gen-check input { accent-color: var(--accent); }
.gen-extra { margin-top: 12px; font-size: 12.5px; color: var(--ink-2); }
.gen-extra summary { cursor: pointer; font-weight: 600; }
.gen-topiclist { max-height: 180px; overflow-y: auto; margin-top: 6px; padding-left: 2px; }
.gen-warn { margin-top: 8px; font-size: 12px; color: var(--warn); }
.gen-hint { margin-top: 6px; font-size: 11.5px; color: var(--ink-3); }
.gen-create { width: 100%; margin-top: 16px; padding: 10px; font-size: 13.5px; justify-content: center; }
.gen-note { margin-top: 10px; font-size: 10.8px; color: var(--ink-3); line-height: 1.45; }

/* ---- manual selection ---- */
.qcheck { display: inline-flex; margin-right: 2px; }
.qcheck input { width: 17px; height: 17px; accent-color: var(--accent); cursor: pointer; }
.qcard.selected { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft), var(--shadow); }
.float-counter {
  position: fixed; bottom: 22px; right: 22px; z-index: 45;
  display: flex; align-items: center; gap: 10px;
  padding: 11px 16px;
  background: var(--glass);
  border: 1px solid var(--accent);
  border-radius: 14px;
  backdrop-filter: blur(16px);
  box-shadow: var(--shadow);
  font-weight: 700; font-size: 13.5px;
  animation: fadeUp .2s ease both;
}

/* ---- builder ---- */
.builder { display: flex; gap: 18px; align-items: flex-start; margin-top: 14px; max-width: 1240px; }
.b-list { flex: 1.15; min-width: 0; }
.b-meta { flex: 1; min-width: 320px; max-width: 470px; position: sticky; top: 0; }
.b-toolbar { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-bottom: 10px; }
.b-count { font-size: 12px; color: var(--ink-3); margin-left: auto; }
.b-rows { display: flex; flex-direction: column; gap: 7px; }
.b-row {
  display: flex; align-items: center; gap: 10px;
  padding: 7px 10px;
  background: var(--surface);
  border: 1px solid var(--hairline);
  border-radius: 11px;
  cursor: grab;
}
.b-row.dragging { opacity: .45; }
.b-row.dragover { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent-soft); }
.b-grip { color: var(--ink-3); font-size: 13px; letter-spacing: -2px; cursor: grab; }
.b-num {
  min-width: 26px; height: 26px;
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--accent-soft); color: var(--accent);
  font-weight: 700; font-size: 12.5px; border-radius: 7px;
}
.b-thumb { width: 100px; height: 44px; object-fit: cover; object-position: left top; border-radius: 6px; background: var(--paper); }
.b-info { min-width: 0; flex: 1; }
.b-ref { font-weight: 600; font-size: 12.8px; }
.b-tags { font-size: 11px; color: var(--ink-3); }
.b-acts { display: flex; gap: 4px; }
.b-x {
  width: 28px; height: 28px;
  border: 1px solid var(--hairline); border-radius: 7px;
  background: var(--surface); color: var(--ink-2);
  font-size: 13px; cursor: pointer;
}
.b-x:hover { border-color: var(--accent); color: var(--ink); }
.b-break { background: transparent; border-style: dashed; cursor: grab; }
.b-break-lbl { flex: 1; text-align: center; color: var(--ink-3); font-size: 12px; letter-spacing: 2px; }
.b-section {
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  padding: 15px 16px;
  margin-bottom: 14px;
}
.b-section h3 { font-size: 13.5px; margin-bottom: 10px; }
.b-field { display: block; margin-bottom: 9px; }
.b-field > span { display: block; font-size: 11px; color: var(--ink-3); margin-bottom: 3px; }
.b-field input, .b-field textarea {
  width: 100%; font: inherit; font-size: 13px;
  padding: 7px 10px;
  background: var(--surface); color: var(--ink);
  border: 1px solid var(--hairline); border-radius: 8px;
}
.b-field input:focus, .b-field textarea:focus { outline: none; border-color: var(--accent); }
.b-grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 10px; }
.b-logo-row { display: flex; gap: 10px; align-items: center; }
.b-logo-row input[type="file"] { font-size: 11.5px; color: var(--ink-3); }
.b-logo-prev { height: 38px; max-width: 90px; object-fit: contain; background: #fff; border-radius: 6px; padding: 2px; }
.b-opt { margin-top: 4px; }
.b-exports { display: flex; flex-wrap: wrap; gap: 7px; }
.btn.danger:hover { border-color: var(--crit); color: var(--crit); }

/* ---- library ---- */
.lib-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(330px, 1fr)); gap: 14px; margin-top: 16px; max-width: 1100px; }
.lib-card {
  background: var(--glass);
  border: 1px solid var(--glass-brd);
  border-radius: var(--radius);
  padding: 15px 16px;
  box-shadow: var(--shadow);
}
.lib-title { font-weight: 700; font-size: 14.5px; cursor: pointer; margin-bottom: 8px; }
.lib-title:hover { color: var(--accent); }
.lib-meta { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 8px; }
.lib-topics { font-size: 12px; color: var(--ink-2); margin-bottom: 12px; min-height: 18px; }
.lib-acts { display: flex; gap: 7px; flex-wrap: wrap; }

