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

/* ---- MD3 tokens : LIGHT (Cloudflare-orange theme) ---- */
:root,
[data-theme="light"] {
  --primary:#C2410C; --on-primary:#FFFFFF; --primary-container:#FFDBC8; --on-primary-container:#4C1A00;
  --secondary:#9A5B3B; --secondary-container:#FFDCC2; --on-secondary-container:#5A2600;
  --tertiary:#1565C0; --tertiary-container:#D6E7FF; --on-tertiary-container:#001B3D;
  --background:#FFF8F4; --on-background:#211A15; --surface:#FFF8F4;
  --surface-container:#F8EEE7; --surface-container-high:#F1E6DD; --surface-variant:#EFDFD3;
  --on-surface:#211A15; --on-surface-variant:#52443B;
  --outline:#85736A; --outline-variant:#D8C5B8; --error:#B3261E; --success:#2E7D32;
  --brand:#F6821F; --brand-2:#FBAD41; --code-bg:#2B2118; --code-fg:#F4E8DD;
  --elev-1:0 1px 2px rgba(120,60,10,.10),0 1px 3px 1px rgba(120,60,10,.06);
  --elev-2:0 2px 6px 2px rgba(120,60,10,.10),0 1px 2px rgba(120,60,10,.12);
  --elev-3:0 4px 8px 3px rgba(120,60,10,.12),0 1px 3px rgba(120,60,10,.14);
  --radius-sm:8px; --radius:16px; --radius-lg:28px;
  --font-body:"Roboto Flex","Roboto","Noto Sans TC",system-ui,sans-serif;
  --font-mono:"Roboto Mono",ui-monospace,SFMono-Regular,Menlo,monospace;
}
/* ---- MD3 tokens : DARK (Cloudflare-orange theme) ---- */
[data-theme="dark"] {
  --primary:#FFB68F; --on-primary:#5A2600; --primary-container:#7C3A12; --on-primary-container:#FFDBC8;
  --secondary:#E6BCA3; --secondary-container:#5C3A23; --on-secondary-container:#FFDCC2;
  --tertiary:#A6C8FF; --tertiary-container:#0B4A87; --on-tertiary-container:#D6E7FF;
  --background:#1A120D; --on-background:#EFE0D6; --surface:#1A120D;
  --surface-container:#271C15; --surface-container-high:#33271F; --surface-variant:#52443B;
  --on-surface:#EFE0D6; --on-surface-variant:#D7C3B6;
  --outline:#A08D81; --outline-variant:#52443B; --error:#F2B8B5; --success:#A5D6A7;
  --brand:#F6821F; --brand-2:#FBAD41; --code-bg:#120C08; --code-fg:#F4E8DD;
}

/* ---- 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: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; }
}

/* =========================================================================
   Cloudflare learning site — custom layouts
   (home · category · lesson · glossary · quiz · flashcards)
   ========================================================================= */

/* brand pop */
.brand__logo { color:var(--brand) !important; }

/* GitHub star button (appbar, top-right) */
.gh-star { display:inline-flex; align-items:center; gap:6px; padding:6px 11px; border-radius:var(--radius-lg);
  border:1px solid var(--outline-variant); background:var(--surface); color:var(--on-surface);
  font-size:.82rem; font-weight:600; line-height:1; cursor:pointer;
  transition:background .15s,color .15s,border-color .15s,transform .15s; }
.gh-star:hover,.gh-star:focus-visible { background:var(--brand); color:#fff; border-color:transparent; transform:translateY(-1px); outline:none; }
.gh-star__mark { fill:currentColor; flex:0 0 auto; }
.gh-star__count { display:inline-flex; align-items:center; gap:3px; font-variant-numeric:tabular-nums; }
.gh-star__count .material-symbols-rounded { font-size:16px; color:#F6B100; }
.gh-star:hover .gh-star__count .material-symbols-rounded,
.gh-star:focus-visible .gh-star__count .material-symbols-rounded { color:#fff; }
@media (max-width:420px){ .gh-star { padding:6px 9px; } .gh-star__count b { display:none; } }

/* ---- reveal-on-scroll ---- */
.reveal { opacity:0; transform:translateY(14px); transition:opacity .5s ease,transform .5s ease; }
.reveal.is-in { opacity:1; transform:none; }
@media (prefers-reduced-motion:reduce){ .reveal{ opacity:1; transform:none; } }

