/* Hacker's Edition — clean light theme. System fonts, no frameworks, no JS. */
:root {
  --bg: #fdfdfa;
  --surface: #ffffff;
  --text: #1a1a1a;
  --muted: #5b5b5b;
  --border: #e4e2dc;
  --accent: #0f766e;
  --accent-dark: #0b5e57;
  --accent-soft: #e6f4f2;
  --max: 1100px;
  --measure: 720px;
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  font-size: 17px;
  line-height: 1.7;
}
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* Header */
.site-header { background: var(--surface); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 24px; padding-top: 14px; padding-bottom: 14px; }
.brand { font-size: 1.35rem; font-weight: 800; letter-spacing: -0.02em; color: var(--text); }
.brand:hover { text-decoration: none; color: var(--accent); }
.main-nav { display: flex; flex-wrap: wrap; gap: 4px 20px; }
.main-nav a { color: var(--text); font-weight: 600; font-size: 0.95rem; }
.main-nav a:hover { color: var(--accent); }

/* Hero */
.hero { background: var(--accent-soft); border-bottom: 1px solid var(--border); padding: 56px 0 48px; }
.hero h1 { font-size: 2.4rem; line-height: 1.15; letter-spacing: -0.02em; margin: 0 0 8px; }
.hero .tagline { font-size: 1.25rem; color: var(--accent-dark); font-weight: 600; margin: 0 0 12px; }
.hero-intro { max-width: var(--measure); margin: 0; color: var(--text); }

/* Sections */
main h2 { font-size: 1.5rem; letter-spacing: -0.01em; margin: 40px 0 16px; }
.page-head { padding-top: 32px; }
.page-head h1 { font-size: 2rem; letter-spacing: -0.02em; margin: 0 0 8px; }
.page-head p { color: var(--muted); max-width: var(--measure); }

/* Guide cards */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 20px; margin-bottom: 48px; }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 20px 22px; }
.card h3 { margin: 0 0 6px; font-size: 1.15rem; line-height: 1.35; }
.card h3 a { color: var(--text); }
.card h3 a:hover { color: var(--accent); }
.card-meta { color: var(--muted); font-size: 0.85rem; margin: 0 0 8px; }
.card p { margin: 0 0 10px; }
.card p:last-child { margin-bottom: 0; }
.read-more { font-weight: 700; }

/* About strip + author box */
.about-strip { border-top: 1px solid var(--border); padding-bottom: 48px; }
.author-box { background: var(--accent-soft); border: 1px solid var(--border); border-radius: 12px; padding: 20px 24px; margin: 40px 0 8px; }
.author-box h2 { margin: 0 0 8px; font-size: 1.1rem; }
.author-box p { margin: 0; }

/* Articles */
.article { max-width: var(--measure); padding-top: 32px; padding-bottom: 40px; }
.article-head h1 { font-size: 2rem; line-height: 1.2; letter-spacing: -0.02em; margin: 0 0 10px; }
.byline { color: var(--muted); font-size: 0.95rem; margin: 0 0 8px; }
.article-body h2 { font-size: 1.35rem; margin: 32px 0 10px; }
.article-body h3 { font-size: 1.1rem; margin: 24px 0 8px; }
.article-body p { margin: 0 0 16px; }
.article-body ul, .article-body ol { margin: 0 0 16px; padding-left: 24px; }
.article-body li { margin-bottom: 6px; }
.article-body li::marker { color: var(--accent); }
.article-body strong { color: var(--text); }
.article-body blockquote { border-left: 4px solid var(--accent); margin: 0 0 16px; padding: 4px 0 4px 16px; color: var(--muted); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); background: var(--surface); padding: 32px 0; margin-top: 16px; }
.footer-brand { font-weight: 700; margin: 0 0 10px; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 6px 20px; margin-bottom: 12px; }
.footer-nav a { color: var(--muted); font-size: 0.95rem; }
.footer-note { color: var(--muted); font-size: 0.9rem; margin: 0; }

@media (max-width: 640px) {
  body { font-size: 16px; }
  .hero { padding: 40px 0 32px; }
  .hero h1 { font-size: 1.9rem; }
  .article-head h1, .page-head h1 { font-size: 1.6rem; }
  .grid { grid-template-columns: 1fr; }
}