/* math20.org — minimal academic reading room. */
:root {
  --paper: #fbfaf6;
  --paper-2: #f3f1ea;
  --ink: #1b1a17;
  --ink-2: #3d3a34;
  --muted: #6f6a60;
  --rule: #e2ded3;
  --accent: #8c2b1f;          /* oxblood, used sparingly */
  --accent-soft: #8c2b1f14;
  --card: #ffffff;
  --shadow: 0 1px 2px #0000000a, 0 8px 24px -12px #00000024;
  --a-geometry: #5b4a8b;
  --a-discrete: #2f6c8f;
  --a-analysis: #2e7d5b;
  --a-algebra: #a8742a;
  --a-physics: #a4473a;
  --serif: "Newsreader", "Iowan Old Style", "Palatino Linotype", Georgia, serif;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, monospace;
  --ease: cubic-bezier(.2, .7, .2, 1);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #14130f; --paper-2: #1b1a15; --ink: #ece8de; --ink-2: #cfc9bb; --muted: #9a9384;
    --rule: #2e2b24; --accent: #e08b6f; --accent-soft: #e08b6f1a; --card: #1a1914;
    --shadow: 0 1px 2px #00000040, 0 10px 30px -14px #00000090;
    --a-geometry: #a596d6; --a-discrete: #7fb5d4; --a-analysis: #7cc4a0; --a-algebra: #d9a95f; --a-physics: #df8c7d;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --paper: #14130f; --paper-2: #1b1a15; --ink: #ece8de; --ink-2: #cfc9bb; --muted: #9a9384;
  --rule: #2e2b24; --accent: #e08b6f; --accent-soft: #e08b6f1a; --card: #1a1914;
  --shadow: 0 1px 2px #00000040, 0 10px 30px -14px #00000090;
  --a-geometry: #a596d6; --a-discrete: #7fb5d4; --a-analysis: #7cc4a0; --a-algebra: #d9a95f; --a-physics: #df8c7d;
  color-scheme: dark;
}
.a-geometry { --area: var(--a-geometry); }
.a-discrete { --area: var(--a-discrete); }
.a-analysis { --area: var(--a-analysis); }
.a-algebra  { --area: var(--a-algebra); }
.a-physics  { --area: var(--a-physics); }

/* ---------------------------------------------------------------- base */
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 400 1.0625rem/1.6 var(--serif); font-optical-sizing: auto;
  text-rendering: optimizeLegibility; -webkit-font-smoothing: antialiased;
  animation: page-in .5s var(--ease) both;   /* fallback where view transitions are unsupported */
}
@keyframes page-in { from { opacity: 0; transform: translateY(6px); } }
.wrap { max-width: 1120px; margin: 0 auto; padding: 0 20px; }
a { color: inherit; text-decoration-color: color-mix(in srgb, currentColor 35%, transparent);
    text-underline-offset: .18em; transition: color .2s, text-decoration-color .2s; }
a:hover { color: var(--accent); text-decoration-color: currentColor; }
h1, h2, h3 { font-weight: 500; letter-spacing: -.01em; line-height: 1.15; margin: 0; }
h1 { font-size: clamp(2.1rem, 4.6vw, 3.4rem); font-weight: 400; }
h2 { font-size: 1.6rem; font-weight: 400; }
h3 { font-size: 1.15rem; }
p { margin: .6em 0; }
.muted { color: var(--muted); }
code, pre { font-family: var(--mono); font-size: .82em; }
.eyebrow { font: 500 .74rem/1.4 var(--sans); letter-spacing: .14em; text-transform: uppercase;
           color: var(--muted); margin: 0 0 .9rem; }
.eyebrow a { text-decoration: none; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 12px; top: 12px; background: var(--card); padding: 6px 10px; z-index: 50; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 3px; }

