/* ================================================================
   Cross-entropy AI — Celestial Editorial
   Typography: Cormorant Garamond (display) + Source Serif 4 (body) + Outfit (UI)
   ================================================================ */

:root {
  --color-ink:       #1a1a1a;
  --color-ink-soft:  #4a4a4a;
  --color-ink-muted: #8a8a8a;
  --color-ink-faint: #b0b0b0;
  --color-bg:        #faf9f7;
  --color-bg-warm:   #f4f2ee;
  --color-rule:      #ddd8d0;
  --color-accent:    #c45a3c;
  --font-display:    'Cormorant Garamond', Georgia, 'Noto Serif SC', serif;
  --font-body:       'Source Serif 4', Charter, 'Bitstream Charter', Georgia, 'Noto Serif SC', serif;
  --font-ui:         'Outfit', -apple-system, 'PingFang SC', 'Noto Sans SC', sans-serif;
  --content-width:   660px;
  --ease-out:        cubic-bezier(0.16, 1, 0.3, 1);
}

/* ===== Reset ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }

/* ===== Staggered Fade Animation ===== */
.anim-fade {
  opacity: 0;
  transform: translateY(16px);
  animation: fadeUp 0.8s var(--ease-out) forwards;
  animation-delay: calc(var(--delay, 0) * 0.12s + 0.1s);
}

@keyframes fadeUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== Blog Wrapper ===== */
.blog-wrapper {
  min-height: 100vh;
  background: var(--color-bg);
  color: var(--color-ink);
  display: flex;
  flex-direction: column;
  position: relative;
}

/* Subtle paper grain texture */
.blog-wrapper::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
  background-size: 256px 256px;
}

/* ===== Header ===== */
.blog-header {
  max-width: var(--content-width);
  width: 100%;
  margin: 0 auto;
  padding: 2.5rem 2rem 0;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
}

.blog-logo {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  color: var(--color-ink);
  text-decoration: none;
  letter-spacing: 0.01em;
  transition: color 0.3s;
}

.blog-logo:hover {
  color: var(--color-accent);
}

.blog-nav {
  display: flex;
  gap: 2rem;
}

.blog-nav a {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 400;
  color: var(--color-ink-muted);
  text-decoration: none;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  transition: color 0.3s;
}

.blog-nav a:hover {
  color: var(--color-ink);
}

/* Decorative rule */
.decorative-rule {
  max-width: var(--content-width);
  width: 100%;
  margin: 1.2rem auto 0;
  padding: 0 2rem;
}

.decorative-rule span {
  display: block;
  height: 1px;
  background: linear-gradient(to right, var(--color-rule), transparent);
}

/* ===== Main ===== */
.blog-main {
  max-width: var(--content-width);
  width: 100%;
  margin: 0 auto;
  padding: 2rem 2rem 4rem;
  flex: 1;
}

.page-title {
  font-family: var(--font-display);
  font-size: 42px;
  font-weight: 300;
  color: var(--color-ink);
  margin-bottom: 2.5rem;
  letter-spacing: 0.01em;
}

/* ===== Post List ===== */
.post-item {
  padding: 1.8rem 0;
  border-bottom: 1px solid var(--color-rule);
}

.post-item:first-of-type {
  padding-top: 0;
}

.post-item:last-of-type {
  border-bottom: none;
}

.post-item-inner {
  display: flex;
  gap: 1rem;
}

.post-item-accent {
  width: 2px;
  flex-shrink: 0;
  border-radius: 1px;
  background: transparent;
  transition: background 0.4s var(--ease-out);
}

.post-item:hover .post-item-accent {
  background: var(--color-accent);
}

.post-item-body {
  flex: 1;
  min-width: 0;
}

.post-date {
  display: block;
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 300;
  color: var(--color-ink-muted);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 0.4rem;
}

.post-title {
  font-family: var(--font-display);
  font-size: 26px;
  font-weight: 600;
  line-height: 1.25;
  margin-bottom: 0.2rem;
}

.post-title a {
  color: var(--color-ink);
  text-decoration: none;
  transition: color 0.3s;
}

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

.post-author {
  display: block;
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 300;
  color: var(--color-ink-muted);
  letter-spacing: 0.04em;
  margin-bottom: 0.6rem;
}

.post-summary {
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  color: var(--color-ink-soft);
}

