:root {
  --bg: #faf8f4;
  --bg-alt: #f1ede4;
  --ink: #211f1c;
  --ink-soft: #55504a;
  --muted: #8b8479;
  --accent: #1f6f5c;
  --accent-soft: #e4efe9;
  --border: #e2ddd2;
  --font-serif: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --font-sans: 'Roboto', -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  --max: 46rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181a;
    --bg-alt: #1e2124;
    --ink: #ece9e2;
    --ink-soft: #c2bdb2;
    --muted: #837e75;
    --accent: #5fbfa2;
    --accent-soft: #1e2c28;
    --border: #2c2f31;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font-serif);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration: none; }

/* header */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 20;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 1rem;
  padding-bottom: 1rem;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}

.brand {
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--ink);
  text-decoration: none;
  letter-spacing: -0.01em;
}

.site-nav {
  display: flex;
  gap: 1.35rem;
  font-family: var(--font-sans);
  font-size: 0.92rem;
}

.site-nav a {
  color: var(--ink-soft);
  text-decoration: none;
  padding: 0.2rem 0;
  border-bottom: 2px solid transparent;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--ink);
  border-bottom-color: var(--accent);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 34px;
  height: 34px;
  background: none;
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
}
.nav-toggle span {
  display: block;
  height: 2px;
  margin: 0 6px;
  background: var(--ink);
}

@media (max-width: 640px) {
  .nav-toggle { display: flex; }
  .site-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 0.9rem;
    padding-top: 0.75rem;
  }
  .site-nav.open { display: flex; }
}

/* page */
.page { padding: 2.75rem 1.5rem 4rem; }

.crumb {
  display: inline-block;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: var(--muted);
  text-decoration: none;
  margin-bottom: 1.5rem;
}
.crumb:hover { color: var(--accent); }

.content h1 {
  font-family: var(--font-sans);
  font-size: 1.9rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 0 0 1.4rem;
  color: var(--ink);
}

.content h2 {
  font-family: var(--font-sans);
  font-size: 1.35rem;
  font-weight: 700;
  margin: 2.4rem 0 1rem;
  padding-top: 0.5rem;
  border-top: 1px solid var(--border);
}

.content h1:first-child, .content h2:first-child { border-top: none; padding-top: 0; }

.content h3 {
  font-family: var(--font-sans);
  font-size: 1.08rem;
  font-weight: 700;
  margin: 1.8rem 0 0.4rem;
  color: var(--ink);
}

.content h4 {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 700;
  margin: 1.6rem 0 0.3rem;
}

.content p { margin: 0 0 1.1rem; }

.content ul, .content ol {
  margin: 0 0 1.1rem;
  padding-left: 1.4rem;
}
.content li { margin-bottom: 0.4rem; }

.content strong { color: var(--ink); }

.content em { color: var(--ink-soft); }

.content blockquote {
  margin: 1.4rem 0;
  padding: 0.2rem 1.2rem;
  border-left: 3px solid var(--accent);
  color: var(--ink-soft);
  font-style: italic;
  background: var(--bg-alt);
}

.content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2.2rem 0;
}

.content code {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 0.88em;
  background: var(--bg-alt);
  padding: 0.1em 0.35em;
  border-radius: 4px;
}

.content img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.5rem 0;
  border-radius: 8px;
  border: 1px solid var(--border);
}

.content img.inline-icon {
  display: inline-block;
  margin: 0 0.2em;
  border: none;
  border-radius: 0;
  vertical-align: middle;
}

.img-center {
  display: flex;
  justify-content: center;
}
.img-center img { margin: 1.5rem auto; }

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

/* timeline */
.timeline {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  border-left: 2px solid var(--border);
}

.timeline-item {
  position: relative;
  padding: 0 0 2.2rem 1.6rem;
}

.timeline-item::before {
  content: '';
  position: absolute;
  left: -6px;
  top: 0.35rem;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--accent);
}

.timeline-date {
  font-family: var(--font-sans);
  font-size: 0.78rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.25rem;
}

.timeline-body h3 { margin: 0 0 0.35rem; font-size: 1.05rem; }
.timeline-body p { margin: 0; color: var(--ink-soft); }

/* footer */
.site-footer {
  border-top: 1px solid var(--border);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--muted);
  padding: 1.75rem 0 3rem;
}