/* ---------------------------------------------------------------- header */
.top { position: sticky; top: 0; z-index: 20; background: color-mix(in srgb, var(--paper) 86%, transparent);
       backdrop-filter: saturate(1.4) blur(10px); border-bottom: 1px solid var(--rule);
       view-transition-name: top; }
.top-in { display: flex; align-items: center; gap: 22px; height: 60px; }
.brand { display: flex; align-items: baseline; gap: 8px; text-decoration: none; font-size: 1.35rem; }
.brand-mark { font-size: 1.3rem; color: var(--accent); transform: translateY(1px); }
.brand-word em { font-style: italic; color: var(--accent); }
.nav { display: flex; gap: 18px; font: 500 .86rem var(--sans); }
.nav a { text-decoration: none; color: var(--ink-2); }
.search { position: relative; margin-left: auto; }
.search input { width: 260px; font: .88rem var(--sans); padding: 8px 34px 8px 12px; border-radius: 8px;
                border: 1px solid var(--rule); background: var(--card); color: var(--ink);
                transition: width .35s var(--ease), border-color .2s; }
.search input:focus { width: 340px; border-color: var(--accent); outline: none; }
.search kbd { position: absolute; right: 9px; top: 50%; transform: translateY(-50%); font: .72rem var(--mono);
              color: var(--muted); border: 1px solid var(--rule); border-radius: 4px; padding: 0 5px; }
.results { position: absolute; right: 0; top: calc(100% + 8px); width: min(520px, 92vw); max-height: 70vh;
           overflow: auto; background: var(--card); border: 1px solid var(--rule); border-radius: 12px;
           box-shadow: var(--shadow); padding: 6px; animation: drop .22s var(--ease); }
@keyframes drop { from { opacity: 0; transform: translateY(-6px); } }
.results a { display: grid; grid-template-columns: 44px 1fr; gap: 2px 10px; padding: 9px 10px;
             border-radius: 8px; text-decoration: none; }
.results a:hover, .results a.sel { background: var(--accent-soft); color: inherit; }
.results .n { grid-row: span 2; font: 500 .82rem var(--mono); color: var(--accent); padding-top: 2px; }
.results .t { font-size: .98rem; line-height: 1.3; }
.results .d { font: .74rem var(--sans); color: var(--muted); }
.results .none { padding: 12px; color: var(--muted); font: .88rem var(--sans); }
.theme { border: 1px solid var(--rule); background: none; color: var(--ink-2); width: 34px; height: 34px;
         border-radius: 50%; cursor: pointer; font-size: 1rem; transition: transform .4s var(--ease); }
.theme:hover { transform: rotate(180deg); }

.crumbs { font: .82rem var(--sans); color: var(--muted); padding: 22px 0 0; display: flex; flex-wrap: wrap; gap: 8px; }
.crumbs a { text-decoration: none; }
.crumbs .sep { opacity: .5; }

/* ---------------------------------------------------------------- buttons, badges */
.btn { display: inline-flex; align-items: center; gap: 6px; font: 500 .9rem var(--sans); text-decoration: none;
       padding: 10px 18px; border-radius: 999px; background: var(--ink); color: var(--paper);
       border: 1px solid var(--ink); transition: transform .25s var(--ease), background .2s, color .2s; }
.btn:hover { color: var(--paper); background: var(--accent); border-color: var(--accent); transform: translateY(-1px); }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--rule); }
.btn.ghost:hover { border-color: var(--accent); color: var(--accent); }
.btn.sm { padding: 6px 13px; font-size: .8rem; }
.badges { display: flex; flex-wrap: wrap; gap: 6px; margin-top: 10px; }
.badge { font: 500 .7rem/1 var(--sans); letter-spacing: .04em; padding: 5px 8px; border-radius: 999px;
         border: 1px solid var(--rule); color: var(--muted); }
.badge.lean { color: var(--a-analysis); border-color: color-mix(in srgb, var(--a-analysis) 40%, transparent); }
.badge.trace { color: var(--a-geometry); border-color: color-mix(in srgb, var(--a-geometry) 40%, transparent); }
.badge.vid { color: var(--accent); border-color: color-mix(in srgb, var(--accent) 40%, transparent); }

