:root {
  color-scheme: light dark;
  --bg: #f5f7fb;
  --card: #ffffff;
  --text: #1a1d26;
  --muted: #5c6478;
  --accent: #4f46e5;
  --border: #e2e8f0;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1117;
    --card: #171a22;
    --text: #eef1f8;
    --muted: #9aa3b8;
    --accent: #818cf8;
    --border: #2a3142;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
}

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 20px 48px;
}

header {
  margin-bottom: 28px;
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
}

.logo-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, #1f4f82, #143252);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: #7dd3fc;
  font-size: 1rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 28px 24px;
}

h1 {
  margin: 0 0 8px;
  font-size: 1.75rem;
  line-height: 1.2;
}

.updated {
  margin: 0 0 24px;
  color: var(--muted);
  font-size: 0.95rem;
}

h2 {
  margin: 28px 0 10px;
  font-size: 1.1rem;
}

p {
  margin: 0 0 14px;
}

ul {
  margin: 0 0 14px;
  padding-left: 1.25rem;
}

li {
  margin-bottom: 6px;
}

nav.links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

nav.links a,
footer a {
  color: var(--accent);
  text-decoration: none;
}

nav.links a:hover,
footer a:hover {
  text-decoration: underline;
}

footer {
  margin-top: 28px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.9rem;
}

.lead {
  font-size: 1.05rem;
}

.notice {
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid #fbbf24;
  background: rgba(251, 191, 36, 0.12);
  font-size: 0.95rem;
}

@media (prefers-color-scheme: dark) {
  .notice {
    border-color: #b45309;
    background: rgba(180, 83, 9, 0.18);
  }
}

.toc ul {
  list-style: none;
  padding-left: 0;
}

.toc li {
  margin-bottom: 4px;
}

.toc a {
  color: var(--accent);
  text-decoration: none;
}

.toc a:hover {
  text-decoration: underline;
}

.peptide-sources h3 {
  margin: 24px 0 8px;
  font-size: 1rem;
}

.source-list a {
  color: var(--accent);
  text-decoration: none;
}

.source-list a:hover {
  text-decoration: underline;
}