:root {
  --bg: #f7f8fb;
  --paper: #ffffff;
  --ink: #111827;
  --muted: #526073;
  --line: #dce3ec;
  --navy: #111827;
  --accent: #154ec1;
  --accent2: #d47b2e;
  --soft: #e6efff;
  --warn: #a16207;
  --danger: #b42318;
  --shadow: 0 8px 30px rgba(18, 32, 53, .07);
  --radius: 22px;
  --surface-soft: #f0f3f8;
  --line-strong: #c9d3e0;
  --panel: var(--paper);
  --text: var(--ink);
  --border: var(--line);
}

html[data-theme="dark"] {
  --bg: #0b1220;
  --paper: #111b2b;
  --ink: #edf2f9;
  --muted: #b6c1d1;
  --line: #26354b;
  --navy: #edf2f9;
  --accent: #77a6ff;
  --accent2: #f2a65f;
  --soft: #152b50;
  --surface-soft: #162235;
  --line-strong: #34445b;
  --shadow: 0 10px 35px rgba(0, 0, 0, .2);
  --panel: var(--paper);
  --text: var(--ink);
  --border: var(--line);
}

html { scroll-padding-top: 132px; }
body {
  background: radial-gradient(circle at 5% -10%, color-mix(in srgb, var(--accent) 9%, transparent), transparent 33rem), var(--bg);
  color: var(--ink);
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

.skip-link { position: fixed; left: 1rem; top: -4rem; z-index: 1000; padding: .75rem 1rem; background: var(--ink); color: var(--bg); border-radius: 10px; transition: top .2s ease; }
.skip-link:focus { top: 1rem; }
.site-header { position: sticky; top: 0; z-index: 100; border-bottom: 1px solid color-mix(in srgb, var(--line) 85%, transparent); background: color-mix(in srgb, var(--bg) 83%, transparent); backdrop-filter: blur(18px); -webkit-backdrop-filter: blur(18px); }
.site-header .wrap { width: min(calc(100% - 40px), 1180px); }
.header-inner { min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.site-header .brand { display: inline-flex; align-items: center; gap: 12px; min-width: max-content; color: var(--ink); text-decoration: none; }
.brand-mark { width: 38px; aspect-ratio: 1; display: grid; place-items: center; border-radius: 11px; background: var(--ink); color: var(--bg); font-size: .78rem; font-weight: 800; letter-spacing: .05em; }
.site-header .brand strong { display: block; font-size: .95rem; line-height: 1.2; }
.site-header .brand small { display: block; margin-top: 3px; color: var(--muted); font-size: .72rem; line-height: 1.2; }
.desktop-nav { display: flex; align-items: center; gap: 26px; margin-left: auto; }
.desktop-nav a { color: var(--muted); font-size: .88rem; font-weight: 600; text-decoration: none; transition: color .2s ease; }
.desktop-nav a:hover, .desktop-nav a:focus-visible, .desktop-nav .nav-current { color: var(--accent); }
.header-actions { display: flex; align-items: center; gap: 10px; }
.icon-button, .menu-button { border: 1px solid var(--line); background: var(--paper); color: var(--ink); cursor: pointer; box-shadow: var(--shadow); }
.icon-button { width: 42px; height: 42px; display: grid; place-items: center; border-radius: 13px; }
.icon-button svg { width: 19px; height: 19px; display: block; fill: none; stroke: currentColor; stroke-width: 1.8; stroke-linecap: round; stroke-linejoin: round; }
html[data-theme="light"] .sun-icon, html[data-theme="dark"] .moon-icon { display: none; }
.menu-button { display: none; width: 42px; height: 42px; border-radius: 13px; padding: 11px; }
.menu-button span { display: block; height: 2px; margin: 4px 0; border-radius: 999px; background: currentColor; transition: transform .2s ease, opacity .2s ease; }
.menu-button[aria-expanded="true"] span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.menu-button[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
.menu-button[aria-expanded="true"] span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }
.mobile-nav { padding: 0 20px 18px; border-top: 1px solid var(--line); background: var(--bg); }
.mobile-nav a { display: block; padding: 13px 0; border-bottom: 1px solid var(--line); color: var(--muted); font-weight: 650; text-decoration: none; }