/* ---------------------------------------------------------------- reveal on scroll */
/* hidden only when JS runs (html.js), so content never depends on the script */
.js .reveal { opacity: 0; transform: translateY(14px); transition: opacity .7s var(--ease), transform .7s var(--ease);
              transition-delay: calc(var(--i, 0) * 55ms); }
.js .reveal.in { opacity: 1; transform: none; }

/* ---------------------------------------------------------------- home */
.hero { display: grid; grid-template-columns: 1.05fr 1fr; gap: 56px; align-items: center; padding: 72px 0 56px; }
.hero h1 { font-size: clamp(2.6rem, 6vw, 4.6rem); line-height: 1.02; letter-spacing: -.02em; }
.hero h1 em { color: var(--accent); }
.lede { font-size: 1.2rem; color: var(--ink-2); max-width: 36ch; margin-top: 1.2rem; }
.cta { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 1.6rem; }
.sec-h { display: flex; justify-content: space-between; align-items: end; gap: 30px; flex-wrap: wrap;
         border-top: 1px solid var(--rule); padding-top: 28px; margin: 40px 0 22px; }
.sec-h p { max-width: 52ch; margin: 0; font-size: .98rem; }

.mosaic { display: grid; grid-template-columns: repeat(auto-fill, minmax(196px, 1fr)); gap: 22px 26px; }
.mlabel { display: block; font: 500 .74rem var(--sans); letter-spacing: .03em; color: var(--ink-2);
          text-decoration: none; margin-bottom: 7px; border-left: 2px solid var(--area); padding-left: 7px; }
.mcells { display: flex; flex-wrap: wrap; gap: 3px; }
.cell { width: 13px; height: 13px; border-radius: 2px; border: 1.5px solid var(--area); background: transparent;
        transition: transform .25s var(--ease), background .2s; }
.js .mosaic .cell { opacity: 0; animation: pop .5s var(--ease) forwards;
                    animation-delay: calc(var(--k) * 14ms + 150ms); animation-play-state: paused; }
.js .mosaic.in .cell { animation-play-state: running; }
.cell.on { background: var(--area); }
.cell:hover { transform: scale(1.6); z-index: 2; position: relative; background: var(--accent); border-color: var(--accent); }
@keyframes pop { from { opacity: 0; transform: scale(.3); } to { opacity: 1; transform: none; } }
.legend { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 22px; font: .78rem var(--sans); color: var(--muted); }
.lg { display: inline-flex; align-items: center; gap: 7px; }
.lg i { width: 11px; height: 11px; border-radius: 2px; border: 1.5px solid var(--area); background: var(--area); }
.lg-k i { --area: var(--muted); background: transparent; }
.lg-k i.f { background: var(--muted); }
.tip { position: fixed; z-index: 40; pointer-events: none; background: var(--ink); color: var(--paper);
       font: .8rem/1.35 var(--sans); padding: 6px 9px; border-radius: 6px; max-width: 320px; box-shadow: var(--shadow); }

.area { margin: 0 0 44px; }
.area-h { display: flex; gap: 18px; align-items: baseline; margin-bottom: 16px; }
.area-n { font: 400 2.3rem/1 var(--serif); color: var(--area); font-style: italic; min-width: 52px; }
.area-h p { margin: 4px 0 0; font-size: .95rem; }
.dgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.dcard { position: relative; display: flex; flex-direction: column; gap: 6px; padding: 18px 18px 16px;
         background: var(--card); border: 1px solid var(--rule); border-radius: 12px; text-decoration: none;
         overflow: hidden; transition: transform .35s var(--ease), box-shadow .35s var(--ease), border-color .3s; }
.dcard::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 3px; background: var(--area);
                 transform: scaleY(.25); transform-origin: top; transition: transform .45s var(--ease); }
.dcard:hover { transform: translateY(-3px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--area) 45%, var(--rule)); color: inherit; }
.dcard:hover::before { transform: none; }
.dname { font-size: 1.18rem; line-height: 1.2; }
.dmeta, .dlean { font: .76rem var(--sans); color: var(--muted); }
.dbar { height: 3px; background: var(--paper-2); border-radius: 2px; overflow: hidden; margin-top: 6px; }
.dbar span { display: block; height: 100%; background: var(--area); transform-origin: left;
             transition: transform 1s var(--ease) .2s; }
.js .dcard:not(.in) .dbar span { transform: scaleX(0); }

