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

/* ---- MD3 tokens : LIGHT ---- */
:root,
[data-theme="light"] {
  --primary:#6A4DFF; --on-primary:#FFFFFF; --primary-container:#E9E1FF; --on-primary-container:#220A66;
  --secondary:#0E9C86; --secondary-container:#CFF5EC; --on-secondary-container:#00352B;
  --tertiary:#E5604D; --tertiary-container:#FFDAD2;
  --background:#FBFAFF; --on-background:#181530; --surface:#FBFAFF;
  --surface-container:#FFFFFF; --surface-container-high:#F2EFFB; --surface-variant:#ECE8F8;
  --on-surface:#181530; --on-surface-variant:#565072;
  --outline:#8A839E; --outline-variant:#E4DEF1; --error:#C0362C; --success:#1E8E5A;
  --elev-1:0 1px 2px rgba(24,21,48,.04),0 6px 18px -10px rgba(24,21,48,.12);
  --elev-2:0 10px 34px -14px rgba(24,21,48,.20);
  --elev-3:0 30px 70px -24px rgba(24,21,48,.32);
  --radius-sm:10px; --radius:18px; --radius-lg:28px;
  --font-display:"Sora","Noto Sans TC",system-ui,sans-serif;
  --font-body:"Plus Jakarta Sans","Noto Sans TC",system-ui,sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,SFMono-Regular,monospace;
  --orb-1:rgba(106,77,255,.16); --orb-2:rgba(14,156,134,.12);
  --glass-bg:rgba(255,255,255,.74); --glass-border:rgba(24,21,48,.08); --hairline:rgba(24,21,48,.07);
  --ease:cubic-bezier(.22,.61,.18,1);
}
/* ---- Tokens : DARK (Ethereal Glass — the default) ---- */
[data-theme="dark"] {
  --primary:#B79CFF; --on-primary:#23115C; --primary-container:#392B66; --on-primary-container:#EADDFF;
  --secondary:#74E6D2; --secondary-container:#123630; --on-secondary-container:#B8F5E9;
  --tertiary:#FFB4A6; --tertiary-container:#5A271E;
  --background:#0A0912; --on-background:#ECEAF6; --surface:#0A0912;
  --surface-container:#16141F; --surface-container-high:#211E2D; --surface-variant:#2B2738;
  --on-surface:#F3F1FA; --on-surface-variant:#B8B2CC;
  --outline:#766F8C; --outline-variant:#322D44; --error:#FFB4AB; --success:#86E0AC;
  --elev-1:0 1px 2px rgba(0,0,0,.4); --elev-2:0 16px 40px -18px rgba(0,0,0,.7);
  --elev-3:0 30px 80px -28px rgba(0,0,0,.8);
  --orb-1:rgba(150,116,255,.22); --orb-2:rgba(86,224,194,.13);
  --glass-bg:rgba(22,20,31,.60); --glass-border:rgba(255,255,255,.09); --hairline:rgba(255,255,255,.07);
}

/* ---- 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; }
/* GitHub star button */
.gh-star { display:inline-flex; align-items:center; gap:6px; flex:0 0 auto; padding:7px 12px; border-radius:var(--radius-lg);
  font-size:.85rem; font-weight:600; color:var(--on-surface); border:1px solid var(--outline-variant); background:transparent;
  transition:background .15s,border-color .15s; }
.gh-star:hover { background:var(--surface-container-high); }
.gh-star .gh-star__icon { font-size:18px; color:#F5B301; font-variation-settings:"FILL" 1,"wght" 400,"GRAD" 0,"opsz" 24; }
.gh-star__count { font-variant-numeric:tabular-nums; }

/* ---- 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:20px; cursor:pointer;
  border:1px solid transparent; transition:box-shadow .18s,transform .18s,border-color .18s; display:flex; flex-direction:column; gap:10px; }
.card:hover,.card:focus-visible { box-shadow:var(--elev-2); transform:translateY(-2px); border-color:var(--outline-variant); 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; }
.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; }
}

/* =========================================================================
   PREMIUM LAYER — "Ethereal Glass" (dark) / "Soft Structuralism" (light)
   Layered on top of the MD3 baseline above; later rules win on equal
   specificity. Pure CSS, no build, GPU-safe (transform + opacity only).
   ========================================================================= */

