/* ============================================================
   VULONE — single article page (sentient-style, dark theme)
   ============================================================ */

:root {
  --ab-bg: #0e0e0e;
  --ab-ink: #f4f4f5;      /* headings / strong text */
  --ab-body: #a1a1aa;     /* body text */
  --ab-muted: #71717a;
  --ab-faint: #52525b;
  --ab-line: #1f1f22;
  --ab-accent: #0ea5e9;
  --ab-accent-bright: #22d3ee;
  --ab-accent-tint: rgba(14, 165, 233, 0.14);
  --ab-serif: Georgia, 'Times New Roman', 'Source Serif 4', serif;
  --ab-sans: 'Aeonik', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
}

.ab-page {
  min-height: 100vh;
  background: var(--ab-bg);
  color: var(--ab-ink);
  font-family: var(--ab-sans);
  padding-top: 96px; /* clear fixed navbar */
  overflow-x: clip;  /* prevent horizontal scroll on mobile (keeps sticky TOC working) */
}

.ab-container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 32px 96px;
}

/* ------------------------------------------------------------------
   Back link
------------------------------------------------------------------ */
.ab-back {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--ab-muted);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  margin-bottom: 48px;
  transition: color .15s ease;
}

.ab-back:hover {
  color: var(--ab-ink);
}

.ab-back-circle {
  width: 32px;
  height: 32px;
  border-radius: 9999px;
  border: 1px solid var(--ab-line);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: border-color .15s ease;
}

.ab-back:hover .ab-back-circle {
  border-color: #2a2a30;
}

.ab-back-circle svg {
  width: 16px;
  height: 16px;
}

/* ------------------------------------------------------------------
   Article header (centered, narrow)
------------------------------------------------------------------ */
.ab-header {
  max-width: 760px;
  margin: 0 auto;
  text-align: center;
  padding-bottom: 48px;
}

.ab-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-bottom: 22px;
}

.ab-pill {
  display: inline-flex;
  align-items: center;
  padding: 5px 14px;
  border-radius: 9999px;
  background: var(--ab-accent-tint);
  color: var(--ab-accent-bright);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.ab-date {
  color: var(--ab-muted);
  font-size: 14px;
}

.ab-title {
  font-family: var(--ab-serif);
  font-size: clamp(1.9rem, 4.2vw, 3rem);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ab-ink);
  margin: 0 0 20px;
}

.ab-subtitle {
  color: var(--ab-muted);
  font-size: 17px;
  line-height: 1.7;
  max-width: 600px;
  margin: 0 auto 24px;
}

.ab-authors {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--ab-ink);
  font-size: 15px;
  font-weight: 600;
}

.ab-authors-sep {
  width: 1px;
  height: 14px;
  background: #3f3f46;
}

/* ------------------------------------------------------------------
   Hero image
------------------------------------------------------------------ */
.ab-hero {
  margin: 0 0 64px;
  border-radius: 24px;
  overflow: hidden;
  background: var(--ab-line);
  aspect-ratio: 21 / 9;
}

.ab-hero img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ------------------------------------------------------------------
   Two-column body: TOC + content
------------------------------------------------------------------ */
.ab-layout {
  display: grid;
  grid-template-columns: 280px minmax(0, 700px);
  gap: 56px;
  justify-content: center;
  align-items: start;
}

/* --- TOC --- */
.ab-toc {
  position: sticky;
  top: 96px;
}

.ab-toc-heading {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ab-faint);
  margin: 0 0 14px;
}

.ab-toc-nav {
  display: flex;
  flex-direction: column;
}

.ab-toc-nav a {
  display: block;
  padding: 7px 0 7px 14px;
  border-left: 2px solid transparent;
  color: var(--ab-muted);
  font-size: 13px;
  line-height: 1.45;
  text-decoration: none;
  transition: color .15s ease, border-color .15s ease;
}

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

.ab-toc-nav a.active {
  border-left-color: var(--ab-accent);
  color: var(--ab-ink);
}

.ab-toc-nav a.toc-h3 {
  padding-left: 26px;
  font-size: 12px;
  color: var(--ab-faint);
}

/* --- Content --- */
.ab-content {
  min-width: 0;
}

.ab-share {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-bottom: 28px;
  margin-bottom: 40px;
  border-bottom: 1px solid var(--ab-line);
}

.ab-share-label {
  color: var(--ab-muted);
  font-size: 14px;
  font-weight: 600;
  margin-right: 2px;
}

