/* =========================================================================
   multipage · Material Design 3 baseline (pure CSS, no build)
   Shared by every page. Tokens + chrome + one block per page layout.
   ========================================================================= */

/* ---- tokens : LIGHT (warm-monochrome editorial on the MD3 contract) ---- */
:root,
[data-theme="light"] {
  --primary:#111111; --on-primary:#FFFFFF; --primary-container:#F1F0EC; --on-primary-container:#111111;
  --secondary:#787774; --secondary-container:#F1F0EC; --on-secondary-container:#111111;
  --tertiary:#9F2F2D; --tertiary-container:#FDEBEC;
  --background:#FBFBFA; --on-background:#171715; --surface:#FFFFFF;
  --surface-container:#FFFFFF; --surface-container-high:#F7F6F3; --surface-variant:#F1F0EC;
  --on-surface:#171715; --on-surface-variant:#787774;
  --outline:#B9B7B0; --outline-variant:#EAEAEA; --error:#9F2F2D; --success:#346538;
  --elev-1:0 1px 2px rgba(0,0,0,.04);
  --elev-2:0 2px 8px rgba(0,0,0,.05);
  --elev-3:0 8px 24px rgba(0,0,0,.08);
  --radius-sm:6px; --radius:10px; --radius-lg:12px;
  --font-body:"Schibsted Grotesk","Noto Sans TC",system-ui,sans-serif;
  --font-serif:"Newsreader","Noto Serif TC",Georgia,serif;
  --font-mono:"JetBrains Mono",ui-monospace,SFMono-Regular,monospace;
  --accent-blue-bg:#E1F3FE; --accent-blue-fg:#1F6C9F;
  --accent-green-bg:#EDF3EC; --accent-green-fg:#346538;
  --accent-yellow-bg:#FBF3DB; --accent-yellow-fg:#956400;
  --accent-red-bg:#FDEBEC; --accent-red-fg:#9F2F2D;
}
/* ---- tokens : DARK (warm near-black, same editorial restraint) ---- */
[data-theme="dark"] {
  --primary:#E8E6E1; --on-primary:#161512; --primary-container:#2E2D29; --on-primary-container:#E8E6E1;
  --secondary:#A6A39B; --secondary-container:#2E2D29; --on-secondary-container:#E8E6E1;
  --tertiary:#EEB1AE; --tertiary-container:#3A1D1C;
  --background:#161512; --on-background:#E8E6E1; --surface:#1A1916;
  --surface-container:#1D1C19; --surface-container-high:#24231F; --surface-variant:#2E2D29;
  --on-surface:#E8E6E1; --on-surface-variant:#A6A39B;
  --outline:#5C5A54; --outline-variant:#2E2D29; --error:#EEB1AE; --success:#A9C8AB;
  --accent-blue-bg:#14293A; --accent-blue-fg:#8FC7EE;
  --accent-green-bg:#1E2B1F; --accent-green-fg:#A9C8AB;
  --accent-yellow-bg:#33290F; --accent-yellow-fg:#E4C778;
  --accent-red-bg:#3A1D1C; --accent-red-fg:#EEB1AE;
}

/* ---- Reset / base ---- */
* { box-sizing:border-box; }
html { scroll-behavior:smooth; }
body {
  margin:0; font-family:var(--font-body); background:var(--background); color:var(--on-background);
  -webkit-font-smoothing:antialiased; transition:background .2s,color .2s; overflow-x:hidden;
}
a { color:inherit; text-decoration:none; }
.material-symbols-rounded { font-variation-settings:"FILL" 0,"wght" 400,"GRAD" 0,"opsz" 24; line-height:1; user-select:none; }
.skip-link {
  position:absolute; left:-999px; top:8px; z-index:60; background:var(--primary); color:var(--on-primary);
  padding:8px 14px; border-radius:var(--radius-lg);
}
.skip-link:focus { left:12px; }

/* ---- App bar ---- */
.appbar { position:sticky; top:0; z-index:30; background:var(--surface-container); box-shadow:var(--elev-1); }
.appbar__inner { max-width:1100px; margin:0 auto; padding:10px 16px; display:flex; align-items:center; gap:12px; }
.brand { display:flex; align-items:center; gap:8px; font-weight:700; font-size:1.1rem; color:var(--on-surface); min-width:0; overflow:hidden; }
.brand__logo { color:var(--primary); flex:0 0 auto; }
.brand__name { overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
.appbar__actions { margin-left:auto; display:flex; align-items:center; gap:8px; flex:0 0 auto; }
.icon-btn { display:inline-flex; align-items:center; gap:4px; border:none; background:transparent; color:var(--on-surface-variant);
  border-radius:var(--radius-lg); padding:8px 10px; cursor:pointer; font:inherit; transition:background .15s; }
.icon-btn:hover { background:var(--surface-container-high); }
.icon-btn__txt { font-size:.85rem; font-weight:500; }