.howto { border-top: 1px solid var(--rule); padding: 36px 0 70px; }
.steps { list-style: none; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 22px; margin-top: 22px; }
.steps li { font-size: .98rem; color: var(--ink-2); }
.steps span { display: block; font: italic 400 2rem/1 var(--serif); color: var(--accent); margin-bottom: 8px; }
.steps strong { display: block; color: var(--ink); font-weight: 500; }

/* ---------------------------------------------------------------- videos */
.video { margin: 0; }
.yt { position: relative; display: block; width: 100%; aspect-ratio: 16 / 9; padding: 0; border: 0;
      border-radius: 12px; overflow: hidden; cursor: pointer; background: #000; box-shadow: var(--shadow); }
.yt img { width: 100%; height: 100%; object-fit: cover; transition: transform .6s var(--ease), opacity .3s; opacity: .92; }
.yt:hover img { transform: scale(1.03); opacity: 1; }
.yt .play { position: absolute; left: 50%; top: 50%; width: 68px; height: 68px; margin: -34px 0 0 -34px;
            border-radius: 50%; background: color-mix(in srgb, var(--paper) 92%, transparent);
            transition: transform .3s var(--ease); }
.yt .play::after { content: ""; position: absolute; left: 27px; top: 21px; border-style: solid;
                   border-width: 13px 0 13px 21px; border-color: transparent transparent transparent var(--accent); }
.yt:hover .play { transform: scale(1.08); }
.yt .dur { position: absolute; right: 10px; bottom: 10px; font: 500 .72rem var(--mono); color: #fff;
           background: #000a; padding: 2px 6px; border-radius: 4px; }
.yt iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; }
.video figcaption { font: .84rem var(--sans); color: var(--muted); margin-top: 8px; }
.pending .ph { position: relative; aspect-ratio: 16 / 9; border-radius: 12px; border: 1px dashed var(--rule);
               display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px;
               text-align: center; padding: 16px; overflow: hidden;
               background: linear-gradient(120deg, var(--paper-2), var(--card), var(--paper-2));
               background-size: 300% 100%; animation: shimmer 6s ease-in-out infinite; }
@keyframes shimmer { 50% { background-position: 100% 0; } }
.ph-mark { font-size: 1.4rem; color: var(--muted); opacity: .6; }
.ph-t { font-size: 1.02rem; color: var(--ink-2); max-width: 30ch; }
.ph-s { font: 500 .68rem var(--sans); letter-spacing: .14em; text-transform: uppercase; color: var(--muted); }

/* ---------------------------------------------------------------- discipline page */
.phead { padding: 34px 0 26px; border-bottom: 1px solid var(--rule); margin-bottom: 24px; }
.phead h1 { max-width: 22ch; }
.phead.a-geometry h1, .phead.a-discrete h1, .phead.a-analysis h1, .phead.a-algebra h1, .phead.a-physics h1 { }
.phead .eyebrow { color: var(--area, var(--muted)); }
.filters { display: flex; flex-wrap: wrap; gap: 8px; margin: 0 0 22px; }
.chip { font: 500 .8rem var(--sans); padding: 7px 14px; border-radius: 999px; border: 1px solid var(--rule);
        background: var(--card); color: var(--ink-2); cursor: pointer; transition: all .25s var(--ease); }
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.on { background: var(--ink); color: var(--paper); border-color: var(--ink); }
.flist { display: grid; gap: 12px; padding-bottom: 60px; }
.fcard { position: relative; display: grid; grid-template-columns: 64px 1fr; gap: 18px; padding: 20px 22px;
         background: var(--card); border: 1px solid var(--rule); border-radius: 12px;
         transition: transform .35s var(--ease), box-shadow .35s var(--ease), border-color .3s, opacity .3s; }
.fcard:hover { transform: translateX(4px); box-shadow: var(--shadow); border-color: color-mix(in srgb, var(--area) 45%, var(--rule)); }
.fcard.hide { display: none; }
.fcard-link { position: absolute; inset: 0; z-index: 1; border-radius: 12px; }
.fcard a:not(.fcard-link) { position: relative; z-index: 2; }
.fnum { font: italic 400 1.7rem/1 var(--serif); color: var(--area); padding-top: 2px; }
.ftitle { font-size: 1.28rem; font-weight: 500; }
.fdesc { color: var(--ink-2); font-size: .98rem; margin: .4em 0 0; display: -webkit-box; -webkit-line-clamp: 3;
         -webkit-box-orient: vertical; overflow: hidden; }
.empty { color: var(--muted); font: .9rem var(--sans); }
.ref { font-family: var(--mono); font-size: .9em; }