.post-tags {
  margin-top: 0.7rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.post-tags a {
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 400;
  color: var(--color-ink-faint);
  text-decoration: none;
  transition: color 0.3s;
  letter-spacing: 0.02em;
}

.post-tags a:hover {
  color: var(--color-accent);
}

/* ===== Single Post ===== */
.post-single header h1 {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 400;
  line-height: 1.2;
  margin-bottom: 0.7rem;
  color: var(--color-ink);
  letter-spacing: 0.005em;
}

.post-meta {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 300;
  color: var(--color-ink-muted);
  letter-spacing: 0.02em;
}

.post-header {
  margin-bottom: 2.5rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-rule);
}

/* ===== Post Content ===== */
.post-content {
  font-family: var(--font-body);
  font-size: 17.5px;
  line-height: 1.75;
  color: var(--color-ink);
}

.post-content h2 {
  font-family: var(--font-display);
  font-size: 28px;
  font-weight: 600;
  margin: 2.5rem 0 1rem;
  letter-spacing: 0.005em;
}

.post-content h3 {
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 600;
  margin: 2rem 0 0.8rem;
}

.post-content p {
  margin-bottom: 1.3rem;
}

.post-content a {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
  text-decoration-color: rgba(196, 90, 60, 0.3);
  transition: text-decoration-color 0.3s;
}

.post-content a:hover {
  text-decoration-color: var(--color-accent);
}

.post-content blockquote {
  border-left: 2px solid var(--color-accent);
  padding-left: 1.2rem;
  margin: 1.5rem 0;
  color: var(--color-ink-soft);
  font-style: italic;
}

.post-content code {
  font-family: 'Berkeley Mono', 'SF Mono', 'Fira Code', monospace;
  font-size: 0.88em;
  background: var(--color-bg-warm);
  padding: 0.15em 0.45em;
  border-radius: 3px;
  border: 1px solid var(--color-rule);
}

.post-content pre {
  background: var(--color-bg-warm);
  padding: 1.2rem 1.4rem;
  border-radius: 6px;
  border: 1px solid var(--color-rule);
  overflow-x: auto;
  margin-bottom: 1.5rem;
}

.post-content pre code {
  background: none;
  padding: 0;
  border: none;
  font-size: 14px;
  line-height: 1.6;
}

.post-content img {
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  margin: 1.5rem 0;
}

.post-content ul, .post-content ol {
  margin-bottom: 1.3rem;
  padding-left: 1.5rem;
}

.post-content li {
  margin-bottom: 0.35rem;
}

.post-content hr {
  border: none;
  height: 1px;
  background: var(--color-rule);
  margin: 2.5rem 0;
}

/* ===== Post Nav ===== */
.post-nav {
  display: flex;
  justify-content: space-between;
  padding: 2rem 0;
  border-top: 1px solid var(--color-rule);
  margin-top: 3rem;
  gap: 2rem;
}

.post-nav a {
  font-family: var(--font-ui);
  font-size: 13px;
  font-weight: 400;
  color: var(--color-ink-muted);
  text-decoration: none;
  transition: color 0.3s;
  letter-spacing: 0.02em;
}

.post-nav a:hover {
  color: var(--color-accent);
}

.post-nav .next {
  margin-left: auto;
}

/* ===== Footer ===== */
.blog-footer {
  max-width: var(--content-width);
  width: 100%;
  margin: 0 auto;
  padding: 0 2rem 3rem;
}

.blog-footer .decorative-rule {
  margin: 0 0 1.5rem;
  padding: 0;
}

.blog-footer p {
  font-family: var(--font-ui);
  font-size: 12px;
  font-weight: 300;
  color: var(--color-ink-faint);
  letter-spacing: 0.06em;
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .blog-header {
    padding: 1.5rem 1.2rem 0;
  }
  .decorative-rule {
    padding: 0 1.2rem;
  }
  .blog-main {
    padding: 1.5rem 1.2rem 3rem;
  }
  .blog-footer {
    padding: 0 1.2rem 2rem;
  }
  .page-title {
    font-size: 32px;
  }
  .post-title {
    font-size: 22px;
  }
  .post-single header h1 {
    font-size: 32px;
  }
  .post-item-accent {
    display: none;
  }
}

/* ===== Selection ===== */
::selection {
  background: rgba(196, 90, 60, 0.15);
  color: var(--color-ink);
}