/* ============================================================
   PhysPlan — academic project page (light, restrained)
   ============================================================ */
:root {
  --bg: #ffffff;
  --bg-alt: #f7f8fa;
  --surface: #ffffff;
  --surface-2: #f3f4f7;
  --border: #e3e6ec;
  --border-strong: #d2d7e0;
  --text: #1b1f2a;
  --text-dim: #4f5666;
  --muted: #8b91a1;
  --accent: #3b5bbd;          /* sober academic blue */
  --accent-dark: #2c4596;
  --accent-soft: #eef1fb;     /* ours-row / highlight tint */
  --good: #2f9e6f;
  --bad: #c7503f;
  --radius: 10px;
  --maxw: 1060px;
  --font: 'Lato', system-ui, -apple-system, 'Segoe UI', sans-serif;
  --mono: 'JetBrains Mono', ui-monospace, 'SF Mono', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  font-size: 17px;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: var(--mono); font-size: .85em; background: var(--surface-2); padding: .08em .38em; border-radius: 5px; color: var(--accent-dark); }
.muted { color: var(--muted); font-size: .9em; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.container.narrow { max-width: 760px; }

/* ---------- NAV ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; gap: 24px;
  padding: 12px 24px;
  background: rgba(255,255,255,.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}
.nav-brand { font-weight: 800; font-size: 1.15rem; color: var(--text); letter-spacing: -.01em; }
.nav-brand span { color: var(--accent); }
.nav-links { display: flex; gap: 22px; margin-left: auto; flex-wrap: wrap; }
.nav-links a { color: var(--text-dim); font-weight: 600; font-size: .92rem; }
.nav-links a:hover, .nav-links a.active { color: var(--accent); text-decoration: none; }

/* ---------- HERO ---------- */
.hero { padding: 54px 0 30px; text-align: center; }
.hero-title {
  font-size: clamp(1.7rem, 3.4vw, 2.5rem); font-weight: 800; line-height: 1.2; letter-spacing: -.01em;
  max-width: 900px; margin: 0 auto 22px; color: var(--text);
}
.hero-title .brand { color: var(--accent); }
.hero-tagline { font-size: 1.06rem; color: var(--text-dim); max-width: 720px; margin: 0 auto 26px; }

.authors { display: flex; flex-wrap: wrap; justify-content: center; gap: 4px 16px; font-size: 1.06rem; margin-bottom: 10px; }
.authors .author { color: var(--text); }
.authors sup { color: var(--accent); font-size: .68em; }
.affiliations { color: var(--text-dim); font-size: .96rem; display: flex; flex-wrap: wrap; gap: 2px 20px; justify-content: center; }
.affiliations sup { color: var(--accent); }
.author-note { color: var(--muted); font-size: .86rem; margin-top: 8px; }

.cta-row { display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; margin: 28px 0 8px; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 20px; border-radius: 22px; font-weight: 600; font-size: .95rem;
  background: #2b2f3a; border: 1px solid #2b2f3a; color: #fff;
  transition: background .15s, border-color .15s;
}
.btn:hover { text-decoration: none; background: #000; border-color: #000; }
.btn.primary { background: var(--accent); border-color: var(--accent); }
.btn.primary:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
.btn[data-disabled="true"] { opacity: .45; pointer-events: none; }

/* ---------- video / image placeholder (quiet) ---------- */
.video-ph {
  position: relative; width: 100%; aspect-ratio: 16/9; border-radius: var(--radius);
  background: var(--surface-2);
  border: 1px dashed var(--border-strong);
  display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 6px;
  color: var(--muted); text-align: center; padding: 16px; overflow: hidden;
}
.ph-play { font-size: 1rem; color: var(--accent); opacity: .8; }
.ph-label { font-weight: 600; color: var(--text-dim); font-size: .85rem; }
.ph-label code { font-size: .8rem; }
.ph-hint { font-size: .76rem; color: var(--muted); }
.video-ph.small { aspect-ratio: 1/1; }
.video-ph video, .vid-real { width: 100%; height: 100%; object-fit: cover; border-radius: var(--radius); display: block; }

figure { margin: 0; }
.fig { margin: 28px auto; }
.fig img, .fig .video-ph, .fig-img { border: 1px solid var(--border); border-radius: var(--radius); }
.fig-img { width: 100%; height: auto; display: block; }
figcaption { color: var(--text-dim); font-size: .9rem; margin-top: 12px; text-align: center; }
figcaption b { color: var(--text); }

