/* ===================== Design tokens ===================== */
:root {
  color-scheme: dark light;

  --bg: #0a0d14;
  --bg-soft: #0d111a;
  --surface: #121725;
  --surface-2: #1a2134;
  --border: #262f45;
  --border-soft: #1c2338;

  --text: #e9edf7;
  --text-dim: #9aa7c0;
  --text-faint: #6b7793;

  --accent: #35d6c4;      /* brand teal — "flow" */
  --accent-soft: rgba(53, 214, 196, 0.12);
  --concat: #5b9dff;      /* MusicFlux-Concat */
  --concat-soft: rgba(91, 157, 255, 0.13);
  --carflow: #b18cff;     /* MusicFlux-CAR */
  --carflow-soft: rgba(177, 140, 255, 0.14);
  --baseline: #f5a623;    /* baselines (SA3 / SonicMaster) */
  --baseline-soft: rgba(245, 166, 35, 0.13);
  --input-chip: #8b97b0;  /* masked / degraded input */

  --good: #3ddc97;
  --bad: #ff6b81;

  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --maxw: 1180px;
}

/* Light theme: applied when the system prefers light AND the user hasn't
   manually forced dark, OR when the user has manually forced light. */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f6f7fb;
    --bg-soft: #eef0f7;
    --surface: #ffffff;
    --surface-2: #f1f3fa;
    --border: #dde1ee;
    --border-soft: #e6e9f3;
    --text: #141829;
    --text-dim: #4b5470;
    --text-faint: #7b84a0;
    --accent-soft: rgba(13, 148, 136, 0.10);
    --concat-soft: rgba(37, 99, 235, 0.10);
    --carflow-soft: rgba(124, 58, 237, 0.10);
    --baseline-soft: rgba(217, 119, 6, 0.12);
    --shadow: 0 10px 30px rgba(20, 24, 41, 0.08);
  }
}
:root[data-theme="light"] {
    --bg: #f6f7fb;
    --bg-soft: #eef0f7;
    --surface: #ffffff;
    --surface-2: #f1f3fa;
    --border: #dde1ee;
    --border-soft: #e6e9f3;
    --text: #141829;
    --text-dim: #4b5470;
    --text-faint: #7b84a0;
    --accent-soft: rgba(13, 148, 136, 0.10);
    --concat-soft: rgba(37, 99, 235, 0.10);
    --carflow-soft: rgba(124, 58, 237, 0.10);
    --baseline-soft: rgba(217, 119, 6, 0.12);
    --shadow: 0 10px 30px rgba(20, 24, 41, 0.08);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; }

.wrap {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

code, .mono { font-family: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; }

/* ===================== Nav ===================== */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(14px) saturate(140%);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  border-bottom: 1px solid var(--border-soft);
}
.nav-inner {
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  text-decoration: none;
  color: var(--text);
}
.brand-mark {
  width: 28px; height: 28px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--carflow));
  display: inline-flex; align-items: center; justify-content: center;
  flex-shrink: 0;
}
.brand-mark svg { width: 16px; height: 16px; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
}
.nav-links a {
  text-decoration: none;
  color: var(--text-dim);
  font-size: 0.88rem;
  font-weight: 500;
  padding: 8px 12px;
  border-radius: 8px;
  transition: color .15s ease, background .15s ease;
  white-space: nowrap;
}
.nav-links a:hover { color: var(--text); background: var(--surface-2); }
.nav-cta {
  display: flex; gap: 8px; flex-shrink: 0;
}
.nav-toggle {
  display: none;
  background: none; border: 1px solid var(--border); border-radius: 8px;
  color: var(--text); padding: 8px 10px; cursor: pointer;
}

.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 36px; height: 36px; flex-shrink: 0;
  border: 1px solid var(--border); border-radius: 10px;
  background: var(--surface-2); color: var(--text-dim);
  cursor: pointer; transition: color .15s ease, border-color .15s ease;
}
.theme-toggle:hover { color: var(--text); border-color: var(--accent); }
.theme-toggle svg { width: 17px; height: 17px; }
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: inline-flex; }
:root[data-theme="dark"] .theme-toggle .icon-sun { display: inline-flex; }
:root[data-theme="dark"] .theme-toggle .icon-moon { display: none; }