/* ---- print preview overlay ---- */
.preview-card { width: min(860px, 96vw); background: var(--surface-2); }
.preview-holder { padding: 10px 0 22px; overflow-x: auto; }
.preview-holder .sheet {
  transform: scale(.78); transform-origin: top center;
  margin: -18mm auto;
}
.preview-holder .sheet:first-child { margin-top: 4mm; }

/* per-question actions inside the print preview (screen only — the print/PDF
   document is rebuilt separately and never contains these) */
.preview-holder .qblock { position: relative; }
.pv-acts {
  position: absolute; top: 4px; right: 4px;
  display: flex; gap: 6px;
  opacity: 0; transition: opacity 0.15s ease;
}
.preview-holder .qblock:hover .pv-acts { opacity: 1; }
.preview-holder .qblock:hover { outline: 1.5px dashed rgba(77, 139, 255, 0.55); outline-offset: 2px; }
.pv-btn {
  font: 600 11px/1 system-ui, sans-serif;
  padding: 6px 10px; border-radius: 999px; cursor: pointer;
  border: 1px solid rgba(0, 0, 0, 0.2); background: #fff; color: #111;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.22);
}
.pv-btn:hover { background: #111; color: #fff; }
.pv-del:hover { background: #b91c1c; border-color: #b91c1c; color: #fff; }

/* replace-picker scope bar + usage chips */
.pv-scope { display: flex; gap: 8px; flex-wrap: wrap; padding: 12px 18px 0; }
.pv-used, .pv-fresh {
  font-size: 10.5px; font-weight: 700; padding: 2px 8px; border-radius: 999px;
  margin-left: auto;
}
.pv-used { background: rgba(255, 170, 0, 0.16); color: #c47f00; }
.pv-fresh { background: rgba(16, 217, 154, 0.16); color: #0a9e6e; }

/* ---- help ---- */
.help-list { padding: 14px 18px 18px; }
.help-row { display: flex; align-items: center; gap: 14px; padding: 6px 0; font-size: 13.5px; color: var(--ink-2); }
.help-row kbd {
  min-width: 34px; text-align: center;
  background: var(--surface-2); border: 1px solid var(--hairline);
  border-bottom-width: 2px; border-radius: 6px;
  padding: 3px 7px; font-size: 12px; font-family: var(--mono); color: var(--ink);
}

@media (max-width: 1100px) {
  /* panel moves below the questions; a floating action button jumps to it */
  .list-split { flex-direction: column; }
  .gen-panel { position: static; width: 100%; max-height: none; overflow: visible; }
  .gen-panel.closed { width: 100%; height: 46px; overflow: hidden; }
  .builder { flex-direction: column; }
  .b-meta { position: static; max-width: none; width: 100%; }
  .gen-fab { display: inline-flex; }
}
/* floating "create" action button — mobile only */
.gen-fab {
  display: none;
  position: fixed; bottom: 22px; right: 22px; z-index: 44;
  align-items: center; gap: 8px;
  padding: 12px 18px;
  border: 0; border-radius: 999px;
  background: var(--accent); color: #fff;
  font: inherit; font-size: 14px; font-weight: 700;
  box-shadow: var(--shadow); cursor: pointer;
}

/* ============================================================
   Phase 2: player, classroom, splash, branding
   ============================================================ */

/* ---- splash ---- */
#splash {
  position: fixed; inset: 0; z-index: 200;
  display: flex; align-items: center; justify-content: center;
  background: var(--page);
  transition: opacity .4s;
}
#splash.done { opacity: 0; pointer-events: none; }
.splash-inner { text-align: center; animation: fadeUp .5s ease both; }
.splash-name { font-size: 26px; font-weight: 800; margin-top: 14px; letter-spacing: -.3px; }
.splash-name span { color: var(--accent); }
.splash-sub { font-size: 13px; color: var(--ink-3); margin-top: 4px; }
.splash-bar { width: 200px; height: 4px; background: var(--surface-2); border-radius: 4px; margin: 18px auto 0; overflow: hidden; }
.splash-fill { height: 100%; width: 40%; background: var(--accent); border-radius: 4px; animation: splashSlide 1s ease-in-out infinite; }
@keyframes splashSlide { 0% { margin-left: -40%; } 100% { margin-left: 100%; } }
.splash-social { margin-top: 16px; font-size: 11.5px; color: var(--ink-3); letter-spacing: .4px; }

/* ---- sidebar social / about ---- */
.side-social { display: flex; flex-direction: column; gap: 2px; margin-top: 8px; }
.side-social a { font-size: 11px; color: var(--ink-3); text-decoration: none; }
.side-social a:hover { color: var(--accent); }
.side-about {
  margin-top: 8px; font: inherit; font-size: 11.5px;
  background: none; border: 0; color: var(--ink-3); cursor: pointer; padding: 0;
}
.side-about:hover { color: var(--accent); }