/* ---------- SECTIONS ---------- */
.section { padding: 56px 0; border-top: 1px solid var(--border); }
.section.section-alt { background: var(--bg-alt); }
.section-title { font-size: clamp(1.4rem, 2.4vw, 1.8rem); font-weight: 800; letter-spacing: -.01em; margin-bottom: 14px; text-align: center; }
.section-lead { color: var(--text-dim); max-width: 740px; margin: 0 auto 28px; text-align: center; }
.subhead { font-size: 1.2rem; font-weight: 700; margin: 44px 0 6px; color: var(--text); padding-bottom: 6px; border-bottom: 2px solid var(--border); }
.subhead-sm { font-size: 1rem; font-weight: 700; margin: 26px 0 12px; }
.abstract { font-size: 1.04rem; color: var(--text-dim); text-align: justify; }
.abstract strong { color: var(--text); font-weight: 700; }

/* ---------- CONTRIBUTIONS (academic list) ---------- */
.contrib-list { max-width: 780px; margin: 22px auto 0; list-style: none; counter-reset: c; }
.contrib-list li { position: relative; padding: 10px 0 10px 44px; border-top: 1px solid var(--border); }
.contrib-list li:first-child { border-top: none; }
.contrib-list li::before {
  counter-increment: c; content: counter(c);
  position: absolute; left: 0; top: 12px; width: 28px; height: 28px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent-dark); font-weight: 800; font-size: .85rem;
  display: flex; align-items: center; justify-content: center;
}
.contrib-list b { color: var(--text); }

/* ---------- METHOD ---------- */
.stage-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin: 18px 0; }
.stage { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; }
.stage .stage-num { font-size: .74rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); }
.stage h4 { font-size: 1.08rem; margin: 4px 0 8px; }
.stage p { color: var(--text-dim); font-size: .94rem; }

.stepper { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 16px; }
.step-btn {
  display: flex; align-items: center; gap: 8px; padding: 8px 14px; border-radius: 8px;
  background: var(--surface); border: 1px solid var(--border); color: var(--text-dim);
  cursor: pointer; font-family: var(--font); font-size: .88rem; font-weight: 600; transition: all .15s;
}
.step-btn .step-n { width: 20px; height: 20px; border-radius: 50%; background: var(--surface-2); color: var(--text-dim); display: flex; align-items: center; justify-content: center; font-size: .74rem; font-weight: 700; }
.step-btn:hover { border-color: var(--accent); color: var(--text); }
.step-btn.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.step-btn.active .step-n { background: rgba(255,255,255,.25); color: #fff; }
.step-arrow { color: var(--muted); }
.stepper-detail { background: var(--surface); border: 1px solid var(--border); border-left: 3px solid var(--accent); border-radius: 8px; padding: 18px 22px; min-height: 84px; }
.stepper-detail h5 { font-size: 1rem; margin-bottom: 4px; }
.stepper-detail p { color: var(--text-dim); }

.mech-row { display: grid; grid-template-columns: 1fr 1fr; gap: 26px; align-items: start; margin-top: 10px; }
.mech-row .mech h4 { font-size: 1.05rem; margin-bottom: 8px; }
.mech-row .mech p { color: var(--text-dim); font-size: .94rem; margin-top: 10px; }

/* ---------- Object-Centric Gradient Routing figure ---------- */
.ocgr-panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px 18px 14px; }
.ocgr-panel svg { display: block; width: 100%; height: auto; }
.ocgr-eq { text-align: center; font-family: Georgia, 'Times New Roman', serif; font-style: italic; font-size: 1.1rem; color: var(--text); margin-top: 12px; letter-spacing: .2px; }
.ocgr-eq sub { font-size: .62em; }
.ocgr-eq b { color: var(--muted); font-weight: 400; font-style: normal; }
.ocgr-legend { text-align: center; font-size: .78rem; color: var(--muted); margin-top: 6px; }

/* ---------- Chain-of-Visual-Thought interactive panel ---------- */
.covt-panel {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden;
}
.covt-kf-img { border: none !important; border-radius: 0 !important; }
.covt-trip-img { border: 1px solid var(--border) !important; border-radius: 5px !important; display: block; }

.covt-prompt-bar {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 10px 18px; background: var(--surface-2); border-bottom: 1px solid var(--border);
}
.covt-prompt-label {
  font-size: .7rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase;
  color: var(--accent); white-space: nowrap;
}
.covt-prompt-text { font-size: .95rem; color: var(--text); font-style: italic; flex: 1; min-width: 0; }
.covt-play-btn {
  background: none; border: 1px solid var(--border-strong); color: var(--text-dim);
  padding: 4px 11px; border-radius: 6px; cursor: pointer;
  font-family: var(--font); font-size: .76rem; font-weight: 600; white-space: nowrap; transition: all .15s;
}
.covt-play-btn:hover { border-color: var(--accent); color: var(--accent); }

.covt-states-strip { display: grid; grid-template-columns: repeat(3, 1fr); }
.covt-state-card {
  position: relative; cursor: pointer;
  border-right: 1px solid var(--border); transition: background .15s;
}
.covt-state-card:last-child { border-right: none; }
.covt-state-card:hover { background: var(--accent-soft); }
.covt-state-card.active { background: var(--accent-soft); }

.covt-kf-wrap {
  position: relative; width: 100%; aspect-ratio: 3/2;
  background: #111; overflow: hidden;
}
.covt-kf-img { width: 100%; height: 100%; object-fit: contain; display: block; }
.covt-anchor-pill {
  position: absolute; bottom: 7px; left: 8px;
  background: rgba(27,31,42,.78); color: #fff;
  font-family: var(--mono); font-size: .67rem; padding: 2px 7px; border-radius: 4px;
}
.covt-delta-tag {
  position: absolute; top: 7px; right: 8px;
  background: var(--accent); color: #fff;
  font-family: var(--mono); font-size: .68rem; font-weight: 700; padding: 2px 7px; border-radius: 4px;
}
.covt-card-body {
  padding: 10px 14px 12px;
  border-top: 2px solid transparent; transition: border-color .15s;
}
.covt-state-card.active .covt-card-body { border-top-color: var(--accent); }
.covt-delta { font-family: var(--mono); font-size: .74rem; color: var(--accent-dark); font-weight: 700; margin-bottom: 2px; }
.covt-state-name { font-weight: 700; font-size: .94rem; color: var(--text); margin-bottom: 2px; }
.covt-law { font-size: .76rem; color: var(--muted); }

.covt-curve-wrap {
  padding: 14px 20px 8px;
  border-top: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.covt-curve-svg { width: 100%; height: auto; display: block; overflow: visible; }
.covt-curve-label { text-align: center; font-size: .73rem; color: var(--muted); margin-top: 2px; padding-bottom: 4px; }

.covt-detail-wrap { background: var(--surface-2); transition: opacity .18s; min-height: 180px; }
.covt-detail-inner { display: grid; grid-template-columns: repeat(3, 1fr); }
.covt-detail-inner.two-pane { grid-template-columns: 1fr 1fr; }
.covt-detail-inner.one-pane { grid-template-columns: 1fr; max-width: 500px; margin: 0 auto; }
.covt-detail-pane { padding: 16px 18px; border-right: 1px solid var(--border); }
.covt-detail-pane:last-child { border-right: none; }
.covt-pane-title {
  font-size: .68rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase;
  color: var(--accent); margin-bottom: 10px;
}
.covt-graph-svg { width: 100%; max-width: 360px; height: auto; display: block; margin: 0 auto; }

.covt-triptych { display: grid; grid-template-columns: repeat(3, 1fr); gap: 6px; }
.covt-trip { display: flex; flex-direction: column; align-items: center; gap: 4px; }
.covt-trip-img { width: 100%; height: auto; }
.covt-mask-img { background: #111; }
.covt-trip-cap { font-size: .64rem; color: var(--muted); text-align: center; }

.covt-reasoning {
  background: #1b1f2a; border-radius: 7px; padding: 12px 14px;
  font-family: var(--mono); font-size: .76rem;
}
.covt-reason-row { display: flex; gap: 8px; margin-bottom: 8px; align-items: flex-start; line-height: 1.5; }
.covt-rkey { color: #7dd3fc; font-weight: 700; min-width: 30px; flex-shrink: 0; }
.covt-rval { color: #c9d1da; }
.covt-reason-score {
  margin-top: 8px; padding-top: 8px;
  border-top: 1px solid rgba(255,255,255,.08); color: #c9d1da; font-size: .8rem;
}
.covt-reason-score strong { color: #7dd3fc; font-size: .94rem; }

@media (max-width: 880px) {
  .covt-states-strip { grid-template-columns: 1fr; }
  .covt-state-card { border-right: none; border-bottom: 1px solid var(--border); }
  .covt-state-card:last-child { border-bottom: none; }
  .covt-detail-inner,
  .covt-detail-inner.two-pane,
  .covt-detail-inner.one-pane { grid-template-columns: 1fr; }
  .covt-detail-pane { border-right: none; border-bottom: 1px solid var(--border); }
  .covt-detail-pane:last-child { border-bottom: none; }
}