/* ---- Cross-page nav ---- */
.pagenav {
  position:sticky; top:56px; z-index:25; border-bottom:1px solid var(--outline-variant);
  background:color-mix(in srgb,var(--background) 88%,transparent); backdrop-filter:saturate(180%) blur(8px);
}
.pagenav__inner { max-width:1100px; margin:0 auto; padding:8px 12px; display:flex; gap:8px; overflow-x:auto; scrollbar-width:none; }
.pagenav__inner::-webkit-scrollbar { display:none; }
.navpill {
  display:inline-flex; align-items:center; gap:6px; flex:0 0 auto; padding:7px 14px; border-radius:var(--radius-lg);
  font-size:.85rem; font-weight:500; color:var(--on-surface-variant); border:1px solid var(--outline-variant);
  background:transparent; white-space:nowrap; cursor:pointer; transition:background .15s,color .15s,border-color .15s;
}
.navpill .material-symbols-rounded { font-size:18px; }
.navpill:hover { background:var(--surface-container-high); }
.navpill--active { background:var(--secondary-container); color:var(--on-secondary-container); border-color:transparent; }

/* ---- Page scaffold ---- */
.page { max-width:1100px; margin:0 auto; padding:32px 16px 16px; }
.page-head { margin-bottom:22px; }
.page-head h1 { margin:0 0 6px; font-size:clamp(1.6rem,4vw,2.2rem); font-weight:700; letter-spacing:-.01em; color:var(--on-surface); }
.page-head__sub { margin:0; max-width:62ch; font-size:1rem; line-height:1.5; color:var(--on-surface-variant); }
.empty { color:var(--on-surface-variant); }

/* ---- Hero stats (hub) ---- */
.hero__stats { display:grid; grid-template-columns:repeat(auto-fit,minmax(140px,1fr)); gap:14px; margin:0 0 26px; }
.hero__stat { background:var(--surface-container); border-radius:var(--radius); padding:20px 18px; display:flex; flex-direction:column; gap:4px; border:1px solid var(--outline-variant); }
.hero__stat-value { font-size:2rem; font-weight:700; color:var(--primary); font-variant-numeric:tabular-nums; line-height:1.1; }
.hero__stat-label { font-size:.85rem; color:var(--on-surface-variant); }

/* ---- Cards grid ---- */
.grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(260px,1fr)); gap:16px; }
.card { background:var(--surface-container); border-radius:var(--radius); padding:24px; cursor:pointer;
  border:1px solid var(--outline-variant); transition:box-shadow .2s,transform .2s,border-color .2s; display:flex; flex-direction:column; gap:10px; }
.card:hover,.card:focus-visible { box-shadow:var(--elev-2); transform:translateY(-2px); border-color:var(--outline); outline:none; }
.card--nav .card__icon { font-size:28px; color:var(--primary); }
.card__title { margin:0; font-size:1.05rem; font-weight:600; color:var(--on-surface); }
.card__summary { margin:0; font-size:.9rem; line-height:1.5; color:var(--on-surface-variant); }
.card__tags { margin-top:auto; display:flex; flex-wrap:wrap; gap:6px; }
.tag { font-size:.72rem; color:var(--on-surface-variant); background:var(--surface-variant); padding:2px 8px; border-radius:var(--radius-sm); }

/* ---- Toolbar / search / chips ---- */
.toolbar { display:flex; flex-wrap:wrap; gap:12px; align-items:center; margin-bottom:14px; }
.search { flex:1 1 220px; min-width:160px; padding:10px 14px; border-radius:var(--radius-lg); border:1px solid var(--outline-variant);
  background:var(--surface-container); color:var(--on-surface); font:inherit; }
.search:focus { outline:2px solid var(--primary); outline-offset:1px; }
.chips { display:flex; flex-wrap:wrap; gap:8px; }
.chip { padding:7px 14px; border-radius:var(--radius-lg); font-size:.85rem; font-weight:500; color:var(--on-surface-variant);
  border:1px solid var(--outline-variant); background:transparent; cursor:pointer; transition:background .15s,color .15s; }
.chip:hover { background:var(--surface-container-high); }
.chip--active { background:var(--secondary-container); color:var(--on-secondary-container); border-color:transparent; }
.result-count { margin:0 0 14px; font-size:.85rem; color:var(--on-surface-variant); }

