/* === Design Tokens === */
:root {
  --google-blue: #4285F4;
  --google-red: #EA4335;
  --google-yellow: #FBBC04;
  --google-green: #34A853;
  --gray-50: #f8f9fa;
  --gray-100: #f1f3f4;
  --gray-200: #e8eaed;
  --gray-300: #dadce0;
  --gray-500: #9aa0a6;
  --gray-700: #5f6368;
  --gray-900: #202124;
  --text: #202124;
  --text-muted: #5f6368;
  --bg: #ffffff;
  --bg-alt: #f8f9fa;
  --radius-sm: 8px;
  --radius: 12px;
  --radius-lg: 24px;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06), 0 1px 3px rgba(0,0,0,0.1);
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.08);
  --max-w: 860px;
  --accent: var(--google-blue);
  --ok: var(--google-green);
  --warn: #f59e0b;
  --danger: var(--google-red);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 80px; }

body {
  font-family: 'Google Sans', 'Roboto', -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  font-size: 16px; line-height: 1.7;
  color: var(--text); background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

/* === Nav === */
.nav {
  max-width: var(--max-w); margin: 0 auto; padding: 1.2rem 24px;
  border-bottom: 1px solid var(--gray-200);
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 0.5rem;
}
.nav-logo { font-weight: 700; font-size: 1.05rem; color: var(--google-blue); text-decoration: none; white-space: nowrap; }
.nav-logo:hover { color: var(--google-red); }
.nav-links { display: flex; list-style: none; gap: 2px; flex-wrap: wrap; align-items: center; }
.nav-links a { display: block; padding: 6px 14px; font-size: 14px; font-weight: 500; color: var(--gray-700); text-decoration: none; border-radius: 20px; transition: background 0.15s, color 0.15s; }
.nav-links a:hover { background: var(--gray-100); color: var(--text); }
.nav-links a.current { color: var(--text); font-weight: 600; }

/* === Main === */
main { max-width: var(--max-w); margin: 0 auto; padding: 0 24px; }

/* === Hero === */
.hero { padding: 3rem 0 2rem; border-bottom: 1px solid var(--gray-200); margin-bottom: 2rem; }
.hero h1 { font-family: 'Google Sans', sans-serif; font-size: clamp(28px, 4vw, 2.2rem); font-weight: 700; line-height: 1.3; margin-bottom: 0.6rem; color: var(--gray-900); }
.hero-sub { color: var(--text-muted); font-size: 1.05rem; line-height: 1.6; }

/* === Typography === */
h2 { font-family: 'Google Sans', sans-serif; font-size: 1.5rem; margin: 2.5rem 0 1rem; padding-bottom: 0.4rem; border-bottom: 1px solid var(--gray-200); }
h3 { font-family: 'Google Sans', sans-serif; font-size: 1.15rem; margin: 1.5rem 0 0.5rem; }
p { margin-bottom: 1rem; }
a { color: var(--google-blue); text-decoration: none; }
a:hover { text-decoration: underline; }
ul, ol { margin: .5rem 0 1rem 1.5rem; }
li { margin-bottom: .35rem; }

/* === Code === */
pre {
  background: #1e1e1e; border: 1px solid #333; color: #e0e0e0;
  border-radius: var(--radius); padding: 1rem 1.2rem;
  overflow-x: auto; font-size: .88rem; line-height: 1.55;
  margin: .8rem 0 1.2rem; position: relative;
}
pre code { font-family: 'Roboto Mono', 'Fira Code', monospace; font-size: .88rem; color: #e0e0e0; }
:not(pre) > code {
  background: var(--gray-100); padding: .12rem .35rem;
  border-radius: 3px; font-size: .87rem; border: 1px solid var(--gray-200);
  color: var(--google-red);
}

/* === Buttons === */
.btn {
  display: inline-block; padding: 10px 24px; border-radius: 24px;
  font-family: 'Google Sans', sans-serif; font-size: .9rem; font-weight: 500;
  text-decoration: none; transition: transform .15s, box-shadow .15s, background .15s;
}
.btn:hover { transform: translateY(-1px); text-decoration: none; }
.btn-primary { background: var(--google-blue); color: #fff; border: none; }
.btn-primary:hover { background: #3367d6; box-shadow: var(--shadow); }
.btn-outline { background: #fff; color: var(--google-blue); border: 1px solid var(--gray-300); }
.btn-outline:hover { background: var(--gray-50); border-color: var(--google-blue); box-shadow: var(--shadow); }

/* === Callouts === */
.callout {
  background: var(--gray-50); border-left: 4px solid var(--google-blue);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 1rem 1.3rem; margin: 1rem 0; font-size: .93rem;
}
.callout p { margin-bottom: .5rem; }
.callout p:last-child { margin-bottom: 0; }
.callout.warn { border-left-color: var(--warn); }
.callout.ok { border-left-color: var(--google-green); }
.callout.danger { border-left-color: var(--danger); }