/* ---- big hero banner (home / category / lesson) ---- */
.lhero {
  position:relative; overflow:hidden; border-radius:var(--radius-lg);
  background:linear-gradient(135deg,var(--brand) 0%,#E8590C 55%,#9A3412 100%);
  color:#fff; padding:34px 30px; margin-bottom:26px; box-shadow:var(--elev-2);
}
.lhero::after { content:""; position:absolute; right:-60px; top:-60px; width:260px; height:260px;
  background:radial-gradient(circle,rgba(255,255,255,.22),transparent 70%); pointer-events:none; }
.lhero__badge { display:inline-flex; align-items:center; gap:6px; background:rgba(255,255,255,.22);
  color:#fff; font-size:.78rem; font-weight:600; padding:5px 12px; border-radius:var(--radius-lg); margin-bottom:14px; backdrop-filter:blur(4px); }
.lhero__badge .material-symbols-rounded { font-size:17px; }
.lhero__top { display:flex; align-items:center; gap:18px; }
.lhero__icon { flex:0 0 auto; width:64px; height:64px; display:grid; place-items:center; border-radius:20px;
  background:rgba(255,255,255,.18); border:1px solid rgba(255,255,255,.3); }
.lhero__icon .material-symbols-rounded { font-size:38px; color:#fff; }
.lhero__title { margin:0; font-size:clamp(1.7rem,4.5vw,2.5rem); font-weight:700; letter-spacing:-.02em; line-height:1.1; }
.lhero__tagline { margin:12px 0 0; font-size:1.05rem; line-height:1.55; max-width:64ch; color:rgba(255,255,255,.94); }
.lhero__stats { display:flex; flex-wrap:wrap; gap:26px; margin-top:22px; }
.lhero__stat b { display:block; font-size:1.7rem; font-weight:700; line-height:1.1; font-variant-numeric:tabular-nums; }
.lhero__stat span { font-size:.82rem; color:rgba(255,255,255,.85); }

/* ---- intro lead / section copy ---- */
.lead { font-size:1.12rem; line-height:1.7; color:var(--on-surface); margin:0 0 16px; }
.muted { color:var(--on-surface-variant); }

/* ---- HOME: section heading, category grid, tools ---- */
.home-section { margin:34px 0 14px; }
.home-section__title { display:flex; align-items:center; gap:10px; font-size:1.3rem; font-weight:700; color:var(--on-surface); margin:0 0 4px; }
.home-section__title .material-symbols-rounded { color:var(--brand); }
.home-section__sub { margin:0 0 16px; color:var(--on-surface-variant); font-size:.95rem; }

.cat-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(300px,1fr)); gap:16px; }
.cat-card { display:flex; flex-direction:column; gap:12px; background:var(--surface-container);
  border:1px solid var(--outline-variant); border-radius:var(--radius-lg); padding:22px; position:relative; overflow:hidden;
  transition:box-shadow .18s,transform .18s,border-color .18s; }
.cat-card:hover,.cat-card:focus-visible { box-shadow:var(--elev-2); transform:translateY(-3px); border-color:var(--brand); outline:none; }
.cat-card::before { content:""; position:absolute; left:0; top:0; bottom:0; width:5px; background:var(--brand); }
.cat-card__head { display:flex; align-items:center; gap:12px; }
.cat-card__icon { width:48px; height:48px; flex:0 0 auto; display:grid; place-items:center; border-radius:14px;
  background:var(--primary-container); color:var(--on-primary-container); }
.cat-card__icon .material-symbols-rounded { font-size:28px; }
.cat-card__name { margin:0; font-size:1.18rem; font-weight:700; color:var(--on-surface); }
.cat-card__count { font-size:.78rem; color:var(--on-surface-variant); }
.cat-card__blurb { margin:0; font-size:.92rem; line-height:1.55; color:var(--on-surface-variant); }
.cat-card__chips { margin-top:auto; display:flex; flex-wrap:wrap; gap:6px; }
.prodchip { font-size:.74rem; font-weight:500; color:var(--on-secondary-container); background:var(--secondary-container);
  padding:3px 10px; border-radius:var(--radius-lg); border:1px solid transparent; transition:background .15s; }
.prodchip:hover { background:var(--brand); color:#fff; }
.cat-card__more { font-size:.8rem; font-weight:600; color:var(--primary); display:inline-flex; align-items:center; gap:3px; }

.tools-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); gap:14px; }
.tool-card { display:flex; align-items:center; gap:14px; background:var(--surface-container); border:1px solid var(--outline-variant);
  border-radius:var(--radius); padding:18px; transition:box-shadow .18s,transform .18s,border-color .18s; }
.tool-card:hover,.tool-card:focus-visible { box-shadow:var(--elev-2); transform:translateY(-2px); border-color:var(--brand); outline:none; }
.tool-card__icon { width:44px; height:44px; flex:0 0 auto; display:grid; place-items:center; border-radius:12px; background:var(--tertiary-container); color:var(--on-tertiary-container); }
.tool-card__icon .material-symbols-rounded { font-size:26px; }
.tool-card__t { margin:0; font-weight:700; color:var(--on-surface); font-size:1rem; }
.tool-card__d { margin:2px 0 0; font-size:.82rem; color:var(--on-surface-variant); line-height:1.4; }

