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

:root {
  --bg: #f8f8f6;
  --surface: #fff;
  --border: #d0d0cc;
  --text: #1a1a18;
  --muted: #666;
  --accent: #3a6ea5;
  --mono: "JetBrains Mono", "Fira Mono", "Cascadia Code", monospace;
  --sans: system-ui, -apple-system, sans-serif;
}

html { background: var(--surface); }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.5;
  min-height: 100vh;
}

header {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.6rem 1.2rem;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.header-title { font-size: 1.05rem; font-weight: 600; }
.header-title-link { color: inherit; text-decoration: none; }
.header-title-link:hover { text-decoration: underline; }
.header-sub { font-size: 0.85rem; color: var(--muted); }

.header-right {
  margin-left: auto;
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}