/* ---- Atmospheric mesh background (fixed, behind everything) ---- */
body::before {
  content:""; position:fixed; inset:0; z-index:-1; pointer-events:none;
  background:
    radial-gradient(60% 50% at 18% 0%, var(--orb-1), transparent 70%),
    radial-gradient(50% 45% at 100% 8%, var(--orb-2), transparent 70%),
    radial-gradient(45% 40% at 50% 100%, var(--orb-1), transparent 75%);
}
body { background:var(--background); }

/* ---- Typography ---- */
h1,h2,h3,.brand__name,.page-head h1,.tl-title,.cmp-plan,.stat-value,.tile__value,.hero__stat-value {
  font-family:var(--font-display); letter-spacing:-.015em;
}
::selection { background:color-mix(in srgb,var(--primary) 30%,transparent); }
.prose code,.prose pre,.quiz-num { font-family:var(--font-mono); }
.material-symbols-rounded { font-variation-settings:"FILL" 0,"wght" 300,"GRAD" 0,"opsz" 24; }

/* ---- Page rhythm: more breathing room ---- */
.page { max-width:1120px; padding:48px 22px 24px; }
.page-head { margin-bottom:30px; }
.page-head h1 { font-size:clamp(2rem,5vw,3.1rem); font-weight:700; line-height:1.05; }
.page-head__sub { font-size:1.06rem; max-width:66ch; line-height:1.65; }

/* hub gets a hero treatment: eyebrow + gradient headline */
.page--hub { padding-top:64px; }
.page--hub .page-head { position:relative; }
.page--hub .page-head::before {
  content:"✦ 06"; display:inline-flex; align-items:center; gap:6px; margin-bottom:16px;
  padding:5px 13px; border-radius:var(--radius-lg); font-family:var(--font-mono); font-size:.7rem;
  letter-spacing:.28em; color:var(--primary); border:1px solid var(--glass-border); background:var(--glass-bg);
}
.page--hub .page-head h1 {
  font-size:clamp(2.4rem,6.5vw,4.2rem); font-weight:800;
  background:linear-gradient(120deg,var(--on-background) 30%,var(--primary) 70%,var(--secondary));
  -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent;
}

/* ---- App bar → floating glass strip ---- */
.appbar { background:var(--glass-bg); backdrop-filter:saturate(180%) blur(16px); -webkit-backdrop-filter:saturate(180%) blur(16px);
  box-shadow:none; border-bottom:1px solid var(--glass-border); }
.brand { font-family:var(--font-display); letter-spacing:-.02em; }
.brand__logo { display:inline-grid; place-items:center; width:32px; height:32px; border-radius:10px; color:var(--on-primary);
  background:linear-gradient(135deg,var(--primary),var(--secondary)); box-shadow:var(--elev-1); }
.icon-btn { border:1px solid transparent; border-radius:var(--radius-lg); }
.icon-btn:hover { background:var(--surface-container-high); border-color:var(--glass-border); }

/* ---- Cross-page nav: glass pills ---- */
.pagenav { top:55px; background:color-mix(in srgb,var(--background) 78%,transparent);
  backdrop-filter:saturate(180%) blur(14px); -webkit-backdrop-filter:saturate(180%) blur(14px);
  border-bottom:1px solid var(--glass-border); }
.navpill { border:1px solid var(--glass-border); background:var(--glass-bg); transition:transform .25s var(--ease),background .25s var(--ease),color .2s,border-color .2s; }
.navpill:hover { transform:translateY(-1px); background:var(--surface-container-high); }
.navpill--active { background:linear-gradient(135deg,var(--primary),var(--secondary)); color:var(--on-primary);
  border-color:transparent; box-shadow:0 6px 18px -8px color-mix(in srgb,var(--primary) 70%,transparent); }
.navpill--active .material-symbols-rounded { color:var(--on-primary); }

