/* Web edition stylesheet (tools/build_site.py). Logical properties throughout,
   so the same rules mirror for the Persian (rtl) edition. */
:root {
  --hdr: 56px; --sb-w: 300px; --toc-w: 250px; --measure: 46rem;
  --bg: #ffffff; --bg-soft: #f4f7fb; --bg-sb: #f7f9fc; --fg: #0f172a; --fg-soft: #475569; --fg-mute: #64748b;
  --line: #e2e8f0; --accent: #0e7490; --accent-2: #4338ca; --accent-3: #047857; --on-accent: #ffffff; --link: #0369a1; --link-v: #6d28d9;
  --grad: linear-gradient(100deg, #0891b2 0%, #10b981 50%, #6366f1 100%); --hero-bg: radial-gradient(900px 420px at 85% -10%, rgba(8,145,178,.13), transparent 70%), radial-gradient(700px 380px at 0% 110%, rgba(99,102,241,.10), transparent 70%);
  --card: #ffffff; --card-line: #e2e8f0; --term-bg: #0b1120; --term-fg: #cbd5e1;
  --code-bg: #f6f8fa; --code-fg: #1f2328; --code-line: #e1e4e8; --sel: #ffe8a3; --mark: #ffe58a;
  --shadow: 0 8px 30px rgba(15, 23, 42, .12);
  --c-tip: #2e7d32; --c-tip-bg: #edf7ee; --c-warn: #c62828; --c-warn-bg: #fdeeee; --c-note: #b7791f; --c-note-bg: #fff8e6;
  --c-try: #1565c0; --c-try-bg: #e9f2fd; --c-deep: #6a1b9a; --c-deep-bg: #f5ecf8; --c-debug: #455a64; --c-debug-bg: #eef1f3;
  --c-algo: #00796b; --c-algo-bg: #e6f4f2; --c-sum: #2f5496; --c-sum-bg: #f1f5fd;
  --font-body: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, 'Vazirmatn', monospace;
}
html[lang="fa"] { --font-body: 'Vazirmatn', 'Inter', Tahoma, sans-serif; --measure: 47rem; }
html[data-theme="dark"] {
  --bg: #0b1120; --bg-soft: #111a2e; --bg-sb: #0d1526; --fg: #e2e8f0; --fg-soft: #cbd5e1; --fg-mute: #94a3b8;
  --line: #1e293b; --accent: #22d3ee; --accent-2: #a5b4fc; --accent-3: #34d399; --on-accent: #04202a; --link: #67e8f9; --link-v: #c4b5fd;
  --grad: linear-gradient(100deg, #22d3ee 0%, #34d399 50%, #818cf8 100%); --hero-bg: radial-gradient(900px 460px at 85% -10%, rgba(34,211,238,.16), transparent 70%), radial-gradient(700px 400px at 0% 110%, rgba(129,140,248,.14), transparent 70%);
  --card: #0f1a2e; --card-line: #1e2b45; --term-bg: #050a16; --term-fg: #cbd5e1;
  --code-bg: #070c18; --code-fg: #e6edf3; --code-line: #262b33; --sel: #4b3f12; --mark: #6b5a12;
  --shadow: 0 8px 30px rgba(0, 0, 0, .5);
  --c-tip: #66bb6a; --c-tip-bg: #17251a; --c-warn: #ef5350; --c-warn-bg: #2b1718; --c-note: #e0b04a; --c-note-bg: #2a2414;
  --c-try: #64a8f0; --c-try-bg: #142131; --c-deep: #c084e0; --c-deep-bg: #241a2b; --c-debug: #a0b0b9; --c-debug-bg: #1d2227;
  --c-algo: #4fc3b0; --c-algo-bg: #10241f; --c-sum: #8fb0ff; --c-sum-bg: #161d2c;
  color-scheme: dark;
}
* { box-sizing: border-box; }
html { scroll-padding-top: calc(var(--hdr) + 16px); -webkit-text-size-adjust: 100%; }
body { margin: 0; background: var(--bg); color: var(--fg); font-family: var(--font-body); font-size: 17px; line-height: 1.7; }
html[lang="fa"] body { line-height: 1.95; font-size: 17.5px; }
::selection { background: var(--sel); }
a { color: var(--link); text-underline-offset: .18em; text-decoration-thickness: 1px; }
a:hover { text-decoration-thickness: 2px; }
:focus-visible { outline: 3px solid var(--link); outline-offset: 2px; border-radius: 3px; }
svg { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
kbd { font-family: var(--font-mono); font-size: .72rem; border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 4px; padding: 0 .35em; color: var(--fg-mute); background: var(--bg); }
.skip { position: absolute; inset-inline-start: 8px; top: -60px; background: var(--fg); color: var(--bg); padding: 8px 14px; border-radius: 6px; z-index: 100; }
.skip:focus { top: 8px; }

/* ---- top bar ---- */
.topbar { position: sticky; top: 0; z-index: 40; height: var(--hdr); display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 0 12px; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--line); }
.tb-start, .tb-end { display: flex; align-items: center; gap: 6px; min-width: 0; }
.brand { font-weight: 700; color: var(--fg); text-decoration: none; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-size: 1rem; }
.brand { display: inline-flex; align-items: center; gap: 9px; }
.brand .logo { flex: none; width: 22px; height: 22px; border-radius: 7px; background: var(--grad); box-shadow: 0 0 0 3px color-mix(in srgb, var(--accent) 18%, transparent); position: relative; }
.brand .logo::after { content: ""; position: absolute; inset: 6px; border-radius: 50%; border: 2px solid rgba(255,255,255,.9); }
.tb-cta { display: inline-flex; align-items: center; gap: 6px; height: 36px; padding: 0 14px; border-radius: 999px; background: var(--grad); color: #fff; font-weight: 700; font-size: .85rem; text-decoration: none; margin-inline-start: 4px; box-shadow: 0 4px 14px color-mix(in srgb, var(--accent) 30%, transparent); }
.tb-cta:hover { filter: brightness(1.07); }
.tb-cta svg { width: 17px; height: 17px; }
html[data-theme="dark"] .tb-cta { color: #04202a; }
.icon-btn { display: inline-flex; align-items: center; gap: 6px; height: 38px; min-width: 38px; justify-content: center; padding: 0 8px; border: 1px solid transparent;
  background: none; color: var(--fg-soft); border-radius: 8px; cursor: pointer; font: inherit; font-size: .85rem; text-decoration: none; }
.icon-btn:hover { background: var(--bg-soft); color: var(--fg); border-color: var(--line); }
.lang-btn span { font-weight: 600; }
#theme-btn .i-moon { display: none; }
html[data-theme="dark"] #theme-btn .i-moon { display: block; }
html[data-theme="dark"] #theme-btn .i-sun { display: none; }
.search-btn { display: inline-flex; align-items: center; gap: 8px; height: 38px; padding: 0 10px; min-width: 240px; border: 1px solid var(--line); border-radius: 9px;
  background: var(--bg-soft); color: var(--fg-mute); cursor: pointer; font: inherit; font-size: .88rem; }
.search-btn:hover { border-color: var(--fg-mute); }
.search-btn .sb-txt { flex: 1; text-align: start; }
.search-btn svg, .icon-btn svg { flex: none; }

/* ---- layout ---- */
.layout { display: grid; grid-template-columns: var(--sb-w) minmax(0, 1fr) var(--toc-w); min-height: calc(100vh - var(--hdr)); }
body.no-toc .layout { grid-template-columns: var(--sb-w) minmax(0, 1fr) 0; }
html.sb-collapsed .layout { grid-template-columns: 0 minmax(0, 1fr) var(--toc-w); }
html.sb-collapsed body.no-toc .layout { grid-template-columns: 0 minmax(0, 1fr) 0; }
html.sb-collapsed .sidebar { visibility: hidden; }
main { min-width: 0; padding: 20px clamp(16px, 4vw, 48px) 40px; outline: none; }
main > * { max-width: var(--measure); margin-inline: auto; }

/* ---- sidebar ---- */
.sidebar { position: sticky; top: var(--hdr); height: calc(100vh - var(--hdr)); background: var(--bg-sb); border-inline-end: 1px solid var(--line); display: flex; flex-direction: column; overflow: hidden; }
.sb-head { display: none; }
.sb-scroll { overflow-y: auto; padding: 14px 10px 40px; scrollbar-width: thin; }
.sb-group { font-size: .72rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--fg-mute); margin: 18px 10px 6px; }
html[lang="fa"] .sb-group { letter-spacing: 0; font-size: .8rem; }
.sb-list, .sb-kids { list-style: none; margin: 0; padding: 0; }
.sb-row { display: flex; align-items: flex-start; }
.sb-link { display: block; flex: 1; padding: 5px 10px; border-radius: 7px; color: var(--fg-soft); text-decoration: none; font-size: .9rem; line-height: 1.45; }
.sb-link:has(.n), .part-list a, .home-toc .ct { display: flex; gap: .45em; }
.sb-link .n, .part-list .n, .home-toc .n { flex: none; min-width: 1.5em; }
.sb-link .n { display: inline-block; color: var(--fg-mute); font-variant-numeric: tabular-nums; }
.sb-link:hover { background: var(--bg-soft); color: var(--fg); }
.sb-link[aria-current="page"] { background: color-mix(in srgb, var(--accent) 12%, transparent); color: var(--fg); font-weight: 600; box-shadow: inset 3px 0 0 var(--accent); }
html[dir="rtl"] .sb-link[aria-current="page"] { box-shadow: inset -3px 0 0 var(--accent); }
.sb-link.part { font-weight: 700; color: var(--accent-2); margin-top: 12px; background: color-mix(in srgb, var(--accent-2) 8%, transparent); }
.sb-part { margin: 12px 4px 4px; padding: 5px 10px; font-size: .8rem; font-weight: 700; color: var(--accent-2); border-radius: 7px; background: color-mix(in srgb, var(--accent-2) 8%, transparent); }
.sb-tog { flex: none; width: 28px; height: 30px; display: inline-flex; align-items: center; justify-content: center; border: 0; background: none; color: var(--fg-mute); cursor: pointer; border-radius: 6px; }
.sb-tog:hover { background: var(--bg-soft); color: var(--fg); }
.sb-tog svg { width: 15px; height: 15px; transition: transform .15s; }
html[dir="rtl"] .sb-tog svg { transform: scaleX(-1); }
.sb-tog[aria-expanded="true"] svg, html[dir="rtl"] .sb-tog[aria-expanded="true"] svg { transform: rotate(90deg); }
.sb-kids { margin: 2px 0 6px; padding-inline-start: 22px; border-inline-start: 1px solid var(--line); margin-inline-start: 18px; }
.sb-sub { display: block; padding: 3px 8px; font-size: .82rem; line-height: 1.45; color: var(--fg-mute); text-decoration: none; border-radius: 5px; }
.sb-sub:hover { color: var(--fg); background: var(--bg-soft); }
.sb-sub.active { color: var(--accent); font-weight: 600; }