/* ---- Article ---- */
.reading-progress { position:fixed; top:0; left:0; height:3px; width:0; background:var(--primary); z-index:40; transition:width .1s linear; }
.article-layout { display:grid; grid-template-columns:200px 1fr; gap:32px; align-items:start; }
.article-layout > * { min-width:0; }
.prose pre, .table-wrap--prose { max-width:100%; }
.toc { position:sticky; top:108px; }
.toc__inner { display:flex; flex-direction:column; gap:4px; border-left:2px solid var(--outline-variant); }
.toc-link { padding:6px 14px; font-size:.9rem; color:var(--on-surface-variant); border-left:2px solid transparent; margin-left:-2px; }
.toc-link:hover { color:var(--on-surface); }
.toc-link--active { color:var(--primary); border-left-color:var(--primary); font-weight:600; }
.prose { max-width:70ch; color:var(--on-surface-variant); }
.prose h2 { color:var(--on-surface); font-size:1.4rem; margin:0 0 12px; scroll-margin-top:120px; }
.prose h3 { color:var(--on-surface); font-size:1.12rem; margin:22px 0 8px; }
.prose p { line-height:1.75; margin:0 0 14px; }
.prose ul { margin:0 0 14px; padding-left:22px; line-height:1.75; }
.prose blockquote { margin:0 0 16px; padding:8px 18px; border-left:4px solid var(--primary); color:var(--on-surface); font-style:italic; }
.prose pre { background:var(--surface-container); padding:14px 16px; border-radius:var(--radius); overflow:auto; border:1px solid var(--outline-variant); }
.prose code { font-family:"Roboto Mono",ui-monospace,monospace; font-size:.85rem; }
.article-section { margin-bottom:28px; }

/* ---- Dashboard ---- */
.stat-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(160px,1fr)); gap:16px; margin-bottom:20px; }
.stat-card { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:18px; display:flex; flex-direction:column; gap:6px; }
.stat-label { font-size:.82rem; color:var(--on-surface-variant); }
.stat-value { font-size:1.6rem; font-weight:700; color:var(--on-surface); font-variant-numeric:tabular-nums; }
.stat-unit { font-size:.85rem; font-weight:500; color:var(--on-surface-variant); }
.stat-delta { font-size:.8rem; font-weight:600; }
.stat-delta--up { color:var(--success); }
.stat-delta--down { color:var(--error); }
.panel-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(280px,1fr)); gap:16px; margin-bottom:20px; }
.panel { margin:0; background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:18px; }
.panel figcaption { font-weight:600; color:var(--on-surface); margin-bottom:10px; }
.panel--wide { grid-column:1/-1; }
.chart-wrap { width:100%; }
.chart-wrap svg { width:100%; height:auto; display:block; }
.bar-rect { fill:var(--primary); transition:fill .15s; }
.bar-rect:hover { fill:var(--tertiary); }
.bar-value { fill:var(--on-surface); font-size:13px; font-weight:600; font-family:var(--font-body); }
.bar-label { fill:var(--on-surface-variant); font-size:12px; font-family:var(--font-body); }
.axis-line { stroke:var(--outline-variant); stroke-width:1.5; }
.line-path { stroke:var(--primary); stroke-width:2.5; }
.line-area { fill:var(--primary); opacity:.12; }
.line-dot { fill:var(--primary); }

/* ---- Data table ---- */
.table-wrap { overflow-x:auto; border-radius:var(--radius); border:1px solid var(--outline-variant); }
.data-table,.cmp-table { width:100%; border-collapse:collapse; background:var(--surface-container); font-size:.9rem; }
.data-table th,.data-table td { padding:11px 14px; text-align:left; border-bottom:1px solid var(--outline-variant); color:var(--on-surface); white-space:nowrap; }
.data-table thead th { background:var(--surface-container-high); font-weight:600; color:var(--on-surface-variant); position:sticky; top:0; }
.th-sort { cursor:pointer; user-select:none; }
.th-sort:hover { color:var(--primary); }
.data-table tbody tr:hover { background:var(--surface-container-high); }
.row-link { color:var(--primary); }

/* ---- Timeline ---- */
.timeline { list-style:none; margin:0; padding:0; position:relative; }
.timeline::before { content:""; position:absolute; left:7px; top:6px; bottom:6px; width:2px; background:var(--outline-variant); }
.tl-item { position:relative; padding:0 0 18px 36px; }
.tl-item:last-child { padding-bottom:0; }
.tl-dot { position:absolute; left:0; top:6px; width:16px; height:16px; border-radius:50%; background:var(--primary); border:3px solid var(--background); box-shadow:0 0 0 2px var(--primary); }
.tl-card { background:var(--surface-container); border-radius:var(--radius); padding:14px 18px; border:1px solid var(--outline-variant); }
.tl-date { font-size:.78rem; font-weight:600; letter-spacing:.04em; color:var(--primary); }
.tl-title { margin:4px 0 6px; font-size:1.05rem; color:var(--on-surface); }
.tl-body { margin:0; font-size:.9rem; line-height:1.5; color:var(--on-surface-variant); }

