/* SWT3 Protocol Design System */
:root {
  --bg: #0a0a0f;
  --surface: #12121a;
  --border: rgba(255,255,255,0.08);
  --text: #e0e0e0;
  --heading: #ffffff;
  --muted: #8890a0;
  --accent: #4a9ead;
  --accent-hover: #5bb8c8;
  --pass: #4ade80;
  --fail: #ef4444;
  --warn: #f59e0b;
  --code-bg: #0d0d15;
  --max-prose: 760px;
  --max-wide: 1000px;
  --nav-h: 48px;
  --font: -apple-system, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "SF Mono", "Fira Code", "Cascadia Code", "Consolas", monospace;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: calc(var(--nav-h) + 24px); }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.65;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* --- Nav --- */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: rgba(10,10,15,0.92);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
}
.nav-inner {
  max-width: var(--max-wide);
  width: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  gap: 32px;
}
.nav-brand {
  font-weight: 700;
  font-size: 16px;
  color: var(--heading);
  text-decoration: none;
  letter-spacing: 1px;
  font-family: var(--mono);
}
.nav-links {
  display: flex;
  gap: 24px;
  list-style: none;
}
.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.3px;
  transition: color 0.15s;
}
.nav-links a:hover,
.nav-links a.active { color: var(--heading); }
.nav-github {
  margin-left: auto;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s;
}
.nav-github:hover { color: var(--heading); }
.nav-github svg { display: block; }

/* --- Layout --- */
.container { max-width: var(--max-prose); margin: 0 auto; padding: 0 24px; }
.container-wide { max-width: var(--max-wide); margin: 0 auto; padding: 0 24px; }

/* --- Typography --- */
h1, h2, h3, h4 { color: var(--heading); font-weight: 600; }
h1 { font-size: 32px; line-height: 1.2; margin-bottom: 12px; }
h2 { font-size: 22px; margin: 48px 0 16px; padding-bottom: 8px; border-bottom: 1px solid var(--border); }
h3 { font-size: 17px; margin: 32px 0 12px; }
h4 { font-size: 15px; margin: 24px 0 8px; }

p { margin-bottom: 16px; }
a { color: var(--accent); text-decoration: none; transition: color 0.15s; }
a:hover { color: var(--accent-hover); }

.subtitle {
  font-size: 17px;
  color: var(--muted);
  margin-bottom: 32px;
  line-height: 1.5;
}

strong { color: var(--heading); font-weight: 600; }
em { font-style: italic; }

/* RFC 2119 keywords */
.rfc { font-weight: 600; color: var(--heading); }

/* --- Code --- */
code {
  font-family: var(--mono);
  font-size: 13px;
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 3px;
  color: var(--accent);
}
pre {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 16px 20px;
  overflow-x: auto;
  margin: 16px 0;
  line-height: 1.5;
}
pre code {
  background: none;
  padding: 0;
  color: var(--text);
  font-size: 13px;
}

/* --- Tables --- */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 14px;
}
th, td {
  text-align: left;
  padding: 10px 12px;
  border-bottom: 1px solid var(--border);
}
th {
  color: var(--muted);
  font-weight: 600;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
td { color: var(--text); }
tr:hover td { background: rgba(255,255,255,0.02); }

/* --- Cards --- */
.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px 24px;
  margin: 16px 0;
}

/* --- Hero --- */
.hero {
  text-align: center;
  padding: 80px 24px 48px;
}
.hero h1 {
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -0.5px;
}
.hero .subtitle {
  font-size: 18px;
  max-width: 480px;
  margin: 8px auto 0;
}

/* --- Anchor format display --- */
.anchor-example {
  font-family: var(--mono);
  font-size: 14px;
  text-align: center;
  margin: 32px 0;
  padding: 20px;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  letter-spacing: 0.5px;
  overflow-x: auto;
  white-space: nowrap;
}
.anchor-example .seg-prefix { color: var(--muted); }
.anchor-example .seg-tier { color: var(--accent); }
.anchor-example .seg-provider { color: #b0b8c8; }
.anchor-example .seg-uct { color: var(--accent); }
.anchor-example .seg-procedure { color: var(--heading); }
.anchor-example .seg-verdict { color: var(--pass); }
.anchor-example .seg-epoch { color: var(--muted); }
.anchor-example .seg-fingerprint { color: var(--warn); }

/* --- Formula box --- */
.formula-box {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 20px 24px;
  margin: 24px 0;
  text-align: center;
}
.formula-box code {
  font-size: 14px;
  background: none;
  color: var(--accent);
}
.formula-box .label {
  display: block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--muted);
  margin-bottom: 8px;
}

/* --- SDK grid --- */
.sdk-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin: 24px 0;
}
.sdk-card {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 12px 16px;
  text-decoration: none;
  color: var(--text);
  font-size: 13px;
  transition: border-color 0.15s;
}
.sdk-card:hover { border-color: var(--accent); color: var(--heading); }
.sdk-card .sdk-name { font-weight: 600; }
.sdk-card .sdk-lang { color: var(--muted); font-size: 11px; }

/* --- Section divider --- */
.section { margin: 48px 0; }
.section-title {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--muted);
  margin-bottom: 16px;
}

/* --- Badges --- */
.badge {
  display: inline-block;
  font-size: 11px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 4px;
  letter-spacing: 0.3px;
}
.badge-accent { background: rgba(74,158,173,0.15); color: var(--accent); }
.badge-pass { background: rgba(74,222,128,0.15); color: var(--pass); }
.badge-fail { background: rgba(239,68,68,0.15); color: var(--fail); }
.badge-muted { background: rgba(136,144,160,0.15); color: var(--muted); }