/* ---- right toc ---- */
.toc { position: sticky; top: var(--hdr); height: calc(100vh - var(--hdr)); overflow-y: auto; padding: 24px 16px 40px; font-size: .83rem; scrollbar-width: thin; }
.toc-title { font-weight: 700; font-size: .75rem; text-transform: uppercase; letter-spacing: .06em; color: var(--fg-mute); margin-bottom: 8px; }
html[lang="fa"] .toc-title { letter-spacing: 0; font-size: .82rem; }
.toc ul, .toc-inline ul { list-style: none; margin: 0; padding: 0; }
.toc li a, .toc-inline li a { display: block; padding: 3px 10px; color: var(--fg-mute); text-decoration: none; border-inline-start: 2px solid var(--line); line-height: 1.45; }
.toc li.l3 a, .toc-inline li.l3 a { padding-inline-start: 22px; font-size: .95em; }
.toc li a:hover { color: var(--fg); }
.toc li a.active { color: var(--accent); border-color: var(--accent); font-weight: 600; }
.toc .num, .toc-inline .num { color: var(--fg-mute); font-variant-numeric: tabular-nums; }
.toc-inline { display: none; border: 1px solid var(--line); border-radius: 10px; padding: 8px 12px; margin-bottom: 18px; background: var(--bg-soft); font-size: .9rem; }
.toc-inline summary { cursor: pointer; font-weight: 600; }
.toc-inline ul { margin-top: 8px; max-height: 50vh; overflow: auto; }

/* ---- breadcrumbs, pager, footer ---- */
.crumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: 4px; margin: 0 auto 14px; padding: 0; font-size: .82rem; color: var(--fg-mute); }
.crumbs li + li::before { content: "›"; margin-inline-end: 6px; color: var(--fg-mute); }
html[dir="rtl"] .crumbs li + li::before { content: "‹"; }
.crumbs a { color: var(--fg-mute); text-decoration: none; }
.crumbs a:hover { color: var(--fg); text-decoration: underline; }
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; margin-top: 48px; padding-top: 22px; border-top: 1px solid var(--line); }
.pg-card { display: flex; flex-direction: column; gap: 2px; border: 1px solid var(--line); border-radius: 10px; padding: 12px 16px; text-decoration: none; color: var(--fg); transition: border-color .15s, box-shadow .15s; }
.pg-card:hover { border-color: var(--accent); box-shadow: var(--shadow); }
.pg-card.next { text-align: end; grid-column: 2; }
.pg-dir { font-size: .78rem; color: var(--fg-mute); }
.pg-card.prev .pg-dir::before { content: "← "; } .pg-card.next .pg-dir::after { content: " →"; }
html[dir="rtl"] .pg-card.prev .pg-dir::before { content: "→ "; } html[dir="rtl"] .pg-card.next .pg-dir::after { content: " ←"; }
.pg-t { font-weight: 600; }
.site-foot { margin-top: 36px; font-size: .78rem; color: var(--fg-mute); text-align: center; }

/* ---- content typography ---- */
.content { overflow-wrap: break-word; }
.content p, .content li, .content dd, .content figcaption { text-align: justify; text-justify: inter-word; }
html[lang="en"] .content { hyphens: auto; -webkit-hyphens: auto; hyphenate-limit-chars: 7 3 3; }
/* Persian: justify between words only. Never letter-spacing or inter-character
   justification on Arabic script (it breaks joining); no kashida insertion. */
html[lang="fa"] .content { hyphens: manual; letter-spacing: 0; word-spacing: .02em; }
.content code, .content pre, .content .en, .content a.url, .content td, .content th { hyphens: manual; -webkit-hyphens: manual; }
.content td, .content th, .content .ansref, .content .lead { text-align: start; }
.page-head { margin: 4px 0 26px; padding-bottom: 18px; border-bottom: 1px solid var(--line); }
.eyebrow { font-size: .82rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; color: var(--accent); margin-bottom: 6px; }
html[lang="fa"] .eyebrow { letter-spacing: 0; font-size: .9rem; }
.content h1 { font-size: clamp(1.75rem, 3.2vw, 2.4rem); line-height: 1.25; margin: 0; letter-spacing: -.01em; }
html[lang="fa"] .content h1 { letter-spacing: 0; line-height: 1.5; }
.content h2 { font-size: 1.5rem; line-height: 1.35; margin: 2.4em 0 .6em; padding-bottom: .3em; border-bottom: 1px solid var(--line); }
.content h3 { font-size: 1.2rem; line-height: 1.4; margin: 1.9em 0 .5em; }
.content h4, .content h5 { font-size: 1.04rem; margin: 1.5em 0 .4em; }
html[lang="fa"] .content h2, html[lang="fa"] .content h3 { line-height: 1.6; }
.content h2 .num, .content h3 .num { color: var(--accent); font-weight: 600; margin-inline-end: .35em; font-variant-numeric: tabular-nums; }
.hanchor { opacity: 0; margin-inline-start: .35em; color: var(--fg-mute); text-decoration: none; font-weight: 400; transition: opacity .1s; }
h2:hover .hanchor, h3:hover .hanchor, h4:hover .hanchor, .hanchor:focus { opacity: 1; }
.content ul, .content ol { padding-inline-start: 1.5em; }
.content ol { list-style: none; padding-inline-start: .4em; }
.content li { margin: .3em 0; }
.content .oln { color: var(--accent); font-weight: 600; margin-inline-end: .3em; font-variant-numeric: tabular-nums; }
.content strong { font-weight: 700; }
.content code { font-family: var(--font-mono); font-size: .86em; background: var(--code-bg); border: 1px solid var(--code-line); border-radius: 5px; padding: .08em .35em; unicode-bidi: isolate; }
.content .en { unicode-bidi: isolate; }
html[lang="fa"] .content .en { font-family: 'Inter', var(--font-body); font-size: .94em; }
.lead { font-size: 1.05rem; color: var(--fg-soft); }

/* ---- code blocks ---- */
.code { position: relative; margin: 1.3em 0; border: 1px solid var(--code-line); border-radius: 10px; background: var(--code-bg); overflow: hidden; }
.code-head { display: flex; justify-content: space-between; align-items: center; padding: 4px 6px 4px 12px; border-bottom: 1px solid var(--code-line); font-size: .75rem; color: var(--fg-mute); direction: ltr; }
.code-head .lang { font-family: var(--font-mono); text-transform: lowercase; }
.copy { font: inherit; font-size: .75rem; border: 1px solid var(--code-line); background: var(--bg); color: var(--fg-soft); border-radius: 6px; padding: 2px 10px; cursor: pointer; }
.copy:hover { color: var(--fg); border-color: var(--fg-mute); }
.copy.done { color: var(--c-tip); border-color: var(--c-tip); }
.code pre { margin: 0; padding: 12px 16px; overflow-x: auto; font-family: var(--font-mono); font-size: .83rem; line-height: 1.6; color: var(--code-fg); direction: ltr; text-align: left; tab-size: 4; }
.code pre code { background: none; border: 0; padding: 0; font-size: inherit; unicode-bidi: plaintext; }
.code.long pre { max-height: 36em; }

/* ---- callouts ---- */
.call, .sum, .box { margin: 1.4em 0; padding: 12px 16px 12px; border-radius: 10px; border: 1px solid color-mix(in srgb, var(--cc, var(--c-note)) 25%, transparent);
  border-inline-start: 4px solid var(--cc, var(--c-note)); background: var(--cb, var(--c-note-bg)); }
.call > p:last-child, .sum > ul:last-child, .box > p:last-child { margin-bottom: 0; }
.call > p, .box > p { margin: .45em 0; }
.call .lab, .sum .lab { font-weight: 700; color: var(--cc); display: flex; align-items: center; gap: 8px; font-size: .95rem; }
.call .ic { font-size: 1rem; }
.call.tip { --cc: var(--c-tip); --cb: var(--c-tip-bg); } .call.warn { --cc: var(--c-warn); --cb: var(--c-warn-bg); }
.call.note { --cc: var(--c-note); --cb: var(--c-note-bg); } .call.try { --cc: var(--c-try); --cb: var(--c-try-bg); }
.call.deep { --cc: var(--c-deep); --cb: var(--c-deep-bg); } .call.debug { --cc: var(--c-debug); --cb: var(--c-debug-bg); }
.sum { --cc: var(--c-sum); --cb: var(--c-sum-bg); } .box { --cc: var(--fg-mute); --cb: var(--bg-soft); }
.call.algo { --cc: var(--c-algo); --cb: var(--c-algo-bg); padding: 0; overflow: hidden; }
.call.algo .lab { padding: 10px 16px; background: color-mix(in srgb, var(--c-algo) 14%, transparent); border-bottom: 1px solid color-mix(in srgb, var(--c-algo) 25%, transparent); }
.call.algo .lab .ic { font-family: var(--font-mono); font-size: 1.1rem; }
.call.algo > p { margin: 0; padding: 7px 16px; font-size: .9rem; color: var(--fg-soft); text-align: start; }
.call.algo > p + p { border-top: 1px dashed color-mix(in srgb, var(--c-algo) 25%, transparent); }
.call.algo > p:last-child { padding-bottom: 10px; }
.call.algo code { word-break: break-word; }
.call.algo + .code { margin-top: -.6em; }

/* ---- figures ---- */
.content figure { margin: 1.8em 0; text-align: center; }
.content figure img { max-width: 100%; height: auto; border-radius: 8px; border: 1px solid var(--line); background: #fff; cursor: zoom-in; transition: box-shadow .15s; }
.content figure img:hover { box-shadow: var(--shadow); }
.content figure.tall img { max-height: 78vh; width: auto; }
html[data-theme="dark"] .content figure img { padding: 6px; border-color: #3a404a; }
.content figcaption { margin-top: 8px; font-size: .88rem; color: var(--fg-soft); line-height: 1.6; text-align: start; }
html[lang="fa"] .content figcaption { line-height: 1.85; }
.content figcaption b { color: var(--fg); }