/* ---- Bento ---- */
.bento { display:grid; grid-template-columns:repeat(4,1fr); grid-auto-rows:120px; gap:14px; }
.tile { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:18px; display:flex; flex-direction:column; gap:6px; overflow:hidden; }
.tile--accent { background:linear-gradient(135deg,var(--primary-container),var(--secondary-container)); border-color:transparent; }
.tile--lg { grid-column:span 2; grid-row:span 2; }
.tile--tall { grid-row:span 2; }
.tile--wide { grid-column:span 2; }
.tile--md { grid-column:span 2; }
.tile__icon { font-size:26px; color:var(--primary); }
.tile__value { font-size:1.7rem; font-weight:700; color:var(--on-surface); }
.tile__title { margin:0; font-size:1rem; color:var(--on-surface); }
.tile__body { margin:0; font-size:.85rem; line-height:1.45; color:var(--on-surface-variant); }

/* ---- Kanban ---- */
.kanban { display:grid; grid-auto-flow:column; grid-auto-columns:minmax(240px,1fr); gap:14px; overflow-x:auto; padding-bottom:8px; }
.kb-col { background:var(--surface-container-high); border-radius:var(--radius); padding:12px; }
.kb-col__head { display:flex; align-items:center; gap:8px; font-weight:600; color:var(--on-surface); margin-bottom:10px; padding:0 4px; }
.kb-col__count { font-size:.75rem; background:var(--secondary-container); color:var(--on-secondary-container); border-radius:var(--radius-lg); padding:1px 8px; }
.kb-col__body { display:flex; flex-direction:column; gap:10px; }
.kb-card { background:var(--surface); border:1px solid var(--outline-variant); border-radius:var(--radius-sm); padding:12px 14px; display:flex; flex-direction:column; gap:8px; }
.kb-card__title { margin:0; font-size:.95rem; color:var(--on-surface); }
.kb-card__body { margin:0; font-size:.82rem; line-height:1.45; color:var(--on-surface-variant); }

/* ---- Accordion (faq) ---- */
.accordion { display:flex; flex-direction:column; gap:10px; }
.acc-item { background:var(--surface-container); border-radius:var(--radius); border:1px solid var(--outline-variant); overflow:hidden; }
.acc-q { display:flex; align-items:center; justify-content:space-between; gap:12px; padding:16px 18px; cursor:pointer; font-weight:600; color:var(--on-surface); list-style:none; }
.acc-q::-webkit-details-marker { display:none; }
.acc-chevron { transition:transform .2s; color:var(--on-surface-variant); }
.acc-item[open] .acc-chevron { transform:rotate(180deg); }
.acc-a { padding:0 18px 18px; font-size:.92rem; line-height:1.6; color:var(--on-surface-variant); }

/* ---- Comparison ---- */
.cmp-table th,.cmp-table td { padding:14px 16px; text-align:center; border-bottom:1px solid var(--outline-variant); color:var(--on-surface); }
.cmp-table thead th { vertical-align:bottom; }
.cmp-feat { text-align:left !important; font-weight:600; color:var(--on-surface-variant); }
.cmp-plan { font-weight:700; font-size:1.05rem; }
.cmp-price { color:var(--primary); font-weight:600; }
.cmp-note { font-size:.78rem; color:var(--on-surface-variant); }
.cmp-col--hl { background:var(--secondary-container); }
.cmp-yes { color:var(--success); }
.cmp-no { color:var(--outline); }

/* ---- Leaderboard ---- */
.seg { display:inline-flex; gap:4px; background:var(--surface-container-high); border-radius:var(--radius-lg); padding:4px; margin-bottom:18px; }
.seg__btn { border:none; background:transparent; color:var(--on-surface-variant); padding:8px 18px; border-radius:var(--radius-lg); cursor:pointer; font:inherit; font-weight:500; }
.seg__btn--active { background:var(--primary); color:var(--on-primary); }
.lb-list { list-style:none; margin:0 0 18px; padding:0; display:flex; flex-direction:column; gap:8px; }
.lb-row { display:grid; grid-template-columns:auto auto 1fr auto auto; align-items:center; gap:12px; background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:12px 16px; }
.lb-rank { font-variant-numeric:tabular-nums; font-weight:700; color:var(--on-surface-variant); min-width:1.5em; }
.lb-tier { font-weight:700; width:1.8em; height:1.8em; display:inline-grid; place-items:center; border-radius:50%; color:#fff; font-size:.8rem; }
.lb-tier--S { background:#B3261E; } .lb-tier--A { background:#7D5260; } .lb-tier--B { background:#6750A4; }
.lb-tier--C { background:#625B71; } .lb-tier--D { background:#79747E; }
.lb-name { font-weight:600; color:var(--on-surface); }
.lb-meta { font-size:.82rem; color:var(--on-surface-variant); }
.lb-score { font-weight:700; font-variant-numeric:tabular-nums; color:var(--primary); }
.lb-tier-group { margin-bottom:16px; }
.lb-tier-head { display:inline-grid; place-items:center; min-width:2em; height:2em; border-radius:var(--radius-sm); color:#fff; font-weight:700; padding:0 10px; margin-bottom:10px; }

