/* Shared styles for every page in /blog. Colours and fonts match index.html. */
:root {
  --bg: #0a0e14;
  --bg-elevated: #0f151d;
  --bg-soft: #121a24;
  --border: #1c2530;
  --border-strong: #2a3542;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --text-dim: #5b6673;
  --accent: #58a6ff;
  --accent-dim: #1f6feb;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max-width: 960px;
  --read-width: 680px;
}

*, *::before, *::after { box-sizing: border-box; }

html { color-scheme: dark; }

body {
  margin: 0;
  font-family: var(--sans);
  color: var(--text);
  background: var(--bg);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.025) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.025) 1px, transparent 1px);
  background-size: 48px 48px;
  line-height: 1.6;
}

::selection {
  background: rgba(88, 166, 255, 0.25);
  color: #fff;
}

a { color: var(--accent); }

/* Nav (same look as the main page) */
header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(10, 14, 20, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

nav {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

.nav-logo {
  font-family: var(--mono);
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.02em;
  text-decoration: none;
}

.nav-logo span { color: var(--accent); }

.nav-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  text-decoration: none;
  color: var(--text-muted);
  font-family: var(--mono);
  font-size: 0.78rem;
  font-weight: 500;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  transition: color 0.15s ease;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] { color: var(--accent); }

main {
  max-width: var(--read-width);
  margin: 0 auto;
  padding: 4rem 1.5rem 5rem;
}

/* Blog list page */
.page-eyebrow {
  font-family: var(--mono);
  font-size: 0.85rem;
  color: var(--text-dim);
  margin: 0 0 0.75rem;
}

.page-eyebrow .prompt { color: var(--accent); }

.page-title {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 0.5rem;
}

.page-intro {
  color: var(--text-muted);
  margin: 0 0 3rem;
}

.post-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1.1rem;
}

.post-card {
  display: block;
  padding: 1.4rem 1.5rem;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent-dim);
  border-radius: 4px;
  text-decoration: none;
  color: inherit;
  transition: border-left-color 0.15s ease, transform 0.15s ease, box-shadow 0.15s ease;
}

.post-card:hover {
  border-left-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -18px rgba(88, 166, 255, 0.4);
}

.post-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin: 0 0 0.35rem;
  color: var(--text);
}

.post-card:hover .post-card-title { color: var(--accent); }

.post-card-summary {
  color: var(--text-muted);
  margin: 0.6rem 0 0;
  font-size: 0.95rem;
}

.feed-link {
  font-family: var(--mono);
  font-size: 0.8rem;
  white-space: nowrap;
}

.post-empty {
  font-family: var(--mono);
  font-size: 0.9rem;
  color: var(--text-dim);
  padding: 1.4rem 1.5rem;
  border: 1px dashed var(--border-strong);
  border-radius: 4px;
  margin: 0;
}

.not-found-links {
  display: flex;
  gap: 1.5rem;
  font-family: var(--mono);
  font-size: 0.85rem;
  margin: 0;
}

/* Date, reading time and tags — used on the list page and on posts */
.post-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem 0.9rem;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-dim);
  letter-spacing: 0.03em;
}

.tag {
  border: 1px solid var(--border-strong);
  color: var(--text-muted);
  padding: 0.15rem 0.5rem;
  border-radius: 3px;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

/* Single post page */
.back-link {
  display: inline-block;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--text-muted);
  text-decoration: none;
  margin-bottom: 2.5rem;
}

.back-link:hover { color: var(--accent); }

.post-header {
  padding-bottom: 1.75rem;
  margin-bottom: 2.25rem;
  border-bottom: 1px solid var(--border);
}

.post-header h1 {
  font-size: 2.25rem;
  line-height: 1.2;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin: 0 0 1rem;
}

.post-body {
  font-size: 1.05rem;
  line-height: 1.75;
  color: #c9d1d9;
}

.post-body > * + * { margin-top: 1.25rem; }
.post-body p { margin-bottom: 0; }

.post-body h2 {
  font-size: 1.4rem;
  color: var(--text);
  margin: 2.75rem 0 0;
  letter-spacing: -0.01em;
}

.post-body h3 {
  font-size: 1.1rem;
  color: var(--text);
  margin: 2rem 0 0;
}

.post-body ul,
.post-body ol { padding-left: 1.4rem; margin-bottom: 0; }

.post-body li + li { margin-top: 0.4rem; }

.post-body li::marker { color: var(--accent); }

.post-body blockquote {
  margin-left: 0;
  margin-right: 0;
  padding: 0.25rem 0 0.25rem 1.25rem;
  border-left: 3px solid var(--accent-dim);
  color: var(--text-muted);
  font-style: italic;
}

.post-body code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 0.1em 0.35em;
}

.post-body pre {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 1rem 1.25rem;
  overflow-x: auto;
  line-height: 1.55;
}

.post-body pre code {
  background: none;
  border: 0;
  padding: 0;
  font-size: 0.85rem;
}

/* Maths (KaTeX): let wide equations scroll sideways on phones instead of breaking the layout */
.post-body .katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.25rem 0;
}

.post-body .katex { color: var(--text); }

.post-footer {
  margin-top: 3.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-family: var(--mono);
  font-size: 0.8rem;
  color: var(--text-dim);
}

footer {
  text-align: center;
  padding: 2rem 1.5rem;
  color: var(--text-dim);
  font-family: var(--mono);
  font-size: 0.78rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 600px) {
  main { padding: 2.5rem 1rem 3.5rem; }
  nav { padding: 0.75rem 1rem; }
  .nav-links { gap: 1rem; }
  .nav-links a { font-size: 0.7rem; }
  .page-title,
  .post-header h1 { font-size: 1.75rem; }
  .post-body { font-size: 1rem; }
}