/* ---- tables ---- */
.table-wrap { overflow-x: auto; margin: 1.3em 0; border: 1px solid var(--line); border-radius: 10px; }
.content table { border-collapse: collapse; width: 100%; font-size: .9rem; line-height: 1.55; }
.content th, .content td { padding: 8px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.content thead th { background: var(--bg-soft); font-weight: 700; text-align: start; border-bottom: 2px solid var(--line); }
.content tbody tr:nth-child(even) td { background: color-mix(in srgb, var(--bg-soft) 55%, transparent); }
.content tbody tr:last-child td { border-bottom: 0; }
.content td.ltr, .content td.cmd, .content td.src { direction: ltr; text-align: left; }
.content tr.subh td { background: var(--bg-soft); font-weight: 600; }
.content ul.refs { list-style: none; padding-inline-start: 0; }
.content ul.refs li { margin: .6em 0; text-align: start; }
.content a.url { font-size: .86em; word-break: break-all; direction: ltr; unicode-bidi: isolate; }
.content .ansref { font-size: .9rem; color: var(--fg-soft); }
.anslink { white-space: nowrap; }
.ixlist { columns: 2 18rem; list-style: none; padding: 0 !important; }
.ixlist li { break-inside: avoid; margin: .2em 0; text-align: start; }
.ixlist .ixt { font-weight: 600; }
.ixlist .ixe { color: var(--fg-soft); font-size: .9rem; margin-inline-start: .25em; }
.ix-jump { position: sticky; top: calc(var(--topbar-h, 56px) + 4px); z-index: 2; display: flex; flex-wrap: wrap; gap: 4px 10px; padding: 8px 10px; margin: 0 0 12px; border: 1px solid var(--line); border-radius: 12px; background: color-mix(in srgb, var(--bg) 92%, transparent); backdrop-filter: blur(6px); }
.ix-jump span { display: flex; flex-wrap: wrap; gap: 2px; }
.ix-jump a { min-width: 28px; height: 28px; display: inline-flex; align-items: center; justify-content: center; border-radius: 7px; text-decoration: none; font-weight: 700; color: var(--accent); }
.ix-jump a:hover, .ix-jump a:focus-visible { background: var(--bg-soft); }
.ix-letter { margin: 1.1em 0 .3em; font-size: 1.15rem; border-bottom: 1px solid var(--line); padding-bottom: .15em; scroll-margin-top: 120px; }
.ix-sec { scroll-margin-top: 120px; }
.ixlist .chs { color: var(--fg-mute); font-size: .88rem; }
.part-list { list-style: none; padding: 0 !important; }
.part-list a { display: block; padding: 8px 12px; border: 1px solid var(--line); border-radius: 8px; margin: 6px 0; text-decoration: none; }
.part-list .n, .home-toc .n { color: var(--accent); font-weight: 700; margin-inline-end: .5em; font-variant-numeric: tabular-nums; }

/* ---- home ---- */
html[data-kind="home"] main > * { max-width: 76rem; }
html[data-kind="home"] main { background: var(--hero-bg) no-repeat; }
.home h2 { border: 0; }
.home .hero { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr); gap: clamp(24px, 5vw, 64px); align-items: center; margin: 18px 0 56px; }
.hbadge { display: inline-flex; align-items: center; gap: 9px; padding: 5px 14px; border-radius: 999px; font-size: .82rem; font-weight: 600; color: var(--accent);
  background: color-mix(in srgb, var(--accent) 9%, transparent); border: 1px solid color-mix(in srgb, var(--accent) 28%, transparent); margin-bottom: 16px; }
.pulse { width: 8px; height: 8px; border-radius: 50%; background: var(--accent-3); box-shadow: 0 0 0 0 color-mix(in srgb, var(--accent-3) 60%, transparent); animation: pulse 2s infinite; }
@keyframes pulse { 70% { box-shadow: 0 0 0 9px transparent; } 100% { box-shadow: 0 0 0 0 transparent; } }
.home h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); line-height: 1.2; margin: .1em 0 .2em; letter-spacing: -.01em; }
html[lang="fa"] .home h1 { letter-spacing: 0; line-height: 1.35; }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.home .subtitle { font-size: 1.15rem; font-weight: 600; color: var(--fg-soft); margin: .3em 0; text-align: start; }
.home .lead { color: var(--fg-soft); font-size: 1.02rem; margin: .6em 0 1.2em; text-align: start; max-width: 38rem; }
.home .cta { display: flex; flex-wrap: wrap; gap: 10px; margin: 0 0 22px; }
.btn { display: inline-flex; align-items: center; gap: 8px; padding: 10px 18px; border-radius: 11px; border: 1px solid var(--line); color: var(--fg); background: var(--card); text-decoration: none; font-weight: 600; font-size: .93rem; margin: 0; transition: transform .15s, box-shadow .15s, border-color .15s; }
.btn:hover { border-color: var(--accent); transform: translateY(-1px); box-shadow: var(--shadow); }
.btn.primary { background: var(--grad); border-color: transparent; color: #fff; }
html[data-theme="dark"] .btn.primary { color: #04202a; }
.btn.ghost { background: transparent; }
.btn svg { width: 18px; height: 18px; }
html[dir="rtl"] .i-arrow { transform: scaleX(-1); }
.stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; margin: 6px 0 20px; max-width: 34rem; }
.stats div { padding: 10px 12px; border: 1px solid var(--card-line); border-radius: 12px; background: color-mix(in srgb, var(--card) 80%, transparent); }
.stats b { display: block; font-size: 1.45rem; line-height: 1.2; font-variant-numeric: tabular-nums; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stats span { display: block; font-size: .78rem; color: var(--fg-mute); }
.home .byline { font-weight: 600; margin: .4em 0 .1em; text-align: start; font-size: .95rem; }
.home .meta { color: var(--fg-mute); font-size: .85rem; margin: 0; text-align: start; }
.hero-art { position: relative; display: flex; justify-content: center; padding: 10px 0 40px; }
.hero-art .glow { position: absolute; inset: 8% 12%; border-radius: 40%; background: var(--grad); filter: blur(60px); opacity: .35; }
.hero-art .cover { position: relative; width: min(300px, 70%); height: auto; border-radius: 10px; box-shadow: 0 30px 60px rgba(2, 6, 23, .35), 0 0 0 1px rgba(255,255,255,.06); transform: rotate(-2deg); }
html[dir="rtl"] .hero-art .cover { transform: rotate(2deg); }
.term { position: absolute; bottom: 0; inset-inline-start: 0; width: min(330px, 78%); border-radius: 12px; background: var(--term-bg); color: var(--term-fg); box-shadow: 0 20px 40px rgba(2, 6, 23, .35); border: 1px solid rgba(148,163,184,.18); overflow: hidden; text-align: left; }
.term-bar { display: flex; align-items: center; gap: 6px; padding: 7px 10px; background: rgba(148,163,184,.1); }
.term-bar i { width: 9px; height: 9px; border-radius: 50%; background: #f87171; }
.term-bar i:nth-child(2) { background: #fbbf24; } .term-bar i:nth-child(3) { background: #34d399; }
.term-bar span { margin-inline-start: auto; font: 600 .68rem var(--font-body); color: #94a3b8; }
.term pre { margin: 0; padding: 10px 14px 12px; font: .74rem/1.55 var(--font-mono); white-space: pre; background: none; border: 0; color: inherit; }
.term .tp { color: #22d3ee; } .term .tok { color: #34d399; }
.hsec { margin: 0 0 56px; }
.hsec-head { text-align: center; margin: 0 auto 24px; max-width: 44rem; }
.hsec-head h2 { font-size: clamp(1.5rem, 3vw, 2rem); margin: 0 0 .3em; }
.hsec-head h2::after { content: ""; display: block; width: 56px; height: 4px; border-radius: 4px; background: var(--grad); margin: 12px auto 0; }
.hsec-head p { color: var(--fg-soft); margin: 0; text-align: center; }
.hgrid { display: grid; gap: 16px; }
.hgrid.roles { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.hgrid.parts { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.hcard, .pcard { position: relative; display: flex; flex-direction: column; gap: 6px; padding: 20px; border: 1px solid var(--card-line); border-radius: 18px; background: var(--card); color: var(--fg); text-decoration: none; transition: transform .18s, box-shadow .18s, border-color .18s; overflow: hidden; }
.hcard::before, .pcard::before { content: ""; position: absolute; inset: 0 0 auto 0; height: 3px; background: var(--grad); opacity: 0; transition: opacity .18s; }
.hcard:hover, .pcard:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--accent) 45%, var(--card-line)); }
.hcard:hover::before, .pcard:hover::before { opacity: 1; }
.hc-ic { display: inline-flex; align-items: center; justify-content: center; width: 42px; height: 42px; border-radius: 12px; color: var(--accent); background: color-mix(in srgb, var(--accent) 11%, transparent); }
.hc-ic svg { width: 22px; height: 22px; }
.r2 .hc-ic, .p2 .hc-ic { color: var(--accent-2); background: color-mix(in srgb, var(--accent-2) 12%, transparent); }
.r3 .hc-ic, .p3 .hc-ic { color: var(--accent-3); background: color-mix(in srgb, var(--accent-3) 12%, transparent); }
.r4 .hc-ic { color: var(--c-warn); background: color-mix(in srgb, var(--c-warn) 11%, transparent); }
.hc-tag { font-size: .76rem; font-weight: 700; color: var(--fg-mute); margin-top: 6px; }
.hc-t { font-size: 1.08rem; font-weight: 700; }
.hc-d { font-size: .9rem; color: var(--fg-soft); line-height: 1.7; flex: 1; }
.hc-go { display: inline-flex; align-items: center; gap: 6px; font-size: .85rem; font-weight: 700; color: var(--accent); margin-top: 6px; }
.hc-go svg { width: 16px; height: 16px; transition: transform .18s; }
.hcard:hover .hc-go svg { transform: translateX(3px); }
html[dir="rtl"] .hcard:hover .hc-go svg { transform: scaleX(-1) translateX(3px); }
.pc-top { display: flex; align-items: center; gap: 10px; }
.pc-top .hc-tag { margin: 0; }
.hc-new { margin-inline-start: auto; font-size: .72rem; font-weight: 800; padding: 2px 10px; border-radius: 999px; background: var(--grad); color: #fff; }
html[data-theme="dark"] .hc-new { color: #04202a; }
.pcard h3 { margin: 8px 0 0; font-size: 1.2rem; }
.pcard h3 a { color: var(--fg); text-decoration: none; }
.pcard h3 a::after { content: ""; position: absolute; inset: 0; }
.pcard p { margin: 0; color: var(--fg-soft); font-size: .92rem; text-align: start; flex: 1; }
.chips { position: relative; z-index: 1; display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.chip { min-width: 2.1em; text-align: center; padding: 1px 8px; border-radius: 8px; font-size: .8rem; font-weight: 600; font-variant-numeric: tabular-nums; color: var(--fg-soft); background: var(--bg-soft); border: 1px solid var(--card-line); text-decoration: none; }
.chip:hover { color: var(--accent); border-color: var(--accent); }
.p4 { border-color: color-mix(in srgb, var(--accent) 40%, var(--card-line)); }
.home .about { background: var(--bg-soft); border: 1px solid var(--line); border-radius: 16px; padding: 4px 22px 10px; font-size: .9rem; }
.home .about h2 { margin-top: .8em; font-size: 1.2rem; }
.home h3, .toc-page h3 { margin-top: 1.6em; font-size: 1.05rem; color: var(--fg-mute); }
.home-toc { list-style: none; padding: 0 !important; display: grid; grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); gap: 10px; }
.home-toc li { margin: 0; }
.home-toc a { display: block; height: 100%; border: 1px solid var(--card-line); border-radius: 12px; padding: 10px 14px; text-decoration: none; color: var(--fg); background: var(--card); transition: border-color .15s, box-shadow .15s; }
.home-toc a:hover { border-color: var(--accent); box-shadow: var(--shadow); }
.home-toc .ct { display: block; font-weight: 600; text-align: start; }
.home-toc .secs { display: block; font-size: .8rem; color: var(--fg-mute); margin-top: 4px; line-height: 1.5; text-align: start; }
.home-toc li.part a { background: color-mix(in srgb, var(--accent-2) 7%, var(--card)); }
@media (max-width: 1100px) { .hgrid.roles { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
@media (max-width: 600px) { .term { display: none; } .hero-art { padding-bottom: 12px; } }