/* ---- about modal ---- */
.about-card { max-width: 520px; }
.about-body { padding: 18px 22px 22px; font-size: 13.5px; color: var(--ink-2); }
.about-body p { margin: 10px 0; }
.about-hero { display: flex; align-items: center; gap: 14px; margin-bottom: 6px; }
.about-name { font-size: 20px; font-weight: 800; color: var(--ink); }
.about-name span { color: var(--accent); }
.about-tag { font-size: 12px; color: var(--ink-3); }
.about-note { font-size: 12px; color: var(--ink-3); border-left: 3px solid var(--accent); padding-left: 10px; }
.about-links { display: flex; gap: 10px; margin-top: 14px; flex-wrap: wrap; }
.about-links a {
  font-size: 12.5px; font-weight: 600; color: var(--ink);
  border: 1px solid var(--hairline); border-radius: 9px;
  padding: 7px 12px; text-decoration: none;
}
.about-links a:hover { border-color: var(--accent); color: var(--accent); }

/* ---- answer panel extras ---- */
.ans-stats { margin-left: auto; font-size: 11px; color: var(--ink-3); text-align: right; max-width: 240px; }
.ans-tips { margin: 10px 0; padding: 10px 12px; background: var(--surface-2); border-radius: 10px; }
.ans-tip { font-size: 12.8px; color: var(--ink-2); margin: 5px 0; }
.ans-tip b { color: var(--ink); }

/* ---- player ---- */
.player { max-width: 900px; margin: 0 auto; }
.p-top { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; margin-bottom: 10px; }
.p-title { display: flex; align-items: center; gap: 8px; flex: 1; min-width: 0; }
.p-title b { white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.p-timer { font-variant-numeric: tabular-nums; font-weight: 700; font-size: 15px; }
.p-timer.danger { color: var(--crit); animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .5; } }
.p-progress { height: 6px; background: var(--surface-2); border-radius: 6px; overflow: hidden; margin-bottom: 14px; }
.p-fill { height: 100%; background: var(--accent); border-radius: 6px; transition: width .3s ease; }
.p-qhead { display: flex; align-items: baseline; gap: 12px; margin-bottom: 8px; }
.p-stage {
  background: var(--paper); border-radius: 12px;
  padding: 18px 22px;
  border: 1px solid var(--glass-brd);
  box-shadow: var(--shadow);
}
.p-stage img { width: 100%; height: auto; display: block; }
.p-answers { display: flex; gap: 10px; margin-top: 14px; flex-wrap: wrap; }
.p-opt {
  flex: 1; min-width: 64px;
  font: inherit; font-size: 18px; font-weight: 800;
  padding: 13px 0;
  border-radius: 12px;
  border: 2px solid var(--hairline);
  background: var(--surface); color: var(--ink);
  cursor: pointer;
  transition: all .12s;
}
.p-opt:hover:not(:disabled) { border-color: var(--accent); transform: translateY(-2px); }
.p-opt:disabled { cursor: default; opacity: .75; }
.p-opt.picked { border-color: var(--accent); background: var(--accent-soft); }
.p-opt.right { border-color: var(--good); background: rgba(12,163,12,.14); }
.p-opt.wrong { border-color: var(--crit); background: rgba(208,59,59,.14); }
.p-unsure { flex: 1.6; font-size: 13.5px; font-weight: 600; color: var(--ink-2); }
.p-feedback { margin-top: 14px; padding: 13px 16px; border-radius: 12px; border: 1px solid; animation: fadeUp .25s ease both; }
.p-feedback.ok { border-color: var(--good); background: rgba(12,163,12,.08); }
.p-feedback.bad { border-color: var(--crit); background: rgba(208,59,59,.08); }
.p-verdict { font-weight: 800; font-size: 15px; margin-bottom: 4px; }
.p-feedback.ok .p-verdict { color: var(--good); }
.p-feedback.bad .p-verdict { color: var(--crit); }
.p-explain { font-size: 13px; color: var(--ink-2); }
.p-tip { margin-top: 5px; }
.p-nav { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-top: 16px; flex-wrap: wrap; }
.p-dots { display: flex; gap: 4px; flex-wrap: wrap; max-width: 60%; }
.p-dot {
  width: 26px; height: 26px;
  font: inherit; font-size: 10.5px; font-weight: 600;
  border-radius: 7px; border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-3); cursor: pointer;
}
.p-dot.done { background: var(--accent-soft); color: var(--ink); border-color: var(--accent); }
.p-dot.cur { outline: 2px solid var(--accent); }
.p-brand { text-align: center; font-size: 10.5px; color: var(--ink-3); margin-top: 22px; letter-spacing: .3px; }