/* ===================== Buttons / chips ===================== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 16px;
  border-radius: 10px;
  font-size: 0.86rem;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--surface-2);
  transition: transform .15s ease, border-color .15s ease, background .15s ease;
  cursor: pointer;
}
.btn:hover { border-color: var(--accent); transform: translateY(-1px); }
.btn-primary {
  background: linear-gradient(135deg, var(--accent), #21a89a);
  border-color: transparent;
  color: #04201c;
}
.btn-primary:hover { filter: brightness(1.08); }

.tag {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  color: var(--text-dim);
}
.tag-dot { width: 7px; height: 7px; border-radius: 50%; flex-shrink: 0; }

/* model color chips, reused across method + audio sections */
.chip-concat { color: var(--concat); background: var(--concat-soft); border-color: transparent; }
.chip-concat .tag-dot { background: var(--concat); }
.chip-carflow { color: var(--carflow); background: var(--carflow-soft); border-color: transparent; }
.chip-carflow .tag-dot { background: var(--carflow); }
.chip-baseline { color: var(--baseline); background: var(--baseline-soft); border-color: transparent; }
.chip-baseline .tag-dot { background: var(--baseline); }
.chip-input { color: var(--input-chip); background: transparent; border-style: dashed; }
.chip-input .tag-dot { background: var(--input-chip); }
.chip-gt { color: var(--text-dim); background: var(--surface-2); border-color: var(--border); }
.chip-gt .tag-dot { background: var(--text-faint); }

/* ===================== Hero ===================== */
.hero {
  position: relative;
  overflow: hidden;
  padding: 88px 0 64px;
  border-bottom: 1px solid var(--border-soft);
}
.hero-bg {
  position: absolute; inset: 0;
  background:
    radial-gradient(640px 320px at 12% -10%, var(--accent-soft), transparent 60%),
    radial-gradient(640px 320px at 95% 0%, var(--carflow-soft), transparent 60%);
  pointer-events: none;
}
.hero-inner { position: relative; z-index: 1; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 0.78rem; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 18px;
}
.eyebrow::before {
  content: ""; width: 20px; height: 1px; background: var(--accent);
}
h1.title {
  font-size: clamp(2.1rem, 4.6vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin: 0 0 18px;
  max-width: 880px;
}
.title .accent-text {
  background: linear-gradient(135deg, var(--accent), var(--carflow));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.subtitle {
  font-size: 1.1rem;
  color: var(--text-dim);
  max-width: 720px;
  margin: 0 0 28px;
}
.authors {
  display: flex; flex-wrap: wrap; gap: 6px 14px;
  font-size: 0.92rem; color: var(--text-dim);
  margin-bottom: 6px;
}
.authors b { color: var(--text); font-weight: 600; }
.affil { font-size: 0.85rem; color: var(--text-faint); margin-bottom: 30px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 10px; }

/* ===================== Sections ===================== */
section { padding: 84px 0; }
section.alt { background: var(--bg-soft); border-top: 1px solid var(--border-soft); border-bottom: 1px solid var(--border-soft); }
.section-head { max-width: 760px; margin: 0 0 44px; }
.section-head p { color: var(--text-dim); font-size: 1.02rem; }
h2.section-title {
  font-size: clamp(1.6rem, 3vw, 2.1rem);
  letter-spacing: -0.015em;
  margin: 0 0 12px;
}
h3.sub-title { font-size: 1.2rem; margin: 0 0 10px; letter-spacing: -0.01em; }

/* ===================== Overview task cards ===================== */
.task-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
  margin-bottom: 48px;
}
@media (max-width: 880px) { .task-grid { grid-template-columns: 1fr; } }
.task-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px;
}
.task-icon {
  width: 42px; height: 42px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px;
  background: var(--accent-soft);
  color: var(--accent);
}
.task-icon svg { width: 22px; height: 22px; }
.task-card h4 { margin: 0 0 8px; font-size: 1.05rem; }
.task-card p { margin: 0; color: var(--text-dim); font-size: 0.93rem; }
.task-card .mask-note {
  margin-top: 14px; padding-top: 14px; border-top: 1px dashed var(--border);
  font-size: 0.8rem; color: var(--text-faint);
}
.task-card .mask-note code { color: var(--text-dim); }