/* ---- Cards: glass with hairline + soft lift (double-bezel feel) ---- */
.card,.hero__stat,.stat-card,.tile,.tl-card,.kb-card,.acc-item,.panel,.place,.scrolly-step {
  background:var(--glass-bg); border:1px solid var(--glass-border); backdrop-filter:blur(6px); -webkit-backdrop-filter:blur(6px);
}
.card { border-radius:var(--radius-lg); padding:24px; position:relative; overflow:hidden;
  transition:transform .4s var(--ease),box-shadow .4s var(--ease),border-color .3s; }
.card::after { content:""; position:absolute; inset:0 0 auto 0; height:2px; opacity:0; transition:opacity .3s;
  background:linear-gradient(90deg,var(--primary),var(--secondary)); }
.card:hover,.card:focus-visible { transform:translateY(-5px); box-shadow:var(--elev-2);
  border-color:color-mix(in srgb,var(--primary) 35%,var(--glass-border)); }
.card:hover::after,.card:focus-visible::after { opacity:1; }
.card--nav .card__icon { width:46px; height:46px; display:inline-grid; place-items:center; border-radius:14px; font-size:24px;
  color:var(--primary); background:color-mix(in srgb,var(--primary) 14%,transparent); border:1px solid var(--glass-border); }
.card__title { font-size:1.12rem; }
.tag { background:color-mix(in srgb,var(--primary) 10%,transparent); border:1px solid var(--glass-border); }

/* ---- Hub hero stats ---- */
.hero__stats { gap:16px; margin-bottom:34px; }
.hero__stat { border-radius:var(--radius-lg); padding:24px 22px; }
.hero__stat-value { font-size:2.6rem; font-weight:800;
  background:linear-gradient(135deg,var(--primary),var(--secondary)); -webkit-background-clip:text; background-clip:text; -webkit-text-fill-color:transparent; }

/* ---- Toolbar / search / chips ---- */
.search { border-radius:var(--radius-lg); background:var(--glass-bg); border:1px solid var(--glass-border); padding:12px 16px; }
.search:focus { outline:2px solid var(--primary); }
.chip { border:1px solid var(--glass-border); background:var(--glass-bg); }
.chip--active { background:linear-gradient(135deg,var(--primary),var(--secondary)); color:var(--on-primary); border-color:transparent; }

/* ---- Article prose ---- */
.article-body.prose { max-width:74ch; }
.prose h2 { font-size:1.55rem; letter-spacing:-.02em; }
.prose p,.prose ul { line-height:1.8; font-size:1.02rem; }
.toc__inner { border-left:1px solid var(--outline-variant); }
.toc-link--active { border-left-color:var(--primary); }
.prose blockquote { border-left:none; padding:18px 22px; border-radius:var(--radius); font-style:normal;
  background:color-mix(in srgb,var(--primary) 9%,transparent); border:1px solid var(--glass-border);
  position:relative; color:var(--on-surface); }
.prose blockquote::before { content:"“"; font-family:var(--font-display); font-size:2.4rem; line-height:0; color:var(--primary);
  position:absolute; left:14px; top:22px; opacity:.5; }
.prose blockquote { padding-left:46px; }
.prose pre { background:#0E0C16; border:1px solid var(--glass-border); border-radius:var(--radius); padding:18px 20px; }
.prose pre code { color:#E7E2F5; font-size:.82rem; line-height:1.6; }
[data-theme="light"] .prose pre { background:#14112A; }
[data-theme="light"] .prose pre code { color:#EDEAFB; }

/* ---- Callout (note) ---- */
.callout { display:flex; gap:12px; align-items:flex-start; margin:0 0 16px; padding:16px 18px; border-radius:var(--radius);
  background:color-mix(in srgb,var(--secondary) 12%,transparent); border:1px solid color-mix(in srgb,var(--secondary) 30%,var(--glass-border));
  color:var(--on-surface); line-height:1.7; font-size:.98rem; }
.callout__icon { color:var(--secondary); flex:0 0 auto; margin-top:2px; }