/* ---- results ---- */
.p-results { animation: fadeUp .3s ease both; }
.p-res-hero {
  text-align: center; padding: 26px 20px 20px;
  border-radius: var(--radius); border: 1px solid var(--glass-brd);
  background: var(--glass); box-shadow: var(--shadow);
  margin-bottom: 16px;
}
.p-res-pct { font-size: 52px; font-weight: 850; letter-spacing: -1px; }
.p-res-hero.ok .p-res-pct { color: var(--good); }
.p-res-hero.mid .p-res-pct { color: var(--warn); }
.p-res-hero.bad .p-res-pct { color: var(--crit); }
.p-res-line { font-size: 14px; color: var(--ink-2); }
.p-res-title { font-size: 12px; color: var(--ink-3); margin-top: 4px; }
.p-res-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 14px; }
.p-weak { font-size: 13px; color: var(--ink-2); margin: 7px 0; }
.p-review { display: flex; flex-direction: column; gap: 12px; max-height: 560px; overflow-y: auto; }
.p-rev-item { border: 1px solid var(--hairline); border-left-width: 4px; border-radius: 10px; overflow: hidden; }
.p-rev-item.ok { border-left-color: var(--good); }
.p-rev-item.bad { border-left-color: var(--crit); }
.p-rev-head { display: flex; gap: 12px; align-items: center; padding: 8px 12px; font-size: 12.5px; color: var(--ink-2); }
.p-rev-ans { font-weight: 700; color: var(--ink); }
.p-rev-item img { width: 100%; display: block; background: var(--paper); }

/* ---- classroom ---- */
#classroom {
  position: fixed; inset: 0; z-index: 150;
  background: #0a0a0a;
  display: flex; flex-direction: column;
  color: #eee;
}
.cr-top { display: flex; align-items: center; gap: 14px; padding: 12px 20px; }
.cr-brand { display: flex; align-items: center; gap: 8px; font-size: 13px; color: #999; flex: 1; min-width: 0; }
.cr-brand b { color: #eee; }
.cr-prog { font-size: 14px; font-weight: 700; font-variant-numeric: tabular-nums; }
.cr-stage {
  flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 14px; padding: 10px 30px 20px; cursor: pointer; min-height: 0;
}
.cr-stage img {
  max-width: min(1100px, 92vw); max-height: 62vh;
  object-fit: contain;
  background: #fff; border-radius: 10px; padding: 16px 20px;
  box-shadow: 0 18px 60px rgba(0,0,0,.6);
}
.cr-hint { font-size: 14px; color: #777; }
.cr-answer { display: flex; align-items: center; gap: 18px; animation: fadeUp .22s ease both; max-width: 900px; }
.cr-letter {
  width: 74px; height: 74px; flex: 0 0 auto;
  display: flex; align-items: center; justify-content: center;
  font-size: 40px; font-weight: 900;
  background: var(--good); color: #fff; border-radius: 18px;
  box-shadow: 0 10px 34px rgba(12,163,12,.4);
}
.cr-meta { font-size: 14.5px; color: #ccc; }
.cr-tip { margin-top: 6px; color: #999; font-size: 13.5px; }
.cr-nav { display: flex; justify-content: center; gap: 12px; padding: 0 20px 22px; }

@media (max-width: 800px) {
  .p-res-grid { grid-template-columns: 1fr; }
  .p-dots { max-width: 100%; order: 3; }
}

/* ============================================================
   Phase 3: modules (home, theory, combined)
   ============================================================ */

/* ---- module tabs (sidebar) ---- */
.mod-tabs { display: flex; gap: 5px; padding: 4px 4px 10px; }
.mod-tab {
  flex: 1; font: inherit; font-size: 12px; font-weight: 700;
  padding: 7px 4px; border-radius: 9px;
  border: 1px solid var(--hairline);
  background: var(--surface); color: var(--ink-2); cursor: pointer;
}
.mod-tab:hover { border-color: var(--accent); color: var(--ink); }
.mod-tab.on { background: var(--accent-soft); border-color: var(--accent); color: var(--ink); }
.mod-tab:last-child { flex: 0 0 38px; }

/* ---- home ---- */
.home-hero { text-align: center; padding: 40px 16px 10px; animation: fadeUp .35s ease both; }
.home-hero h1 { font-size: 40px; font-weight: 850; letter-spacing: 2px; margin-top: 10px; }
.home-sub { color: var(--ink-2); font-size: 14.5px; margin-top: 6px; }
.home-brandline { color: var(--ink-3); font-size: 11.5px; margin-top: 8px; letter-spacing: .4px; }
.home-cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 18px; max-width: 1060px; margin: 30px auto 0; padding: 0 4px;
}
.home-card {
  background: var(--glass); border: 1px solid var(--glass-brd);
  border-radius: 18px; padding: 24px 22px;
  box-shadow: var(--shadow); cursor: pointer;
  transition: transform .16s, border-color .16s;
  animation: fadeUp .4s ease both;
}
.home-card:hover { transform: translateY(-4px); border-color: var(--accent); }
.home-card .hc-dot { font-size: 30px; }
.home-card h2 { font-size: 18px; margin: 10px 0 2px; }
.home-card .hc-sub { font-size: 12.5px; color: var(--ink-3); margin-bottom: 12px; }
.home-card ul { list-style: none; }
.home-card li { font-size: 13px; color: var(--ink-2); padding: 3px 0; }
.home-card li::before { content: "· "; color: var(--accent); font-weight: 700; }
.home-card .hc-go { margin-top: 14px; font-weight: 700; font-size: 13px; color: var(--accent); }
.home-foot { display: flex; gap: 10px; justify-content: center; margin-top: 28px; flex-wrap: wrap; }