/* ---- search ---- */
.search-dlg { position: fixed; inset: 0; z-index: 80; background: rgba(10, 12, 16, .45); display: flex; align-items: flex-start; justify-content: center; padding: 8vh 12px 12px; }
.search-dlg[hidden] { display: none; }
.search-box { width: min(720px, 100%); max-height: 80vh; display: flex; flex-direction: column; background: var(--bg); border: 1px solid var(--line); border-radius: 14px; box-shadow: var(--shadow); overflow: hidden; }
.search-row { display: flex; align-items: center; gap: 6px; padding: 10px; border-bottom: 1px solid var(--line); }
#search-input { flex: 1; font: inherit; font-size: 1.05rem; padding: 10px 12px; border: 1px solid var(--line); border-radius: 9px; background: var(--bg-soft); color: var(--fg); }
#search-input:focus { outline: 2px solid var(--link); }
.search-status { margin: 0; padding: 8px 16px; font-size: .82rem; color: var(--fg-mute); }
.search-results { list-style: none; margin: 0; padding: 0 8px 10px; overflow-y: auto; }
.search-results a { display: block; padding: 10px 12px; border-radius: 9px; text-decoration: none; color: var(--fg); }
.search-results a:hover, .search-results li[aria-selected="true"] a { background: var(--bg-soft); box-shadow: inset 0 0 0 1px var(--line); }
.search-results .r-t { font-weight: 600; display: block; }
.search-results .r-c { font-size: .75rem; color: var(--accent); display: block; }
.search-results .r-s { font-size: .85rem; color: var(--fg-soft); display: block; line-height: 1.6; }
.search-results mark { background: var(--mark); color: inherit; border-radius: 2px; padding: 0 1px; }

/* ---- lightbox ---- */
.lb { position: fixed; inset: 0; z-index: 90; background: #0b0d12; display: flex; flex-direction: column; }
.lb[hidden] { display: none; }
.lb-stage { flex: 1; position: relative; overflow: hidden; touch-action: none; cursor: grab; display: flex; align-items: center; justify-content: center; }
.lb-stage.dragging { cursor: grabbing; }
.lb-img { max-width: 94vw; max-height: calc(100vh - 120px); background: #fff; border-radius: 4px; transform-origin: 50% 50%; user-select: none; -webkit-user-drag: none; will-change: transform; }
.lb-img[src$=".svg"] { width: 94vw; height: auto; object-fit: contain; }
.lb-bar { position: absolute; top: 10px; inset-inline-end: 10px; display: flex; gap: 6px; direction: ltr; }
.lb-bar button { width: 42px; height: 42px; border-radius: 10px; border: 1px solid rgba(255,255,255,.25); background: rgba(30,32,38,.85); color: #fff; font-size: 1.15rem; cursor: pointer; }
.lb-bar button:hover { background: rgba(60,64,72,.95); }
.lb-bar .lb-zoomv { width: auto; padding: 0 10px; font-size: .8rem; font-variant-numeric: tabular-nums; }
.lb-cap { color: #e8e8e8; font-size: .85rem; padding: 8px 18px 14px; text-align: center; max-height: 22vh; overflow: auto; line-height: 1.6; }

/* ---- backdrop / mobile ---- */
.backdrop { position: fixed; inset: 0; background: rgba(10, 12, 16, .45); z-index: 45; }
.backdrop[hidden] { display: none; }
@media (max-width: 1240px) {
  .layout, body.no-toc .layout { grid-template-columns: var(--sb-w) minmax(0, 1fr) 0; }
  html.sb-collapsed .layout, html.sb-collapsed body.no-toc .layout { grid-template-columns: 0 minmax(0, 1fr) 0; }
  .toc { display: none; }
  .toc-inline { display: block; }
}
@media (max-width: 900px) {
  body { font-size: 16.5px; }
  html[lang="fa"] body { font-size: 16.5px; }
  .layout, body.no-toc .layout, html.sb-collapsed .layout, html.sb-collapsed body.no-toc .layout { grid-template-columns: minmax(0, 1fr); }
  .sidebar, html.sb-collapsed .sidebar { visibility: hidden; position: fixed; top: 0; bottom: 0; inset-inline-start: 0; height: 100%; width: min(86vw, 340px); z-index: 50;
    transform: translateX(-100%); transition: transform .2s ease, visibility .2s; box-shadow: var(--shadow); }
  html[dir="rtl"] .sidebar { transform: translateX(100%); }
  html.sb-open .sidebar, html.sb-open[dir="rtl"] .sidebar { visibility: visible; transform: none; }
  .sb-head { display: flex; align-items: center; justify-content: space-between; gap: 8px; padding: 10px 10px 10px 16px; border-bottom: 1px solid var(--line); height: var(--hdr); }
  html[dir="rtl"] .sb-head { padding: 10px 16px 10px 10px; }
  .sb-home { font-weight: 700; color: var(--fg); text-decoration: none; }
  .search-btn { min-width: 38px; padding: 0 9px; justify-content: center; }
  .search-btn .sb-txt, .search-btn kbd, .lang-btn span { display: none; }
  main { padding: 14px 16px 32px; }
  .home .hero { grid-template-columns: 1fr; gap: 8px; margin-bottom: 36px; }
  .hero-art { order: -1; padding-bottom: 70px; }
  .hero-art .cover { width: min(190px, 52%); }
  .term { width: min(300px, 88%); left: 50%; right: auto; transform: translateX(-50%); }
  .stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .hgrid.roles, .hgrid.parts, .home-toc { grid-template-columns: 1fr; }
  .tb-cta span { display: none; }
  .tb-cta { padding: 0 10px; }
  .pager { grid-template-columns: 1fr; }
  .pg-card.next { grid-column: 1; }
  .content h2 { font-size: 1.3rem; }
  .code pre { font-size: .78rem; }
  .lb-img { max-width: 100vw; max-height: calc(100vh - 150px); }
}
@media (prefers-reduced-motion: reduce) { * { transition: none !important; scroll-behavior: auto !important; } }