/* ---------------------------------------------------------------- family page */
.phead.fam h1 { max-width: 26ch; }
.summary { font-size: 1.2rem; line-height: 1.55; color: var(--ink-2); max-width: 68ch; margin-top: 18px; }
.block { padding: 28px 0 10px; }
.block > h2 { margin-bottom: 18px; display: flex; align-items: baseline; gap: 10px; }
.count { font: 500 .8rem var(--sans); color: var(--muted); }
.vgrid { display: grid; grid-template-columns: 1.35fr 1fr; gap: 22px; align-items: start; }
.expl-list { display: grid; gap: 16px; }
.papers { display: grid; gap: 18px; }
.paper { display: grid; grid-template-columns: 150px 1fr; gap: 24px; padding: 22px; background: var(--card);
         border: 1px solid var(--rule); border-radius: 12px; }
.pthumb { display: block; align-self: start; border-radius: 4px; overflow: hidden; border: 1px solid var(--rule);
          background: #fff; aspect-ratio: 8.5 / 11; transition: transform .4s var(--ease), box-shadow .4s var(--ease); }
.pthumb:hover { transform: translateY(-3px) rotate(-.6deg); box-shadow: var(--shadow); }
.pthumb img { width: 100%; height: 100%; object-fit: cover; object-position: top; display: block; }
.nothumb { display: grid; place-items: center; height: 100%; font: .8rem var(--sans); color: var(--muted); }
.paper h3 { font-size: 1.2rem; }
.pmeta { font: .78rem var(--sans); color: var(--muted); margin: 4px 0 10px; }
.abstract { color: var(--ink-2); font-size: .98rem; position: relative; max-height: 9.6em; overflow: hidden;
            transition: max-height .6s var(--ease); }
.abstract.clamped::after { content: ""; position: absolute; inset: auto 0 0 0; height: 3em;
                           background: linear-gradient(transparent, var(--card)); }
.abstract.open { max-height: 80em; }
.abstract.open::after { display: none; }
.more { font: 500 .78rem var(--sans); background: none; border: 0; color: var(--accent); cursor: pointer; padding: 4px 0; }
.vnote { font: .8rem/1.5 var(--sans); color: var(--muted); border-left: 2px solid var(--rule); padding-left: 10px; }
.pact { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.cite { margin-top: 10px; font: .8rem var(--sans); }
.cite summary { cursor: pointer; color: var(--muted); }
.cite pre { background: var(--paper-2); padding: 12px; border-radius: 8px; overflow: auto; font-size: .74rem; line-height: 1.5; }
.copy { font: 500 .76rem var(--sans); border: 1px solid var(--rule); background: var(--card); color: var(--ink-2);
        padding: 5px 10px; border-radius: 6px; cursor: pointer; }
.prose { max-width: 72ch; color: var(--ink-2); }
.prose h3 { margin: 1.4em 0 .4em; font-size: 1.1rem; }
.prose.narrow { padding-bottom: 60px; }
.prose.narrow h2 { margin: 1.6em 0 .4em; }
.table { overflow-x: auto; }
table { border-collapse: collapse; font: .86rem var(--sans); margin: .8em 0; }
th, td { text-align: left; padding: 8px 12px; border-bottom: 1px solid var(--rule); vertical-align: top; }
th { color: var(--muted); font-weight: 500; }
.lean.none p { max-width: 60ch; }
.related { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 10px; }
.rel { display: flex; gap: 12px; align-items: baseline; padding: 12px 14px; border: 1px solid var(--rule);
       border-radius: 10px; text-decoration: none; background: var(--card); transition: transform .3s var(--ease), border-color .3s; }
.rel:hover { transform: translateY(-2px); border-color: var(--accent); }
.rel span { font: italic 1.1rem var(--serif); color: var(--accent); }
.pn { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; border-top: 1px solid var(--rule);
      margin: 40px 0 60px; padding-top: 22px; }
.pn a { text-decoration: none; display: flex; flex-direction: column; gap: 4px; font-size: 1.05rem; }
.pn small { font: .74rem var(--sans); color: var(--muted); letter-spacing: .06em; }
.pn .next { text-align: right; align-items: flex-end; }