/* ---- theory cards ---- */
.chip.marks { background: var(--accent); color: #fff; border-color: var(--accent); font-weight: 700; }
.qimg-wrap img + img { border-top: 1px dashed #bbb; margin-top: 6px; padding-top: 6px; }
.ms-block { margin-bottom: 10px; }
.ms-badge { background: var(--accent); font-size: 14px; }
.ms-imgs { margin-top: 10px; display: flex; flex-direction: column; gap: 8px; }
.ms-imgs img { width: 100%; height: auto; display: block; background: #fff; border-radius: 8px; border: 1px solid var(--hairline); }

/* ---- combined builder ---- */
.comb-wrap { max-width: 1000px; margin-top: 16px; }
.comb-secs { display: flex; flex-direction: column; gap: 12px; }
.comb-sec {
  background: var(--glass); border: 1px solid var(--glass-brd);
  border-radius: var(--radius); padding: 12px 14px;
  animation: fadeUp .3s ease both;
}
.comb-label {
  font: inherit; font-size: 14px; font-weight: 700;
  background: none; border: 0; border-bottom: 1px dashed var(--hairline);
  color: var(--ink); width: 100%; padding: 2px 0 6px; margin-bottom: 8px; outline: none;
}
.comb-label:focus { border-bottom-color: var(--accent); }
.comb-row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.comb-count { width: 74px !important; margin-top: 0 !important; }
.comb-pool { font-size: 11.5px; color: var(--ink-3); margin-left: auto; }
.comb-controls { display: flex; gap: 10px; align-items: center; margin-top: 16px; flex-wrap: wrap; }
.comb-summary { font-size: 13px; font-weight: 700; color: var(--ink-2); margin-left: auto; }
.comb-create { padding: 10px 18px; }

/* ---- builder section rows ---- */
.b-secrow { background: var(--accent-soft); border-color: var(--accent); }
.b-seclabel {
  flex: 1; font: inherit; font-size: 13px; font-weight: 700;
  background: none; border: 0; color: var(--ink); outline: none;
}

/* ---- classroom theory segments ---- */
.cr-theory { overflow-y: auto; justify-content: flex-start; }
.cr-segs { display: flex; flex-direction: column; gap: 10px; align-items: center; max-width: min(1100px, 92vw); }
.cr-segs img {
  width: 100%; background: #fff; border-radius: 10px; padding: 14px 18px;
  box-shadow: 0 18px 60px rgba(0,0,0,.6);
}

/* ============================================================
   Usage intelligence
   ============================================================ */
.u-chip { font-weight: 700; }
.chip.u-never { color: var(--good); border-color: var(--good); background: transparent; }
.chip.u-once { color: var(--warn); border-color: var(--warn); background: transparent; }
.chip.u-multi { color: #e87b34; border-color: #e87b34; background: transparent; }
.chip.u-freq { color: var(--crit); border-color: var(--crit); background: transparent; }
.u-panel { margin-top: 10px; border-top: 1px dashed var(--hairline); padding-top: 9px; }
.u-history { font-size: 12px; color: var(--ink-2); display: flex; gap: 5px; flex-wrap: wrap; align-items: center; }
.u-notes {
  width: 100%; margin-top: 8px;
  font: inherit; font-size: 12.5px;
  background: var(--surface); color: var(--ink);
  border: 1px solid var(--hairline); border-radius: 8px;
  padding: 7px 10px; resize: vertical;
}
.u-notes:focus { outline: none; border-color: var(--accent); }

.dup-body { padding: 14px 20px 20px; font-size: 13.5px; color: var(--ink-2); }
.dup-list { display: flex; flex-direction: column; gap: 6px; margin: 12px 0; }
.dup-item { display: flex; gap: 9px; align-items: center; font-size: 12.8px; padding: 6px 10px; border: 1px solid var(--hairline); border-radius: 8px; }
.dup-meta { margin-left: auto; color: var(--ink-3); font-size: 11.5px; }
.dup-acts { display: flex; gap: 8px; margin-top: 12px; }

.lib-tools {
  display: flex; gap: 9px; align-items: center; flex-wrap: wrap;
  margin-top: 12px; padding: 11px 14px;
  background: var(--glass); border: 1px solid var(--glass-brd);
  border-radius: var(--radius); font-size: 13px;
}

.cmp-body { padding: 14px 20px 20px; font-size: 13px; color: var(--ink-2); }
.cmp-cols { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-bottom: 12px; }
.cmp-sec { margin: 11px 0; }
.cmp-chips { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 5px; }

.u-ranked { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 12px; }
.u-rankcol > b { display: block; margin-bottom: 7px; font-size: 12.5px; }
@media (max-width: 800px) { .u-ranked, .cmp-cols { grid-template-columns: 1fr; } }

