/* TutorDuel site.
   Layout: one reading column (68ch) for prose; figures, tables and the session player break out to a 1120px frame.
   Color: a cool paper ground, near-black ink, garnet for the method and the chosen answer, slate blue for references. */
:root {
  --bg: #f4f5f7; --panel: #ffffff; --panel-2: #eceef2; --fg: #181b20; --muted: #5b636e;
  --line: #d8dce2; --line-strong: #b4bcc6;
  --accent: #8b1d2c; --accent-ink: #ffffff; --accent-soft: #f6e6e9;
  --blue: #2c5282; --blue-soft: #e4ebf5;
  --code-bg: #1d2026; --code-fg: #e9ebf0;
  --c-coduel: #8b1d2c; --c-notransfer: #3a3f47; --c-coldb: #2c5282; --c-coldblr: #1d7f8f;
  --c-colstim: #b4761a; --c-rucb: #6b46c1; --c-pooled: #2f855a;
  --c-metats: #c05621; --c-hierts: #b83280;
  --font-display: "IBM Plex Serif", Georgia, "Times New Roman", serif;
  --font-body: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --radius: 6px;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #13161b; --panel: #1b1f26; --panel-2: #242931; --fg: #e7e9ee; --muted: #9aa3ae;
    --line: #2b313a; --line-strong: #3f4854;
    --accent: #e4707f; --accent-ink: #1b1f26; --accent-soft: #3a2026;
    --blue: #8fb3e6; --blue-soft: #1f2b3d;
    --code-bg: #0e1014; --code-fg: #e3e6ec;
    --c-coduel: #e4707f; --c-notransfer: #c3c9d2; --c-coldb: #8fb3e6; --c-coldblr: #5fc1d3;
    --c-colstim: #e0b25b; --c-rucb: #b094f0; --c-pooled: #6ccf9a;
    --c-metats: #f6a868; --c-hierts: #f093c4;
    color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --bg: #13161b; --panel: #1b1f26; --panel-2: #242931; --fg: #e7e9ee; --muted: #9aa3ae;
  --line: #2b313a; --line-strong: #3f4854;
  --accent: #e4707f; --accent-ink: #1b1f26; --accent-soft: #3a2026;
  --blue: #8fb3e6; --blue-soft: #1f2b3d;
  --code-bg: #0e1014; --code-fg: #e3e6ec;
  --c-coduel: #e4707f; --c-notransfer: #c3c9d2; --c-coldb: #8fb3e6; --c-coldblr: #5fc1d3;
  --c-colstim: #e0b25b; --c-rucb: #b094f0; --c-pooled: #6ccf9a;
  --c-metats: #f6a868; --c-hierts: #f093c4;
  color-scheme: dark;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body {
  margin: 0; background: var(--bg); color: var(--fg);
  font-family: var(--font-body); font-size: 16px; line-height: 1.55; -webkit-font-smoothing: antialiased;
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}
a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: 500; line-height: 1.15; text-wrap: balance; margin: 0; }
h1 { font-size: clamp(1.9rem, 1.2rem + 2.6vw, 3rem); }
h2 { font-size: clamp(1.5rem, 1.1rem + 1.4vw, 2.1rem); }
h3 { font-size: 1.12rem; }
p { margin: 0; }
ul, ol { margin: 0; padding-left: 1.2em; }
code { font-family: var(--font-mono); font-size: .92em; background: var(--panel-2); padding: 1px 5px; border-radius: 4px; }
:focus-visible { outline: 2px solid var(--blue); outline-offset: 2px; }
.wrap { max-width: 1120px; margin-inline: auto; padding-inline: clamp(16px, 4vw, 40px); }
.prose { max-width: 68ch; display: grid; gap: .9em; }
.prose p, .prose li { font-size: 1.02rem; }
.eyebrow { font-family: var(--font-mono); font-size: .74rem; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); }
.mono, .num { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--muted); }
section { padding-block: clamp(40px, 7vw, 88px); border-top: 1px solid var(--line); }
.section-head { display: grid; gap: 10px; margin-bottom: 28px; max-width: 72ch; }
.section-head p { font-size: 1.04rem; }
.stack { display: grid; gap: 28px; }
.stack > *, .two > *, .player > *, .cols > *, .hero .wrap > * { min-width: 0; }

/* top bar */
.top {
  position: sticky; top: env(safe-area-inset-top, 0px); z-index: 20;