/* ---- Source links list ---- */
.src-links { list-style:none; margin:8px 0 4px; padding:0; display:flex; flex-wrap:wrap; gap:10px; }
.src-link { display:inline-flex; align-items:center; gap:7px; padding:8px 14px 8px 12px; border-radius:var(--radius-lg);
  font-size:.86rem; font-weight:500; color:var(--on-surface); background:var(--glass-bg); border:1px solid var(--glass-border);
  transition:transform .25s var(--ease),border-color .2s,background .2s; }
.src-link .material-symbols-rounded { font-size:16px; color:var(--primary); }
.src-link:hover { transform:translateY(-1px); border-color:color-mix(in srgb,var(--primary) 45%,var(--glass-border));
  background:color-mix(in srgb,var(--primary) 8%,var(--glass-bg)); }

/* ---- Tables ---- */
.table-wrap { border:1px solid var(--glass-border); border-radius:var(--radius-lg); background:var(--glass-bg); backdrop-filter:blur(6px); }
.data-table,.cmp-table { background:transparent; }
.data-table thead th { background:color-mix(in srgb,var(--primary) 8%,transparent); border-bottom:1px solid var(--glass-border); }
.data-table th,.data-table td,.cmp-table th,.cmp-table td { border-bottom:1px solid var(--hairline); }
.data-table tbody tr:hover { background:color-mix(in srgb,var(--primary) 7%,transparent); }
.row-link { color:var(--primary); font-family:var(--font-mono); font-size:.82rem; word-break:break-all; white-space:normal; }

/* ---- Segmented control (practice tabs) ---- */
.seg { background:var(--glass-bg); border:1px solid var(--glass-border); padding:5px; gap:5px; }
.seg__btn { display:inline-flex; align-items:center; gap:7px; }
.seg__btn .material-symbols-rounded { font-size:18px; }
.seg__btn--active { background:linear-gradient(135deg,var(--primary),var(--secondary)); color:var(--on-primary); }
.seg__btn--active .material-symbols-rounded { color:var(--on-primary); }
.practice-view { margin-top:6px; }
.practice-hint { color:var(--on-surface-variant); font-size:.9rem; margin:0 0 16px; }

/* ---- Glossary ---- */
.glossary { display:grid; grid-template-columns:repeat(auto-fill,minmax(300px,1fr)); gap:14px; margin:0; }
.gloss-item { background:var(--glass-bg); border:1px solid var(--glass-border); border-radius:var(--radius); padding:16px 18px; }
.gloss-term { margin:0 0 6px; font-family:var(--font-display); font-weight:600; color:var(--on-surface); font-size:1rem; }
.gloss-def { margin:0; font-size:.9rem; line-height:1.6; color:var(--on-surface-variant); }

/* ---- Flashcards (3D flip) ---- */
.flash-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(240px,1fr)); gap:16px; }
.flip-card { background:transparent; border:none; padding:0; cursor:pointer; perspective:1200px; height:170px; font:inherit; text-align:left; }
.flip-card__inner { display:block; position:relative; width:100%; height:100%; transition:transform .6s var(--ease); transform-style:preserve-3d; }
.flip-card.flipped .flip-card__inner { transform:rotateY(180deg); }
.flip-face { position:absolute; inset:0; display:flex; align-items:center; justify-content:center; text-align:center;
  padding:20px; border-radius:var(--radius-lg); border:1px solid var(--glass-border); backface-visibility:hidden; -webkit-backface-visibility:hidden; }
.flip-face--front { background:var(--glass-bg); font-family:var(--font-display); font-weight:600; font-size:1.1rem; color:var(--on-surface); }
.flip-face--front::after { content:"⤿"; position:absolute; right:14px; bottom:10px; color:var(--primary); font-size:1rem; opacity:.6; }
.flip-face--back { background:linear-gradient(140deg,color-mix(in srgb,var(--primary) 22%,var(--surface-container)),var(--surface-container));
  color:var(--on-surface); font-size:.9rem; line-height:1.55; transform:rotateY(180deg); }
.flip-card:focus-visible { outline:2px solid var(--primary); outline-offset:3px; border-radius:var(--radius-lg); }