/* ---- reading progress, bookmarks, motion ---- */
.btn[hidden], .pc-prog[hidden], .rp[hidden], .read-tog[hidden] { display: none !important; }
.vh { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.topbar { position: sticky; }
.rbar { position: absolute; inset-inline: 0; bottom: -1px; height: 3px; pointer-events: none; }
.rbar i { display: block; height: 100%; background: var(--grad); transform: scaleX(0); transform-origin: left center; transition: transform .12s linear; }
html[dir="rtl"] .rbar i { transform-origin: right center; }
html[data-kind="home"] .rbar { display: none; }
.mk-btn { position: relative; }
.mk-btn svg { width: 19px; height: 19px; }
.mk-n { position: absolute; top: 3px; inset-inline-end: 2px; min-width: 16px; height: 16px; padding: 0 4px; border-radius: 999px; font-size: .62rem; font-weight: 700; line-height: 16px; text-align: center; background: var(--accent); color: var(--on-accent); }
.mk-n:empty { display: none; }
.ring { width: 36px; height: 36px; transform: rotate(-90deg); }
html[dir="rtl"] .ring { transform: rotate(-90deg) scaleY(-1); }
.ring circle { fill: none; stroke-width: 3.2; }
.ring .trk { stroke: color-mix(in srgb, var(--fg-mute) 22%, transparent); }
.ring .val { stroke: var(--accent); stroke-linecap: round; stroke-dasharray: 100; stroke-dashoffset: calc(100 - var(--p, 0)); transition: stroke-dashoffset .6s cubic-bezier(.2,.7,.2,1); }
.ring.big { width: 74px; height: 74px; }
.ring.big circle { stroke-width: 3; }
.ring.big .val { stroke: var(--accent-3); }
.ring-wrap { position: relative; flex: none; display: inline-flex; align-items: center; justify-content: center; }
.ring-wrap b { position: absolute; font-size: 1rem; font-weight: 800; font-variant-numeric: tabular-nums; }
/* chapter header meta */
.ph-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 14px; margin-top: 10px; font-size: .88rem; color: var(--fg-mute); }
.ph-meta .rt { display: inline-flex; align-items: center; gap: 6px; }
.ph-meta svg, .rt-s svg, .pc-time svg { width: 16px; height: 16px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.read-tog { display: inline-flex; align-items: center; gap: 6px; height: 32px; padding: 0 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--bg); color: var(--fg-soft); font: inherit; font-size: .85rem; cursor: pointer; transition: background .15s, border-color .15s, color .15s, transform .15s; }
.read-tog svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 2.4; stroke-linecap: round; stroke-linejoin: round; opacity: .45; }
.read-tog:hover { border-color: var(--accent-3); color: var(--fg); transform: translateY(-1px); }
.read-tog.on { background: color-mix(in srgb, var(--accent-3) 14%, transparent); border-color: color-mix(in srgb, var(--accent-3) 55%, transparent); color: var(--accent-3); font-weight: 700; }
.read-tog.on svg { opacity: 1; }
.read-tog.pop { animation: pop .45s cubic-bezier(.3,1.6,.5,1); }
@keyframes pop { 0% { transform: scale(1); } 40% { transform: scale(1.12); } 100% { transform: scale(1); } }
/* bookmark buttons on headings: always visible (subtle), stronger on hover/focus; keyboard + touch friendly.
   Opacity .85 on --fg-mute keeps >= 3:1 non-text contrast in light and dark. */
.hbm { display: inline-flex; vertical-align: middle; align-items: center; justify-content: center; width: 32px; height: 32px; margin-inline-start: .3em; padding: 0; border: 0; border-radius: 8px; background: none; color: var(--fg-mute); cursor: pointer; opacity: .85; transition: opacity .15s, color .15s, background .15s, transform .15s; -webkit-tap-highlight-color: transparent; touch-action: manipulation; }
.hbm svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linejoin: round; transition: transform .15s; }
h2:hover .hbm, h3:hover .hbm { opacity: 1; color: var(--fg-soft); }
.hbm:hover, .hbm:focus-visible { opacity: 1; background: var(--bg-soft); color: var(--accent); transform: scale(1.12); }
.hbm:hover svg, .hbm:focus-visible svg { transform: scale(1.1); }
.hbm:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.hbm[aria-pressed="true"] { opacity: 1; color: var(--accent-2); }
.hbm[aria-pressed="true"] svg { fill: currentColor; }
@media (pointer: coarse) { .hbm { width: 44px; height: 44px; margin-block: -6px; } .hbm svg { width: 20px; height: 20px; } }
.content h2.marked, .content h3.marked { background: linear-gradient(90deg, color-mix(in srgb, var(--accent-2) 10%, transparent), transparent 70%); border-radius: 8px; padding-inline-start: 10px; box-shadow: inset 3px 0 0 var(--accent-2); }
html[dir="rtl"] .content h2.marked, html[dir="rtl"] .content h3.marked { background: linear-gradient(270deg, color-mix(in srgb, var(--accent-2) 10%, transparent), transparent 70%); box-shadow: inset -3px 0 0 var(--accent-2); }
/* read state on links */
.sb-link[data-slug] { position: relative; padding-inline-end: 26px; }
.sb-st { position: absolute; inset-inline-end: 6px; top: 8px; width: 14px; height: 14px; border-radius: 50%; }
.sb-link.in-prog .sb-st { background: conic-gradient(var(--accent) calc(var(--p, 0) * 1%), color-mix(in srgb, var(--fg-mute) 22%, transparent) 0); -webkit-mask: radial-gradient(circle, transparent 4px, #000 4.5px); mask: radial-gradient(circle, transparent 4px, #000 4.5px); }
.sb-link.is-read .sb-st { background: var(--accent-3); }
.sb-link.is-read .sb-st::after { content: ""; position: absolute; left: 4.6px; top: 2.2px; width: 3px; height: 6.5px; border: solid #fff; border-width: 0 2px 2px 0; transform: rotate(40deg); }
.sb-link.is-read { color: var(--fg-mute); }
.sb-link.is-read[aria-current="page"] { color: var(--fg); }
.chip.is-read { background: color-mix(in srgb, var(--accent-3) 16%, var(--bg-soft)); border-color: color-mix(in srgb, var(--accent-3) 50%, transparent); color: var(--accent-3); }
.chip.in-prog { border-color: color-mix(in srgb, var(--accent) 55%, transparent); box-shadow: inset 0 -2px 0 var(--accent); }
.home-toc a.is-read .ct::after { content: "✓"; margin-inline-start: auto; color: var(--accent-3); font-weight: 800; }
.home-toc a.is-read { border-color: color-mix(in srgb, var(--accent-3) 40%, var(--card-line)); }
.rt-s, .pc-time { display: inline-flex; align-items: center; gap: 5px; font-size: .78rem; color: var(--fg-mute); margin-top: 6px; }
.pc-time { margin: 0 0 10px; }
.pc-prog { display: inline-flex; align-items: center; gap: 6px; margin-inline-start: auto; font-size: .76rem; color: var(--fg-mute); font-variant-numeric: tabular-nums; }
.pc-prog .ring { width: 26px; height: 26px; }
.pc-prog.done .val { stroke: var(--accent-3); }
.hc-new + .pc-prog { margin-inline-start: 8px; }
/* home progress panel */
.rp { display: flex; align-items: center; gap: 16px; max-width: 34rem; margin: 0 0 20px; padding: 14px 16px; border-radius: 16px; border: 1px solid var(--card-line);
  background: linear-gradient(135deg, color-mix(in srgb, var(--accent) 8%, var(--card)), color-mix(in srgb, var(--accent-2) 7%, var(--card))); animation: rise .6s .15s both; }
.rp-t { font-weight: 800; font-size: .95rem; }
.rp-line, .my-line { margin: 2px 0 8px; font-size: .85rem; color: var(--fg-mute); line-height: 1.7; }
.rp-acts { display: flex; flex-wrap: wrap; gap: 8px; }
.rp-acts .btn, .my-actions .btn { padding: 7px 14px; font-size: .85rem; }
.rp-acts svg, .my-actions svg, .my-head h2 svg { width: 17px; height: 17px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.rp-ct { max-width: 22rem; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
/* my-reading dialog */
.my-dlg { position: fixed; inset: 0; z-index: 90; display: flex; align-items: flex-start; justify-content: center; padding: 8vh 16px 16px; background: rgba(2, 6, 23, .55); backdrop-filter: blur(3px); }
.my-dlg[hidden] { display: none; }
.my-box { width: min(560px, 100%); max-height: 84vh; overflow: auto; padding: 18px 20px 20px; border-radius: 18px; background: var(--bg); border: 1px solid var(--line); box-shadow: 0 24px 60px rgba(2, 6, 23, .35); animation: rise .25s ease-out both; }
.my-head { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.my-head h2 { display: inline-flex; align-items: center; gap: 8px; margin: 0; font-size: 1.15rem; }
.my-prog { display: flex; align-items: center; gap: 16px; margin: 14px 0 6px; padding: 12px 14px; border-radius: 14px; background: var(--bg-soft); }
.my-box h3 { font-size: .95rem; margin: 16px 0 8px; }
.mk-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.mk-list li { display: flex; align-items: center; gap: 6px; border: 1px solid var(--line); border-radius: 12px; padding: 4px 6px 4px 4px; transition: border-color .15s, transform .15s; }
.mk-list li:hover { border-color: var(--accent); transform: translateY(-1px); }
.mk-list a { flex: 1; min-width: 0; display: flex; flex-direction: column; padding: 4px 8px; text-decoration: none; color: var(--fg); }
.mk-t { font-weight: 600; font-size: .9rem; }
.mk-p { font-size: .76rem; color: var(--fg-mute); overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.mk-del svg { width: 16px; height: 16px; }
.mk-empty { color: var(--fg-mute); font-size: .86rem; }
.my-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; padding-top: 14px; border-top: 1px solid var(--line); }
.file-btn { position: relative; cursor: pointer; }
.file-btn input { position: absolute; inset: 0; opacity: 0; width: 100%; cursor: pointer; }
.file-btn:focus-within { outline: 2px solid var(--accent); outline-offset: 2px; }
.btn.danger:hover { border-color: #dc2626; color: #dc2626; }
.my-note { margin: 12px 0 0; font-size: .78rem; color: var(--fg-mute); }
/* back to top */
.totop { position: fixed; bottom: 20px; inset-inline-end: 20px; z-index: 35; width: 48px; height: 48px; border-radius: 50%; border: 1px solid var(--line); background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(6px); color: var(--fg); cursor: pointer; display: grid; place-items: center; box-shadow: var(--shadow); animation: rise .25s ease-out both; transition: transform .15s, color .15s; }
.totop[hidden] { display: none; }
.totop .ring { position: absolute; inset: -1px; width: 48px; height: 48px; }
.totop .ring circle { stroke-width: 2.6; }
.totop > svg:last-child { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2.2; stroke-linecap: round; stroke-linejoin: round; }
.totop:hover { transform: translateY(-3px); color: var(--accent); }
@media (min-width: 1241px) { body.has-toc .totop { inset-inline-end: calc(var(--toc-w) + 18px); } }
/* scroll reveal + entrance */
@keyframes rise { from { opacity: 0; transform: translateY(14px); } to { opacity: 1; transform: none; } }
.rv { opacity: 0; transform: translateY(18px); transition: opacity .55s ease-out var(--rv-d, 0ms), transform .55s cubic-bezier(.2,.7,.2,1) var(--rv-d, 0ms); }
.rv.in { opacity: 1; transform: none; }
html[data-kind="home"] .hero-text > * { animation: rise .6s both; }
html[data-kind="home"] .hero-text > :nth-child(2) { animation-delay: .05s; }
html[data-kind="home"] .hero-text > :nth-child(3) { animation-delay: .1s; }
html[data-kind="home"] .hero-text > :nth-child(n+4) { animation-delay: .16s; }
html[data-kind="home"] .hero-art { animation: rise .8s .1s both; }
.term { animation: floaty 7s ease-in-out infinite; }
@keyframes floaty { 0%, 100% { translate: 0 0; } 50% { translate: 0 -8px; } }
/* micro-interactions */
.hcard .hc-ic, .pcard .hc-ic { transition: transform .25s cubic-bezier(.3,1.5,.5,1); }
.hcard:hover .hc-ic, .pcard:hover .hc-ic { transform: rotate(-8deg) scale(1.1); }
.hc-go .i-arrow, .btn .i-arrow { transition: translate .2s; }
.hcard:hover .hc-go .i-arrow, .btn:hover .i-arrow { translate: 4px 0; }
html[dir="rtl"] .hcard:hover .hc-go .i-arrow, html[dir="rtl"] .btn:hover .i-arrow { translate: -4px 0; }
.chip { transition: transform .15s, border-color .15s, color .15s; }
.chip:hover { transform: translateY(-2px); }
.sb-link { transition: background .15s, color .15s, padding .15s; }
.btn.primary { background-size: 160% 100%; transition: background-position .4s, transform .15s, box-shadow .15s; }
.btn.primary:hover { background-position: 100% 0; }
.icon-btn:active, .btn:active, .read-tog:active, .totop:active { transform: scale(.96); }
/* cross-document view transitions (Chrome 126+); others just navigate */
@view-transition { navigation: auto; }
.topbar { view-transition-name: topbar; }
::view-transition-old(root) { animation: vt-out .18s ease-in both; }
::view-transition-new(root) { animation: vt-in .28s ease-out both; }
@keyframes vt-out { to { opacity: 0; transform: translateY(-6px); } }
@keyframes vt-in { from { opacity: 0; transform: translateY(8px); } }
@media (prefers-reduced-motion: reduce) {
  @view-transition { navigation: none; }
  *, *::before, *::after { animation: none !important; }
  .rv { opacity: 1 !important; transform: none !important; }
  .rbar i, .ring .val { transition: none !important; }
}
/* mobile header: keep the full title readable */
@media (max-width: 600px) {
  .topbar { gap: 6px; padding-inline: 8px; }
  .tb-cta { display: none; }
  .tb-end { flex: none; gap: 2px; }
  .tb-end .icon-btn, .search-btn { min-width: 36px; padding: 0 6px; }
  .brand { font-size: .92rem; gap: 7px; overflow: visible; }
  .brand .logo { width: 18px; height: 18px; border-radius: 6px; }
  .brand .logo::after { inset: 5px; border-width: 1.6px; }
  .rp { align-items: flex-start; gap: 12px; padding: 12px; }
  .rp .ring.big { width: 58px; height: 58px; }
  .rp-ct { max-width: 10.5rem; }
  .totop { bottom: 14px; inset-inline-end: 14px; }
}

