/* ═══════════════════════════════════════════
   CODE TUTORIUM — blog.css
   Shared styles for all blog post pages
   ═══════════════════════════════════════════ */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:           #0a0a0f;
  --surface:      #111118;
  --surface2:     #18181f;
  --border:       rgba(255,255,255,0.08);
  --border2:      rgba(255,255,255,0.14);
  --text:         #f0f0f5;
  --muted:        #888896;
  --accent:       #a5f3fc;
  --accent-dim:   rgba(165,243,252,0.10);
  --radius-sm:    8px;
  --radius-md:    12px;
  --radius-lg:    18px;
  --font-sans:    'Outfit', system-ui, sans-serif;
  --font-mono:    'DM Mono', monospace;
  --font-display: 'Syne', system-ui, sans-serif;
  --nav-h:        60px;
  /* Override per-post: --post-color */
  --post-color:   #a5f3fc;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }

/* ── NAV ── */
.nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  height: var(--nav-h);
  background: rgba(10,10,15,0.88);
  -webkit-backdrop-filter: blur(18px);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border);
  display: flex; align-items: center;
}
.nav-inner {
  max-width: 1100px; margin: 0 auto; padding: 0 1.5rem;
  width: 100%; display: flex; align-items: center; justify-content: space-between;
}
.nav-logo { font-family: var(--font-display); font-size: 1.2rem; font-weight: 800; letter-spacing: .05em; }
.nav-logo span { color: var(--accent); }
.nav-links { display: flex; gap: .5rem; }
.nav-link { font-size: .875rem; color: var(--muted); padding: .35rem .8rem; border-radius: var(--radius-sm); transition: color .2s, background .2s; }
.nav-link:hover { color: var(--text); background: var(--surface2); }
.nav-link.active { color: var(--accent); }

/* ── PAGE LAYOUT ── */
.page-wrap {
  max-width: 1100px; margin: 0 auto; padding: 0 1.5rem;
  display: grid; grid-template-columns: 1fr 300px; gap: 3rem;
  padding-top: calc(var(--nav-h) + 3rem); padding-bottom: 5rem;
}

/* ── ARTICLE ── */
article { min-width: 0; }

.post-breadcrumb {
  font-family: var(--font-mono); font-size: .72rem; color: var(--muted);
  display: flex; align-items: center; gap: .4rem; margin-bottom: 1.75rem; flex-wrap: wrap;
}
.post-breadcrumb a:hover { color: var(--accent); }
.post-breadcrumb .sep { opacity: .4; }

.post-tag {
  display: inline-block;
  font-family: var(--font-mono); font-size: .7rem; letter-spacing: .05em;
  color: var(--post-color);
  background: rgba(165,243,252,0.07);
  border: 1px solid rgba(165,243,252,0.2);
  border-radius: 999px; padding: .2rem .75rem; margin-bottom: 1rem;
}

.post-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 4vw, 2.6rem);
  font-weight: 800; line-height: 1.15; letter-spacing: -.02em; margin-bottom: 1rem;
}

.post-meta {
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  font-family: var(--font-mono); font-size: .72rem; color: var(--muted);
  margin-bottom: 2rem; padding-bottom: 1.5rem; border-bottom: 1px solid var(--border);
}

/* ── CONTENT TYPOGRAPHY ── */
.post-body h2 {
  font-family: var(--font-display); font-size: 1.35rem; font-weight: 700;
  color: var(--text); margin: 2.5rem 0 .75rem; line-height: 1.3;
}
.post-body h3 {
  font-family: var(--font-display); font-size: 1.1rem; font-weight: 600;
  color: var(--text); margin: 1.75rem 0 .5rem;
}
.post-body p { color: rgba(240,240,245,.85); margin-bottom: 1.15rem; }
.post-body ul, .post-body ol { margin: .75rem 0 1.25rem 1.25rem; color: rgba(240,240,245,.85); }
.post-body li { margin-bottom: .45rem; }
.post-body strong { color: var(--text); font-weight: 600; }
.post-body a { color: var(--post-color); text-decoration: underline; text-underline-offset: 3px; }
.post-body a:hover { opacity: .8; }
.post-body code {
  font-family: var(--font-mono); font-size: .875em;
  color: var(--post-color);
  background: rgba(165,243,252,0.07);
  border: 1px solid rgba(165,243,252,0.12);
  border-radius: 4px; padding: .1em .4em;
}