/* ============================================================
   Phase 4: four modules (Practical Mastery)
   ============================================================ */
.mod-tabs-4 { flex-wrap: wrap; }
.mod-tabs-4 .mod-tab { flex: 1 1 40%; font-size: 11.5px; padding: 6px 3px; }
.mod-tabs-4 .mod-home { flex: 0 0 30px; }
.home-cards-4 { grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.home-card.practical:hover { border-color: #3987e5; }
.home-card.combined:hover { border-color: #9085e9; }
/* practical skill chip on cards uses the flag style already; graph chip accent */

/* Practical Mastery: classification block in the reveal panel */
.prac-class { margin: 10px 0; padding: 10px 12px; background: var(--surface-2); border-radius: 10px; font-size: 12.8px; color: var(--ink-2); }
.prac-class b { color: var(--ink); }
.prac-class .chip { margin: 2px 3px 2px 0; }

/* Practical Mastery: skills-first sidebar navigation */
.nav-section-h { font-size: 10.5px; text-transform: uppercase; letter-spacing: .7px; color: var(--ink-3); padding: 12px 10px 5px; font-weight: 700; }
.skill-list { display: flex; flex-direction: column; }
.skill-item { display: flex; align-items: center; gap: 8px; width: 100%; padding: 6px 10px; border: 0; background: none; color: var(--ink-2); font: inherit; font-size: 13px; border-radius: var(--radius-sm); cursor: pointer; text-align: left; }
.skill-item:hover { background: var(--surface-2); color: var(--ink); }
.skill-item.active { background: var(--accent-soft); color: var(--ink); font-weight: 600; }
.skill-item .ico { width: 18px; text-align: center; flex: 0 0 auto; }
.skill-item .sk-label { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.skill-item .count { margin-left: auto; font-size: 11px; color: var(--ink-3); font-variant-numeric: tabular-nums; }
.nav-collapse-h { display: flex; align-items: center; gap: 6px; width: 100%; border: 0; background: none; cursor: pointer; text-align: left; }
.nav-collapse-h .cw { transition: transform .15s; font-size: 9px; color: var(--ink-3); }
.nav-collapse.open .nav-collapse-h .cw { transform: rotate(90deg); }
.nav-collapse .topics-wrap { display: none; }
.nav-collapse.open .topics-wrap { display: block; }

/* generator: count / marks segmented toggle */
.gen-seg { display: flex; gap: 0; margin: 4px 0 2px; border: 1px solid var(--hairline); border-radius: 9px; overflow: hidden; }
.seg-btn { flex: 1; font: inherit; font-size: 12px; padding: 7px 4px; border: 0; background: var(--surface); color: var(--ink-2); cursor: pointer; }
.seg-btn.on { background: var(--accent); color: #fff; font-weight: 600; }

/* generator: mock exam button */
.gen-mock { width: 100%; margin-top: 8px; border-color: var(--accent); color: var(--accent); font-weight: 600; }
.gen-mock:hover { background: var(--accent-soft); }

/* fatal boot-error screen (shown instead of a stuck splash) */
#fatal { position: fixed; inset: 0; z-index: 300; display: flex; align-items: center; justify-content: center; background: var(--page); padding: 20px; }
.fatal-card { max-width: 460px; text-align: center; background: var(--surface); border: 1px solid var(--glass-brd); border-radius: 16px; padding: 30px 26px; box-shadow: var(--shadow); }
.fatal-mark { font-size: 40px; }
.fatal-card h1 { font-size: 20px; margin: 8px 0; }
.fatal-card p { color: var(--ink-2); font-size: 13.5px; margin-bottom: 16px; }
.fatal-card button { font: inherit; font-size: 13.5px; font-weight: 600; padding: 10px 16px; margin: 4px; border-radius: 10px; border: 1px solid var(--hairline); background: var(--surface); color: var(--ink); cursor: pointer; }
.fatal-card button:first-of-type { background: var(--accent); color: #fff; border-color: var(--accent); }
.fatal-card details { margin-top: 14px; text-align: left; }
.fatal-card summary { cursor: pointer; font-size: 12px; color: var(--ink-3); }
.fatal-card pre { white-space: pre-wrap; font-size: 10.5px; color: var(--ink-3); margin-top: 8px; max-height: 180px; overflow: auto; }
.fatal-brand { margin-top: 16px; font-size: 11px; color: var(--ink-3); }

/* ============================================================
   Teacher toolkit additions (PHYDB): starred pins, Formula Lab,
   Definitions Bank, hot-topics trends, combined presets
   ============================================================ */

/* star / pin button on question cards */
.pin-btn {
  margin-left: auto; border: 1px solid var(--hairline); background: transparent;
  color: var(--ink-3); border-radius: 8px; cursor: pointer; font-size: 14px;
  line-height: 1; padding: 3px 7px; transition: transform .12s ease, color .12s ease;
}
.pin-btn:hover { transform: scale(1.15); color: #eab308; }
.pin-btn.on { color: #eab308; border-color: #eab30855; background: #eab30814; }