/* ---- gamification (game.js); html.no-game hides every game element ---- */
html.no-game .game, html.no-game .g-chip, html.no-game .rp-game { display: none !important; }
.g-offnote { display: none; }
html.no-game .g-offnote { display: block; padding: 10px 14px; border-radius: 12px; background: var(--bg-soft); color: var(--fg-mute); }
.gi { width: 18px; height: 18px; flex: none; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.g-chip { display: inline-flex; align-items: center; gap: 5px; height: 32px; padding: 0 10px; border-radius: 999px; border: 1px solid var(--line); color: var(--fg-soft); font-size: .8rem; font-weight: 700; text-decoration: none; font-variant-numeric: tabular-nums; transition: border-color .15s, transform .15s; }
.g-chip[hidden] { display: none; }
.g-chip svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linejoin: round; color: var(--fg-mute); }
.g-chip.lit svg { color: #f97316; fill: color-mix(in srgb, #f97316 35%, transparent); }
.g-chip .g-l { padding-inline-start: 6px; border-inline-start: 1px solid var(--line); color: var(--accent); }
.g-chip:hover { border-color: var(--accent); transform: translateY(-1px); }
.sb-link.app { display: flex; align-items: center; gap: 8px; }
.sb-link.app svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; color: var(--accent); }
.sb-due { margin-inline-start: auto; min-width: 20px; padding: 0 6px; border-radius: 999px; background: var(--accent); color: var(--on-accent); font-size: .72rem; font-weight: 700; text-align: center; line-height: 20px; }
.sb-due[hidden] { display: none; }
.rp-game { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin-top: 10px; padding-top: 10px; border-top: 1px dashed var(--card-line); font-size: .8rem; color: var(--fg-soft); text-decoration: none; }
.rp-game[hidden] { display: none; }
.rp-game .gi { width: 15px; height: 15px; color: var(--accent); }
.rp-game .sep { width: 4px; height: 4px; border-radius: 50%; background: var(--fg-mute); opacity: .5; margin: 0 4px; }
.rp-game:hover { color: var(--accent); }
/* chapter-end quiz card */
.quiz-cta { display: flex; align-items: center; gap: 16px; margin: 2.5em 0 1em; padding: 16px 18px; border-radius: 16px; border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--card-line)); background: linear-gradient(135deg, color-mix(in srgb, var(--accent) 7%, var(--card)), color-mix(in srgb, var(--accent-3) 6%, var(--card))); }
.quiz-cta .hc-ic svg { width: 22px; height: 22px; fill: none; stroke: currentColor; stroke-width: 2; }
.quiz-cta div { flex: 1; }
.content .quiz-cta h2.qz-h { margin: 0 0 2px; padding: 0; border: 0; font-size: 1.05rem; }
.quiz-cta p { margin: 0; font-size: .88rem; color: var(--fg-mute); }
.quiz-cta .btn svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-width: 2; }
/* toasts and confetti */
.g-toasts { position: fixed; z-index: 95; bottom: 22px; left: 50%; transform: translateX(-50%); display: flex; flex-direction: column; align-items: center; gap: 8px; pointer-events: none; width: min(420px, calc(100vw - 32px)); }
.g-toast { display: flex; align-items: center; gap: 10px; padding: 9px 14px; border-radius: 14px; background: var(--bg); color: var(--fg); border: 1px solid var(--line); box-shadow: 0 12px 32px rgba(2, 6, 23, .22); font-size: .88rem; pointer-events: auto; animation: toast-in .35s cubic-bezier(.2,1.2,.4,1) both; }
.g-toast.out { animation: toast-out .35s ease-in both; }
.g-toast div { display: flex; flex-direction: column; }
.g-toast span { font-size: .78rem; color: var(--fg-mute); }
.g-toast.xp { padding: 6px 12px; font-size: .82rem; }
.g-toast.xp .gi { color: #f59e0b; }
.g-toast.level { border-color: color-mix(in srgb, #eab308 60%, var(--line)); background: linear-gradient(135deg, color-mix(in srgb, #eab308 14%, var(--bg)), var(--bg)); padding: 12px 18px; }
.g-toast.level .gi { width: 28px; height: 28px; color: #eab308; }
.g-toast.goal .gi { color: #f97316; }
.g-toast.freeze .gi { color: #38bdf8; }
@keyframes toast-in { from { opacity: 0; transform: translateY(16px) scale(.96); } }
@keyframes toast-out { to { opacity: 0; transform: translateY(10px); } }
.g-confetti { position: fixed; inset: 0; z-index: 94; pointer-events: none; overflow: hidden; }
.g-confetti i { position: absolute; top: -12px; left: var(--x); width: 8px; height: 12px; border-radius: 2px; animation: fall var(--t) cubic-bezier(.3,.5,.6,1) forwards; }
@keyframes fall { to { transform: translate(var(--dx), 105vh) rotate(var(--r)); opacity: .2; } }
/* medals */
.g-medal { display: inline-grid; place-items: center; flex: none; width: 40px; height: 40px; border-radius: 50%; color: #fff; background: var(--bg-soft); }
.g-medal .gi { width: 20px; height: 20px; }
.g-medal.big { width: 54px; height: 54px; }
.g-medal.big .gi { width: 26px; height: 26px; }
.g-medal.t0 { color: var(--fg-mute); background: var(--bg-soft); box-shadow: inset 0 0 0 2px var(--line); }
.g-medal.t1 { background: radial-gradient(circle at 30% 30%, #f3b37b, #b45309); box-shadow: 0 3px 10px rgba(180, 83, 9, .35); }
.g-medal.t2 { background: radial-gradient(circle at 30% 30%, #f1f5f9, #64748b); box-shadow: 0 3px 10px rgba(100, 116, 139, .35); }
.g-medal.t3 { background: radial-gradient(circle at 30% 30%, #fde68a, #ca8a04); box-shadow: 0 3px 12px rgba(202, 138, 4, .4); }
/* app pages */
html[data-kind="app"] main > * { max-width: 64rem; }
.gm-loading { color: var(--fg-mute); }
.g-top { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; margin-bottom: 8px; }
.g-card { display: flex; align-items: center; gap: 12px; padding: 14px; border-radius: 16px; border: 1px solid var(--card-line); background: var(--card); color: var(--fg); text-decoration: none; min-width: 0; }
a.g-card:hover { border-color: var(--accent); transform: translateY(-2px); box-shadow: var(--shadow); }
.g-card > div:last-child { min-width: 0; flex: 1; }
.g-k { font-size: .75rem; color: var(--fg-mute); font-weight: 600; }
.g-v { font-weight: 800; font-size: 1.02rem; line-height: 1.5; }
.g-card small { display: block; font-size: .74rem; color: var(--fg-mute); margin-top: 4px; }
.g-flame { display: grid; place-items: center; width: 54px; height: 54px; border-radius: 50%; background: var(--bg-soft); color: var(--fg-mute); flex: none; }
.g-flame .gi { width: 28px; height: 28px; }
.g-streak.lit .g-flame { background: color-mix(in srgb, #f97316 14%, var(--bg-soft)); color: #f97316; }
.g-streak.lit .g-flame .gi { fill: color-mix(in srgb, #f97316 35%, transparent); animation: flicker 2.4s ease-in-out infinite; }
@keyframes flicker { 0%, 100% { transform: scale(1); } 50% { transform: scale(1.08) rotate(-3deg); } }
.g-bar { height: 8px; border-radius: 999px; background: color-mix(in srgb, var(--fg-mute) 18%, transparent); overflow: hidden; margin: 6px 0 2px; }
.g-bar i { display: block; height: 100%; border-radius: inherit; background: var(--grad); transition: width .6s cubic-bezier(.2,.7,.2,1); }
.g-sec { margin: 28px 0; }
.g-sec h2 { font-size: 1.2rem; margin: 0 0 4px; }
.g-sub { color: var(--fg-mute); font-size: .85rem; margin: 0 0 12px; }
.g-nudges { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 10px; }
.g-nudge { display: flex; align-items: center; gap: 12px; padding: 12px 16px; border-radius: 14px; border: 1px solid var(--card-line); background: var(--card); color: var(--fg); text-decoration: none; flex: 1 1 18rem; transition: border-color .15s, transform .15s; }
.g-nudge:hover { border-color: var(--accent); transform: translateY(-2px); }
.g-nudge .gi { width: 24px; height: 24px; color: var(--accent); }
.g-nudge span { display: flex; flex-direction: column; }
.g-nudge small { color: var(--fg-mute); font-size: .76rem; }
.heat-wrap { overflow-x: auto; padding: 8px 2px 4px; }
.heat { display: grid; grid-auto-flow: column; grid-template-rows: repeat(7, 13px); grid-auto-columns: 13px; gap: 3px; width: max-content; }
.heat i, .heat-legend i { display: block; width: 13px; height: 13px; border-radius: 3px; background: color-mix(in srgb, var(--fg-mute) 14%, transparent); }
.heat .h1, .heat-legend .h1 { background: color-mix(in srgb, var(--accent-3) 30%, transparent); }
.heat .h2, .heat-legend .h2 { background: color-mix(in srgb, var(--accent-3) 55%, transparent); }
.heat .h3, .heat-legend .h3 { background: color-mix(in srgb, var(--accent-3) 80%, transparent); }
.heat .h4, .heat-legend .h4 { background: var(--accent-3); }
.heat .h-fz, .heat-legend .h-fz { background: color-mix(in srgb, #38bdf8 45%, transparent); }
.heat .h-x { background: transparent; }
.heat .h-today { outline: 2px solid var(--accent); outline-offset: 1px; }
.heat .h-gm { box-shadow: inset 0 0 0 1.5px color-mix(in srgb, var(--fg) 25%, transparent); }
.heat-legend { display: flex; align-items: center; gap: 4px; margin-top: 8px; font-size: .74rem; color: var(--fg-mute); }
.heat-legend span { margin: 0 4px; }
.g-stats { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 10px; }
.g-stats div { padding: 12px; border-radius: 14px; border: 1px solid var(--card-line); background: var(--card); }
.g-stats b { display: block; font-size: 1.1rem; font-variant-numeric: tabular-nums; }
.g-stats span { font-size: .76rem; color: var(--fg-mute); }
.quests, .paths, .badges { list-style: none; margin: 0; padding: 0; }
.quests { display: grid; gap: 8px; }
.quests li { display: flex; align-items: center; gap: 12px; padding: 10px 14px; border-radius: 14px; border: 1px solid var(--card-line); background: var(--card); }