.project-nav { position: sticky; top: 78px; z-index: 30; border-bottom: 1px solid var(--line); background: color-mix(in srgb, var(--paper) 94%, transparent); backdrop-filter: blur(14px); }
.project-nav-inner { min-height: 50px; display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.project-title { color: var(--ink); font-size: .78rem; font-weight: 850; letter-spacing: .07em; text-transform: uppercase; }
.project-nav .links { gap: 22px; }
.project-nav .links a { color: var(--muted); font-size: .8rem; font-weight: 700; }
.project-nav .links a:hover, .project-nav .links a[aria-current="page"] { color: var(--accent); }

.hero { padding: 72px 0 54px; border-bottom-color: var(--line); background: linear-gradient(180deg, var(--paper) 0%, color-mix(in srgb, var(--bg) 94%, var(--soft))); }
.eyebrow { color: var(--accent); background: var(--soft); }
.dot { background: var(--accent); }
h1, .section-head h2, .card h3, .step b, .metric strong, .barval, .bigstat { color: var(--ink); }
h1 { font-size: clamp(2.7rem, 5.2vw, 5.1rem); }
.lead, .section-head p, .card p, .phase .body p, .small, .caption, .metric span, .barlabel, .footer { color: var(--muted); }
.btn { min-height: 46px; padding: 0 19px; border-radius: 13px; border-color: var(--line); background: var(--paper); color: var(--ink); box-shadow: var(--shadow); transition: transform .2s ease, border-color .2s ease, background .2s ease; }
.btn.primary, .btn.demo { border-color: var(--accent); background: var(--accent); color: #fff; }
html[data-theme="dark"] .btn.primary, html[data-theme="dark"] .btn.demo { color: #07101d; }
.toc a { border-color: var(--line); background: var(--paper); color: var(--muted); }
main { padding-top: 56px; }
.card, .step, .metric, .tablewrap { border-color: var(--line); background: var(--paper); box-shadow: var(--shadow); }
.chip { border-color: var(--line); background: var(--surface-soft); color: var(--muted); }
th { background: var(--surface-soft); color: var(--muted); }
th, td { border-bottom-color: var(--line); }
.track { background: var(--surface-soft); }
.fill { background: linear-gradient(90deg, var(--accent), var(--accent2)); }
.best, .kicker, .step .n, .status-ok { color: var(--accent); }
.note { border-left-color: var(--accent); background: var(--soft); color: var(--ink); }
.warning { border-left-color: var(--warn); background: color-mix(in srgb, var(--paper) 78%, #fff8e8); }
.phase-num { background: var(--ink); color: var(--bg); }
.mono { border-color: var(--line); background: var(--surface-soft); color: var(--ink); }
.callout { border: 1px solid color-mix(in srgb, var(--accent) 38%, transparent); border-radius: 24px; background: linear-gradient(135deg, #0c1422, #15335e); }
.footer { padding-top: 30px; }
:focus-visible { outline: 3px solid color-mix(in srgb, var(--accent) 55%, transparent); outline-offset: 3px; }

@media (max-width: 1040px) {
  .desktop-nav { display: none; }
  .menu-button { display: block; }
}

@media (max-width: 900px) {
  .project-nav { top: 78px; }
  .project-nav-inner { overflow-x: auto; }
  .project-title { display: none; }
  .project-nav .links { display: flex; min-width: max-content; padding-right: 8px; }
}

@media (max-width: 560px) {
  html { scroll-padding-top: 118px; }
  .site-header .wrap { width: min(calc(100% - 28px), 1180px); }
  .header-inner { min-height: 68px; }
  .site-header .brand small { display: none; }
  .project-nav { top: 68px; }
  .project-nav .wrap { width: min(calc(100% - 28px), 1160px); }
  .hero { padding-top: 52px; }
  h1 { font-size: clamp(2.35rem, 12vw, 3.45rem); }
}