.ab-share-btn {
  width: 38px;
  height: 38px;
  border-radius: 9999px;
  border: 1px solid var(--ab-line);
  background: transparent;
  color: var(--ab-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  text-decoration: none;
  transition: color .15s ease, border-color .15s ease, background .15s ease;
}

.ab-share-btn:hover {
  color: var(--ab-ink);
  border-color: #2a2a30;
  background: rgba(255, 255, 255, 0.04);
}

.ab-share-btn svg {
  width: 16px;
  height: 16px;
}

.ab-share-btn svg.fill {
  fill: currentColor;
}

/* --- Article body typography --- */
.ab-article-body {
  color: var(--ab-body);
  font-size: 17px;
  line-height: 1.85;
  word-wrap: break-word;
}

.ab-article-body h1,
.ab-article-body h2,
.ab-article-body h3,
.ab-article-body h4 {
  color: var(--ab-ink);
  font-family: var(--ab-sans);
  font-weight: 700;
  line-height: 1.25;
  letter-spacing: -0.02em;
  scroll-margin-top: 110px;
}

.ab-article-body h1 { font-size: 1.9rem; margin: 2.2em 0 0.7em; }
.ab-article-body h2 { font-size: 1.6rem; margin: 2.2em 0 0.7em; }
.ab-article-body h3 { font-size: 1.3rem; margin: 1.8em 0 0.6em; }
.ab-article-body h4 { font-size: 1.1rem; margin: 1.6em 0 0.5em; }

.ab-article-body p {
  margin: 0 0 1.4em;
}

.ab-article-body a {
  color: var(--ab-accent-bright);
  text-decoration: none;
}

.ab-article-body a:hover {
  text-decoration: underline;
}

.ab-article-body ul,
.ab-article-body ol {
  margin: 0 0 1.4em;
  padding-left: 1.5em;
}

.ab-article-body li {
  margin: 0.45em 0;
}

.ab-article-body li > strong,
.ab-article-body li > b {
  color: var(--ab-ink);
}

.ab-article-body strong,
.ab-article-body b {
  color: var(--ab-ink);
}

.ab-article-body img {
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  margin: 2em auto;
  display: block;
}

.ab-article-body blockquote {
  border-left: 2px solid var(--ab-accent);
  padding-left: 20px;
  margin: 1.8em 0;
  color: var(--ab-muted);
  font-style: italic;
}

.ab-article-body code {
  font-family: 'JetBrains Mono', ui-monospace, Menlo, monospace;
  font-size: 0.85em;
  background: #1f1f22;
  padding: 2px 6px;
  border-radius: 6px;
  color: #e4e4e7;
  overflow-wrap: break-word;
}

.ab-article-body pre {
  background: #111113;
  border: 1px solid var(--ab-line);
  border-radius: 12px;
  padding: 18px 20px;
  overflow-x: auto;
  max-width: 100%;
  margin: 1.6em 0;
}

.ab-article-body pre code {
  background: none;
  padding: 0;
  font-size: 14px;
  color: inherit;
}

.ab-article-body hr {
  border: none;
  border-top: 1px solid var(--ab-line);
  margin: 2.5em 0;
}

/* --- Tables --- */
.ab-article-body table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.6em 0;
  font-size: 0.9rem;
  color: var(--ab-body);
  table-layout: fixed;
}

.ab-article-body thead {
  border-bottom: 2px solid var(--ab-line);
}

.ab-article-body th {
  text-align: left;
  padding: 10px 12px;
  font-size: 0.78rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--ab-muted);
  border-bottom: 1px solid var(--ab-line);
  white-space: nowrap;
}

.ab-article-body td {
  padding: 10px 12px;
  border-bottom: 1px solid var(--ab-line);
  vertical-align: top;
  overflow-wrap: break-word;
}

.ab-article-body tbody tr:hover td {
  background: rgba(255, 255, 255, 0.02);
}

.ab-article-body tbody tr:last-child td {
  border-bottom: none;
}

/* ------------------------------------------------------------------
   Responsive
------------------------------------------------------------------ */
@media (max-width: 900px) {
  .ab-layout {
    grid-template-columns: 1fr;
  }

  .ab-toc {
    display: none; /* TOC collapses on mobile */
  }
}

@media (max-width: 600px) {
  .ab-container {
    padding: 0 20px 64px;
  }

  .ab-page {
    padding-top: 80px;
  }

  .ab-hero {
    aspect-ratio: 16 / 10;
    border-radius: 16px;
  }

  .ab-article-body {
    font-size: 16px;
  }
}