.quests li > div { flex: 1; }
.quests .q-ic .gi { width: 22px; height: 22px; color: var(--accent); }
.quests li.done { border-color: color-mix(in srgb, var(--accent-3) 50%, var(--card-line)); }
.quests li.done .q-ic .gi { color: var(--accent-3); }
.q-n { font-size: .8rem; color: var(--fg-mute); font-variant-numeric: tabular-nums; }
.paths { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.paths li { display: flex; align-items: center; gap: 12px; padding: 12px 14px; border-radius: 14px; border: 1px solid var(--card-line); background: var(--card); }
.paths li > div:nth-child(2) { flex: 1; min-width: 0; }
.paths li small { display: block; color: var(--fg-mute); font-size: .76rem; }
.paths li.done { border-color: color-mix(in srgb, #ca8a04 50%, var(--card-line)); }
.paths .ring { width: 40px; height: 40px; }
.p-chips { display: flex; flex-wrap: wrap; gap: 4px; margin-top: 6px; }
.p-chips .chip { font-size: .72rem; padding: 0 6px; }
.paths .btn { padding: 6px 12px; font-size: .82rem; }
.badges { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 10px; }
.badge { display: flex; flex-direction: column; align-items: center; text-align: center; gap: 4px; padding: 14px 10px; border-radius: 16px; border: 1px solid var(--card-line); background: var(--card); transition: transform .2s, box-shadow .2s; }
.badge:hover { transform: translateY(-3px); box-shadow: var(--shadow); }
.badge b { font-size: .86rem; }
.badge small { font-size: .72rem; color: var(--fg-mute); line-height: 1.5; }
.badge.t0 .g-medal { filter: grayscale(1); opacity: .7; }
.badge.t0 b { color: var(--fg-soft); }
.badge.hid { border-style: dashed; }
.badge .g-bar { width: 100%; height: 6px; }
.b-tier { font-size: .68rem; font-weight: 700; padding: 1px 8px; border-radius: 999px; background: var(--bg-soft); color: var(--fg-mute); }
.badge.t1 .b-tier { background: color-mix(in srgb, #b45309 16%, transparent); color: #b45309; }
.badge.t2 .b-tier { background: color-mix(in srgb, #64748b 18%, transparent); color: var(--fg-soft); }
.badge.t3 .b-tier { background: color-mix(in srgb, #ca8a04 18%, transparent); color: #a16207; }
html[data-theme="dark"] .badge.t3 .b-tier { color: #fde047; }
html[data-theme="dark"] .badge.t1 .b-tier { color: #fdba74; }
.b-p { font-size: .7rem; color: var(--fg-mute); font-variant-numeric: tabular-nums; }
/* settings */
.g-set { display: flex; align-items: flex-start; gap: 12px; padding: 10px 0; border-bottom: 1px solid var(--line); }
.g-set label { cursor: pointer; font-weight: 600; font-size: .92rem; }
.g-set small { display: block; font-weight: 400; color: var(--fg-mute); font-size: .78rem; margin-top: 2px; }
.g-switch { flex: none; position: relative; width: 44px; height: 26px; border-radius: 999px; border: 0; padding: 0; background: color-mix(in srgb, var(--fg-mute) 35%, transparent); cursor: pointer; transition: background .2s; margin-top: 2px; }
.g-switch .knob { position: absolute; top: 3px; inset-inline-start: 3px; width: 20px; height: 20px; border-radius: 50%; background: #fff; box-shadow: 0 1px 3px rgba(0,0,0,.3); transition: inset-inline-start .2s; }
.g-switch[aria-checked="true"] { background: var(--accent-3); }
.g-switch[aria-checked="true"] .knob { inset-inline-start: 21px; }
.g-switch:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.g-goalpick { border: 0; padding: 12px 0 4px; margin: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.g-goalpick legend { font-weight: 600; font-size: .92rem; margin-bottom: 8px; padding: 0; }
.pill { position: relative; }
.pill input { position: absolute; opacity: 0; inset: 0; }
.pill span { display: inline-block; padding: 6px 14px; border-radius: 999px; border: 1px solid var(--line); font-size: .84rem; cursor: pointer; transition: all .15s; }
.pill input:checked + span { background: color-mix(in srgb, var(--accent) 14%, transparent); border-color: var(--accent); color: var(--accent); font-weight: 700; }
.pill input:focus-visible + span { outline: 2px solid var(--accent); outline-offset: 2px; }
.g-acts { display: flex; flex-wrap: wrap; gap: 8px; margin: 14px 0 8px; }
.g-acts .btn { padding: 7px 14px; font-size: .85rem; }
/* review */
.rv-tabs { display: flex; gap: 4px; border-bottom: 1px solid var(--line); margin-bottom: 18px; overflow-x: auto; }
.rv-tabs [role="tab"] { padding: 10px 14px; border: 0; background: none; color: var(--fg-mute); font: inherit; font-weight: 600; font-size: .9rem; cursor: pointer; border-bottom: 3px solid transparent; margin-bottom: -1px; white-space: nowrap; }
.rv-tabs [role="tab"][aria-selected="true"] { color: var(--accent); border-color: var(--accent); }
.rv-tabs [role="tab"]:focus-visible { outline: 2px solid var(--accent); outline-offset: -2px; border-radius: 6px; }
.rv-pick, .rv-gloss { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; font-size: .88rem; }
.rv-pick select { font: inherit; padding: 6px 10px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); color: var(--fg); max-width: 100%; }
.rv-meta { display: flex; justify-content: space-between; font-size: .8rem; color: var(--fg-mute); }
.flash { margin: 14px 0; padding: 26px 24px; min-height: 180px; border-radius: 20px; border: 1px solid var(--card-line); background: var(--card); box-shadow: var(--shadow); }
.flash.flip { animation: flipin .45s cubic-bezier(.2,.8,.2,1); }
@keyframes flipin { 0% { transform: perspective(900px) rotateX(10deg); opacity: .6; } 100% { transform: none; opacity: 1; } }
.f-q { font-size: 1.15rem; font-weight: 700; line-height: 1.9; }
.f-a { margin-top: 16px; padding-top: 16px; border-top: 1px dashed var(--line); line-height: 2; }
.f-src { margin-top: 10px; font-size: .78rem; }
.rv-acts { display: flex; justify-content: center; }
.rv-rate { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.rv-rate[hidden] { display: none; }
.rv-rate .r0:hover { border-color: #dc2626; color: #dc2626; }
.rv-rate .r1:hover { border-color: #d97706; color: #d97706; }
.rv-rate .r2 { border-color: color-mix(in srgb, var(--accent-3) 60%, var(--line)); }
.rv-rate .r2:hover { border-color: var(--accent-3); color: var(--accent-3); }
.rv-acts kbd, .qz-o kbd { font-size: .7rem; padding: 0 5px; border-radius: 5px; border: 1px solid var(--line); background: var(--bg-soft); color: var(--fg-mute); margin-inline-start: 4px; font-family: inherit; }
.rv-keys { text-align: center; margin-top: 12px; font-size: .76rem; }
.rv-empty, .rv-done { text-align: center; padding: 30px 10px; color: var(--fg-soft); }
.rv-empty .gi { display: block; width: 36px; height: 36px; margin: 0 auto 10px; color: var(--fg-mute); }
.rv-done .g-medal { margin-bottom: 8px; }
.qz-p { font-weight: 700; font-size: 1.05rem; margin: 14px 0 8px; }
.qz-def { margin: 0 0 12px; padding: 12px 16px; border-radius: 12px; background: var(--bg-soft); border-inline-start: 3px solid var(--accent); }
.qz-opts { display: grid; gap: 8px; }
.qz-o { display: flex; align-items: flex-start; gap: 10px; text-align: start; padding: 10px 14px; border-radius: 12px; border: 1px solid var(--line); background: var(--card); color: var(--fg); font: inherit; font-size: .9rem; line-height: 1.8; cursor: pointer; transition: border-color .15s, transform .15s, background .15s; }
.qz-o:hover:not(:disabled) { border-color: var(--accent); transform: translateY(-1px); }
.qz-o:disabled { cursor: default; }
.qz-o.right { border-color: var(--accent-3); background: color-mix(in srgb, var(--accent-3) 12%, var(--card)); }
.qz-o.wrong { border-color: #dc2626; background: color-mix(in srgb, #dc2626 10%, var(--card)); animation: shake .35s; }
@keyframes shake { 25% { transform: translateX(-4px); } 75% { transform: translateX(4px); } }
.qz-fb { min-height: 1.6em; font-weight: 700; margin: 10px 0; }
.qz-fb.ok { color: var(--accent-3); }
.qz-fb.bad { color: #dc2626; }
/* certificate */
.cert-form { display: flex; flex-wrap: wrap; align-items: center; gap: 8px 12px; margin-bottom: 18px; }
.cert-form input { font: inherit; padding: 8px 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); color: var(--fg); min-width: 16rem; }
.cert-form small { color: var(--fg-mute); font-size: .78rem; flex-basis: 100%; }
.cert { padding: 10px; border-radius: 20px; background: var(--grad); }
.cert-in { padding: 34px 30px; border-radius: 14px; background: var(--bg); text-align: center; }
.cert-k { letter-spacing: .08em; font-size: .85rem; font-weight: 700; color: var(--accent); margin-top: 10px; }
.cert-path { font-size: 1.6rem; margin: 8px 0 14px; }
.cert-body { font-size: 1.05rem; line-height: 2.1; max-width: 40rem; margin: 0 auto 14px; }
.cert-chs { display: inline-block; text-align: start; margin: 0 auto 14px; font-size: .88rem; color: var(--fg-soft); }
.cert-foot { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; border-top: 1px solid var(--line); padding-top: 12px; font-size: .85rem; }
.cert-note { font-size: .74rem; color: var(--fg-mute); margin: 10px 0 0; }
@media (max-width: 900px) {
  .g-top, .g-stats { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .paths { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .g-top { grid-template-columns: 1fr; }
  .g-chip .g-l { display: none; }
  .g-chip { padding: 0 8px; }
  .badges { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .quiz-cta { flex-wrap: wrap; }
  .flash { padding: 18px 16px; }
}
@media (prefers-reduced-motion: reduce) { .g-confetti { display: none !important; } }
@media (max-width: 480px) { .g-chip { display: none !important; } }

