*, *::before, *::after { box-sizing: border-box; }
:root {
  --bg: #ffffff;
  --fg: #111111;
  --text: #333333;
  --muted: #777777;
  --soft: #cccccc;
  --surface: #f7f7f7;
  --border: #e4e4e4;
  --font-sans: 'Lora', Georgia, serif;
  --font-mono: 'Geist Mono', 'Courier New', monospace;
}
[data-theme="dark"] {
  --bg: #111111;
  --fg: #f3f3f3;
  --text: #d5d5d5;
  --muted: #999999;
  --soft: #555555;
  --surface: #181818;
  --border: #333333;
}
html { color-scheme: light; }
html[data-theme="dark"] { color-scheme: dark; }
body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.7;
  margin: 0;
  transition: background-color 0.2s ease, color 0.2s ease;
}
a {
  color: var(--fg);
  text-decoration: underline;
  text-decoration-color: var(--soft);
  text-underline-offset: 3px;
}
a:hover { text-decoration-color: var(--fg); }
.notes-shell {
  max-width: 720px;
  margin: 0 auto;
  padding: 48px 32px 72px;
}
.notes-nav {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-bottom: 52px;
}
.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 28px;
}
.notes-nav a {
  color: var(--muted);
  font-size: 0.85rem;
  text-decoration: none;
}
.notes-nav a:hover { color: var(--fg); }
.theme-toggle {
  appearance: none;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  color: var(--muted);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 30px;
  margin-left: auto;
  padding: 0;
  width: 30px;
}
.theme-toggle:hover {
  border-color: var(--muted);
  color: var(--fg);
}
.theme-toggle svg {
  height: 15px;
  width: 15px;
}
.page-kicker {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.02em;
  margin-bottom: 12px;
  text-transform: uppercase;
}
h1 {
  font-size: 1.55rem;
  font-weight: 500;
  line-height: 1.3;
  margin: 0 0 16px;
}
.intro {
  color: var(--text);
  margin: 0 0 40px;
  max-width: 620px;
}
.note-list {
  border-top: 1px solid var(--border);
}
.note-row {
  display: grid;
  gap: 8px;
  padding: 22px 0;
  text-decoration: none;
  border-bottom: 1px solid var(--border);
}
.note-row h2 {
  font-size: 1.05rem;
  font-weight: 500;
  line-height: 1.35;
  margin: 0;
}
.note-row p {
  color: var(--text);
  margin: 0;
}
.note-meta {
  color: var(--muted);
  font-family: var(--font-mono);
  font-size: 0.72rem;
}
.note {
  color: var(--text);
}
.note-header {
  margin-bottom: 36px;
}
.note h2, .note h3, .note h4 {
  color: var(--fg);
  font-weight: 500;
  line-height: 1.35;
  margin: 34px 0 12px;
}
.note p, .note li {
  font-size: 0.98rem;
}
.note p {
  margin: 0 0 16px;
}
.note ul {
  margin: 0 0 18px 1.3rem;
  padding: 0;
}
.note blockquote {
  border-left: 1px solid var(--soft);
  color: var(--text);
  margin: 24px 0;
  padding-left: 18px;
}
.note pre {
  background: var(--surface);
  border: 1px solid var(--border);
  overflow-x: auto;
  padding: 14px;
}
.note code {
  font-family: var(--font-mono);
  font-size: 0.88em;
}
.note img {
  display: block;
  height: auto;
  margin: 28px auto;
  max-width: 100%;
}
.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 4px 0;
}
@media (max-width: 600px) {
  .notes-shell { padding: 28px 20px 56px; }
  .notes-nav { gap: 16px; margin-bottom: 40px; }
  .nav-links { gap: 18px; }
}