  background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.top .wrap { display: flex; align-items: center; gap: 18px; min-height: 52px; }
.brand { font-family: var(--font-display); font-weight: 600; font-size: 1.1rem; color: var(--fg); text-decoration: none; white-space: nowrap; }
.brand small { font-family: var(--font-mono); font-weight: 400; color: var(--muted); font-size: .72rem; margin-left: 8px; }
.nav { margin-left: auto; display: flex; gap: 2px; overflow-x: auto; scrollbar-width: none; }
.nav::-webkit-scrollbar { display: none; }
.nav a { font-size: .86rem; color: var(--muted); text-decoration: none; padding: 6px 9px; border-radius: 4px; white-space: nowrap; }
.nav a:hover, .nav a[aria-current="true"] { color: var(--fg); background: var(--panel-2); }
.theme { font: inherit; font-size: 1rem; line-height: 1; width: 32px; height: 32px; display: inline-grid; place-items: center; border: 1px solid var(--line-strong); border-radius: 999px; background: var(--panel); color: var(--fg); cursor: pointer; flex: none; }
.theme:hover { border-color: var(--fg); }

/* hero */
.hero { padding-block: clamp(40px, 8vw, 96px) clamp(28px, 5vw, 56px); border-top: 0; }
.hero .wrap { display: grid; gap: 22px; }
.hero .lede { max-width: 72ch; font-size: 1.12rem; }
.authors { display: grid; gap: 8px; }
.authors .names { display: flex; flex-wrap: wrap; gap: 6px 24px; font-size: 1.08rem; font-weight: 500; }
.authors sup { font-size: .68em; line-height: 0; margin-left: 1px; }
.authors .affil { display: flex; flex-wrap: wrap; gap: 4px 18px; color: var(--muted); font-size: .98rem; }
.authors .affil .mono { font-size: .9rem; }
.authors .eqc { font-size: .84rem; color: var(--muted); }
.actions { display: flex; flex-wrap: wrap; gap: 10px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 9px 14px; border-radius: var(--radius);
  border: 1px solid var(--line-strong); background: var(--panel); color: var(--fg);
  font: inherit; font-size: .92rem; text-decoration: none; cursor: pointer;
}
.btn:hover { border-color: var(--fg); }
.btn.primary { background: var(--accent); border-color: var(--accent); color: var(--accent-ink); }
.btn.primary:hover { filter: brightness(1.08); }
.btn:disabled, .btn[aria-disabled="true"] { opacity: .5; cursor: not-allowed; filter: none; }
.btn small { font-family: var(--font-mono); font-size: .7rem; color: inherit; opacity: .75; }
.facts { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); border-block: 1px solid var(--line); }
.facts div { padding: 14px 16px 14px 0; display: grid; gap: 2px; }
.facts div + div { padding-left: 16px; border-left: 1px solid var(--line); }
.facts b { font-family: var(--font-display); font-weight: 500; font-size: 1.4rem; font-variant-numeric: tabular-nums; }
.facts span { font-size: .84rem; color: var(--muted); }
@media (max-width: 640px) {
  .facts div + div { border-left: 0; padding-left: 0; border-top: 1px solid var(--line); }
}

/* cards and columns */
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; }
.cols { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 18px 24px; }
.cols.three { grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); }
.col { display: grid; gap: 8px; padding-top: 12px; border-top: 2px solid var(--fg); align-content: start; }
.col h3 { font-size: 1.05rem; }
.col p, .col li { font-size: .93rem; }
.col .k { font-family: var(--font-mono); font-size: .74rem; color: var(--muted); }
.formula { font-family: var(--font-mono); font-size: .95rem; line-height: 1.9; padding: 12px 16px; background: var(--panel-2); border-radius: var(--radius); overflow-x: auto; }