/* ---- language chooser ---- */
body.chooser main { max-width: 760px; margin: 0 auto; padding: 8vh 20px; text-align: center; }
body.chooser h1 { font-size: 1.6rem; }
.choose-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; margin-top: 28px; }
.choose-card { display: flex; flex-direction: column; align-items: center; gap: 10px; padding: 18px; border: 1px solid var(--line); border-radius: 14px; text-decoration: none; color: var(--fg); font-weight: 700; }
.choose-card:hover { border-color: var(--accent); box-shadow: var(--shadow); }
.choose-card img { width: 100%; max-width: 240px; height: auto; border-radius: 6px; }
.choose-card[lang="fa"] { font-family: 'Vazirmatn', sans-serif; }
.choose-card small { font-weight: 400; color: var(--fg-mute); }
.lic { color: var(--fg-mute); font-size: .8rem; margin-top: 30px; }
@media (max-width: 600px) { .choose-grid { grid-template-columns: 1fr; } }

/* ---- print ---- */
@page { margin: 18mm 16mm; }
/* ---- UI consistency: one font, one control scale ----
   Browsers give <button>, <input>, <select> and <textarea> their own system font (13.33px);
   every control inherits the site font instead (Vazirmatn in fa, Inter in en). */
:root { --ctl-fs: .875rem; --ctl-fs-sm: .8rem; --ctl-fw: 600; --ctl-lh: 1.4; }
button, input, select, textarea, optgroup { font: inherit; font-family: var(--font-body); letter-spacing: inherit; line-height: var(--ctl-lh); }
.btn, .sim-btn, .read-tog, .tb-cta, .g-chip, .hbadge, .pill span, .rv-tabs [role="tab"], .rv-rate .btn, .rv-acts .btn,
.rp-acts .btn, .my-actions .btn, .g-acts .btn, .paths .btn, .quiz-cta .btn, .file-btn, .icon-btn {
  font-family: var(--font-body); font-size: var(--ctl-fs); font-weight: var(--ctl-fw); line-height: var(--ctl-lh); }
.sim-btn.sm, .sim-seg button, .cr-tg, .chip, .p-chips .chip, .b-tier, .lang-btn { font-family: var(--font-body); font-size: var(--ctl-fs-sm); line-height: var(--ctl-lh); }
.sim-seg button { font-weight: 500; }
.qz-o { font-family: var(--font-body); font-weight: 400; }
.sim-seg button[aria-checked="true"], .sim-seg button[aria-pressed="true"] { font-weight: 700; }
input, select, textarea, .sim input[type=number], .sim input[type=text], .sim select, .rv-pick select, .cert-form input, #search-input {
  font-family: var(--font-body); font-weight: 400; line-height: var(--ctl-lh); }
.sim input[type=number], .sim input[type=text], .sim select, .rv-pick select, .cert-form input { font-size: var(--ctl-fs); }
.sim input[type=number] { font-variant-numeric: tabular-nums; }
.cr-tg { font-variant-numeric: tabular-nums; font-weight: 600; }

/* ---- equal cards: badge gallery, learning paths, weekly challenges, part cards ---- */
.badges { grid-template-columns: repeat(auto-fill, minmax(168px, 1fr)); grid-auto-rows: 1fr; align-items: stretch; }
.badge { height: 100%; box-sizing: border-box; justify-content: flex-start; min-width: 0; }
.content li.badge { text-align: center; }
.content .paths li, .content .quests li { text-align: start; }
.badge .g-medal { flex: none; }
.badge b { display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 2; line-clamp: 2; overflow: hidden;
  line-height: 1.45; min-height: calc(2 * 1.45em); width: 100%; overflow-wrap: anywhere; text-align: center; }
.badge small { display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 3; line-clamp: 3; overflow: hidden; width: 100%; text-align: center; hyphens: none; }
.badge .b-tier, .badge .g-bar:first-of-type { margin-top: auto; }
.badge small + .g-bar, .badge small + .b-tier { margin-top: auto; }
.badge .b-tier + .g-bar { margin-top: 6px; }
.paths { grid-auto-rows: 1fr; }
.paths li { height: 100%; box-sizing: border-box; }
.quests li { min-height: 3.6rem; box-sizing: border-box; }
.hgrid { align-items: stretch; }
.hcard, .pcard { height: 100%; box-sizing: border-box; }
.hcard .hc-go { margin-top: auto; }
@media (max-width: 600px) { .badges { grid-template-columns: repeat(2, minmax(0, 1fr)); } .badge { padding: 12px 8px; } }

@media print {
  :root, html[data-theme="dark"] { --bg: #fff; --fg: #000; --fg-soft: #222; --fg-mute: #444; --line: #bbb; --code-bg: #f6f6f6; --code-fg: #000; --link: #000; }
  .topbar, .sidebar, .toc, .toc-inline, .pager, .crumbs, .copy, .hanchor, .backdrop, .search-dlg, .lb, .skip, .site-foot, .home .cta, .tb-cta, .term, .glow, .hbadge, .chips, .game, .g-chip, .g-toasts, .g-confetti, .quiz-cta, .rp-game, .g-settings, .cert-form, .rbar, .totop, .my-dlg, .rp, .hbm, .read-tog, .mk-btn, .sb-st { display: none !important; }
  .rv { opacity: 1 !important; transform: none !important; }
  html[data-slug="certificate"] .page-head, html[data-slug="certificate"] .crumbs { display: none !important; }
  .cert { background: none; padding: 0; border: 3px double #000; }
  .cert-in { padding: 24mm 16mm; }
  .content h2.marked, .content h3.marked { background: none; box-shadow: none; padding: 0; }
  .layout { display: block; }
  main { padding: 0; }
  main > * { max-width: none; }
  body { font-size: 11pt; line-height: 1.55; }
  .content h2, .content h3 { break-after: avoid; }
  .content figure, .call, .code, .table-wrap, .sum { break-inside: avoid; }
  .code pre { white-space: pre-wrap; max-height: none !important; overflow: visible; }
  .content figure img { border: 0; padding: 0; max-height: 18cm; }
  .table-wrap { overflow: visible; border: 0; }
  a { text-decoration: none; }
  html[data-theme="dark"] .hl * { color: #000 !important; }
}
/* inline math (KaTeX, pre-rendered at build time): always LTR and isolated inside RTL prose */
.math { direction: ltr; unicode-bidi: isolate; white-space: nowrap; }
.math .katex { font-size: 1.06em; }
html[data-theme="dark"] .math .katex { color: inherit; }

/* Ceph release labels (Reef+, Squid+ ...) on command blocks; see tools/booklib/cephver.py */
.code-head .ch-l { display: inline-flex; align-items: center; gap: 8px; }
.since { display: inline-block; font: 700 .68rem/1.5 var(--font-mono); color: #fff; background: #4b5563; border-radius: 999px; padding: 0 8px; text-decoration: none; letter-spacing: .02em; white-space: nowrap; direction: ltr; unicode-bidi: isolate; }
a.since:hover { filter: brightness(1.12); text-decoration: none; }
.since.s-reef { background: #2f6f4f; } .since.s-squid { background: #1d5fa8; } .since.s-tentacle { background: #7a3fa0; }
.since.s-umbrella { background: #a6531b; } .since.s-main { background: #b42318; } .since.s-quincy { background: #5b6472; }
.cmds .since { margin-inline-start: 6px; font-size: .62rem; vertical-align: middle; }

/* appendix: changes in Reef, Squid and Tentacle */
.relchg td.area, .relchg td.st { white-space: nowrap; }
.relchg span.st-review { color: var(--c-warn, #a6531b); font-weight: 700; }
.relchg span.st-review::before { content: "⚑ "; }
.relchg span.st-confirmed { color: var(--c-tip, #2f6f4f); }
.rel-meta { font-size: .9rem; color: var(--fg-soft); }
h2 .since { vertical-align: middle; font-size: .8rem; }

/* chapter-opening TL;DR («حوصله ندارم»): collapsible, open by default */
details.tldr { --cc: #a86f00; --cb: #fff7e3; margin: .6em 0 1.6em; padding: 10px 16px; border-radius: 10px; background: var(--cb);
  border: 1px solid color-mix(in srgb, var(--cc) 30%, transparent); border-inline-start: 4px solid var(--cc); }
html[data-theme="dark"] details.tldr { --cc: #f0b84a; --cb: #2a2213; }
details.tldr > summary { cursor: pointer; font-weight: 700; color: var(--cc); display: flex; align-items: baseline; gap: 8px; list-style: none; }
details.tldr > summary::-webkit-details-marker { display: none; }
details.tldr > summary::before { content: "⚡"; }
details.tldr > summary::after { content: "▾"; margin-inline-start: auto; transition: transform .2s; }
details.tldr:not([open]) > summary::after { transform: rotate(90deg); }
details.tldr > summary .s { font-weight: 400; font-size: .85rem; color: var(--fg-soft); }
details.tldr > ul { margin: .5em 0 0; }
details.tldr > ul > li { margin: .25em 0; }
@media print { details.tldr { break-inside: avoid; } }

/* "Edit this page" */
.ph-meta .edit-link { display: inline-flex; align-items: center; gap: 5px; margin-inline-start: auto; font-size: .85rem; color: var(--fg-mute); text-decoration: none; }
.ph-meta .edit-link:hover { color: var(--link); text-decoration: underline; }
/* "Was this section helpful?" */
.fb { display: flex; flex-wrap: wrap; align-items: center; gap: 6px 10px; margin: 1.6em 0 1.2em; padding: 6px 0; border-top: 1px dashed var(--line); font-size: .85rem; color: var(--fg-mute); }
.fb[hidden] { display: none; }
.fb .fb-b { font: inherit; font-size: .82rem; padding: 2px 10px; border-radius: 999px; border: 1px solid var(--line); background: transparent; color: var(--fg-soft); cursor: pointer; }
.fb .fb-b:hover:not(:disabled) { border-color: var(--accent); color: var(--fg); }
.fb .fb-b[aria-pressed="true"] { background: color-mix(in srgb, var(--accent) 18%, transparent); border-color: var(--accent); color: var(--fg); }
.fb .fb-b:disabled { cursor: default; }
.fb .fb-t a { color: var(--link); }
@media print { .fb, .ph-meta .edit-link { display: none !important; } }
/* newsletter / release notices */
.newsletter .nl-form { display: flex; flex-wrap: wrap; gap: 8px; max-width: 34rem; }
.newsletter .nl-form input[type=email] { flex: 1 1 16rem; font: inherit; padding: 8px 12px; border-radius: 10px; border: 1px solid var(--line); background: var(--bg); color: var(--fg); }
.newsletter .nl-acts { display: flex; flex-wrap: wrap; gap: 10px; }
.newsletter .nl-hint, .newsletter .nl-privacy { font-size: .85rem; color: var(--fg-mute); max-width: 46rem; }
.site-foot .privacy { font-size: .8rem; color: var(--fg-mute); }
.sr-only { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }