/* QuarkMind — Site CSS */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg:       #0d1117;
  --surface:  #161b22;
  --border:   #30363d;
  --fg:       #e6edf3;
  --muted:    #8b949e;
  --blue:     #388bfd;
  --gold:     #c8a52e;
  --gold-dim: #6e5a19;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  min-height: 100vh;
}

/* ── Nav ── */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.9rem 2rem;
  background: rgba(13,17,23,0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  font-weight: 700;
  font-size: 1rem;
  color: var(--fg);
  letter-spacing: -0.01em;
}

.nav-logo span { color: var(--gold); }

.nav-links { display: flex; gap: 1.75rem; align-items: center; }

.nav-link {
  font-size: 0.875rem;
  color: var(--muted);
  text-decoration: none;
  transition: color 0.15s;
}
.nav-link:hover, .nav-link.active { color: var(--fg); }

/* ── Landing ── */
.hero {
  padding: 7rem 2rem 5rem;
  text-align: center;
  max-width: 760px;
  margin: 0 auto;
}

.hero-eyebrow {
  font-size: 0.72rem;
  letter-spacing: 0.3em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 1.25rem;
}

.hero h1 em { font-style: normal; color: var(--gold); }

.hero-desc {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 560px;
  margin: 0 auto 2.5rem;
  line-height: 1.75;
}

.hero-cta { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  padding: 0.6rem 1.4rem;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.15s;
}
.btn-primary { background: var(--gold); color: #0d1117; }
.btn-primary:hover { background: #d4b040; }
.btn-ghost { border: 1px solid var(--border); color: var(--muted); }
.btn-ghost:hover { border-color: var(--muted); color: var(--fg); }

.pillar-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 1.5rem;
  max-width: 900px;
  margin: 5rem auto;
  padding: 0 2rem;
}

.pillar {
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1.5rem;
  background: var(--surface);
}
.pillar-num { font-size: 0.65rem; letter-spacing: 0.3em; color: var(--gold); margin-bottom: 0.75rem; }
.pillar h3 { font-size: 1rem; margin-bottom: 0.5rem; }
.pillar p { font-size: 0.875rem; color: var(--muted); line-height: 1.65; }

/* ── Blog listing ── */
.blog-header {
  padding: 5rem 2rem 2rem;
  max-width: 760px;
  margin: 0 auto;
  border-bottom: 1px solid var(--border);
}
.blog-header h1 { font-size: 2rem; font-weight: 700; margin-bottom: 0.4rem; }
.blog-header p { font-size: 0.9rem; color: var(--muted); }

.blog-list { max-width: 760px; margin: 0 auto; padding: 0 2rem 4rem; }

.post-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 1.5rem;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--border);
  text-decoration: none;
  color: inherit;
  transition: opacity 0.15s;
}
.post-item:hover { opacity: 0.75; }
.post-item:first-child { border-top: 1px solid var(--border); }

.post-date { font-size: 0.72rem; color: var(--muted); font-family: monospace; padding-top: 0.2rem; }
.post-title { font-size: 1rem; font-weight: 600; color: var(--fg); margin-bottom: 0.3rem; line-height: 1.35; }
.post-excerpt { font-size: 0.875rem; color: var(--muted); line-height: 1.6; }

/* ── Post ── */
.post-wrap { max-width: 760px; margin: 0 auto; padding: 4rem 2rem 5rem; }

.post-back {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--muted);
  text-decoration: none;
  margin-bottom: 2.5rem;
  transition: color 0.15s;
}
.post-back:hover { color: var(--fg); }

.post-meta { display: flex; gap: 1rem; align-items: center; margin-bottom: 0.75rem; flex-wrap: wrap; }
.post-meta time { font-size: 0.8rem; color: var(--muted); font-family: monospace; }

.post-body h1 { font-size: clamp(1.6rem, 4vw, 2.2rem); font-weight: 800; letter-spacing: -0.02em; line-height: 1.2; margin-bottom: 2rem; }
.post-body h2 { font-size: 1.2rem; font-weight: 700; margin-top: 2.5rem; margin-bottom: 0.75rem; padding-bottom: 0.5rem; border-bottom: 1px solid var(--border); }
.post-body h3 { font-size: 1rem; font-weight: 600; color: var(--gold); margin-top: 2rem; margin-bottom: 0.5rem; }
.post-body p { color: var(--muted); margin-bottom: 1.25rem; }
.post-body strong { color: var(--fg); }
.post-body a { color: var(--blue); }
.post-body ul, .post-body ol { color: var(--muted); padding-left: 1.5rem; margin-bottom: 1.25rem; }
.post-body li { margin-bottom: 0.3rem; }
.post-body pre { background: var(--surface); border: 1px solid var(--border); border-radius: 6px; padding: 1.25rem; overflow-x: auto; margin-bottom: 1.25rem; }
.post-body code { font-family: 'JetBrains Mono', 'Fira Code', monospace; font-size: 0.85em; }
.post-body p code { background: var(--surface); color: var(--gold); padding: 0.1em 0.35em; border-radius: 4px; }
.post-body blockquote { border-left: 3px solid var(--gold-dim); padding-left: 1rem; margin: 1.5rem 0; color: var(--muted); font-style: italic; }
.post-body hr { border: none; border-top: 1px solid var(--border); margin: 2.5rem 0; }
.post-body img { max-width: 100%; border-radius: 6px; margin: 1.5rem 0; border: 1px solid var(--border); }
.post-body table { width: 100%; border-collapse: collapse; margin-bottom: 1.5rem; font-size: 0.875rem; }
.post-body th { font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); border-bottom: 1px solid var(--border); padding: 0.5rem 0.75rem; text-align: left; }
.post-body td { border-bottom: 1px solid var(--border); padding: 0.5rem 0.75rem; color: var(--muted); }

/* ── Footer ── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--muted);
}
.site-footer a { color: var(--muted); text-decoration: none; }
.site-footer a:hover { color: var(--fg); }
.footer-links { display: flex; gap: 1.5rem; }

@media (max-width: 640px) {
  .site-nav { padding: 0.75rem 1rem; }
  .nav-links { gap: 1rem; }
  .post-item { grid-template-columns: 1fr; gap: 0.25rem; }
  .pillar-grid { grid-template-columns: 1fr; }
}