/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;700&family=Source+Serif+4:ital,opsz,wght@0,8..60,400;0,8..60,600;0,8..60,700;1,8..60,400&display=swap');

/* --- Base --- */
body {
  background-color: #F7F4EF;
  color: #1B2A4A;
  font-family: "Source Serif 4", Georgia, serif;
  -webkit-font-smoothing: antialiased;
}

/* --- Nav --- */
nav a {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.8rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: color 300ms ease;
  text-decoration: none;
  color: #1B2A4A;
}
nav a:hover { color: #E8C340; }

/* --- Post header --- */
.post-title {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: clamp(1.5rem, 4vw, 2.25rem);
  font-weight: 700;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: #1B2A4A;
}

.post-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  line-height: 1.6;
  color: rgba(27, 42, 74, 0.5);
  margin-top: 1rem;
}

.post-author {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 0.875rem;
  font-weight: 700;
  color: #1B2A4A;
  text-decoration: none;
}
.post-date {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: #6B7280;
}

/* --- Prose --- */
.prose-doc {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.1rem;
  font-weight: 400;
  line-height: 1.58;
  letter-spacing: -0.003em;
  color: #1B2A4A;
  padding: 0 1.5rem;
}

.prose-doc h2 {
  font-family: "JetBrains Mono", monospace;
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.012em;
  line-height: 1.22;
  margin-top: 2.2em;
  margin-bottom: 0.4em;
  padding-bottom: 0.3em;
  border-bottom: 2px solid #1B2A4A;
  display: inline-block;
  color: #1B2A4A;
}

.prose-doc h3 {
  font-family: "Source Serif 4", Georgia, serif;
  font-size: 1.15rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.25;
  margin-top: 2rem;
  margin-bottom: 0.75rem;
  color: #1B2A4A;
}

.prose-doc p {
  margin-bottom: 1.5rem;
}

.prose-doc a {
  color: #1B2A4A;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: rgba(27, 42, 74, 0.4);
  transition: text-decoration-color 300ms ease;
}
.prose-doc a:hover { text-decoration-color: #E8C340; }

.prose-doc ul, .prose-doc ol {
  padding-left: 1.5rem;
  margin-bottom: 1.5rem;
}
.prose-doc ul { list-style: disc; }
.prose-doc ol { list-style: decimal; }
.prose-doc li { margin-bottom: 0.4rem; }

.prose-doc blockquote {
  border-left: 3px solid #1B2A4A;
  padding-left: 1.25rem;
  margin: 2rem 0;
  color: rgba(27, 42, 74, 0.65);
  font-style: italic;
}

.prose-doc code {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.85em;
  background: rgba(27, 42, 74, 0.07);
  padding: 0.15em 0.4em;
  border-radius: 3px;
}

.prose-doc pre {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.875rem;
  background: rgba(27, 42, 74, 0.06);
  border: 1px solid rgba(27, 42, 74, 0.12);
  padding: 1.25rem 1.5rem;
  border-radius: 3px;
  overflow-x: auto;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}
.prose-doc pre code {
  background: none;
  padding: 0;
  font-size: inherit;
}

.prose-doc .post-image {
  border: 1px solid rgba(27, 42, 74, 0.1);
  overflow: hidden;
  margin-bottom: 2rem;
}
.prose-doc .post-image img {
  width: 100%;
  display: block;
}
.prose-doc .post-image figcaption {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  color: rgba(27, 42, 74, 0.5);
  padding: 0.6rem 1rem;
  border-top: 1px solid rgba(27, 42, 74, 0.08);
}

/* --- Mobile --- */
@media (max-width: 640px) {
  .post-title { letter-spacing: -0.01em; }
  .prose-doc { font-size: 1rem; }
  .prose-doc h2 { font-size: 1.15rem; }
  .prose-doc h3 { font-size: 1rem; }
  .prose-doc pre { font-size: 0.8rem; padding: 1rem; }
}

/* Responsive left vertical line (≥720px) */
@media (min-width: 720px) {
  .prose-doc {
    position: relative;
    padding-left: 2.75rem;
    padding-right: 2.75rem;
  }
  .prose-doc::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 1px;
    background: rgba(27, 42, 74, 0.1);
  }
}

/* --- Extras --- */
.katex { font-size: 1em; }

.katex-display {
  overflow-x: auto;
  padding: 0.5rem 0;
  margin: 1.5rem 0;
}

hr.section-divider {
  border: none;
  border-top: 1px solid rgba(27, 42, 74, 0.15);
  margin: 3rem 0;
}

.callout {
  background: rgba(232, 195, 64, 0.12);
  border-left: 3px solid #E8C340;
  padding: 1rem 1.25rem;
  margin-bottom: 1.5rem;
  border-radius: 0 3px 3px 0;
}
.callout p { margin-bottom: 0; }
.callout code { background: rgba(232, 195, 64, 0.2); }