.figure-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-align: center;
}
.figure-card img { border-radius: 8px; margin: 0 auto; }
.figure-caption {
  margin-top: 16px; font-size: 0.86rem; color: var(--text-faint);
  text-align: left;
}
.figure-caption b { color: var(--text-dim); }

/* ===================== Method ===================== */
.bg-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-bottom: 48px;
}
@media (max-width: 880px) { .bg-grid { grid-template-columns: 1fr; } }
.info-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px;
}
.info-card h4 { margin: 0 0 10px; font-size: 1rem; }
.info-card p { margin: 0 0 10px; color: var(--text-dim); font-size: 0.93rem; }
.formula {
  background: var(--surface-2);
  border: 1px solid var(--border-soft);
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 0.86rem;
  color: var(--accent);
  overflow-x: auto;
  white-space: nowrap;
}

.method-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin: 28px 0 10px;
}
@media (max-width: 880px) { .method-grid { grid-template-columns: 1fr; } }
.method-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px;
  display: flex; flex-direction: column; gap: 14px;
}
.method-card.concat { border-top: 3px solid var(--concat); }
.method-card.carflow { border-top: 3px solid var(--carflow); }
.method-card h4 { margin: 0; font-size: 1.1rem; display: flex; align-items: center; gap: 10px; }
.method-card ul { margin: 0; padding-left: 18px; color: var(--text-dim); font-size: 0.92rem; }
.method-card li { margin-bottom: 7px; }
.method-card .formula { font-size: 0.8rem; }
.trait-row { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 4px; }

/* ===================== Datasets / cards ===================== */
.card-grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
@media (max-width: 880px) { .card-grid-3 { grid-template-columns: 1fr; } }
.data-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px;
}
.data-card h4 { margin: 0 0 4px; font-size: 1rem; }
.data-card .data-role { font-size: 0.76rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 12px; display: block; }
.data-card p { margin: 0; color: var(--text-dim); font-size: 0.89rem; }
.stat-row { display: flex; gap: 18px; margin: 14px 0; flex-wrap: wrap; }
.stat { }
.stat b { display: block; font-size: 1.25rem; color: var(--text); }
.stat span { font-size: 0.74rem; color: var(--text-faint); text-transform: uppercase; letter-spacing: 0.04em; }

/* setup / baseline two-col */
.two-col { display: grid; grid-template-columns: 1.1fr 0.9fr; gap: 28px; margin-top: 48px; }
@media (max-width: 880px) { .two-col { grid-template-columns: 1fr; } }
.kv-list { margin: 0; padding: 0; list-style: none; }
.kv-list li {
  display: flex; justify-content: space-between; gap: 16px;
  padding: 10px 0; border-bottom: 1px solid var(--border-soft);
  font-size: 0.88rem;
}
.kv-list li span:first-child { color: var(--text-faint); }
.kv-list li span:last-child { color: var(--text); font-weight: 500; text-align: right; }
.baseline-card { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; margin-bottom: 14px; }
.baseline-card h5 { margin: 0 0 8px; font-size: 0.95rem; }
.baseline-card p { margin: 0; font-size: 0.87rem; color: var(--text-dim); }

/* ===================== Metrics grid ===================== */
.metric-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; margin: 48px 0;
}
@media (max-width: 880px) { .metric-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .metric-grid { grid-template-columns: 1fr; } }
.metric-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 16px 18px;
}
.metric-card .mhead { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
.metric-card .mname { font-weight: 700; font-size: 0.9rem; }
.metric-card .mdir { font-size: 0.78rem; font-weight: 700; }
.mdir.up { color: var(--good); }
.mdir.down { color: var(--bad); }
.metric-card p { margin: 0; font-size: 0.82rem; color: var(--text-dim); }

