:root {
  --bg: #0d1117;
  --bg-elev: #161b22;
  --bg-elev-2: #1f2937;
  --fg: #c9d1d9;
  --fg-dim: #8b949e;
  --grid: #30363d;
  --signal: #a9e85a;
  --cyan: #5ed9e8;
  --amber: #ffc76a;
  --violet: #b4a4ff;
  --danger: #ff8c93;
  --sans: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans CJK SC", "Microsoft YaHei", Arial, sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 24px;
}

.page-header {
  background: linear-gradient(180deg, #161b22 0%, #0d1117 100%);
  border-bottom: 1px solid var(--grid);
  padding: 48px 0 36px;
}

.page-header h1 {
  margin: 12px 0 16px;
  font-size: 2.1rem;
  line-height: 1.2;
  color: var(--signal);
  font-weight: 700;
}

.eyebrow {
  margin: 0;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--cyan);
  font-family: var(--mono);
}

.subtitle {
  margin: 0 0 12px;
  font-size: 1.1rem;
  color: var(--fg);
  line-height: 1.5;
}

.meta {
  margin: 0;
  font-size: 0.85rem;
  color: var(--fg-dim);
  font-family: var(--mono);
}

main section {
  padding: 36px 0;
  border-bottom: 1px solid var(--grid);
}

main section:last-child {
  border-bottom: none;
}

h2 {
  margin: 0 0 20px;
  font-size: 1.4rem;
  color: var(--signal);
  font-weight: 600;
  letter-spacing: 0.01em;
}

h3 {
  margin: 24px 0 12px;
  font-size: 1.1rem;
  color: var(--cyan);
  font-weight: 600;
}

p {
  margin: 0 0 16px;
}

.lead {
  font-size: 1.15rem;
  color: var(--fg);
}

.formula {
  font-family: var(--mono);
  font-size: 1.05rem;
  background: var(--bg-elev);
  border-left: 3px solid var(--cyan);
  padding: 12px 16px;
  margin: 16px 0;
  border-radius: 0 4px 4px 0;
}

strong {
  color: var(--signal);
  font-weight: 600;
}

em {
  color: var(--amber);
  font-style: italic;
}

code {
  font-family: var(--mono);
  font-size: 0.9em;
  background: var(--bg-elev);
  padding: 1px 5px;
  border-radius: 3px;
  color: var(--violet);
  word-break: break-word;
}

a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px dotted var(--cyan);
}

a:hover {
  color: var(--signal);
  border-bottom-color: var(--signal);
}

sub {
  font-size: 0.75em;
  vertical-align: sub;
}

figure {
  margin: 24px 0;
  padding: 16px;
  background: var(--bg-elev);
  border: 1px solid var(--grid);
  border-radius: 6px;
}

figure img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 0 auto 12px;
  border-radius: 4px;
}

figcaption {
  font-size: 0.85rem;
  color: var(--fg-dim);
  text-align: center;
  line-height: 1.5;
  font-style: italic;
}

.gate-table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0;
  font-size: 0.92rem;
}

.gate-table th,
.gate-table td {
  padding: 10px 14px;
  text-align: left;
  vertical-align: top;
  border: 1px solid var(--grid);
}

.gate-table thead th {
  background: var(--bg-elev-2);
  color: var(--signal);
  font-weight: 600;
  font-family: var(--mono);
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.gate-table tbody tr:nth-child(even) {
  background: var(--bg-elev);
}

.gate-table tbody td:first-child {
  font-family: var(--mono);
  font-weight: 600;
  white-space: nowrap;
}

.status-blocked {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(255, 140, 147, 0.15);
  color: var(--danger);
  border: 1px solid var(--danger);
  border-radius: 3px;
  font-size: 0.82rem;
  font-family: var(--mono);
  font-weight: 600;
}

.status-open {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(255, 199, 106, 0.15);
  color: var(--amber);
  border: 1px solid var(--amber);
  border-radius: 3px;
  font-size: 0.82rem;
  font-family: var(--mono);
  font-weight: 600;
}

.status-closed {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(94, 217, 232, 0.15);
  color: var(--cyan);
  border: 1px solid var(--cyan);
  border-radius: 3px;
  font-size: 0.82rem;
  font-family: var(--mono);
  font-weight: 600;
}

.status-narrowed {
  display: inline-block;
  padding: 2px 8px;
  background: rgba(180, 164, 255, 0.15);
  color: var(--violet);
  border: 1px solid var(--violet);
  border-radius: 3px;
  font-size: 0.82rem;
  font-family: var(--mono);
  font-weight: 600;
}

ul {
  margin: 0 0 16px;
  padding-left: 24px;
}

ul li {
  margin-bottom: 8px;
  line-height: 1.55;
}

footer {
  background: var(--bg-elev);
  border-top: 1px solid var(--grid);
  padding: 24px 0;
  margin-top: 24px;
}

footer p {
  margin: 0 0 8px;
  font-size: 0.85rem;
  color: var(--fg-dim);
  line-height: 1.5;
}

footer p:last-child {
  margin-bottom: 0;
}

@media (max-width: 720px) {
  .container {
    padding: 0 16px;
  }

  .page-header {
    padding: 32px 0 24px;
  }

  .page-header h1 {
    font-size: 1.6rem;
  }

  .subtitle {
    font-size: 1rem;
  }

  main section {
    padding: 24px 0;
  }

  h2 {
    font-size: 1.2rem;
  }

  .gate-table {
    font-size: 0.82rem;
  }

  .gate-table th,
  .gate-table td {
    padding: 8px 10px;
  }

  figure {
    padding: 12px;
  }
}

@media (max-width: 480px) {
  .gate-table {
    font-size: 0.78rem;
  }

  .gate-table th,
  .gate-table td {
    padding: 6px 8px;
  }

  .status-blocked,
  .status-open,
  .status-closed,
  .status-narrowed {
    font-size: 0.72rem;
    padding: 1px 5px;
  }
}