/* ---------------------------------------------------------------- index page */
.index { columns: 2 420px; column-gap: 48px; padding-bottom: 60px; }
.idx { break-inside: avoid; margin-bottom: 30px; }
.idx h2 { font-size: 1.2rem; margin-bottom: 8px; padding-left: 10px; border-left: 3px solid var(--area); }
.idx h2 a { text-decoration: none; }
.idx ol { list-style: none; margin: 0; padding: 0; }
.idx li a { display: grid; grid-template-columns: 40px 1fr auto; gap: 10px; padding: 5px 0; text-decoration: none;
            border-bottom: 1px solid var(--rule); font-size: .96rem; }
.idx .n { font: .8rem var(--mono); color: var(--muted); padding-top: 3px; }
.idx .m { font: .72rem var(--sans); color: var(--muted); padding-top: 4px; white-space: nowrap; }

/* ---------------------------------------------------------------- footer */
.foot { border-top: 1px solid var(--rule); background: var(--paper-2); }
.foot-in { padding: 28px 20px 36px; font-size: .9rem; max-width: 1120px; }
.foot p { margin: .3em 0; max-width: 80ch; }
.foot-nav { display: flex; flex-wrap: wrap; gap: 8px 20px; font: 500 .84rem var(--sans); margin-bottom: 14px; }
.foot-nav a { text-decoration: none; color: var(--ink-2); }

/* ---------------------------------------------------------------- page transitions */
@view-transition { navigation: auto; }
::view-transition-old(root) { animation: vt-out .28s var(--ease) both; }
::view-transition-new(root) { animation: vt-in .45s var(--ease) both; }
::view-transition-group(*) { animation-duration: .5s; animation-timing-function: var(--ease); }
@keyframes vt-out { to { opacity: 0; transform: translateY(-8px); } }
@keyframes vt-in { from { opacity: 0; transform: translateY(12px); } }
@supports (view-transition-name: x) { body { animation: none; } }

/* ---------------------------------------------------------------- responsive, motion */
@media (max-width: 900px) {
  .hero, .vgrid { grid-template-columns: 1fr; gap: 32px; }
  .hero { padding-top: 40px; }
  .steps { grid-template-columns: 1fr 1fr; }
  .nav { display: none; }
  .search input, .search input:focus { width: 100%; }
  .search { flex: 1; }
  .search kbd { display: none; }
}
@media (max-width: 560px) {
  body { font-size: 1rem; }
  .paper { grid-template-columns: 1fr; }
  .pthumb { max-width: 160px; }
  .fcard { grid-template-columns: 1fr; gap: 6px; padding: 18px; }
  .steps { grid-template-columns: 1fr; }
  .pn { grid-template-columns: 1fr; }
  .pn .next { text-align: left; align-items: flex-start; }
  .top-in { gap: 12px; }
  .brand-word { display: none; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
  .js .reveal, .js .mosaic .cell { opacity: 1; transform: none; }
  @view-transition { navigation: none; }
}
@media print {
  .top, .foot, .videos, .filters, .pact, .cite, .pn { display: none; }
  .js .reveal { opacity: 1; transform: none; }
}
.search input:focus ~ kbd, .search input:not(:placeholder-shown) ~ kbd { opacity: 0; }