/* ---------- KIP live chart ---------- */
.kip-panel { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; }
.kip-controls { display: flex; align-items: center; gap: 14px; margin-top: 8px; }
.kip-controls button { background: var(--accent); border: none; color: #fff; width: 38px; height: 38px; border-radius: 50%; cursor: pointer; font-size: .95rem; }
.kip-controls button:hover { background: var(--accent-dark); }
.kip-readout { font-family: var(--mono); font-size: .82rem; color: var(--text-dim); }
.kip-readout b { color: var(--accent-dark); }

/* ---------- QUALITATIVE COMPARE ---------- */
.domain-tabs { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; margin-bottom: 18px; }
.domain-tab { padding: 7px 15px; border-radius: 20px; background: var(--surface); border: 1px solid var(--border); color: var(--text-dim); cursor: pointer; font-size: .86rem; font-weight: 600; transition: all .15s; font-family: var(--font); }
.domain-tab:hover { border-color: var(--accent); color: var(--accent); }
.domain-tab.active { background: var(--accent); border-color: var(--accent); color: #fff; }
.domain-tab .dt-domain { opacity: .7; font-size: .85em; font-weight: 400; }
.compare-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.compare-cell .cell-label { text-align: center; font-size: .82rem; font-weight: 700; color: var(--text-dim); margin-bottom: 7px; }
.compare-cell.ours .cell-label { color: var(--accent); }
.compare-cell.ours .video-ph, .compare-cell.ours .vid-real { outline: 2px solid var(--accent); outline-offset: 0; }
.compare-controls { display: flex; align-items: center; justify-content: center; gap: 16px; margin-top: 16px; color: var(--text-dim); font-size: .9rem; }
.compare-controls button { background: var(--surface); border: 1px solid var(--border-strong); color: var(--text); padding: 7px 16px; border-radius: 8px; cursor: pointer; font-family: var(--font); font-weight: 600; }
.compare-controls button:hover { border-color: var(--accent); color: var(--accent); }
.compare-prompt-text { font-style: italic; }

/* ---------- background-lock slider ---------- */
.bglock { position: relative; max-width: 820px; margin: 0 auto; aspect-ratio: 16/9; border-radius: var(--radius); overflow: hidden; border: 1px solid var(--border); user-select: none; }
.bglock .bg-layer { position: absolute; inset: 0; }
.bglock .bg-right { clip-path: inset(0 0 0 50%); }
.bglock .bg-handle { position: absolute; top: 0; bottom: 0; left: 50%; width: 2px; background: var(--accent); cursor: ew-resize; z-index: 5; }
.bglock .bg-handle::after { content: "‹ ›"; position: absolute; top: 50%; left: 50%; transform: translate(-50%,-50%); width: 34px; height: 34px; border-radius: 50%; background: var(--accent); color: #fff; display: flex; align-items: center; justify-content: center; font-size: .9rem; }
.bglock .bg-tag { position: absolute; bottom: 12px; padding: 4px 11px; border-radius: 6px; font-size: .76rem; font-weight: 600; background: rgba(27,31,42,.82); color: #fff; z-index: 6; }
.bglock .bg-tag.left { left: 12px; } .bglock .bg-tag.right { right: 12px; }
.bglock .video-ph { border: none; border-radius: 0; height: 100%; }

/* ---------- TABLES ---------- */
.table-wrap { overflow-x: auto; margin: 14px 0; border: 1px solid var(--border); border-radius: var(--radius); }
table.data { width: 100%; border-collapse: collapse; font-size: .85rem; background: var(--surface); table-layout: auto; }
table.data th, table.data td { padding: 8px 9px; text-align: right; border-bottom: 1px solid var(--border); white-space: nowrap; }
table.data th:first-child, table.data td:first-child { white-space: normal; }
table.data th:first-child, table.data td:first-child { text-align: left; }
table.data thead th { color: var(--text-dim); font-weight: 700; font-size: .78rem; text-transform: uppercase; letter-spacing: .02em; background: var(--surface-2); }
table.data tbody tr:last-child td { border-bottom: none; }
table.data tr.group-row td { background: var(--surface-2); color: var(--accent-dark); font-weight: 700; font-size: .76rem; text-transform: uppercase; letter-spacing: .04em; text-align: left; }
table.data tr.ours { background: var(--accent-soft); }
table.data tr.ours td { color: var(--text); font-weight: 700; }
table.data tr.base td { color: var(--text-dim); }
table.data td.best { color: var(--accent-dark); font-weight: 800; }

