/* ─── Reading Progress Bar ───────────────────────────── */
#reading-progress-bar {
  position: fixed;
  top: 0;
  left: 0;
  height: 2px;
  width: 0%;
  background: var(--color-accent);
  z-index: 9999;
  transition: width 0.1s linear;
  border-radius: 0 2px 2px 0;
}

@media (prefers-color-scheme: dark) {
  #reading-progress-bar {
    background: var(--color-text-muted);
  }
}

/* ─── Main Container ─────────────────────────────────── */
.post-main {
  min-height: 100vh;
  background: var(--color-bg);
}

/* ─── Sticky Nav ─────────────────────────────────────── */
.post-nav {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.75rem 1.25rem;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.post-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  height: 2.125rem;
  padding: 0 0.875rem;
  border-radius: 999px;
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: 0.8125rem;
  font-weight: 500;
  letter-spacing: -0.01em;
  text-decoration: none;
  border: 1px solid var(--color-border);
  transition:
    background 0.2s ease,
    color 0.2s ease,
    border-color 0.2s ease;
  flex-shrink: 0;
}

.post-nav-btn:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
  border-color: var(--color-border-hover);
}

.post-nav-title {
  flex: 1;
  text-align: center;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.02em;
  padding: 0 1rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  opacity: 0;
  transform: translateY(-6px);
  transition:
    opacity 0.3s ease,
    transform 0.3s ease;
}

.post-nav-title.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ─── Hero Image ─────────────────────────────────────── */
.post-hero {
  position: relative;
  width: 100%;
  max-width: 820px;
  margin: 2.5rem auto 0;
  padding: 0 1.25rem;
  box-sizing: border-box;
}

.post-hero-img {
  width: 100%;
  aspect-ratio: 16 / 7;
  object-fit: var(--hero-fit, cover);
  border-radius: 14px;
  display: block;
  box-shadow: 0 8px 40px rgba(0, 0, 0, 0.14);
}

@media (prefers-color-scheme: dark) {
  .post-hero-img {
    box-shadow: 0 8px 40px rgba(0, 0, 0, 0.4);
  }
}

.post-hero-overlay {
  position: absolute;
  inset: 0 1.25rem;
  border-radius: 14px;
  background: linear-gradient(
    to bottom,
    transparent 50%,
    rgba(0, 0, 0, 0.18) 100%
  );
  pointer-events: none;
}

.post-hero-source {
  display: block;
  margin-top: 0.5rem;
  text-align: right;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--color-text-subtle);
  letter-spacing: 0.02em;
}

/* ─── Article Header ─────────────────────────────────── */
.post-header-wrap {
  max-width: 820px;
  margin: 2.5rem auto 0;
  padding: 0 1.25rem;
}

.post-header-wrap--no-hero {
  margin-top: 3.5rem;
}

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

.post-category {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-accent);
  background: var(--color-accent-light);
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  border: 1px solid var(--color-border);
  margin-bottom: 0.875rem;
}

.post-title {
  font-size: clamp(1.875rem, 5vw, 2.75rem);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin: 0 0 0.625rem;
}

.post-description {
  font-size: 1.0625rem;
  color: var(--color-text-muted);
  line-height: 1.55;
  margin: 0 0 1.125rem;
  max-width: 56ch;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.post-meta-item {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--color-text-subtle);
}

.post-meta-dot {
  color: var(--color-border-hover);
  font-size: 0.75rem;
}

/* ─── Article Content ────────────────────────────────── */
.post-content-wrap {
  max-width: 820px;
  margin: 0 auto;
  padding: 2.5rem 1.25rem 0;
}

.post-content {
  /* override global p max-width */
}

/* ─── TOC Sidebar ──────────────────────────────────── */
.toc-sidebar {
  display: none;
  position: fixed;
  top: 100px;
  width: 200px;
  max-height: calc(100vh - 140px);
  overflow-y: auto;
  font-family: var(--font-mono);
  font-size: 0.8rem;
}

@media (min-width: 1360px) {
  .toc-sidebar {
    display: block;
    right: calc((100% - 820px) / 2 - 220px);
  }
}

.toc-label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-subtle);
  margin-bottom: 0.75rem;
}

#table-of-contents ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

#table-of-contents li {
  line-height: 1.5;
}

#table-of-contents a {
  color: var(--color-text-muted);
  text-decoration: none;
  transition: color 0.15s;
  display: block;
  padding: 2px 0;
  border-left: 2px solid transparent;
  padding-left: 0.5rem;
}

#table-of-contents a:hover {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

#table-of-contents a.font-semibold {
  color: var(--color-accent);
  border-left-color: var(--color-accent);
}

/* Prose overrides — ensure full column width */
.post-content p {
  max-width: 100%;
  font-size: 1.0625rem;
  line-height: 1.75;
  color: var(--color-text-muted);
  margin-bottom: 1.5rem;
}