/* published video: accent ring + play triangle, distinct from the Lean fill */
.cell { position: relative; }
.cell.vid, .cell.vid.on { background: var(--ink); border-color: var(--ink);
  outline: 2px solid var(--ink); outline-offset: 2px; z-index: 1; }
.cell.vid::after, .legend i.v::after { content: ""; position: absolute; left: 50%; top: 50%;
  border-style: solid; border-width: 3.5px 0 3.5px 6px; border-color: transparent transparent transparent var(--paper);
  margin: -3.5px 0 0 -2px; }
.js .mosaic .cell.vid { animation: pop .5s var(--ease) forwards, vidpulse 2.4s ease-in-out 1.2s infinite; }
@keyframes vidpulse { 0%, 100% { outline-color: var(--ink); } 50% { outline-color: transparent; } }
.legend i.v { position: relative; background: var(--ink); border-color: var(--ink);
  outline: 2px solid var(--ink); outline-offset: 2px; margin-right: 3px; }
@media (prefers-reduced-motion: reduce) { .js .mosaic .cell.vid { animation: none; opacity: 1; } }

/* comments */
.comments .clist { list-style: none; padding: 0; margin: 18px 0 26px; }
.comments .clist li { border-top: 1px solid var(--rule); padding: 14px 0; }
.comments .clist li:last-child { border-bottom: 1px solid var(--rule); }
.comments .clist p { margin: 6px 0 0; }
.cform { display: flex; flex-direction: column; gap: 14px; max-width: 640px; padding: 20px 22px;
  background: var(--card); border: 1px solid var(--rule); border-radius: 12px; }
.cform .cf { display: flex; flex-direction: column; gap: 6px; font: .8rem var(--sans); color: var(--muted);
  letter-spacing: .04em; text-transform: uppercase; }
.cform input, .cform textarea, .admin input { font: 1rem var(--serif, inherit); text-transform: none; letter-spacing: 0;
  color: var(--ink); background: var(--paper); border: 1px solid var(--rule); border-radius: 8px; padding: 10px 12px;
  width: 100%; box-sizing: border-box; resize: vertical; }
.cform input:focus, .cform textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.cform .hp { position: absolute !important; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.cfoot { display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.cmsg { font: .9rem var(--sans); }
.acard { border: 1px solid var(--rule); border-radius: 8px; padding: 10px 14px; margin: 10px 0; }
.acard.pend { border-color: var(--accent); }

/* family page: two kinds of video */
.vtrack { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; align-items: start; }
.vstep { border: 1px solid var(--rule); border-radius: 14px; padding: 18px 20px 20px; background: var(--card); }
.vstep-h { display: flex; gap: 14px; align-items: flex-start; margin-bottom: 14px; }
.vstep-h h3 { margin: 0 0 4px; font-size: 1.25rem; }
.vstep-h p { margin: 0; font-size: .95rem; }
.vstep-n { flex: none; width: 34px; height: 34px; border-radius: 50%; display: grid; place-items: center;
  font: 600 1rem var(--sans); color: var(--paper); background: var(--ink); }
.parts { display: grid; gap: 16px; }
.parts:has(.part:nth-child(3)) { grid-template-columns: 1fr 1fr; }
.part-n { display: block; font: .75rem var(--sans); letter-spacing: .06em; text-transform: uppercase; color: var(--muted); margin-bottom: 6px; }
.vstep .pl { margin-left: 6px; white-space: nowrap; }
@media (max-width: 820px) { .vtrack, .parts:has(.part:nth-child(3)) { grid-template-columns: 1fr; } }