/* ---- CATEGORY: product card grid ---- */
.prod-card { display:flex; flex-direction:column; gap:10px; background:var(--surface-container);
  border:1px solid var(--outline-variant); border-radius:var(--radius); padding:20px; position:relative;
  transition:box-shadow .18s,transform .18s,border-color .18s; }
.prod-card:hover,.prod-card:focus-visible { box-shadow:var(--elev-2); transform:translateY(-3px); border-color:var(--brand); outline:none; }
.prod-card__head { display:flex; align-items:center; gap:12px; }
.prod-card__icon { width:46px; height:46px; flex:0 0 auto; display:grid; place-items:center; border-radius:13px;
  background:var(--primary-container); color:var(--on-primary-container); }
.prod-card__icon .material-symbols-rounded { font-size:27px; }
.prod-card__name { margin:0; font-size:1.1rem; font-weight:700; color:var(--on-surface); }
.prod-card__sub { margin:0; font-size:.9rem; line-height:1.5; color:var(--on-surface-variant); }
.prod-card__go { margin-top:auto; font-size:.82rem; font-weight:600; color:var(--primary); display:inline-flex; align-items:center; gap:3px; }

/* ---- LESSON ---- */
.lesson-layout { display:grid; grid-template-columns:210px 1fr; gap:36px; align-items:start; }
.lesson-toc { position:sticky; top:112px; }
.lesson-toc__inner { display:flex; flex-direction:column; gap:2px; border-left:2px solid var(--outline-variant); }
.lesson-toc a { display:flex; align-items:center; gap:8px; padding:7px 14px; font-size:.88rem; color:var(--on-surface-variant);
  border-left:2px solid transparent; margin-left:-2px; }
.lesson-toc a .material-symbols-rounded { font-size:18px; }
.lesson-toc a:hover { color:var(--on-surface); }
.lesson-toc a.is-active { color:var(--primary); border-left-color:var(--brand); font-weight:600; }
.lesson-body { min-width:0; max-width:760px; }
.lsec { margin-bottom:34px; scroll-margin-top:120px; }
.lsec__head { display:flex; align-items:center; gap:12px; margin:0 0 14px; }
.lsec__icon { width:40px; height:40px; flex:0 0 auto; display:grid; place-items:center; border-radius:11px;
  background:var(--primary-container); color:var(--on-primary-container); }
.lsec__icon .material-symbols-rounded { font-size:24px; }
.lsec__head h2 { margin:0; font-size:1.4rem; font-weight:700; color:var(--on-surface); letter-spacing:-.01em; }
.lsec p { line-height:1.75; color:var(--on-surface-variant); margin:0 0 14px; }
.lsec h3 { color:var(--on-surface); font-size:1.1rem; margin:20px 0 8px; }
.lsec ul { margin:0 0 16px; padding-left:4px; list-style:none; display:flex; flex-direction:column; gap:8px; }
.lsec ul li { position:relative; padding-left:28px; line-height:1.65; color:var(--on-surface-variant); }
.lsec ul li::before { content:"check_circle"; font-family:"Material Symbols Rounded"; position:absolute; left:0; top:1px;
  color:var(--brand); font-size:19px; }
.lsec blockquote { margin:0 0 16px; padding:12px 20px; border-left:4px solid var(--brand);
  background:var(--surface-container); border-radius:0 var(--radius) var(--radius) 0; color:var(--on-surface); font-style:italic; line-height:1.7; }
/* prevent long unbreakable tokens (keys, URLs, IDs) from overflowing on narrow screens */
.lsec p, .lsec li, .lead, .callout__text, .callout__title, .icard__d, .icard__t,
.step__t, .step__d, .gloss-def, .gloss-item > summary, .cat-card__blurb,
.prod-card__sub, .lhero__tagline, .quiz-q, .quiz-explain, .fc__def, .fc__term {
  overflow-wrap:anywhere; word-break:break-word;
}

/* callouts */
.callout { display:flex; gap:14px; padding:16px 18px; border-radius:var(--radius); margin:0 0 18px;
  background:var(--surface-container); border:1px solid var(--outline-variant); border-left:4px solid var(--brand); }
.callout__icon { flex:0 0 auto; color:var(--brand); }
.callout__icon .material-symbols-rounded { font-size:24px; }
.callout__body { min-width:0; }
.callout__title { font-weight:700; color:var(--on-surface); margin:0 0 4px; }
.callout__text { margin:0; line-height:1.65; color:var(--on-surface-variant); }
.callout--analogy { border-left-color:#1565C0; } .callout--analogy .callout__icon { color:#1565C0; }
.callout--tip { border-left-color:var(--success); } .callout--tip .callout__icon { color:var(--success); }
.callout--warn { border-left-color:var(--error); } .callout--warn .callout__icon { color:var(--error); }
.callout--note { border-left-color:var(--secondary); } .callout--note .callout__icon { color:var(--secondary); }
[data-theme="dark"] .callout--analogy { border-left-color:#A6C8FF; } [data-theme="dark"] .callout--analogy .callout__icon { color:#A6C8FF; }