.note { padding: 12px 16px; border: 1px dashed var(--line-strong); border-radius: var(--radius); font-size: .9rem; color: var(--muted); max-width: 72ch; }
figure { margin: 0; display: grid; gap: 10px; }
figure img { width: 100%; height: auto; border: 1px solid var(--line); border-radius: 8px; background: #fff; display: block; }
figcaption { font-size: .88rem; color: var(--muted); max-width: 92ch; }
details.plain summary { cursor: pointer; color: var(--accent); font-size: .9rem; }
details.plain[open] summary { margin-bottom: 8px; }
details.plain .inner { font-size: .9rem; color: var(--fg); line-height: 1.5; }

/* session player */
.player { display: grid; grid-template-columns: minmax(0, 1fr) 320px; gap: 22px; align-items: start; }
@media (max-width: 900px) { .player { grid-template-columns: minmax(0, 1fr); } }
.stage { padding: 18px; display: grid; gap: 16px; }
.stage-top { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; justify-content: space-between; }
.seg { display: inline-flex; border: 1px solid var(--line-strong); border-radius: var(--radius); overflow: hidden; }
.seg button { font: inherit; font-size: .84rem; padding: 6px 10px; background: var(--panel); color: var(--muted); border: 0; border-right: 1px solid var(--line); cursor: pointer; }
.seg button:last-child { border-right: 0; }
.seg button[aria-pressed="true"] { background: var(--fg); color: var(--bg); }
.q { display: grid; gap: 6px; padding: 14px 16px; background: var(--panel-2); border-radius: var(--radius); }
.q .eyebrow { display: flex; justify-content: space-between; gap: 10px; }
.q p { font-size: 1.05rem; }
.personas { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 10px; }
@media (max-width: 560px) { .personas { grid-template-columns: repeat(2, minmax(0, 1fr)); } }
.persona {
  font: inherit; text-align: left; display: grid; gap: 4px; align-content: start; padding: 12px; min-height: 76px;
  border: 1px solid var(--line-strong); border-radius: var(--radius); background: var(--panel); color: var(--fg); cursor: pointer;
  position: relative;
}
.persona:hover { border-color: var(--fg); }
.persona[aria-pressed="true"] { border-color: var(--accent); box-shadow: inset 0 0 0 1px var(--accent); background: var(--accent-soft); }
.persona:disabled { cursor: default; }
.persona:disabled:hover { border-color: var(--line-strong); }
.persona:disabled[aria-pressed="true"]:hover { border-color: var(--accent); }
.persona b { font-weight: 600; font-size: .95rem; }
.persona span { font-size: .8rem; color: var(--muted); }
.persona .tag { justify-self: start; font-family: var(--font-mono); font-size: .66rem; letter-spacing: .04em; text-transform: uppercase; padding: 2px 6px; border-radius: 3px; margin-bottom: 2px; }
.persona .tag.best { background: var(--blue-soft); color: var(--blue); }
.persona .tag.chosen { background: var(--accent); color: var(--accent-ink); }
.stage-actions { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; }
.hint { font-size: .88rem; color: var(--muted); }
.result { display: grid; gap: 14px; padding: 16px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel); }
.result .verdict { font-size: 1.05rem; }
.bars { display: grid; grid-template-columns: repeat(6, minmax(0, 1fr)); gap: 8px; height: 140px; }
.bar { display: grid; grid-template-rows: auto 1fr auto; gap: 4px; min-width: 0; }
.bar i { display: block; align-self: end; background: var(--line-strong); border-radius: 3px 3px 0 0; height: var(--h); }
.bar.shown i { background: var(--accent); }