/* ===================== Results tables ===================== */
.table-scroll { overflow-x: auto; border-radius: var(--radius); border: 1px solid var(--border); }
table.results {
  border-collapse: collapse;
  width: 100%;
  min-width: 820px;
  font-size: 0.85rem;
  background: var(--surface);
}
table.results caption { caption-side: top; }
table.results th, table.results td {
  padding: 10px 14px;
  text-align: center;
  border-bottom: 1px solid var(--border-soft);
  white-space: nowrap;
}
table.results thead tr:first-child th {
  background: var(--surface-2);
  font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-dim);
  border-bottom: 1px solid var(--border);
}
table.results thead tr:nth-child(2) th {
  font-size: 0.74rem; color: var(--text-faint); font-weight: 600;
  border-bottom: 1px solid var(--border);
}
table.results thead tr:last-child th {
  font-size: 0.76rem; color: var(--text-dim); font-weight: 600;
}
table.results td:first-child, table.results th:first-child {
  text-align: left; position: sticky; left: 0; background: var(--surface);
}
table.results tbody tr.highlight td { background: var(--accent-soft); }
table.results tbody tr.highlight td:first-child { background: var(--accent-soft); }
table.results td.best { font-weight: 800; color: var(--text); }
table.results td.second { text-decoration: underline; text-decoration-color: var(--text-faint); text-underline-offset: 3px; }
table.results td.dash { color: var(--text-faint); }
table.results .model-name { font-weight: 600; }
table.results .model-name.mf { color: var(--text); }

.table-legend { display: flex; gap: 18px; flex-wrap: wrap; margin-top: 14px; font-size: 0.78rem; color: var(--text-faint); }
.table-legend b { color: var(--text); }
.table-note { font-size: 0.82rem; color: var(--text-faint); margin-top: 10px; }

/* findings callouts */
.findings-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; margin-top: 44px; }
@media (max-width: 880px) { .findings-grid { grid-template-columns: 1fr; } }
.finding {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-sm);
  padding: 18px 20px; font-size: 0.89rem; color: var(--text-dim);
  border-left: 3px solid var(--accent);
}
.finding b { color: var(--text); }

/* ===================== Audio examples ===================== */
.audio-important {
  display: flex; align-items: center; gap: 10px;
  background: var(--carflow-soft);
  border: 1px solid transparent;
  color: var(--carflow);
  padding: 10px 16px;
  border-radius: 10px;
  font-size: 0.85rem; font-weight: 600;
  margin-bottom: 26px;
}

.task-goal {
  font-size: 0.92rem; color: var(--text-dim);
  background: var(--surface); border: 1px solid var(--border-soft); border-left: 3px solid var(--accent);
  border-radius: var(--radius-sm);
  padding: 12px 16px; margin: 0 0 22px;
}

.tabbar { display: flex; gap: 6px; flex-wrap: wrap; border-bottom: 1px solid var(--border); margin-bottom: 26px; }
.tabbar button {
  background: none; border: none; cursor: pointer;
  color: var(--text-dim); font-size: 0.92rem; font-weight: 600;
  padding: 10px 6px; margin-right: 18px;
  border-bottom: 2px solid transparent;
  transition: color .15s ease, border-color .15s ease;
  font-family: inherit;
}
.tabbar button:hover { color: var(--text); }
.tabbar button.active { color: var(--accent); border-bottom-color: var(--accent); }

.subtabbar { display: flex; gap: 8px; margin-bottom: 22px; flex-wrap: wrap; }
.subtabbar button {
  background: var(--surface); border: 1px solid var(--border); cursor: pointer;
  color: var(--text-dim); font-size: 0.82rem; font-weight: 600;
  padding: 7px 14px; border-radius: 999px;
  font-family: inherit;
}
.subtabbar button.active { background: var(--accent-soft); color: var(--accent); border-color: transparent; }

.task-pane, .dataset-pane { display: none; }
.task-pane.active, .dataset-pane.active { display: block; }