/* ---- Quiz ---- */
.quiz-score { display:inline-block; font-family:var(--font-mono); font-weight:600; color:var(--on-surface);
  background:var(--glass-bg); border:1px solid var(--glass-border); border-radius:var(--radius-lg); padding:8px 16px; margin-bottom:20px; }
.quiz-list { list-style:none; margin:0; padding:0; display:flex; flex-direction:column; gap:18px; }
.quiz-item { background:var(--glass-bg); border:1px solid var(--glass-border); border-radius:var(--radius-lg); padding:20px 22px; }
.quiz-q { margin:0 0 14px; font-family:var(--font-display); font-weight:600; font-size:1.05rem; line-height:1.5; color:var(--on-surface);
  display:flex; gap:10px; align-items:baseline; }
.quiz-num { flex:0 0 auto; width:1.7em; height:1.7em; display:inline-grid; place-items:center; border-radius:8px; font-size:.7rem;
  color:var(--primary); background:color-mix(in srgb,var(--primary) 14%,transparent); }
.quiz-opts { display:grid; gap:10px; }
.quiz-opt { text-align:left; padding:12px 16px; border-radius:var(--radius); border:1px solid var(--glass-border); background:var(--surface-container);
  color:var(--on-surface); font:inherit; cursor:pointer; transition:transform .2s var(--ease),border-color .2s,background .2s; }
.quiz-opt:hover:not(:disabled) { transform:translateX(3px); border-color:color-mix(in srgb,var(--primary) 45%,var(--glass-border)); }
.quiz-opt:disabled { cursor:default; }
.quiz-opt--correct { background:color-mix(in srgb,var(--success) 20%,transparent); border-color:var(--success); color:var(--on-surface); font-weight:600; }
.quiz-opt--wrong { background:color-mix(in srgb,var(--error) 16%,transparent); border-color:var(--error); }
.quiz-explain { margin:14px 0 0; padding:12px 14px; border-radius:var(--radius); font-size:.9rem; line-height:1.6;
  color:var(--on-surface-variant); background:color-mix(in srgb,var(--primary) 7%,transparent); border:1px solid var(--glass-border); }

/* ---- Dialog ---- */
.dialog { background:var(--surface-container-high); border:1px solid var(--glass-border); border-radius:var(--radius-lg); }
.dialog::backdrop { background:color-mix(in srgb,var(--background) 55%,rgba(0,0,0,.6)); backdrop-filter:blur(4px); }

/* ---- Footer ---- */
.footer { border-top:1px solid var(--glass-border); font-family:var(--font-mono); letter-spacing:.02em; }

/* ---- Scroll/entry reveal (load entrance, GPU-safe) ---- */
@keyframes ldwRise { from { opacity:0; transform:translateY(20px); } to { opacity:1; transform:none; } }
.page [data-item] { animation:ldwRise .7s var(--ease) both; }
.page [data-item]:nth-child(2) { animation-delay:.05s; }
.page [data-item]:nth-child(3) { animation-delay:.10s; }
.page [data-item]:nth-child(4) { animation-delay:.15s; }
.page [data-item]:nth-child(5) { animation-delay:.20s; }
.page [data-item]:nth-child(n+6) { animation-delay:.25s; }

/* ---- Overflow containment: let grid/flex children shrink so <pre> scrolls
        internally instead of widening the page (CSS min-width:auto gotcha). ---- */
.article-layout, .article-body, .prose { min-width:0; }
.prose pre { max-width:100%; }
.callout, .quiz-item, .gloss-item { min-width:0; }
.callout span { min-width:0; overflow-wrap:anywhere; }
.src-link { max-width:100%; overflow:hidden; text-overflow:ellipsis; }

/* ---- Responsive (premium layer) ---- */
@media (max-width:600px) {
  .page { padding:32px 16px 16px; }
  .page--hub .page-head h1 { font-size:2.2rem; }
  .flash-grid { grid-template-columns:1fr; }
  .glossary { grid-template-columns:1fr; }
  .seg { display:flex; width:100%; }
  .seg__btn { flex:1 1 0; min-width:0; justify-content:center; padding:9px 6px; }
  .seg__btn .material-symbols-rounded { display:none; }
  .quiz-q { font-size:.98rem; }
}

/* ---- Respect reduced motion: no entrance animation ---- */
@media (prefers-reduced-motion:reduce) {
  .page [data-item] { animation:none !important; opacity:1 !important; transform:none !important; }
  .flip-card__inner,.card,.navpill,.quiz-opt,.src-link { transition:none !important; }
}