.bar.best i { outline: 2px solid var(--blue); outline-offset: -2px; }
.bar span { font-size: .7rem; color: var(--muted); text-align: center; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bar em { font-style: normal; font-family: var(--font-mono); font-size: .72rem; text-align: center; }
.keyline { display: flex; flex-wrap: wrap; gap: 6px 16px; font-size: .78rem; color: var(--muted); }
.keyline i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; vertical-align: -1px; margin-right: 5px; background: var(--line-strong); }
.keyline i.shown { background: var(--accent); } .keyline i.best { background: transparent; outline: 2px solid var(--blue); outline-offset: -2px; }
.keyline i.you { background: var(--accent); } .keyline i.rand { background: var(--muted); } .keyline i.bf { background: var(--blue); }
.regret-line { font-family: var(--font-mono); font-size: .86rem; line-height: 1.6; }
.answers-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 14px; margin-top: 12px; }
@media (max-width: 700px) { .answers-grid { grid-template-columns: minmax(0, 1fr); } }
.answer { padding: 12px; border: 1px solid var(--line); border-radius: var(--radius); background: var(--panel-2); font-size: .86rem; line-height: 1.5; min-width: 0; }
.answer h4 { margin: 0 0 8px; font-size: .8rem; font-family: var(--font-mono); font-weight: 500; }
.answer pre { margin: 0; white-space: pre-wrap; overflow-wrap: anywhere; font-family: inherit; max-height: 380px; overflow: auto; }
.answer.chosen { border-color: var(--accent); }
.aside { display: grid; gap: 14px; }
.profile { padding: 14px 16px; display: grid; gap: 10px; }
.profile .text { font-size: .9rem; line-height: 1.5; transition: filter .25s; }
.profile .text[data-hidden="true"] { filter: blur(6px); user-select: none; pointer-events: none; }
.profile .row { display: flex; justify-content: space-between; align-items: center; gap: 10px; }
.tally { padding: 14px 16px; display: grid; gap: 12px; }
.score { display: grid; gap: 2px; }
.score b { font-family: var(--font-display); font-weight: 500; font-size: 2.3rem; line-height: 1; font-variant-numeric: tabular-nums; }
.score span { font-size: .82rem; color: var(--muted); }
.tally dl { margin: 0; display: grid; grid-template-columns: 1fr auto auto; gap: 6px 12px; font-size: .86rem; align-items: baseline; }
.tally dt { color: var(--muted); }
.tally dd { margin: 0; font-family: var(--font-mono); text-align: right; font-variant-numeric: tabular-nums; }
.tally dd.sc { color: var(--muted); font-size: .8rem; }
.tally .you dt, .tally .you dd { color: var(--accent); font-weight: 600; }
.tally .head { font-family: var(--font-mono); font-size: .7rem; color: var(--muted); text-transform: uppercase; letter-spacing: .06em; }
.minichart { width: 100%; height: auto; display: block; font-family: var(--font-mono); font-size: 10px; }
.minichart text { fill: var(--muted); }
.minichart .ax { stroke: var(--line-strong); }
.minichart .you { stroke: var(--accent); fill: none; stroke-width: 2.2; }
.minichart .rand { stroke: var(--muted); fill: none; stroke-width: 1.4; stroke-dasharray: 4 3; }
.minichart .bf { stroke: var(--blue); fill: none; stroke-width: 1.4; }
.aside .btn { justify-content: center; }
.done { padding: 14px 16px; background: var(--accent-soft); border-radius: var(--radius); font-size: .95rem; display: grid; gap: 6px; }

/* tables */
.tablewrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 8px; background: var(--panel); }
table { border-collapse: collapse; width: 100%; min-width: 600px; font-size: .9rem; }
