/* ================================================================
   blog.css — shared styles for all post pages on introtoalgo.com
   Include this file in every post page:
   <link rel="stylesheet" href="../assets/css/blog.css">
   (or "assets/css/blog.css" from root-level pages)
================================================================ */

/* ── Tokens ──────────────────────────────────────────────────── */
:root {
  --bg:         #0c0c0d;
  --bg-raised:  #131315;
  --border:     #1f1f23;
  --border-mid: #2e2e34;
  --text:       #ede9dc;
  --text-mid:   #a8a090;
  --text-dim:   #5e5a52;
  --accent:     #c8f047;
  --accent-dim: #6a8020;
  --accent-bg:  rgba(200, 240, 71, 0.06);

  --font-display: 'Syne', sans-serif;
  --font-mono:    'JetBrains Mono', monospace;
  --font-body:    'Crimson Pro', Georgia, serif;

  --max-w:  860px;
  --gutter: clamp(1.25rem, 5vw, 2.5rem);
}

/* ── Reset ───────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 18px; scroll-behavior: smooth; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 300;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }

/* ── Fonts ───────────────────────────────────────────────────── */
@import url('https://fonts.googleapis.com/css2?family=Syne:wght@700;800&family=JetBrains+Mono:wght@300;400;500&family=Crimson+Pro:ital,wght@0,300;0,400;1,300;1,400&display=swap');

/* ── Layout ──────────────────────────────────────────────────── */
.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ── Noise overlay ───────────────────────────────────────────── */
body::after {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='300' height='300'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.75' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='300' height='300' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 9000;
  opacity: 0.5;
}

/* ── Header ──────────────────────────────────────────────────── */
.site-header {
  padding: 2.5rem 0 2rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
}

.logo {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.35em;
}
.logo-prompt {
  color: var(--accent);
  font-family: var(--font-mono);
  font-size: 1em;
  font-weight: 400;
  animation: blink 1.1s step-end infinite;
}
@keyframes blink { 0%,100%{opacity:1} 50%{opacity:0} }

.site-nav { display: flex; align-items: center; gap: 0.2rem; }
.nav-link {
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-dim);
  padding: 0.4rem 0.85rem;
  border: 1px solid transparent;
  border-radius: 3px;
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.nav-link:hover, .nav-link.active {
  color: var(--accent);
  border-color: var(--accent-dim);
  background: var(--accent-bg);
}

/* ── Post header ─────────────────────────────────────────────── */
.post-header {
  padding: 3.5rem 0 2.5rem;
  border-bottom: 1px solid var(--border);
  animation: fadeUp 0.5s ease both;
}

.post-meta {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}
.post-date {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
  text-transform: uppercase;
}
.post-tag {
  font-family: var(--font-mono);
  font-size: 0.58rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  background: var(--accent-bg);
  border: 1px solid rgba(200, 240, 71, 0.2);
  padding: 0.12rem 0.5rem;
  border-radius: 2px;
}

.post-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 1rem;
}

.post-lead {
  font-size: 1.1rem;
  color: var(--text-mid);
  line-height: 1.65;
  font-style: italic;
  max-width: 580px;
}

/* ── Cover image ─────────────────────────────────────────────── */
.post-cover {
  width: 100%;
  margin: 2.5rem 0;
  border-radius: 3px;
  filter: brightness(0.8) contrast(1.05);
  animation: fadeUp 0.5s 0.1s ease both;
}

/* ── Post body ───────────────────────────────────────────────── */
.post-body {
  padding: 2.5rem 0 3rem;
  animation: fadeUp 0.5s 0.15s ease both;
}

.post-body p {
  margin-bottom: 1.5rem;
  font-size: 1.05rem;
  color: var(--text-mid);
}

.post-body h2 {
  font-family: var(--font-display);
  font-size: 1.55rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  margin: 2.5rem 0 0.75rem;
}

.post-body h3 {
  font-family: var(--font-display);
  font-size: 1.2rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--text);
  margin: 2rem 0 0.6rem;
}

.post-body strong { color: var(--text); font-weight: 400; }
.post-body em { font-style: italic; color: var(--text); }

.post-body a {
  color: var(--accent);
  border-bottom: 1px solid var(--accent-dim);
  transition: border-color 0.2s;
}
.post-body a:hover { border-color: var(--accent); }

.post-body ul,
.post-body ol {
  padding-left: 1.5rem;
  margin-bottom: 1.5rem;
  color: var(--text-mid);
}
.post-body li { margin-bottom: 0.35rem; }

/* ── Code blocks ─────────────────────────────────────────────── */
.post-body pre {
  background: var(--bg-raised);
  border: 1px solid var(--border-mid);
  border-left: 3px solid var(--accent-dim);
  border-radius: 3px;
  padding: 1.25rem 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  line-height: 1.6;
  color: var(--text);
}

.post-body code {
  font-family: var(--font-mono);
  font-size: 0.82em;
  background: var(--bg-raised);
  border: 1px solid var(--border-mid);
  padding: 0.1em 0.35em;
  border-radius: 2px;
  color: var(--accent);
}
.post-body pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--text);
}

/* ── Blockquote ──────────────────────────────────────────────── */
.post-body blockquote {
  border-left: 3px solid var(--accent-dim);
  margin: 1.75rem 0;
  padding: 0.5rem 1.5rem;
  color: var(--text-mid);
  font-style: italic;
  font-size: 1.05rem;
}

/* ── Images in post body ─────────────────────────────────────── */
.post-body img {
  border-radius: 3px;
  margin: 1.75rem 0;
  filter: brightness(0.85);
}

/* ── Back link ───────────────────────────────────────────────── */
.back-link {
  font-family: var(--font-mono);
  font-size: 0.65rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-dim);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  margin-top: 2.5rem;
  padding-bottom: 2.5rem;
  transition: color 0.2s, gap 0.2s;
}
.back-link::before { content: '←'; }
.back-link:hover { color: var(--accent); gap: 0.8rem; }

/* ── Footer ──────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem 0;
  margin-top: 2rem;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.footer-text {
  font-family: var(--font-mono);
  font-size: 0.62rem;
  letter-spacing: 0.08em;
  color: var(--text-dim);
}
.footer-text a {
  color: var(--text-mid);
  border-bottom: 1px solid var(--border-mid);
  transition: color 0.2s, border-color 0.2s;
}
.footer-text a:hover { color: var(--accent); border-color: var(--accent-dim); }

/* ── Animations ──────────────────────────────────────────────── */
@keyframes fadeUp {
  from { opacity: 0; transform: translateY(14px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Custom cursor ───────────────────────────────────────────── */
@media (hover: hover) {
  body { cursor: none; }
  .cursor {
    width: 7px;
    height: 7px;
    background: var(--accent);
    border-radius: 50%;
    position: fixed;
    pointer-events: none;
    z-index: 9999;
    transform: translate(-50%, -50%);
    transition: width 0.18s, height 0.18s, background 0.18s;
  }
  .cursor.hover {
    width: 28px;
    height: 28px;
    background: transparent;
    border: 1.5px solid var(--accent);
  }
}

/* ── Responsive ──────────────────────────────────────────────── */
@media (max-width: 600px) {
  .site-header { flex-direction: column; align-items: flex-start; gap: 1rem; }
  .post-body pre { padding: 1rem; font-size: 0.75rem; }
}