/* icon-card grid */
.icards { display:grid; grid-template-columns:repeat(auto-fill,minmax(220px,1fr)); gap:14px; margin:0 0 18px; }
.icard { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); padding:16px; }
.icard__icon { width:38px; height:38px; display:grid; place-items:center; border-radius:10px;
  background:var(--primary-container); color:var(--on-primary-container); margin-bottom:10px; }
.icard__icon .material-symbols-rounded { font-size:22px; }
.icard__t { margin:0 0 4px; font-weight:700; color:var(--on-surface); font-size:.98rem; }
.icard__d { margin:0; font-size:.85rem; line-height:1.55; color:var(--on-surface-variant); }

/* steps */
.steps { list-style:none; margin:0 0 18px; padding:0; counter-reset:step; display:flex; flex-direction:column; gap:14px; }
.step { position:relative; padding-left:48px; }
.step::before { counter-increment:step; content:counter(step); position:absolute; left:0; top:0; width:32px; height:32px;
  display:grid; place-items:center; border-radius:50%; background:var(--brand); color:#fff; font-weight:700; font-size:.95rem; }
.step::after { content:""; position:absolute; left:15px; top:34px; bottom:-14px; width:2px; background:var(--outline-variant); }
.step:last-child::after { display:none; }
.step__t { margin:4px 0 4px; font-weight:700; color:var(--on-surface); }
.step__d { margin:0 0 8px; line-height:1.65; color:var(--on-surface-variant); }

/* code block with copy */
.codeblock { margin:0 0 18px; border-radius:var(--radius); overflow:hidden; border:1px solid var(--outline-variant); box-shadow:var(--elev-1); }
.codeblock__bar { display:flex; align-items:center; gap:8px; padding:8px 12px; background:var(--surface-container-high);
  border-bottom:1px solid var(--outline-variant); }
.codeblock__dot { width:11px; height:11px; border-radius:50%; flex:0 0 auto; }
.codeblock__lang { font-family:var(--font-mono); font-size:.75rem; color:var(--on-surface-variant); margin-left:4px; }
.codeblock__name { font-size:.78rem; color:var(--on-surface-variant); margin-right:10px; font-family:var(--font-mono); }
.copy-btn { display:inline-flex; align-items:center; gap:4px; border:1px solid var(--outline-variant); background:var(--surface);
  color:var(--on-surface-variant); border-radius:var(--radius-lg); padding:4px 10px; font:inherit; font-size:.74rem; cursor:pointer; transition:background .15s,color .15s; }
.copy-btn:hover { background:var(--brand); color:#fff; border-color:transparent; }
.copy-btn .material-symbols-rounded { font-size:15px; }
.codeblock pre { margin:0; padding:16px; overflow:auto; background:var(--code-bg); }
.codeblock code { font-family:var(--font-mono); font-size:.84rem; line-height:1.6; color:var(--code-fg); white-space:pre; }

/* mermaid diagram blocks */
.diagram { margin:0 0 18px; background:var(--surface-container); border:1px solid var(--outline-variant);
  border-radius:var(--radius); padding:18px; overflow-x:auto; }
.diagram__title { margin:0 0 12px; font-weight:600; color:var(--on-surface); font-size:.95rem; display:flex; align-items:center; gap:6px; }
.diagram__title .material-symbols-rounded { color:var(--brand); font-size:20px; }
.mermaid-block { display:flex; justify-content:center; min-height:30px; }
.mermaid-block svg { max-width:100%; height:auto; }
.diagram-fallback { margin:0; font-family:var(--font-mono); font-size:.78rem; line-height:1.5;
  color:var(--on-surface-variant); white-space:pre; overflow-x:auto; }
.group-count { font-size:.78rem; font-weight:600; color:var(--on-secondary-container);
  background:var(--secondary-container); padding:1px 9px; border-radius:var(--radius-lg); }
.prodchip--more { background:var(--primary-container); color:var(--on-primary-container); font-weight:600; }
.prodchip--more:hover { background:var(--brand); color:#fff; }