th, td { padding: 9px 12px; text-align: left; border-bottom: 1px solid var(--line); vertical-align: middle; }
tbody tr:last-child td { border-bottom: 0; }
th { font-weight: 500; color: var(--muted); font-size: .78rem; letter-spacing: .02em; white-space: nowrap; background: var(--panel); }
th button { all: unset; cursor: pointer; }
th button:hover, th[aria-sort] button { color: var(--fg); }
th[aria-sort] button::after { content: " ↓"; }
td.num, th.num { text-align: right; font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
tr.ref td { font-style: italic; color: var(--muted); }
tr.ours td { font-weight: 600; }
tr.ablation td { color: var(--muted); }
tr.sep td { border-top: 2px solid var(--line-strong); }
.scorecell { display: grid; grid-template-columns: 36px 1fr; gap: 8px; align-items: center; min-width: 130px; }
.scorecell em { font-style: normal; font-family: var(--font-mono); font-variant-numeric: tabular-nums; text-align: right; }
.scorecell i { display: block; height: 8px; border-radius: 2px; background: var(--line-strong); width: var(--w); }
tr.ours .scorecell i { background: var(--accent); }
tr.ref .scorecell i { background: var(--line); }
.excess { display: block; font-size: .72rem; color: var(--muted); font-family: var(--font-mono); font-weight: 400; margin-top: 2px; }
.table-tools { display: flex; flex-wrap: wrap; gap: 10px 18px; align-items: center; justify-content: space-between; margin-bottom: 10px; font-size: .88rem; color: var(--muted); }
.table-tools label { display: inline-flex; gap: 6px; align-items: center; cursor: pointer; }

/* learning curves */
.chart { display: grid; gap: 12px; padding: 16px; }
.chart-top { display: flex; flex-wrap: wrap; gap: 10px; justify-content: space-between; align-items: center; }
.legend { display: flex; flex-wrap: wrap; gap: 6px; }
.legend button {
  font: inherit; font-size: .8rem; display: inline-flex; align-items: center; gap: 6px; padding: 4px 9px;
  border: 1px solid var(--line-strong); border-radius: 999px; background: var(--panel); color: var(--fg); cursor: pointer;
}
.legend button i { width: 14px; height: 3px; border-radius: 2px; background: currentColor; display: inline-block; color: var(--sw); }
.legend button[aria-pressed="false"] { opacity: .45; }
.curves { width: 100%; height: auto; display: block; font-family: var(--font-mono); font-size: 11px; touch-action: pan-y; }
.curves text { fill: var(--muted); }
.curves .grid { stroke: var(--line); }
.curves .axis { stroke: var(--line-strong); }
.curves .line { fill: none; stroke-width: 1.5; stroke-linejoin: round; }
.curves .line.em { stroke-width: 2.6; }
.curves .band { opacity: .14; stroke: none; }
.curves .cursor { stroke: var(--fg); stroke-dasharray: 3 3; }
.curves .dot { stroke: var(--panel); stroke-width: 1.5; }
.m-coduel { stroke: var(--c-coduel); fill: var(--c-coduel); --sw: var(--c-coduel); }
.m-notransfer { stroke: var(--c-notransfer); fill: var(--c-notransfer); --sw: var(--c-notransfer); }
.m-coldb { stroke: var(--c-coldb); fill: var(--c-coldb); --sw: var(--c-coldb); }
.m-coldblr { stroke: var(--c-coldblr); fill: var(--c-coldblr); --sw: var(--c-coldblr); }
.m-colstim { stroke: var(--c-colstim); fill: var(--c-colstim); --sw: var(--c-colstim); }
.m-rucb { stroke: var(--c-rucb); fill: var(--c-rucb); --sw: var(--c-rucb); }
.m-pooled { stroke: var(--c-pooled); fill: var(--c-pooled); --sw: var(--c-pooled); }
.m-metats { stroke: var(--c-metats); fill: var(--c-metats); --sw: var(--c-metats); }
.m-hierts { stroke: var(--c-hierts); fill: var(--c-hierts); --sw: var(--c-hierts); }