/* formula lab */
.formula-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 10px; }
.formula-card {
  border: 1px solid var(--hairline); border-radius: 12px; padding: 12px 14px;
  background: var(--panel-2, rgba(127,127,127,.04));
}
.formula-card.sup { border-left: 3px solid #3987e5; }
.f-eq { font-family: Cambria, Georgia, "Times New Roman", serif; font-size: 17.5px; font-weight: 700; margin-bottom: 4px; }
.f-name { font-size: 12.5px; font-weight: 600; margin-bottom: 5px; display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.f-sym { font-size: 11.5px; color: var(--ink-3); line-height: 1.45; }
.core-tag {
  background: #10b98122; color: #10b981; border-radius: 4px;
  padding: 1px 5px; font-size: 9.5px; font-weight: 800; letter-spacing: .04em;
}

/* definitions bank */
.def-row { padding: 8px 0; border-bottom: 1px solid var(--hairline); display: grid; grid-template-columns: minmax(190px, 34%) 1fr; gap: 12px; }
.def-row:last-child { border-bottom: 0; }
.def-term { font-size: 13px; display: flex; align-items: center; gap: 6px; flex-wrap: wrap; }
.def-text { font-size: 12.8px; color: var(--ink-2, inherit); line-height: 1.5; }
.def-text.def-hidden { filter: blur(6px); cursor: pointer; user-select: none; }
.def-text.def-hidden:hover { filter: blur(4px); }
@media (max-width: 720px) { .def-row { grid-template-columns: 1fr; gap: 4px; } }

/* hot-topics trend arrows */
.hbar.hot { background: linear-gradient(90deg, #f59e0b, #ef4444); }
.trend-up { color: #ef4444; font-size: 10.5px; font-weight: 700; white-space: nowrap; margin-left: 8px; }
.trend-down { color: #3987e5; font-size: 10.5px; font-weight: 700; white-space: nowrap; margin-left: 8px; }
.trend-flat { color: var(--ink-3); font-size: 10.5px; font-weight: 700; white-space: nowrap; margin-left: 8px; }

/* combined builder presets */
.comb-presets { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; margin-bottom: 12px; }

/* ---------- keyboard focus (accessibility) ---------- */
:is(a, button, input, select, textarea, summary):focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
:is(a, button, input, select, textarea, summary):focus:not(:focus-visible) { outline: none; }

/* ---------- revision notes (Sir Huzaifa's own PDFs) ---------- */
.notes-sec { margin: 22px 0 10px; font-size: 11px; letter-spacing: .09em; text-transform: uppercase;
  opacity: .72; padding-bottom: 6px; border-bottom: 1px solid var(--hairline); }
.note-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 14px; }
.note-card { padding: 16px 17px; border: 1px solid var(--hairline); border-radius: 16px;
  background: var(--surface); display: flex; flex-direction: column; gap: 7px; transition: transform .2s, box-shadow .2s; }
.note-card:hover { transform: translateY(-3px); box-shadow: 0 18px 40px rgba(0,0,0,.35); }
.note-top { display: flex; align-items: baseline; gap: 10px; }
.note-topic { font-family: var(--mono); font-size: 10.5px; padding: 2px 8px; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.note-meta { margin-left: auto; font-size: 11px; opacity: .65; }
.note-card h3 { margin: 2px 0 0; font-size: 16.5px; }
.note-desc { margin: 0; font-size: 13px; line-height: 1.55; opacity: .88; }
.note-sub { font-size: 11.5px; opacity: .6; }
.note-acts { display: flex; gap: 8px; margin-top: 6px; }
.note-by { font-size: 11px; opacity: .55; }

/* ---- ZAINORA brand lockup: wordmark with the H&N sub-brand beneath ---- */
.brand-lock{display:inline-flex;flex-direction:column;line-height:1;gap:.16em;
            vertical-align:middle}
.brand-name-word{font:inherit;letter-spacing:.02em}
.zn-sub{font-size:.54em;letter-spacing:.32em;font-weight:600;
           color:var(--gold,#C9A75E);text-transform:uppercase}
@media (max-width:640px){.brand-sub{font-size:.5em;letter-spacing:.24em}}

/* keep the app tag (CHEMDB/PHYDB/...) beside the lockup, not under H&N,
   and pin the sub-brand to gold so it reads the same in every app */
.brand-name{display:inline-flex;align-items:center;gap:.5em}
.brand-lock{display:inline-flex;flex-direction:column;line-height:1;gap:.16em}
.zn-sub{color:#C9A75E !important;font-size:.54em;letter-spacing:.32em;
           font-weight:600;text-transform:uppercase}

