/* 408 Notes Style */
:root {
  --bg: #0f1117;
  --surface: #161822;
  --border: #2a2d3a;
  --text: #c9d1d9;
  --text-muted: #6e7681;
  --accent: #58a6ff;
  --code-bg: #1c1e2a;
  --mark-bg: #3d2c00;
  --mark-text: #ffd866;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Noto Sans SC', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  min-height: 100vh;
}

.top-nav {
  display: flex;
  gap: 20px;
  padding: 16px 24px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.top-nav a {
  color: var(--accent);
  text-decoration: none;
}
.top-nav a:hover { text-decoration: underline; }
.top-nav span { color: var(--text-muted); }

article.note-content, .index-main {
  max-width: 800px;
  margin: 0 auto;
  padding: 32px 24px 60px;
}

h1 { font-size: 1.8em; margin: 24px 0 16px; color: #fff; }
h2 { font-size: 1.4em; margin: 20px 0 12px; color: #e6edf3; border-bottom: 1px solid var(--border); padding-bottom: 6px; }
h3 { font-size: 1.15em; margin: 16px 0 8px; color: #d0d7de; }
h4, h5, h6 { margin: 12px 0 6px; }

p { margin: 8px 0; }

ul, ol { margin: 8px 0; padding-left: 24px; }
li { margin: 4px 0; }

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

code {
  background: var(--code-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
}

pre {
  background: var(--code-bg);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 12px 0;
}

pre code {
  background: none;
  padding: 0;
}

mark {
  background: var(--mark-bg);
  color: var(--mark-text);
  padding: 1px 4px;
  border-radius: 3px;
}

img {
  max-width: 100%;
  border-radius: 6px;
  margin: 8px 0;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 24px 0;
}

.missing-link {
  color: #f85149;
  text-decoration: line-through;
}

.tree {
  margin-top: 24px;
}

.tree ul {
  list-style: none;
  padding-left: 20px;
}

.tree li {
  margin: 6px 0;
}

.tree details > summary {
  cursor: pointer;
  color: #e6edf3;
  font-weight: 600;
  padding: 4px 0;
}

.tree details > summary:hover {
  color: var(--accent);
}

.tree a {
  color: var(--text);
  font-size: 0.95em;
}

.tree a:hover {
  color: var(--accent);
}

.subtitle {
  color: var(--text-muted);
  margin-bottom: 24px;
}

/* Mobile */
@media (max-width: 640px) {
  article.note-content, .index-main {
    padding: 20px 16px 40px;
  }
  h1 { font-size: 1.4em; }
}