.post-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.025em;
  margin-top: 3rem;
  margin-bottom: 1rem;
  border-bottom: 1px solid var(--color-border);
  padding-bottom: 0.5rem;
}

.post-content h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text);
  letter-spacing: -0.02em;
  margin-top: 2.25rem;
  margin-bottom: 0.75rem;
}

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

.post-content li {
  font-size: 1.0625rem;
  line-height: 1.7;
  color: var(--color-text-muted);
  margin-bottom: 0.35rem;
}

.post-content strong {
  color: var(--color-text);
  font-weight: 600;
}

.post-content a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  transition: color 0.2s;
}

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

.post-content blockquote {
  border-left: 3px solid var(--color-border-hover);
  margin: 2rem 0;
  padding: 0.75rem 1.25rem;
  background: var(--color-accent-light);
  border-radius: 0 8px 8px 0;
  font-style: italic;
  color: var(--color-text-muted);
}

/* ─── Callout Components ─────────────────────────────── */
.callout {
  position: relative;
  margin: 1.75rem 0;
  padding: 1rem 1.125rem;
  border-radius: 10px;
  border-left: 4px solid;
  background: var(--callout-bg);
  border-left-color: var(--callout-accent);
  transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  animation: callout-enter 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.callout:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.08);
}
.callout-info {
  --callout-accent: #3b82f6;
  --callout-bg: rgba(59, 130, 246, 0.08);
}
.callout-warning {
  --callout-accent: #f59e0b;
  --callout-bg: rgba(245, 158, 11, 0.08);
}
.callout-success {
  --callout-accent: #10b981;
  --callout-bg: rgba(16, 185, 129, 0.08);
}
.callout-danger {
  --callout-accent: #ef4444;
  --callout-bg: rgba(239, 68, 68, 0.08);
}
.callout-note {
  --callout-accent: #8b7355;
  --callout-bg: rgba(139, 115, 85, 0.08);
}
.callout-gray {
  --callout-accent: #9ca3af;
  --callout-bg: rgba(107, 114, 128, 0.08);
}

@media (prefers-color-scheme: dark) {
  .callout-info {
    --callout-bg: rgba(59, 130, 246, 0.12);
  }
  .callout-warning {
    --callout-bg: rgba(245, 158, 11, 0.12);
  }
  .callout-success {
    --callout-bg: rgba(16, 185, 129, 0.12);
  }
  .callout-danger {
    --callout-bg: rgba(239, 68, 68, 0.12);
  }
  .callout-note {
    --callout-bg: rgba(139, 115, 85, 0.12);
  }
  .callout-gray {
    --callout-bg: rgba(107, 114, 128, 0.12);
  }
  .callout:hover {
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.3);
  }
}

.callout-header {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  margin-bottom: 0.375rem;
}
.callout-title {
  font-family: var(--font-sans);
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--callout-accent);
  letter-spacing: -0.01em;
}
.callout-content {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  line-height: 1.65;
}
.callout-content p {
  margin: 0;
}
.callout-content p + p {
  margin-top: 0.625rem;
}
.callout-content a {
  color: var(--callout-accent);
  text-decoration-color: var(--callout-accent);
}

@keyframes callout-enter {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ─── Syntax Highlight ───────────────────────────────── */
.highlight {
  border-radius: 8px;
  overflow: hidden;
  margin: 1.5rem 0;
}

/* ─── Footer ─────────────────────────────────────────── */
.post-footer {
  width: 100%;
  margin-top: 5rem;
  border-top: 1px solid var(--color-border);
  padding: 2rem 1.25rem;
}

.post-footer-inner {
  max-width: 820px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.post-footer-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  height: 2.125rem;
  padding: 0 0.875rem;
  border-radius: 999px;
  background: var(--color-surface);
  color: var(--color-text-muted);
  font-size: 0.8125rem;
  font-weight: 500;
  text-decoration: none;
  border: 1px solid var(--color-border);
  transition:
    background 0.2s ease,
    color 0.2s ease,
    border-color 0.2s ease;
}

.post-footer-btn:hover {
  background: var(--color-accent-light);
  color: var(--color-accent);
  border-color: var(--color-border-hover);
}

.post-footer-link {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  text-decoration: none;
  letter-spacing: -0.01em;
  transition: color 0.2s ease;
}

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

/* ─── Responsive ─────────────────────────────────────── */
@media (max-width: 640px) {
  .post-nav {
    padding: 0.625rem 1rem;
  }

  .post-hero {
    padding: 0 1rem;
    margin-top: 1.5rem;
  }

  .post-header-wrap {
    padding: 0 1rem;
    margin-top: 1.75rem;
  }

  .post-content-wrap {
    padding: 1.75rem 1rem 0;
  }

  .post-title {
    font-size: 1.75rem;
  }

  .post-footer {
    padding: 1.5rem 1rem;
  }
}