/* ---- Student practice bar: the way into solving from any question list ---- */
.practice-bar{display:flex;align-items:center;gap:14px;flex-wrap:wrap;
  margin:0 0 18px;padding:14px 16px;border-radius:14px;
  background:linear-gradient(135deg,rgba(168,85,247,.10),rgba(168,85,247,.03));
  border:1px solid rgba(168,85,247,.22)}
.practice-bar .pb-left{flex:1 1 auto;min-width:170px}
.practice-bar .pb-title{font-weight:650;font-size:15px}
.practice-bar .pb-sub{font-size:12.5px;opacity:.72;margin-top:2px}
.practice-bar .btn{white-space:nowrap}
.pb-streak{display:inline-flex;align-items:baseline;gap:5px;padding:6px 12px;
  border-radius:999px;background:rgba(255,255,255,.05);
  border:1px solid rgba(255,255,255,.10);cursor:default}
.pb-streak.on{border-color:rgba(255,168,60,.45);background:rgba(255,168,60,.10)}
.pb-flame{font-size:15px;line-height:1}
.pb-days{font-weight:700;font-size:16px}
.pb-lbl{font-size:11.5px;opacity:.7}
@media (max-width:560px){
  .practice-bar{gap:10px;padding:12px}
  .practice-bar .btn{flex:1 1 auto}
}

/* ---- Written practice (Paper 4 / 6): answer, reveal scheme, self-mark ---- */
.p-written{display:flex;flex-direction:column;gap:14px;margin-top:14px}
.p-answerbox{width:100%;padding:14px 16px;border-radius:12px;font:inherit;
  font-size:15px;line-height:1.7;resize:vertical;
  background:rgba(255,255,255,.04);border:1px solid rgba(255,255,255,.14);
  color:inherit;
  background-image:repeating-linear-gradient(transparent,transparent 27px,rgba(255,255,255,.07) 27px,rgba(255,255,255,.07) 28px)}
.p-answerbox:focus{outline:none;border-color:rgba(168,85,247,.55)}
.p-written-actions{display:flex;gap:10px;flex-wrap:wrap}
.p-ms{display:flex;flex-direction:column;gap:8px}
.p-ms img{max-width:100%;height:auto;border-radius:10px;background:#fff}
.p-ms-head{font-weight:650;font-size:13.5px;opacity:.85}
.p-selfmark{display:flex;align-items:center;gap:8px;flex-wrap:wrap;
  padding:12px 14px;border-radius:12px;background:rgba(255,255,255,.04);
  border:1px solid rgba(255,255,255,.10)}
.p-selfmark-q{font-weight:650;font-size:14px;margin-right:4px;width:100%}
.p-mark{min-width:40px;padding:8px 12px;border-radius:9px;cursor:pointer;
  font-weight:650;background:rgba(255,255,255,.06);color:inherit;
  border:1px solid rgba(255,255,255,.14)}
.p-mark:hover{border-color:rgba(168,85,247,.5)}
.p-mark.picked{background:rgba(168,85,247,.85);border-color:transparent;color:#fff}
.p-mark-total{font-size:12.5px;opacity:.7;margin-left:4px}
.p-nav{display:flex;gap:10px;justify-content:flex-end;flex-wrap:wrap}

/* ---- written question with no mark scheme available ---- */
.p-noms{padding:13px 15px;border-radius:11px;line-height:1.6;font-size:13.5px;
  background:rgba(255,255,255,.045);border:1px solid rgba(255,255,255,.12)}
.p-noms b{display:block;margin-bottom:4px;font-size:14px}
.p-noms div{opacity:.75}

/* theory and practical questions can have several image segments */
.q-imgs { display: flex; flex-direction: column; gap: 6px; }
.q-imgs img { width: 100%; height: auto; display: block; }
.q-noimg { padding: 18px; color: var(--dim, #8b93a7); font-size: 13px; }

/* ---- Founder presence: Huzaifa in the background, both founders in the top bar ---- */
#founder-bg{position:fixed;inset:0;z-index:0;pointer-events:none;
  background:url("../assets/founders/noor-1000.jpg") no-repeat right bottom / auto 90vh;
  opacity:.14;filter:grayscale(1) contrast(1.05);
  -webkit-mask-image:linear-gradient(to left,#000 30%,transparent 78%);
  mask-image:linear-gradient(to left,#000 30%,transparent 78%)}
[data-theme="light"] #founder-bg{opacity:.09}
@media (max-width:760px){#founder-bg{background-size:auto 62vh;opacity:.11}}
#app{position:relative;z-index:1}
.founder-chip{display:inline-flex;align-items:center;gap:8px;margin-left:auto;padding:4px 11px 4px 4px;
  border-radius:999px;border:1px solid var(--hairline,rgba(255,255,255,.14));background:var(--glass,rgba(18,20,42,.55));
  color:var(--ink,#eef0ff);text-decoration:none;font-size:.78rem;line-height:1;white-space:nowrap;flex-shrink:0}
.founder-chip:hover{border-color:var(--gold,#C9A75E)}
.founder-chip img{width:26px;height:26px;border-radius:50%;object-fit:cover;border:2px solid var(--surface,#0d0f20)}
.founder-chip img+img{margin-left:-10px}
.founder-chip b{font-weight:600}
.founder-chip small{color:var(--gold,#C9A75E);letter-spacing:.1em;text-transform:uppercase;font-size:.6rem;margin-left:4px}
@media (max-width:640px){.founder-chip .t{display:none}.founder-chip{padding-right:4px}}