.legend button.m-coduel, .legend button.m-notransfer, .legend button.m-coldb, .legend button.m-coldblr,
.legend button.m-colstim, .legend button.m-rucb, .legend button.m-pooled, .legend button.m-metats,
.legend button.m-hierts { stroke: none; fill: none; }
.readout { font-family: var(--font-mono); font-size: .8rem; color: var(--muted); min-height: 1.5em; display: flex; flex-wrap: wrap; gap: 4px 14px; }
.readout b { color: var(--fg); font-weight: 500; }
.callouts { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 12px; }
.callout { padding: 12px 14px; border-left: 3px solid var(--accent); background: var(--panel); display: grid; gap: 2px; }
.callout b { font-family: var(--font-display); font-size: 1.5rem; font-weight: 500; color: var(--accent); font-variant-numeric: tabular-nums; }
.callout span { font-size: .82rem; color: var(--muted); }

/* code */
.codeblock { display: grid; gap: 6px; min-width: 0; }
.codehead { display: flex; justify-content: space-between; align-items: center; gap: 10px; font-size: .82rem; color: var(--muted); }
pre.code { margin: 0; padding: 14px 16px; background: var(--code-bg); color: var(--code-fg); border-radius: 8px; overflow-x: auto; font-family: var(--font-mono); font-size: .83rem; line-height: 1.55; }
pre.code .c { opacity: .55; }
.copy { font: inherit; font-size: .76rem; padding: 4px 9px; border: 1px solid var(--line-strong); background: var(--panel); border-radius: 4px; cursor: pointer; color: var(--fg); }
.copy:hover { border-color: var(--fg); }
.two { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 22px; align-items: start; }

footer { border-top: 1px solid var(--line); padding-block: 28px; font-size: .84rem; color: var(--muted); }
footer .wrap { display: flex; flex-wrap: wrap; gap: 10px 24px; justify-content: space-between; }

/* opening loop */
.loop { display: grid; grid-template-columns: minmax(0, 1fr) 300px; }
.loop-stage { position: relative; height: 500px; min-width: 0; }
.loop-stage canvas { display: block; width: 100%; height: 100%; }
.loop-hud { border-left: 1px solid var(--line); padding: 16px 18px; display: grid; gap: 16px; align-content: start; min-width: 0; }
.loop-hud > * { min-width: 0; }
.h-top { display: grid; gap: 4px; }
.h-top strong { font-family: var(--font-display); font-weight: 500; font-size: 1.25rem; line-height: 1.2; }
.h-stats { margin: 0; display: grid; gap: 8px; }
.h-stats div { display: flex; justify-content: space-between; gap: 10px; font-size: .86rem; }
.h-stats dt { color: var(--muted); }
.h-stats dd { margin: 0; font-family: var(--font-mono); font-variant-numeric: tabular-nums; }
.h-stats dd[data-on="true"] { color: var(--blue); font-weight: 600; }
.h-chart { display: grid; gap: 6px; }
.h-chart canvas { width: 100%; max-width: 100%; height: 150px; display: block; }
.loop-rail { grid-column: 1 / -1; border-top: 1px solid var(--line); padding: 12px 16px; display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.loop-rail .btn { padding: 7px 12px; font-family: var(--font-mono); font-size: .8rem; }
.chip { font: inherit; font-family: var(--font-mono); font-size: .8rem; padding: 7px 12px; border: 1px solid var(--line-strong); border-radius: var(--radius); background: var(--panel); color: var(--muted); cursor: pointer; }
.chip:hover { color: var(--fg); }
.chip[aria-current="true"] { color: var(--fg); border-color: var(--fg); }
@media (max-width: 900px) {
  .loop { grid-template-columns: minmax(0, 1fr); }
  .loop-hud { border-left: 0; border-top: 1px solid var(--line); }
  .loop-stage { height: 440px; }
}