:root {
  color-scheme: light;
  --bg: #f7f4ee;
  --surface: #fffaf2;
  --text: #26231f;
  --muted: #6f675d;
  --line: #ded4c5;
  --accent: #2f6f73;
  --accent-soft: #dceceb;
  --link: #245f63;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.7;
}

a {
  color: var(--link);
  text-decoration-thickness: 0.08em;
  text-underline-offset: 0.18em;
}

.site-header,
.site-footer,
main {
  width: min(100% - 32px, 920px);
  margin: 0 auto;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 24px 0;
  border-bottom: 1px solid var(--line);
}

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

.site-header nav a {
  color: var(--muted);
  font-size: 0.95rem;
}

.hero {
  padding: 72px 0 48px;
}

.eyebrow,
.note-date {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.9rem;
}

h1,
h2,
h3 {
  line-height: 1.25;
}

h1 {
  margin: 0 0 18px;
  font-size: clamp(2.25rem, 7vw, 4.5rem);
  letter-spacing: 0;
}

h2 {
  margin: 0 0 20px;
  font-size: 1.5rem;
}

.hero p:last-child {
  max-width: 620px;
  margin: 0;
  color: var(--muted);
  font-size: 1.08rem;
}

.content-section {
  padding: 32px 0;
  border-top: 1px solid var(--line);
}

.note-list {
  display: grid;
  gap: 16px;
}

.note-card {
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.note-card h3 {
  margin: 0 0 8px;
  font-size: 1.25rem;
}

.note-card p {
  margin: 0 0 12px;
}

.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 2px 10px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.9rem;
  text-decoration: none;
}

.tag-index {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
}

.tag-group {
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 250, 242, 0.7);
}

.tag-group h3 {
  margin: 0 0 10px;
}

.tag-group ul {
  margin: 0;
  padding-left: 20px;
}

.note-page {
  max-width: 760px;
  padding: 48px 0;
}

.breadcrumb {
  margin-bottom: 32px;
}

.note-header {
  margin-bottom: 36px;
  padding-bottom: 24px;
  border-bottom: 1px solid var(--line);
}

.note-header p {
  color: var(--muted);
}

.prose {
  font-size: 1.05rem;
  overflow-wrap: break-word;
}

.prose img {
  max-width: 100%;
  height: auto;
}

.prose blockquote {
  margin: 24px 0;
  padding: 12px 18px;
  border-left: 4px solid var(--accent);
  border-radius: 0 8px 8px 0;
  background: var(--accent-soft);
  color: var(--text);
}

.prose code {
  padding: 0.15em 0.3em;
  border-radius: 4px;
  background: #ebe3d6;
}

.prose pre {
  overflow-x: auto;
  padding: 16px;
  border-radius: 8px;
  background: #1f2526;
  color: #f5f2ea;
}

.prose pre code {
  padding: 0;
  background: transparent;
}

.prose pre.mermaid {
  background: var(--surface);
  color: var(--text);
}

.prose table {
  display: block;
  width: 100%;
  margin: 24px 0;
  border-collapse: collapse;
  font-size: 0.95rem;
  overflow-x: auto;
}

.prose th,
.prose td {
  padding: 10px 12px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

.prose th {
  background: rgba(220, 236, 235, 0.55);
}

.summary-box {
  margin: 24px 0;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: linear-gradient(135deg, #fffaf2, #eef7f6);
}

.golden {
  margin: 40px 0;
  padding: 24px 18px;
  border-top: 2px solid var(--accent);
  border-bottom: 2px solid var(--accent);
  color: var(--accent);
  font-size: 1.25rem;
  font-weight: 700;
  line-height: 1.6;
  text-align: center;
}

.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 4px 0;
}

.site-footer {
  padding: 36px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.95rem;
}

.empty-state {
  color: var(--muted);
}

@media (max-width: 640px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero {
    padding: 48px 0 32px;
  }

  .note-card,
  .tag-group {
    padding: 16px;
  }
}