/* ---- Scrolly ---- */
.scrolly { display:grid; grid-template-columns:1fr 1fr; gap:32px; align-items:start; }
.scrolly-sticky { position:sticky; top:120px; height:60vh; display:flex; }
.scrolly-visual { flex:1; display:flex; align-items:center; justify-content:center; background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius-lg); padding:24px; }
.scrolly-stat { font-size:2.4rem; font-weight:700; text-align:center; }
.scrolly-steps { display:flex; flex-direction:column; gap:60vh; padding:20vh 0; }
.scrolly-step { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:20px 22px; opacity:.4; transition:opacity .3s; }
.scrolly-step p { margin:0; font-size:1.1rem; line-height:1.6; color:var(--on-surface); }
.scrolly-step--active { opacity:1; }

/* ---- Map ---- */
.map-layout { display:grid; grid-template-columns:1fr 300px; gap:18px; align-items:start; }
.map-box { height:460px; border-radius:var(--radius); overflow:hidden; border:1px solid var(--outline-variant); background:var(--surface-container); }
.map-fallback { height:100%; display:flex; align-items:center; justify-content:center; color:var(--on-surface-variant); padding:20px; text-align:center; }
.map-list { list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:8px; max-height:460px; overflow:auto; }
.place { display:flex; flex-direction:column; gap:3px; background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius-sm); padding:12px 14px; cursor:pointer; }
.place:hover,.place:focus-visible { border-color:var(--primary); outline:none; }
.place b { color:var(--on-surface); }
.place span { font-size:.82rem; color:var(--on-surface-variant); }

/* ---- Dialog ---- */
.dialog { border:none; border-radius:var(--radius-lg); background:var(--surface-container-high); color:var(--on-surface); max-width:600px; width:calc(100% - 32px); padding:0; box-shadow:var(--elev-3); }
.dialog::backdrop { background:rgba(0,0,0,.5); }
.dialog__bar { display:flex; align-items:center; padding:8px 12px; border-bottom:1px solid var(--outline-variant); position:sticky; top:0; background:var(--surface-container-high); }
.dialog__spacer { flex:1; }
.dialog__body { padding:24px; }
.dialog__body h2 { margin-top:0; color:var(--on-surface); }
.dialog__body p { color:var(--on-surface-variant); line-height:1.65; }
.dialog__body .card__tags { margin:0 0 14px; }

/* ---- Footer ---- */
.footer { text-align:center; padding:32px 16px; margin-top:32px; color:var(--on-surface-variant); font-size:.85rem; border-top:1px solid var(--outline-variant); }

/* ---- Responsive ---- */
@media (max-width:860px) {
  .article-layout { grid-template-columns:1fr; }
  .toc { position:static; }
  .toc__inner { flex-direction:row; flex-wrap:wrap; border-left:none; }
  .scrolly { grid-template-columns:1fr; }
  .scrolly-sticky { position:sticky; top:64px; height:auto; }
  .scrolly-steps { gap:30vh; padding:10vh 0; }
  .map-layout { grid-template-columns:1fr; }
  .map-list { flex-direction:row; max-height:none; }
  .bento { grid-template-columns:repeat(2,1fr); }
  .tile--lg,.tile--wide,.tile--md { grid-column:span 2; }
}
@media (max-width:600px) {
  .grid { grid-template-columns:1fr; }
  .bento { grid-template-columns:1fr; }
  .tile--lg,.tile--wide,.tile--md,.tile--tall { grid-column:span 1; grid-row:span 1; }
  .lb-row { grid-template-columns:auto auto 1fr auto; }
  .lb-meta { display:none; }
  .icon-btn__txt { font-size:.8rem; }
}
@media (max-width:375px) {
  .appbar__inner,.pagenav__inner,.page { padding-left:12px; padding-right:12px; }
  .page-head h1 { font-size:1.4rem; }
}

/* Respect reduced motion */
@media (prefers-reduced-motion:reduce) {
  html { scroll-behavior:auto; }
  * { transition:none !important; }
}