.example-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 24px; margin-bottom: 18px;
}
.example-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 16px; margin-bottom: 16px; }
.example-label { font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-faint); }
.example-quote {
  font-size: 0.95rem; color: var(--text); font-style: italic;
  border-left: 2px solid var(--border);
  padding-left: 14px; margin: 0 0 18px;
}
.player-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 14px;
}
.player-cell { background: var(--surface-2); border: 1px solid var(--border-soft); border-radius: 10px; padding: 12px 14px; }
.player-cell audio {
  width: 100%; height: 34px; display: block; margin-top: 8px;
  accent-color: var(--accent);
}

/* Gap timeline: highlights the masked / reconstructed region under an
   inpainting player and tracks playback with a moving playhead. */
.gap-timeline { margin-top: 10px; }
.gap-track {
  position: relative; width: 100%; height: 16px;
  background: var(--border-soft); border-radius: 6px;
  cursor: pointer; overflow: hidden;
}
.gap-region {
  position: absolute; top: 0; height: 100%;
  background: repeating-linear-gradient(
    45deg,
    var(--baseline), var(--baseline) 5px,
    color-mix(in srgb, var(--baseline) 35%, transparent) 5px,
    color-mix(in srgb, var(--baseline) 35%, transparent) 10px
  );
}
.gap-playhead {
  position: absolute; top: 0; height: 100%; width: 2px;
  background: var(--text); pointer-events: none;
}
.gap-labels {
  display: flex; justify-content: space-between; align-items: baseline;
  margin-top: 5px; font-size: 0.68rem; color: var(--text-faint); gap: 8px;
}
.gap-region-label { color: var(--baseline); font-weight: 600; text-align: center; }

/* ===================== Takeaways ===================== */
.takeaway-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; }
@media (max-width: 880px) { .takeaway-grid { grid-template-columns: 1fr; } }
.takeaway-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; display: flex; gap: 16px;
}
.takeaway-num {
  flex-shrink: 0; width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--accent-soft), var(--carflow-soft));
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; color: var(--accent); font-size: 0.9rem;
}
.takeaway-card h4 { margin: 0 0 6px; font-size: 1rem; }
.takeaway-card p { margin: 0; font-size: 0.88rem; color: var(--text-dim); }

/* ===================== Footer ===================== */
footer { padding: 56px 0 72px; border-top: 1px solid var(--border-soft); }

.logo-strip { margin-bottom: 32px; }
.logo-strip-label {
  display: block; font-size: 0.74rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.06em; color: var(--text-faint); margin-bottom: 14px;
}
.logo-row { display: flex; flex-wrap: wrap; align-items: center; gap: 14px; }
.logo-chip {
  display: inline-flex; align-items: center; justify-content: center;
  height: 68px; padding: 10px 20px;
  background: #ffffff; border: 1px solid var(--border); border-radius: 10px;
  transition: transform .15s ease, border-color .15s ease;
}
.logo-chip:hover { transform: translateY(-2px); border-color: var(--accent); }
.logo-chip img { height: 100%; max-height: 44px; width: auto; object-fit: contain; display: block; }

.citation-box {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px 24px; font-size: 0.86rem; color: var(--text-dim);
  margin-bottom: 28px; overflow-x: auto;
}
.citation-head { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; flex-wrap: wrap; }
.citation-head .btn { flex-shrink: 0; }
.citation-box pre { margin: 14px 0 0; white-space: pre-wrap; font-size: 0.8rem; color: var(--text-dim); }
.footer-bottom {
  display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 12px;
  font-size: 0.82rem; color: var(--text-faint);
}
.footer-links { display: flex; gap: 16px; }
.footer-links a { text-decoration: none; color: var(--text-faint); }
.footer-links a:hover { color: var(--text); }
.back-to-top { color: var(--accent); text-decoration: none; font-weight: 600; font-size: 0.82rem; }

/* ===================== Responsive nav ===================== */
@media (max-width: 920px) {
  .nav-links { display: none; }
  .nav-toggle { display: inline-flex; }
  body.nav-open .nav-links {
    display: flex; flex-direction: column; align-items: flex-start;
    position: absolute; top: 64px; left: 0; right: 0;
    background: var(--bg); border-bottom: 1px solid var(--border);
    padding: 10px 24px 18px;
  }
}