/* ============================================================
   ReLU.chat — Blog Article Styles
   Fixes undefined CSS variables, removes AI-slop patterns
   (no blur, no gradients, no glows), aligns with design system
   ============================================================ */

/* ── Skip link ── */
.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  z-index: 200;
  padding: var(--space-2) var(--space-4);
  background: var(--accent);
  color: #0d1117;
  font-size: 0.875rem;
  font-weight: 500;
  border-radius: var(--radius);
  text-decoration: none;
  transition: top 0.15s ease;
}
.skip-link:focus { top: var(--space-2); }

/* ── Reset & base (shared with design system tokens) ── */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100dvh;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* ── Nav: solid bg, no blur/glass ── */
nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--border);
  padding: 0 var(--space-6);
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 56px;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 600;
  font-size: 0.9375rem;
}
.nav-logo img { width: 24px; height: 24px; }
.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  list-style: none;
}
.nav-links a {
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  transition: color 0.15s ease;
}
.nav-links a:hover { color: var(--text-primary); }
.nav-links a.active { color: var(--accent); }
.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius);
  background: transparent;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.8125rem;
  font-weight: 500;
  border: 1px solid var(--accent);
  transition: border-color 0.15s ease, background 0.15s ease, color 0.15s ease;
}
.nav-cta:hover { background: rgba(20, 184, 166, 0.10); color: var(--accent); }

/* ── Article container ── */
.article-container {
  max-width: 760px;
  margin: 0 auto;
  padding: var(--space-12) var(--space-6) var(--space-16);
}

.article-breadcrumb {
  font-size: 0.8125rem;
  color: var(--text-muted);
  margin-bottom: var(--space-6);
}
.article-breadcrumb a {
  color: var(--text-secondary);
  text-decoration: none;
}
.article-breadcrumb a:hover { color: var(--text-primary); }
.article-breadcrumb .sep { margin: 0 var(--space-2); opacity: 0.4; }

/* ── Title: weight 600, no 800 ── */
.article-hero-title {
  font-size: clamp(1.75rem, 5.5vw, 2.625rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 0;
}

/* ── Meta bar ── */
.article-meta-bar {
  display: flex;
  align-items: center;
  margin: var(--space-3) 0 var(--space-6);
  padding: var(--space-3) 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}
.article-meta-item {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  padding: 0 var(--space-4);
  border-right: 1px solid var(--border);
}
.article-meta-item:first-child { padding-left: 0; }
.article-meta-item:last-child { border-right: none; }
.article-meta-item svg { width: 14px; height: 14px; opacity: 0.5; flex-shrink: 0; }

/* ── Divider: solid, no gradient ── */
.article-divider {
  width: 48px;
  height: 2px;
  background: var(--border-strong);
  margin: 0 0 var(--space-8);
}

/* ── Tags: pill shape ok, but use accent color, not warm tones ── */
.article-tags {
  display: flex;
  gap: var(--space-1);
  flex-wrap: wrap;
  margin-bottom: var(--space-6);
}
.article-tag {
  display: inline-block;
  padding: 2px var(--space-2);
  border-radius: var(--radius);
  background: var(--bg-elevated);
  color: var(--text-muted);
  border: 1px solid var(--border);
  font-weight: 500;
  letter-spacing: 0.02em;
  font-size: 0.6875rem;
  white-space: nowrap;
}

/* ── Cover image ── */
.article-cover {
  width: 100%;
  max-height: 420px;
  object-fit: cover;
  border-radius: var(--radius);
  margin-bottom: var(--space-10);
  border: 1px solid var(--border);
}

/* ── Body typography ── */
.article-body { font-size: 0.9375rem; line-height: 1.75; }
.article-body h2 {
  font-size: 1.375rem;
  font-weight: 600;
  letter-spacing: -0.02em;
  margin: var(--space-14) 0 var(--space-4);
  padding-bottom: var(--space-3);
  border-bottom: 1px solid var(--border);
  color: var(--text-primary);
}
.article-body h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  margin: var(--space-6) 0 var(--space-2);
  color: var(--text-primary);
}
.article-body h4 {
  font-size: 0.9375rem;
  font-weight: 600;
  margin: var(--space-6) 0 var(--space-2);
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.article-body p {
  color: var(--text-secondary);
  margin-bottom: var(--space-4);
  font-size: 0.9375rem;
}
.article-body a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-strong);
  transition: text-decoration-color 0.15s ease;
}
.article-body a:hover { text-decoration-color: var(--accent); }
.article-body strong { color: var(--text-primary); font-weight: 600; }
.article-body em { font-style: italic; }
.article-body ul, .article-body ol {
  color: var(--text-secondary);
  padding-left: var(--space-5);
  margin-bottom: var(--space-4);
}
.article-body li { margin-bottom: 6px; }
.article-body li::marker { color: var(--text-muted); }

/* ── Code: cool bg, not warm ── */
.article-body code {
  font-family: var(--font-mono);
  font-size: 0.85em;
  background: var(--bg-elevated);
  color: var(--text-primary);
  padding: 0.125em 0.375em;
  border-radius: 3px;
  border: 1px solid var(--border);
}
.article-body pre {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-4) var(--space-5);
  overflow-x: auto;
  margin-bottom: var(--space-5);
  font-size: 0.8125rem;
  line-height: 1.6;
}
.article-body pre code {
  background: transparent;
  color: var(--text-secondary);
  padding: 0;
  font-size: inherit;
  border: none;
}

/* ── Images ── */
.article-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius);
  margin: var(--space-5) 0;
  border: 1px solid var(--border);
}

/* ── Blockquote: subtle left border, no italic bias ── */
.article-body blockquote {
  border-left: 2px solid var(--border-strong);
  background: var(--bg-elevated);
  padding: var(--space-3) var(--space-4);
  margin: var(--space-5) 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text-secondary);
}
.article-body blockquote p:last-child { margin-bottom: 0; }

.article-body hr {
  border: none;
  height: 1px;
  background: var(--border);
  margin: var(--space-10) 0;
}

/* ── Drop cap: weight 600 ── */
.article-body .drop-cap::first-letter {
  float: left;
  font-size: 2.5em;
  line-height: 0.9;
  padding-right: var(--space-2);
  padding-top: 2px;
  color: var(--text-primary);
  font-weight: 600;
}

/* ── Footer ── */
.article-footer {
  margin-top: var(--space-14);
  padding-top: var(--space-8);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}
.back-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 500;
  transition: color 0.15s ease;
}
.back-link:hover { color: var(--accent); }

.share-links { display: flex; gap: var(--space-2); }
.share-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.8125rem;
  transition: border-color 0.15s ease, color 0.15s ease;
}
.share-link:hover { border-color: var(--border-strong); color: var(--text-primary); }

/* ── Page footer ── */
footer {
  border-top: 1px solid var(--border);
  padding: var(--space-6);
  text-align: center;
  color: var(--text-muted);
  font-size: 0.8125rem;
}
footer p { margin-bottom: var(--space-1); font-size: 0.8125rem; }
footer a { color: var(--text-secondary); text-decoration: underline; }
footer a:hover { color: var(--accent); }

/* ── Responsive ── */
@media (max-width: 640px) {
  .article-container { padding: var(--space-6) var(--space-4) var(--space-12); }
  .article-meta-bar { flex-wrap: wrap; gap: var(--space-2); padding: var(--space-3) 0; }
  .article-meta-item { border-right: none; padding: 0 var(--space-3) 0 0; }
  .article-footer { flex-direction: column; align-items: flex-start; }
  .nav-cta span.nav-label { display: none; }
}

/* ── Reduced motion ── */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}