/* ---------- charts (SVG) ---------- */
.chart { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; margin: 8px 0; }
.chart svg { width: 100%; height: auto; display: block; overflow: visible; }
.chart .legend { display: flex; flex-wrap: wrap; gap: 14px; justify-content: center; margin-top: 12px; font-size: .8rem; color: var(--text-dim); }
.chart .legend span { display: inline-flex; align-items: center; gap: 6px; }
.chart .legend i { width: 11px; height: 11px; border-radius: 2px; display: inline-block; }
.bar-val { font-size: 10px; fill: var(--text-dim); font-family: var(--mono); }
.bar-lbl { font-size: 11px; fill: var(--text-dim); }
.grid-line { stroke: var(--border); stroke-width: 1; stroke-dasharray: 3 4; }

/* ---------- gauges ---------- */
.gauges { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; max-width: 720px; margin: 0 auto; }
.gauge { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; text-align: center; }
.gauge svg { width: 132px; height: 132px; }
.gauge .g-track { fill: none; stroke: var(--surface-2); stroke-width: 11; }
.gauge .g-fill { fill: none; stroke: var(--accent); stroke-width: 11; stroke-linecap: round; transition: stroke-dashoffset 1.3s cubic-bezier(.2,.8,.2,1); }
.gauge .g-pct { font-size: 1.5rem; font-weight: 800; fill: var(--text); font-family: var(--font); }
.gauge .g-label { font-weight: 700; margin-top: 6px; font-size: .96rem; }
.gauge .g-sub { color: var(--muted); font-size: .78rem; }

/* ---------- efficiency + diagnostics ---------- */
.eff-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 14px; margin-bottom: 16px; }
.eff-cell { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 18px; text-align: center; }
.eff-cell .big { font-size: 1.5rem; font-weight: 800; color: var(--accent-dark); }
.eff-cell .small { color: var(--text-dim); font-size: .8rem; margin-top: 4px; }
.diag-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.diag-cell { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 16px; }
.diag-cell .d-comp { font-weight: 700; }
.diag-cell .d-metric { color: var(--muted); font-size: .78rem; margin-bottom: 10px; }
.diag-bar { display: flex; align-items: center; gap: 8px; font-family: var(--mono); font-size: .78rem; margin: 5px 0; }
.diag-bar .lbl { width: 40px; color: var(--text-dim); }
.diag-bar .track { flex: 1; height: 7px; background: var(--surface-2); border-radius: 4px; overflow: hidden; }
.diag-bar .fill { height: 100%; border-radius: 4px; }
.diag-bar.fg .fill { background: var(--border-strong); }
.diag-bar.ours .fill { background: var(--accent); }
.diag-bar .num { width: 44px; text-align: right; }
.diag-bar.ours .num { color: var(--accent-dark); font-weight: 700; }

.two-col { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; align-items: center; }
.fail-gallery { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; }
.fail-gallery .video-ph { aspect-ratio: 4/3; }

/* ---------- BIBTEX ---------- */
.bibtex-box { position: relative; background: var(--surface-2); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.bibtex-box pre { font-family: var(--mono); font-size: .82rem; color: var(--text-dim); overflow-x: auto; line-height: 1.7; }
.copy-btn { position: absolute; top: 12px; right: 12px; background: var(--surface); border: 1px solid var(--border-strong); color: var(--text); padding: 5px 13px; border-radius: 7px; cursor: pointer; font-size: .8rem; font-weight: 600; }
.copy-btn:hover { border-color: var(--accent); color: var(--accent); }
.copy-btn.done { color: var(--good); border-color: var(--good); }

/* ---------- FOOTER + to-top ---------- */
.footer { padding: 34px 0; border-top: 1px solid var(--border); text-align: center; color: var(--muted); font-size: .88rem; background: var(--bg-alt); }
.footer p { margin: 3px 0; }
.to-top { position: fixed; bottom: 22px; right: 22px; width: 42px; height: 42px; border-radius: 50%; background: var(--accent); color: #fff; border: none; font-size: 1.1rem; cursor: pointer; opacity: 0; pointer-events: none; transition: opacity .3s; z-index: 90; }
.to-top.show { opacity: .92; pointer-events: auto; }
.to-top:hover { opacity: 1; }

/* ---------- RESPONSIVE ---------- */
@media (max-width: 880px) {
  .compare-grid { grid-template-columns: repeat(2, 1fr); }
  .eff-grid { grid-template-columns: repeat(2, 1fr); }
  .two-col, .stage-row, .mech-row { grid-template-columns: 1fr; }
  .nav-links { display: none; }
  .diag-row { grid-template-columns: 1fr; }
}
@media (max-width: 540px) {
  .compare-grid, .gauges, .eff-grid, .fail-gallery { grid-template-columns: 1fr; }
  .section { padding: 42px 0; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }