:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --muted: #6b7280;
  --border: #e5e7eb;
  --link: #2563eb;
  --code-bg: #f3f4f6;
  --nav-bg: #f9fafb;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111827;
    --text: #f3f4f6;
    --muted: #9ca3af;
    --border: #374151;
    --link: #60a5fa;
    --code-bg: #1f2937;
    --nav-bg: #1f2937;
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
    'PingFang SC', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  font-size: 16px;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Nav */
nav {
  background: var(--nav-bg);
  border-bottom: 1px solid var(--border);
  padding: 0.75rem 0;
  position: sticky;
  top: 0;
  z-index: 10;
}

nav .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

nav .site-title {
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text);
  text-decoration: none;
}

nav .nav-links {
  display: flex;
  gap: 1rem;
  list-style: none;
}

nav .nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
}

nav .nav-links a:hover,
nav .nav-links a.active {
  color: var(--link);
}

/* Content */
main {
  padding: 2rem 0 4rem;
}

h1 { font-size: 1.75rem; margin: 1.5rem 0 1rem; }
h2 { font-size: 1.35rem; margin: 1.5rem 0 0.75rem; border-bottom: 1px solid var(--border); padding-bottom: 0.3rem; }
h3 { font-size: 1.1rem; margin: 1.25rem 0 0.5rem; }

p { margin: 0.75rem 0; }

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; }

ul, ol { margin: 0.75rem 0; padding-left: 1.5rem; }
li { margin: 0.25rem 0; }

/* Tables */
table {
  width: 100%;
  border-collapse: collapse;
  margin: 1rem 0;
  font-size: 0.9rem;
}

th, td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}

th {
  background: var(--nav-bg);
  font-weight: 600;
}

/* Code */
code {
  background: var(--code-bg);
  padding: 0.15rem 0.4rem;
  border-radius: 3px;
  font-size: 0.9em;
}

pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 6px;
  overflow-x: auto;
  margin: 1rem 0;
}

/* Blockquote */
blockquote {
  border-left: 3px solid var(--link);
  padding-left: 1rem;
  margin: 1rem 0;
  color: var(--muted);
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}

/* Report nav */
.report-nav {
  display: flex;
  justify-content: space-between;
  margin: 1.5rem 0;
  padding: 0.75rem 0;
  border-top: 1px solid var(--border);
  font-size: 0.9rem;
}

/* Archive */
.archive-list {
  list-style: none;
  padding: 0;
}

.archive-list li {
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--border);
}

.archive-list li:last-child {
  border-bottom: none;
}

/* Footer */
footer {
  padding: 1.5rem 0;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}

@media (max-width: 600px) {
  body { font-size: 15px; }
  h1 { font-size: 1.4rem; }
  table { font-size: 0.8rem; }
  th, td { padding: 0.35rem 0.5rem; }
}

@media print {
  nav, .report-nav, footer { display: none; }
  main { padding: 0; }
  .container { max-width: 100%; }
}