/* related + docs */
.lesson-foot { margin-top:30px; padding-top:22px; border-top:1px solid var(--outline-variant); }
.lesson-foot__label { font-size:.82rem; font-weight:600; color:var(--on-surface-variant); margin:0 0 10px; text-transform:uppercase; letter-spacing:.05em; }
.related { display:flex; flex-wrap:wrap; gap:10px; margin-bottom:20px; }
.related a { display:inline-flex; align-items:center; gap:6px; background:var(--surface-container); border:1px solid var(--outline-variant);
  border-radius:var(--radius-lg); padding:8px 14px; font-size:.88rem; font-weight:500; color:var(--on-surface); transition:background .15s,border-color .15s; }
.related a:hover { background:var(--primary-container); border-color:var(--brand); }
.related a .material-symbols-rounded { font-size:18px; color:var(--primary); }
.docs-btn { display:inline-flex; align-items:center; gap:8px; background:var(--brand); color:#fff; font-weight:600;
  padding:11px 20px; border-radius:var(--radius-lg); transition:filter .15s,transform .15s; box-shadow:var(--elev-1); }
.docs-btn:hover { filter:brightness(1.05); transform:translateY(-1px); }
.docs-btn .material-symbols-rounded { font-size:19px; }

/* ---- GLOSSARY ---- */
.gloss-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(300px,1fr)); gap:14px; }
.gloss-item { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius); overflow:hidden; }
.gloss-item > summary { display:flex; align-items:center; gap:10px; padding:15px 16px; cursor:pointer; list-style:none; font-weight:700; color:var(--on-surface); }
.gloss-item > summary::-webkit-details-marker { display:none; }
.gloss-item > summary .gloss-cat { margin-left:auto; font-size:.68rem; font-weight:600; color:var(--on-secondary-container);
  background:var(--secondary-container); padding:2px 8px; border-radius:var(--radius-lg); white-space:nowrap; }
.gloss-item > summary .material-symbols-rounded.gloss-chevron { color:var(--on-surface-variant); transition:transform .2s; font-size:20px; }
.gloss-item[open] .gloss-chevron { transform:rotate(180deg); }
.gloss-def { padding:0 16px 16px; line-height:1.65; color:var(--on-surface-variant); font-size:.92rem; }
.gloss-empty { padding:24px; text-align:center; color:var(--on-surface-variant); }

/* ---- QUIZ ---- */
.quiz { max-width:680px; }
.quiz-top { display:flex; align-items:center; justify-content:space-between; gap:12px; margin-bottom:16px; flex-wrap:wrap; }
.quiz-progress { font-size:.85rem; color:var(--on-surface-variant); font-weight:600; }
.quiz-score { font-size:.85rem; font-weight:700; color:var(--primary); background:var(--primary-container); padding:5px 14px; border-radius:var(--radius-lg); }
.quiz-bar { height:6px; border-radius:99px; background:var(--surface-variant); overflow:hidden; margin-bottom:22px; }
.quiz-bar__fill { height:100%; background:var(--brand); width:0; transition:width .3s; }
.quiz-card { background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius-lg); padding:24px; }
.quiz-q { font-size:1.18rem; font-weight:700; color:var(--on-surface); margin:0 0 18px; line-height:1.5; }
.quiz-opts { display:flex; flex-direction:column; gap:10px; }
.quiz-opt { display:flex; align-items:center; gap:12px; text-align:left; width:100%; background:var(--surface);
  border:1.5px solid var(--outline-variant); border-radius:var(--radius); padding:14px 16px; font:inherit; font-size:.96rem;
  color:var(--on-surface); cursor:pointer; transition:background .15s,border-color .15s; }
.quiz-opt:hover:not(:disabled) { border-color:var(--brand); background:var(--surface-container-high); }
.quiz-opt:disabled { cursor:default; }
.quiz-opt__mark { width:26px; height:26px; flex:0 0 auto; display:grid; place-items:center; border-radius:50%;
  border:2px solid var(--outline); font-weight:700; font-size:.85rem; color:var(--on-surface-variant); }
.quiz-opt--correct { border-color:var(--success); background:color-mix(in srgb,var(--success) 14%,transparent); }
.quiz-opt--correct .quiz-opt__mark { border-color:var(--success); background:var(--success); color:#fff; }
.quiz-opt--wrong { border-color:var(--error); background:color-mix(in srgb,var(--error) 12%,transparent); }
.quiz-opt--wrong .quiz-opt__mark { border-color:var(--error); background:var(--error); color:#fff; }
.quiz-explain { margin:16px 0 0; padding:14px 16px; border-radius:var(--radius); background:var(--surface-container-high);
  border-left:4px solid var(--brand); line-height:1.6; color:var(--on-surface-variant); font-size:.92rem; }
.quiz-explain b { color:var(--on-surface); }
.quiz-nav { display:flex; justify-content:flex-end; gap:10px; margin-top:18px; }
.quiz-btn { display:inline-flex; align-items:center; gap:6px; background:var(--brand); color:#fff; border:none; font:inherit; font-weight:600;
  padding:11px 22px; border-radius:var(--radius-lg); cursor:pointer; transition:filter .15s,transform .15s; }
.quiz-btn:hover { filter:brightness(1.05); transform:translateY(-1px); }
.quiz-btn--ghost { background:transparent; color:var(--primary); border:1px solid var(--outline-variant); }
.quiz-btn:disabled { opacity:.4; cursor:not-allowed; transform:none; filter:none; }
.quiz-result { text-align:center; padding:30px 20px; }
.quiz-result__ring { font-size:3rem; font-weight:800; color:var(--brand); }
.quiz-result__msg { margin:8px 0 20px; color:var(--on-surface-variant); }

/* ---- FLASHCARDS ---- */
.fc-tip { font-size:.85rem; color:var(--on-surface-variant); margin:0 0 16px; display:flex; align-items:center; gap:6px; }
.fc-tip .material-symbols-rounded { font-size:18px; color:var(--brand); }
.fc-grid { display:grid; grid-template-columns:repeat(auto-fill,minmax(240px,1fr)); gap:16px; }
.fc { perspective:1200px; height:190px; cursor:pointer; border:none; background:none; padding:0; font:inherit; text-align:inherit; }
.fc__inner { position:relative; width:100%; height:100%; transition:transform .5s; transform-style:preserve-3d; }
.fc.is-flipped .fc__inner { transform:rotateY(180deg); }
.fc__face { position:absolute; inset:0; backface-visibility:hidden; -webkit-backface-visibility:hidden; border-radius:var(--radius);
  padding:20px; display:flex; flex-direction:column; align-items:center; justify-content:center; text-align:center; gap:8px;
  border:1px solid var(--outline-variant); overflow:auto; }
.fc__front { background:var(--surface-container); }
.fc__front .fc__term { font-size:1.15rem; font-weight:700; color:var(--on-surface); }
.fc__hint { font-size:.72rem; color:var(--on-surface-variant); display:inline-flex; align-items:center; gap:4px; }
.fc__hint .material-symbols-rounded { font-size:15px; }
.fc__back { background:linear-gradient(135deg,var(--primary-container),var(--secondary-container)); color:var(--on-primary-container);
  transform:rotateY(180deg); }
.fc__back .fc__def { font-size:.92rem; line-height:1.55; }
@media (prefers-reduced-motion:reduce){ .fc__inner{ transition:none; } }

/* ---- shared responsive for custom layouts ---- */
@media (max-width:860px){
  .lesson-layout { grid-template-columns:1fr; }
  .lesson-toc { position:static; }
  .lesson-toc__inner { flex-direction:row; flex-wrap:wrap; border-left:none; gap:6px; }
  .lesson-toc a { border-left:none; border:1px solid var(--outline-variant); border-radius:var(--radius-lg); margin-left:0; }
  .lesson-toc a.is-active { border-color:var(--brand); }
}
@media (max-width:600px){
  .lhero { padding:24px 20px; }
  .lhero__stats { gap:18px; }
  .icards,.cat-grid,.gloss-grid,.tools-grid,.fc-grid { grid-template-columns:1fr; }
}

/* =========================================================================
   Arcade mini-games
   ========================================================================= */
.gamebox { max-width:760px; }
.game-bar { display:flex; align-items:center; gap:10px; flex-wrap:wrap; margin-bottom:14px; }
.game-stat { font-size:.85rem; font-weight:600; color:var(--on-surface-variant); }
.game-win { display:inline-flex; align-items:center; gap:6px; font-weight:700; color:var(--success); }
.game-win .material-symbols-rounded { color:var(--success); }
.game-btn { display:inline-flex; align-items:center; gap:6px; background:var(--brand); color:#fff; border:none; font:inherit; font-weight:600;
  padding:10px 18px; border-radius:var(--radius-lg); cursor:pointer; transition:filter .15s,transform .15s; }
.game-btn:hover { filter:brightness(1.05); transform:translateY(-1px); }
.game-btn--ghost { background:transparent; color:var(--primary); border:1px solid var(--outline-variant); margin-left:auto; }
.game-btn .material-symbols-rounded { font-size:18px; }
.hearts { display:inline-flex; gap:2px; }
.hearts .heart { color:var(--error); font-size:20px; font-variation-settings:"FILL" 1; }
.hearts .heart--lost { color:var(--outline-variant); font-variation-settings:"FILL" 0; }
.timer-track { height:6px; border-radius:99px; background:var(--surface-variant); overflow:hidden; margin-bottom:18px; }
.timer-fill { display:block; height:100%; background:linear-gradient(90deg,var(--brand),var(--brand-2)); width:100%; transition:width .1s linear; }
.game-result { text-align:center; padding:28px 18px; background:var(--surface-container); border:1px solid var(--outline-variant); border-radius:var(--radius-lg); }
.game-result__icon { font-size:46px; color:var(--brand); font-variation-settings:"FILL" 1; }
.game-result__big { font-size:2.6rem; font-weight:800; color:var(--brand); font-variant-numeric:tabular-nums; }
.game-result p { color:var(--on-surface-variant); margin:6px 0 18px; }