/* --- Chip --- */
.chip {
  display: inline-block;
  font-size: 11px;
  padding: 2px 8px;
  border-radius: 3px;
  background: rgba(74,158,173,0.1);
  color: var(--accent);
  margin: 2px 4px 2px 0;
  white-space: nowrap;
}

/* --- Footer --- */
.footer {
  border-top: 1px solid var(--border);
  padding: 32px 24px;
  text-align: center;
  margin-top: 80px;
  font-size: 12px;
  color: var(--muted);
  line-height: 1.8;
}
.footer a { color: var(--muted); }
.footer a:hover { color: var(--accent); }
.citation {
  font-family: var(--mono);
  font-size: 12px;
  color: var(--muted);
  margin-top: 12px;
}

/* --- Form inputs (verify page) --- */
.input-group { margin-bottom: 12px; }
.input-group label {
  display: block;
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--muted);
  margin-bottom: 4px;
}
input[type="text"], input[type="number"], textarea {
  width: 100%;
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 8px 12px;
  color: var(--text);
  font-family: var(--mono);
  font-size: 13px;
  outline: none;
  transition: border-color 0.15s;
}
input:focus, textarea:focus { border-color: var(--accent); }
textarea { resize: vertical; min-height: 80px; }

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface);
  color: var(--text);
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  transition: border-color 0.15s, color 0.15s;
  text-decoration: none;
}
.btn:hover { border-color: var(--accent); color: var(--heading); }
.btn-primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #000;
  font-weight: 600;
}
.btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); color: #000; }

/* --- Result cards (verify) --- */
.result { padding: 16px 20px; border-radius: 6px; margin: 16px 0; }
.result-pass { background: rgba(74,222,128,0.1); border: 1px solid rgba(74,222,128,0.2); }
.result-fail { background: rgba(239,68,68,0.1); border: 1px solid rgba(239,68,68,0.2); }
.result-title { font-weight: 600; font-size: 14px; margin-bottom: 4px; }
.result-pass .result-title { color: var(--pass); }
.result-fail .result-title { color: var(--fail); }
.result-detail { font-size: 12px; color: var(--muted); font-family: var(--mono); word-break: break-all; }

/* --- Expandable rows (registry) --- */
.expandable-row { cursor: pointer; }
.expandable-row:hover td { background: rgba(74,158,173,0.04); }
.expand-content { display: none; padding: 12px 16px; background: var(--surface); border-bottom: 1px solid var(--border); }
.expand-content.open { display: table-row; }

/* --- Search/Filter bar --- */
.filter-bar {
  display: flex;
  gap: 12px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}
.filter-bar input[type="text"] { flex: 1; min-width: 200px; }
.filter-bar select {
  background: var(--code-bg);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 8px 12px;
  color: var(--text);
  font-size: 13px;
  outline: none;
}

/* --- TOC sidebar (spec page) --- */
.spec-layout { display: flex; gap: 40px; max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.spec-toc {
  position: sticky;
  top: calc(var(--nav-h) + 24px);
  width: 220px;
  flex-shrink: 0;
  max-height: calc(100vh - var(--nav-h) - 48px);
  overflow-y: auto;
  padding-right: 16px;
  font-size: 12px;
}
.spec-toc a {
  display: block;
  padding: 4px 0;
  color: var(--muted);
  text-decoration: none;
  line-height: 1.4;
}
.spec-toc a:hover { color: var(--heading); }
.spec-toc a.toc-h3 { padding-left: 12px; font-size: 11px; }
.spec-content { flex: 1; min-width: 0; max-width: var(--max-prose); }

/* --- Vector cards --- */
.vector-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 16px 20px;
  margin: 12px 0;
}
.vector-card .vector-id {
  font-size: 12px;
  color: var(--muted);
  font-family: var(--mono);
}
.vector-card .vector-fields {
  font-family: var(--mono);
  font-size: 13px;
  margin-top: 8px;
  line-height: 1.6;
}
.vector-card .vector-expected {
  margin-top: 8px;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--pass);
}

/* --- Tabs --- */
.tabs {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
}
.tab {
  padding: 8px 16px;
  font-size: 13px;
  color: var(--muted);
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: color 0.15s;
  background: none;
  border-top: none;
  border-left: none;
  border-right: none;
  font-family: var(--font);
}
.tab:hover { color: var(--text); }
.tab.active { color: var(--heading); border-bottom-color: var(--accent); }

/* --- Privacy notice --- */
.privacy-notice {
  font-size: 12px;
  color: var(--muted);
  text-align: center;
  padding: 12px;
  background: rgba(74,158,173,0.05);
  border-radius: 4px;
  margin: 16px 0;
}

/* --- Responsive --- */
@media (max-width: 768px) {
  .hero h1 { font-size: 28px; }
  .hero .subtitle { font-size: 15px; }
  .nav-inner { gap: 16px; padding: 0 16px; }
  .nav-links { gap: 16px; }
  .nav-links a { font-size: 12px; }
  .sdk-grid { grid-template-columns: repeat(2, 1fr); }
  .spec-layout { flex-direction: column; }
  .spec-toc { position: static; width: 100%; max-height: none; padding-right: 0; margin-bottom: 24px; }
  .filter-bar { flex-direction: column; }
  .container, .container-wide { padding: 0 16px; }
  table { font-size: 13px; }
  th, td { padding: 8px; }
}

/* --- Print --- */
@media print {
  body { background: #fff; color: #000; font-size: 11pt; }
  .nav, .footer { display: none; }
  a { color: #000; }
  a[href]::after { content: " (" attr(href) ")"; font-size: 9pt; color: #666; }
  .card, .vector-card { border: 1px solid #ccc; break-inside: avoid; }
  pre { border: 1px solid #ccc; background: #f5f5f5; }
  code { background: #f5f5f5; color: #333; }
  h2 { break-before: page; }
}