/* ── CODE BLOCK ── */
.code-block {
  background: var(--surface); border: 1px solid var(--border2);
  border-radius: var(--radius-md); overflow: hidden; margin: 1.25rem 0;
}
.code-header {
  display: flex; align-items: center; gap: .75rem;
  padding: .6rem 1rem; border-bottom: 1px solid var(--border); background: var(--surface2);
}
.code-dots { display: flex; gap: .35rem; }
.code-dots span { width: 10px; height: 10px; border-radius: 50%; background: var(--border2); }
.code-dots span:nth-child(1) { background: #ff5f56; }
.code-dots span:nth-child(2) { background: #ffbd2e; }
.code-dots span:nth-child(3) { background: #27c93f; }
.code-filename { font-family: var(--font-mono); font-size: .75rem; color: var(--muted); }
.code-block pre {
  padding: 1.25rem; overflow-x: auto;
  font-family: var(--font-mono); font-size: .875rem; line-height: 1.7; color: #c9d1d9;
}
.kw   { color: #ff7b72; }
.fn   { color: #d2a8ff; }
.str  { color: #a5d6ff; }
.cmt  { color: #8b949e; font-style: italic; }
.num  { color: #79c0ff; }
.prop { color: var(--post-color); }
.val  { color: #ffa657; }
.tag  { color: #7ee787; }
.attr { color: var(--post-color); }

/* ── CALLOUT BOXES ── */
.callout {
  border-left: 3px solid var(--post-color);
  background: rgba(165,243,252,0.04);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 1rem 1.25rem; margin: 1.5rem 0;
}
.callout.warning { border-color: #fbbf24; background: rgba(251,191,36,0.04); }
.callout.info    { border-color: #818cf8; background: rgba(129,140,248,0.04); }
.callout-title {
  font-family: var(--font-display); font-size: .85rem; font-weight: 700;
  color: var(--post-color); margin-bottom: .4rem;
}
.callout.warning .callout-title { color: #fbbf24; }
.callout.info .callout-title    { color: #818cf8; }
.callout p { color: rgba(240,240,245,.8); margin: 0; font-size: .9rem; }

/* ── QUICK-ANSWER SUMMARY ── */
.post-summary {
  background: var(--surface); border: 1px solid var(--border2);
  border-radius: var(--radius-md); padding: 1.25rem 1.5rem; margin-bottom: 2rem;
}
.post-summary-title {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .08em;
  color: var(--post-color); text-transform: uppercase; margin-bottom: .75rem;
}
.post-summary ul { margin-left: 1rem; color: rgba(240,240,245,.8); }
.post-summary li { margin-bottom: .35rem; font-size: .9rem; }

/* ── RELATED ── */
.related { margin-top: 3rem; padding-top: 2rem; border-top: 1px solid var(--border); }
.related-title { font-family: var(--font-display); font-size: 1.1rem; font-weight: 700; margin-bottom: 1rem; }
.related-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.related-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-md);
  padding: 1rem 1.1rem; transition: border-color .2s, transform .2s;
}
.related-card:hover { border-color: var(--accent); transform: translateY(-2px); }
.related-card-tag { font-family: var(--font-mono); font-size: .65rem; color: var(--muted); margin-bottom: .3rem; }
.related-card-title { font-size: .9rem; font-weight: 600; color: var(--text); line-height: 1.35; }
.related-card:hover .related-card-title { color: var(--accent); }

/* ── SIDEBAR ── */
.sidebar { position: sticky; top: calc(var(--nav-h) + 2rem); align-self: start; }
.sidebar-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius-lg);
  padding: 1.25rem; margin-bottom: 1.25rem;
}
.sidebar-card-title {
  font-family: var(--font-mono); font-size: .72rem; letter-spacing: .08em;
  color: var(--accent); text-transform: uppercase; margin-bottom: 1rem;
}
.toc-list { display: flex; flex-direction: column; gap: .4rem; }
.toc-link {
  font-size: .85rem; color: var(--muted); padding: .3rem .6rem;
  border-radius: var(--radius-sm); transition: color .2s, background .2s; display: block;
}
.toc-link:hover { color: var(--text); background: var(--surface2); }
.toc-link.active { color: var(--accent); background: var(--accent-dim); }

.course-promo { display: flex; flex-direction: column; gap: .75rem; text-align: center; }
.course-promo-icon { font-size: 2rem; }
.course-promo-name { font-family: var(--font-display); font-size: 1rem; font-weight: 700; }
.course-promo-desc { font-size: .83rem; color: var(--muted); }
.course-promo-btn {
  display: block; background: var(--post-color); color: #0a0a0f;
  font-size: .875rem; font-weight: 700; padding: .65rem 1rem;
  border-radius: var(--radius-sm); transition: opacity .2s;
}
.course-promo-btn:hover { opacity: .88; }

/* ── FOOTER ── */
.footer {
  background: #0d0d12; border-top: 1px solid var(--border);
  padding: 2rem 1.5rem; text-align: center;
}
.footer-links { display: flex; justify-content: center; gap: 1.5rem; flex-wrap: wrap; margin-bottom: .75rem; }
.footer-links a { font-size: .85rem; color: var(--muted); transition: color .2s; }
.footer-links a:hover { color: var(--accent); }
.footer-copy { font-family: var(--font-mono); font-size: .72rem; color: var(--muted); }

/* ── RESPONSIVE ── */
@media (max-width: 800px) {
  .page-wrap { grid-template-columns: 1fr; }
  .sidebar { display: none; }
  .related-grid { grid-template-columns: 1fr; }
  .nav-links { display: none; }
}