/* match (連連看) */
.match { display:grid; grid-template-columns:1fr 1fr; gap:14px; }
.match-col { display:flex; flex-direction:column; gap:10px; }
.match-item { text-align:left; background:var(--surface-container); border:1.5px solid var(--outline-variant); border-radius:var(--radius);
  padding:13px 15px; font:inherit; font-size:.92rem; color:var(--on-surface); cursor:pointer; transition:background .15s,border-color .15s,transform .1s; }
.match-item:hover:not(:disabled) { border-color:var(--brand); }
.match-item.is-sel { border-color:var(--brand); background:var(--primary-container); color:var(--on-primary-container); }
.match-item.is-done { border-color:var(--success); background:color-mix(in srgb,var(--success) 14%,transparent); cursor:default; opacity:.9; }
.match-item.is-wrong { border-color:var(--error); background:color-mix(in srgb,var(--error) 12%,transparent); animation:shake .35s; }
@keyframes shake { 0%,100%{transform:translateX(0);} 25%{transform:translateX(-5px);} 75%{transform:translateX(5px);} }

/* memory (記憶翻牌) */
.mem-grid { display:grid; grid-template-columns:repeat(4,1fr); gap:12px; }
.mem-card { position:relative; aspect-ratio:3/4; border:none; background:none; padding:0; cursor:pointer; perspective:800px; }
.mem-card .mem-face { position:absolute; inset:0; display:flex; align-items:center; justify-content:center; text-align:center; padding:8px;
  border-radius:var(--radius); border:1.5px solid var(--outline-variant); backface-visibility:hidden; transition:transform .35s; }
.mem-back { background:linear-gradient(135deg,var(--brand),#E8590C); color:#fff; }
.mem-back .material-symbols-rounded { font-size:30px; opacity:.9; }
.mem-front { background:var(--surface-container); transform:rotateY(180deg); }
.mem-card.is-up .mem-back { transform:rotateY(180deg); }
.mem-card.is-up .mem-front { transform:rotateY(360deg); }
.mem-card.is-matched .mem-front { border-color:var(--success); background:color-mix(in srgb,var(--success) 16%,transparent); }
.mem-icon { font-size:30px; color:var(--primary); }
.mem-text { font-size:.82rem; font-weight:600; color:var(--on-surface); line-height:1.2; }
@media (prefers-reduced-motion:reduce){ .mem-card .mem-face { transition:none; } }

/* sort (分類挑戰) */
.sort-card { display:flex; flex-direction:column; align-items:center; gap:8px; background:var(--surface-container);
  border:1px solid var(--outline-variant); border-radius:var(--radius-lg); padding:26px 18px; margin-bottom:6px; }
.sort-card__icon { font-size:42px; color:var(--brand); }
.sort-card__label { font-size:1.2rem; font-weight:700; color:var(--on-surface); }
.sort-q { text-align:center; color:var(--on-surface-variant); margin:8px 0 12px; }
.sort-buckets { display:grid; grid-template-columns:repeat(auto-fit,minmax(120px,1fr)); gap:10px; }
.sort-bucket { display:flex; flex-direction:column; align-items:center; gap:5px; background:var(--surface-container);
  border:1.5px solid var(--outline-variant); border-radius:var(--radius); padding:14px 8px; font:inherit; font-size:.85rem; font-weight:600;
  color:var(--on-surface); cursor:pointer; transition:background .15s,border-color .15s; }
.sort-bucket:hover:not(:disabled) { border-color:var(--brand); background:var(--surface-container-high); }
.sort-bucket .material-symbols-rounded { font-size:26px; color:var(--primary); }
.sort-bucket.is-correct { border-color:var(--success); background:color-mix(in srgb,var(--success) 14%,transparent); }
.sort-bucket.is-correct .material-symbols-rounded { color:var(--success); }
.sort-bucket.is-wrong { border-color:var(--error); background:color-mix(in srgb,var(--error) 12%,transparent); }
.sort-fb { display:flex; align-items:center; gap:8px; margin-top:14px; padding:12px 16px; border-radius:var(--radius); font-weight:600; }
.sort-fb--ok { background:color-mix(in srgb,var(--success) 14%,transparent); color:var(--success); }
.sort-fb--no { background:color-mix(in srgb,var(--error) 12%,transparent); color:var(--error); }