/* GitHub star button */
.gh-star {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border: 1px solid var(--outline-variant);
  border-radius: var(--radius-lg);
  font-size: .85rem;
  font-weight: 500;
  color: var(--on-surface);
  transition: background .15s;
}
.gh-star:hover { background: var(--surface-container-high); }
.gh-star .material-symbols-rounded { color: #f5a623; font-size: 20px; }
.gh-star__count {
  padding-left: 6px;
  border-left: 1px solid var(--outline-variant);
  color: var(--on-surface-variant);
  font-variant-numeric: tabular-nums;
}
@media (max-width: 600px) { .gh-star__label { display: none; } }
/* footer profile links (home + LinkedIn) */
.footer__links {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin-top: 12px;
}
.footer__link svg { display: block; }

/* =========================================================================
   Editorial layer — serif display type, kickers, and the lesson /
   glossary / flashcards / quiz / syllabus components
   ========================================================================= */

/* display type */
.page-head h1, .prose h2, .hub-h2, .quiz-group__h, .dialog__body h2 {
  font-family:var(--font-serif); letter-spacing:-.02em; font-weight:600;
}
.page-head h1 { font-size:clamp(1.9rem,4.5vw,2.75rem); line-height:1.12; }
.page-head { margin-bottom:30px; }
.page-head__sub { font-size:1.05rem; line-height:1.65; }
.prose h2 { font-size:1.55rem; }
.prose blockquote {
  font-family:var(--font-serif); font-size:1.18rem; line-height:1.55; letter-spacing:-.01em;
  border-left:3px solid var(--on-surface); padding:4px 22px; margin:20px 0 22px;
}
.prose pre { box-shadow:none; }
.prose code { font-family:var(--font-mono); }
.kicker {
  font-family:var(--font-mono); font-size:.72rem; letter-spacing:.14em; text-transform:uppercase;
  color:var(--on-surface-variant); margin:0 0 12px;
}
.kicker--inline { display:inline-block; margin:0 10px 4px 0; }
.lesson-head { max-width:72ch; }
.lesson-head__actions { margin-top:16px; }
.btn-ink {
  display:inline-flex; align-items:center; gap:6px; background:var(--primary); color:var(--on-primary);
  border:none; border-radius:var(--radius-sm); padding:9px 16px; font:inherit; font-size:.9rem; font-weight:500;
  cursor:pointer; transition:opacity .15s,transform .1s;
}
.btn-ink:hover { opacity:.85; }
.btn-ink:active { transform:scale(.98); }
.btn-ink .material-symbols-rounded { font-size:17px; }

/* compact numeric nav pills for the 19 classes */
.navpill--compact { padding:7px 11px; font-variant-numeric:tabular-nums; }

/* hub: about + sources */
.hub-about { max-width:70ch; margin:0 0 28px; }
.hub-about__p { margin:0 0 12px; line-height:1.75; color:var(--on-surface-variant); }
.hub-about__srcs { display:flex; flex-wrap:wrap; align-items:baseline; gap:12px; margin:16px 0 0; }
.hub-src { color:var(--on-surface); font-size:.88rem; font-weight:500; border-bottom:1px solid var(--outline); padding-bottom:1px; }
.hub-src .material-symbols-rounded { font-size:13px; vertical-align:baseline; }
.hub-src:hover { border-bottom-color:var(--on-surface); }
.hub-h2 { font-size:1.45rem; margin:40px 0 16px; color:var(--on-surface); }

/* hub: editorial syllabus list (rows, not a card wall) */
.syllabus { border-top:1px solid var(--outline-variant); }
.syl-row {
  display:flex; align-items:center; gap:18px; padding:16px 6px;
  border-bottom:1px solid var(--outline-variant); transition:background .15s;
}
.syl-row:hover { background:var(--surface-container-high); }
.syl-num {
  font-family:var(--font-mono); font-size:.85rem; color:var(--on-surface-variant);
  min-width:2ch; text-align:right; font-variant-numeric:tabular-nums; flex:0 0 auto;
}
.syl-main { display:flex; flex-direction:column; gap:2px; min-width:0; }
.syl-title { font-family:var(--font-serif); font-size:1.12rem; font-weight:600; letter-spacing:-.01em; color:var(--on-surface); }
.syl-sub { font-size:.88rem; line-height:1.5; color:var(--on-surface-variant); }
.syl-arrow { margin-left:auto; flex:0 0 auto; color:var(--outline); font-size:20px; transition:transform .15s,color .15s; }
.syl-row:hover .syl-arrow { transform:translateX(3px); color:var(--on-surface); }
.grid--tools { grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); }