/* order (流程排序) */
.order-prompt { font-size:1.05rem; font-weight:600; color:var(--on-surface); margin:0 0 14px; }
.order-list { list-style:none; margin:0 0 16px; padding:0; display:flex; flex-direction:column; gap:8px; }
.order-step { display:flex; align-items:center; gap:12px; background:var(--surface-container); border:1.5px solid var(--outline-variant);
  border-radius:var(--radius); padding:12px 14px; }
.order-step.is-right { border-color:var(--success); background:color-mix(in srgb,var(--success) 12%,transparent); }
.order-step.is-wrong { border-color:var(--outline-variant); opacity:.85; }
.order-num { width:26px; height:26px; flex:0 0 auto; display:grid; place-items:center; border-radius:50%; background:var(--brand); color:#fff; font-weight:700; font-size:.85rem; }
.order-text { flex:1; color:var(--on-surface); font-size:.92rem; }
.order-moves { display:flex; gap:4px; }
.order-mv { border:1px solid var(--outline-variant); background:var(--surface); color:var(--on-surface-variant); border-radius:var(--radius-sm);
  width:30px; height:30px; display:grid; place-items:center; cursor:pointer; }
.order-mv:hover:not(:disabled) { background:var(--brand); color:#fff; border-color:transparent; }
.order-mv:disabled { opacity:.35; cursor:not-allowed; }
.order-mv .material-symbols-rounded { font-size:18px; }
.order-hint { color:var(--on-surface-variant); font-size:.85rem; margin:0 0 10px; }
.order-foot { display:flex; flex-direction:column; gap:10px; align-items:flex-start; }

/* true/false (真假快答) */
.tf-statement { font-size:1.25rem !important; }
.tf-btns { display:grid; grid-template-columns:1fr 1fr; gap:12px; }
.tf-btn { display:flex; flex-direction:column; align-items:center; gap:4px; padding:18px; border-radius:var(--radius);
  border:2px solid var(--outline-variant); background:var(--surface); font:inherit; font-size:1.05rem; font-weight:700; cursor:pointer; transition:background .15s,border-color .15s; }
.tf-btn .material-symbols-rounded { font-size:30px; }
.tf-btn--true { color:var(--success); } .tf-btn--true:hover:not(:disabled){ background:color-mix(in srgb,var(--success) 12%,transparent); border-color:var(--success); }
.tf-btn--false { color:var(--error); } .tf-btn--false:hover:not(:disabled){ background:color-mix(in srgb,var(--error) 10%,transparent); border-color:var(--error); }
.tf-btn.is-correct { border-color:var(--success); background:color-mix(in srgb,var(--success) 16%,transparent); }
.tf-btn.is-wrong { border-color:var(--error); background:color-mix(in srgb,var(--error) 14%,transparent); }

/* build (架構拼圖) */
.build-goal { display:flex; align-items:center; gap:8px; font-size:1.15rem; font-weight:700; color:var(--on-surface);
  background:var(--primary-container); color:var(--on-primary-container); padding:14px 18px; border-radius:var(--radius); margin-bottom:6px; }
.build-goal .material-symbols-rounded { color:var(--brand); }
.build-hint { color:var(--on-surface-variant); font-size:.9rem; margin:8px 0 12px; }
.build-palette { display:grid; grid-template-columns:repeat(auto-fit,minmax(150px,1fr)); gap:10px; }
.build-chip { display:flex; align-items:center; gap:8px; background:var(--surface-container); border:1.5px solid var(--outline-variant);
  border-radius:var(--radius); padding:12px 14px; font:inherit; font-size:.9rem; font-weight:600; color:var(--on-surface); cursor:pointer; transition:background .15s,border-color .15s; }
.build-chip > .material-symbols-rounded:first-child { color:var(--primary); font-size:22px; }
.build-chip__tick { margin-left:auto; color:var(--outline); font-size:20px; }
.build-chip.is-sel { border-color:var(--brand); background:var(--primary-container); color:var(--on-primary-container); }
.build-chip.is-sel .build-chip__tick { color:var(--brand); }
.build-chip.is-right { border-color:var(--success); background:color-mix(in srgb,var(--success) 14%,transparent); }
.build-chip.is-right .build-chip__tick { color:var(--success); }
.build-chip.is-missing { border-style:dashed; border-color:var(--success); }
.build-chip.is-extra { border-color:var(--error); background:color-mix(in srgb,var(--error) 10%,transparent); }
.build-fb { display:flex; gap:8px; margin:16px 0; padding:14px 16px; border-radius:var(--radius); line-height:1.55; font-size:.92rem; }
.build-fb .material-symbols-rounded { flex:0 0 auto; }
.build-fb--ok { background:color-mix(in srgb,var(--success) 14%,transparent); color:var(--on-surface); }
.build-fb--ok .material-symbols-rounded { color:var(--success); }
.build-fb--no { background:var(--surface-container-high); color:var(--on-surface); }
.build-fb--no .material-symbols-rounded { color:var(--brand); }

@media (max-width:600px){
  .mem-grid { grid-template-columns:repeat(3,1fr); gap:9px; }
  .match { gap:10px; }
  .match-item { font-size:.82rem; padding:11px 12px; }
  .build-palette { grid-template-columns:1fr 1fr; }
}
@media (max-width:375px){
  .mem-text { font-size:.72rem; }
}