/* lesson: objectives */
.objectives {
  background:var(--surface-container-high); border:1px solid var(--outline-variant);
  border-radius:var(--radius); padding:22px 26px; margin:0 0 30px;
}
.objectives__h { font-family:var(--font-mono) !important; font-size:.75rem !important; letter-spacing:.14em;
  text-transform:uppercase; color:var(--on-surface-variant); margin:0 0 12px; font-weight:500; }
.objectives__list { list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:9px; }
.objectives__list li { display:flex; gap:10px; align-items:flex-start; line-height:1.55; color:var(--on-surface); }
.objectives__list .material-symbols-rounded { font-size:19px; color:var(--accent-green-fg); margin-top:2px; flex:0 0 auto; }

/* lesson: one-sentence summary callout */
.summary {
  background:var(--accent-yellow-bg); border-radius:var(--radius-sm);
  padding:14px 18px; margin:0 0 18px;
}
.summary__label {
  display:block; font-family:var(--font-mono); font-size:.68rem; letter-spacing:.14em;
  text-transform:uppercase; color:var(--accent-yellow-fg); margin-bottom:4px;
}
.summary__text { margin:0; font-size:.98rem; line-height:1.6; color:var(--on-surface); }

/* lesson: numbered strategy/case cards */
.strat-cards { list-style:none; margin:0 0 18px; padding:0; display:flex; flex-direction:column; gap:10px; counter-reset:strat; }
.strat-card {
  display:flex; gap:14px; align-items:flex-start; background:var(--surface-container);
  border:1px solid var(--outline-variant); border-radius:var(--radius-sm); padding:16px 18px;
}
.strat-card__num {
  font-family:var(--font-mono); font-size:.8rem; font-weight:500; color:var(--on-surface-variant);
  border:1px solid var(--outline-variant); border-radius:50%; width:1.9em; height:1.9em;
  display:inline-grid; place-items:center; flex:0 0 auto; margin-top:2px;
}
.strat-card__title { margin:0 0 4px; font-weight:600; color:var(--on-surface); }
.strat-card__text { margin:0; font-size:.92rem; line-height:1.6; color:var(--on-surface-variant); }

/* lesson: prose tables */
.table-wrap--prose { margin:0 0 18px; }
.table-wrap--prose .data-table th, .table-wrap--prose .data-table td { white-space:normal; }

/* lesson: then-vs-now fact checks */
.facts { display:flex; flex-direction:column; gap:12px; }
.fact { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius-sm); padding:16px 18px; }
.fact__then, .fact__now { margin:0; line-height:1.65; }
.fact__then { color:var(--on-surface-variant); margin-bottom:8px; }
.fact__now { color:var(--on-surface); }
.fact__tag {
  display:inline-block; font-family:var(--font-mono); font-size:.68rem; letter-spacing:.1em;
  border-radius:9999px; padding:2px 10px; margin-right:8px; vertical-align:1px;
  background:var(--surface-variant); color:var(--on-surface-variant);
}
.fact__tag--now { background:var(--accent-green-bg); color:var(--accent-green-fg); }
.fact__src { font-size:.85rem; font-weight:500; color:var(--accent-blue-fg); border-bottom:1px solid currentColor; margin-left:6px; }

/* quiz */
.quiz-hint { margin:0 0 6px; font-size:.92rem; color:var(--on-surface-variant); }
.quiz-score { margin:0 0 16px; font-family:var(--font-mono); font-size:.85rem; color:var(--on-surface); min-height:1.2em; }
.quiz-score--sticky {
  position:sticky; top:104px; z-index:10; display:inline-block;
  background:var(--surface-container-high); border:1px solid var(--outline-variant);
  border-radius:9999px; padding:6px 16px;
}
.quiz-card { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:20px 22px; margin:0 0 14px; }
.quiz-card__q { margin:0 0 14px; font-weight:600; line-height:1.55; color:var(--on-surface); }
.quiz-card__n { font-family:var(--font-mono); font-weight:500; color:var(--on-surface-variant); margin-right:8px; }
.quiz__opts { list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:8px; }
.quiz__opt {
  display:flex; align-items:center; justify-content:space-between; gap:10px; width:100%;
  text-align:left; font:inherit; font-size:.95rem; line-height:1.5; cursor:pointer;
  background:var(--surface); color:var(--on-surface);
  border:1px solid var(--outline-variant); border-radius:var(--radius-sm); padding:11px 15px;
  transition:border-color .15s,background .15s;
}
.quiz__opt:hover:not(:disabled) { border-color:var(--on-surface); }
.quiz__opt:disabled { cursor:default; }
.quiz__opt.is-correct { background:var(--accent-green-bg); border-color:var(--accent-green-fg); color:var(--accent-green-fg); font-weight:500; }
.quiz__opt.is-wrong { background:var(--accent-red-bg); border-color:var(--accent-red-fg); color:var(--accent-red-fg); }
.quiz__opt.is-dim { opacity:.45; }
.quiz__mark { font-size:19px; flex:0 0 auto; }
.quiz__feedback { margin:12px 0 0; font-size:.92rem; line-height:1.6; border-radius:var(--radius-sm); padding:12px 15px; }
.quiz__feedback.is-correct { background:var(--accent-green-bg); color:var(--accent-green-fg); }
.quiz__feedback.is-wrong { background:var(--accent-red-bg); color:var(--accent-red-fg); }
.quiz-group { margin:0 0 34px; }
.quiz-group__h { font-size:1.3rem; margin:0 0 14px; color:var(--on-surface); }

/* glossary: borderless editorial definition rows */
.glossary { margin:0; columns:2; column-gap:40px; }
.gloss { break-inside:avoid; border-bottom:1px solid var(--outline-variant); padding:14px 2px 16px; }
.gloss__term { font-weight:600; font-size:1.02rem; color:var(--on-surface); display:flex; align-items:baseline; gap:10px; flex-wrap:wrap; }
.gloss__cls {
  font-family:var(--font-mono); font-size:.68rem; letter-spacing:.08em; font-weight:400;
  background:var(--accent-blue-bg); color:var(--accent-blue-fg); border-radius:9999px; padding:2px 10px;
}
.gloss__cls:hover { text-decoration:underline; }
.gloss__def { margin:6px 0 0; font-size:.92rem; line-height:1.65; color:var(--on-surface-variant); }

/* flashcards deck */
.deck-hint { margin:0 0 22px; font-size:.92rem; color:var(--on-surface-variant); }
.deck { display:flex; flex-direction:column; align-items:center; gap:18px; }
.deck-stage { width:100%; max-width:560px; perspective:1200px; }
.flip-card { position:relative; width:100%; min-height:280px; cursor:pointer; outline-offset:4px; }
.flip-inner { position:absolute; inset:0; transform-style:preserve-3d; transition:transform .45s cubic-bezier(.2,.7,.2,1); }
.flip-card.is-flipped .flip-inner { transform:rotateY(180deg); }
.flip-face {
  position:absolute; inset:0; backface-visibility:hidden; -webkit-backface-visibility:hidden;
  display:flex; flex-direction:column; align-items:center; justify-content:center; gap:12px; text-align:center;
  background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius);
  padding:32px 36px; box-shadow:var(--elev-1);
}
.flip-face p { margin:0; font-size:1.15rem; line-height:1.6; color:var(--on-surface); }
.flip-front p { font-family:var(--font-serif); font-size:1.35rem; letter-spacing:-.01em; }
.flip-back { transform:rotateY(180deg); background:var(--surface-container-high); }
.flip-label {
  font-family:var(--font-mono); font-size:.68rem; letter-spacing:.14em; text-transform:uppercase;
  color:var(--on-surface-variant);
}
.flip-cls {
  font-family:var(--font-mono); font-size:.7rem; letter-spacing:.08em;
  background:var(--accent-blue-bg); color:var(--accent-blue-fg); border-radius:9999px; padding:2px 10px;
}
.deck-ctrls { display:flex; align-items:center; gap:10px; }
.deck-btn { border:1px solid var(--outline-variant); }
.deck-count { margin:0; font-family:var(--font-mono); font-size:.85rem; color:var(--on-surface-variant); font-variant-numeric:tabular-nums; }

/* prev / next pager */
.pager { display:flex; justify-content:space-between; gap:16px; margin-top:44px; border-top:1px solid var(--outline-variant); padding-top:20px; }
.pager__link { display:flex; flex-direction:column; gap:3px; max-width:46%; }
.pager__link--next { text-align:right; margin-left:auto; }
.pager__dir { font-family:var(--font-mono); font-size:.7rem; letter-spacing:.12em; text-transform:uppercase; color:var(--on-surface-variant); }
.pager__link b { font-family:var(--font-serif); font-size:1.05rem; font-weight:600; letter-spacing:-.01em; color:var(--on-surface); }
.pager__link:hover b { text-decoration:underline; }

/* gentle scroll-entry reveal (lesson sections & syllabus rows) */
@media (prefers-reduced-motion:no-preference) {
  .reveal { opacity:0; transform:translateY(12px); }
  .reveal.reveal--in { opacity:1; transform:none; transition:opacity .6s cubic-bezier(.16,1,.3,1),transform .6s cubic-bezier(.16,1,.3,1); }
}

@media (max-width:860px) {
  .glossary { columns:1; }
  .quiz-score--sticky { position:static; }
}
@media (max-width:600px) {
  .syl-row { gap:12px; padding:14px 2px; }
  .syl-sub { display:none; }
  .flip-card { min-height:320px; }
}