/* === Breaking Change Card === */
.breaking-change {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 1.2rem 1.4rem; margin: 1rem 0;
  box-shadow: var(--shadow-sm);
}
.breaking-change h3 { margin-top: 0; display: flex; align-items: center; gap: .5rem; }

/* === Checklist === */
.checklist { list-style: none; margin-left: 0; }
.checklist li {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm); padding: .7rem 1rem; margin-bottom: .5rem;
  display: flex; align-items: flex-start; gap: .6rem;
  box-shadow: var(--shadow-sm);
}
.checklist li::before { content: "☐"; color: var(--gray-500); font-size: 1.1rem; flex-shrink: 0; }
.checklist code { font-size: .82rem; }

/* === Use Case === */
.use-case {
  background: var(--gray-50); border-left: 3px solid var(--google-blue);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 1rem 1.3rem; margin: .8rem 0;
}
.use-case h3 { margin-top: 0; }

/* === Rollback Warning === */
.rollback {
  background: #fef2f2; border: 1px solid #fecaca;
  border-radius: var(--radius); padding: 1rem 1.3rem; margin: 1.5rem 0 0;
}
.rollback strong { color: var(--danger); }
.rollback pre, .rollback pre code { color: #111 !important; }

/* === Other Changes === */
.other-changes {
  background: var(--gray-50); border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 1rem 1.3rem;
}
.other-changes ul { margin-bottom: 0; }

/* === Priority Tags === */
.priority-tag { display: inline-block; padding: .15rem .5rem; border-radius: 3px; font-size: .8rem; font-weight: 600; margin-right: .3rem; }
.tag-p0 { background: #fef2f2; color: var(--danger); }
.tag-p1 { background: #fefce8; color: #b06000; }
.tag-p2 { background: var(--gray-100); color: var(--gray-700); }
.tag-skip { background: #f0fdf4; color: #137333; }
.eta { color: #b06000; font-weight: 600; }

/* === Tables === */
table {
  width: 100%; border-collapse: collapse; margin: 1rem 0;
  border: 1px solid var(--gray-200); border-radius: var(--radius); overflow: hidden;
}
thead { background: var(--gray-900); color: #fff; }
th, td { padding: .7rem 1rem; text-align: left; border-bottom: 1px solid var(--gray-200); font-size: .9rem; }
th { font-family: 'Google Sans', sans-serif; font-weight: 500; }
tbody tr:nth-child(even) { background: var(--gray-50); }
tr:last-child td { border-bottom: none; }

/* === FAQ (details/summary) === */
details {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm); margin-bottom: .5rem;
}
details summary { padding: .8rem 1rem; cursor: pointer; font-weight: 500; list-style: none; }
details summary::-webkit-details-marker { display: none; }
details summary::before { content: "▸"; margin-right: .5rem; color: var(--google-blue); font-size: .8rem; }
details[open] summary::before { content: "▾"; }
details[open] { border-color: var(--google-blue); }
.faq-answer { padding: 0 1rem 1rem 2rem; color: var(--text-muted); font-size: .93rem; }
.faq-answer p { color: var(--text-muted); }
.faq-answer code { font-size: .82rem; }

/* === Copy Button === */
.copy-btn {
  position: absolute; top: .5rem; right: .5rem;
  background: #333; border: 1px solid #555;
  color: #ccc; padding: .25rem .6rem; border-radius: 3px;
  font-size: .75rem; cursor: pointer;
}
.copy-btn:hover { color: #fff; border-color: #999; }
.copy-btn.copied { color: var(--google-green); border-color: var(--google-green); }

/* === Footer === */
.footer {
  max-width: var(--max-w); margin: 3rem auto 0; padding: 1.5rem 24px 0;
  border-top: 1px solid var(--gray-200);
  color: var(--text-muted); font-size: .85rem; text-align: center;
}
.footer a { color: var(--google-blue); }

/* === 404 === */
.page-404 { display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 100vh; padding: 2rem; text-align: center; }
.page-404 h1 { font-size: 4rem; margin-bottom: .5rem; }
.page-404 p { color: var(--text-muted); margin-bottom: 1.5rem; }

/* === Legal Pages === */
.legal { max-width: 720px; margin: 0 auto; padding: 0 24px; }
.legal h1 { font-size: 1.8rem; margin: 2.5rem 0 1.5rem; }
.legal h2 { font-size: 1.15rem; margin: 2rem 0 .8rem; color: var(--google-blue); border: none; padding: 0; }

/* === CTA Section === */
.cta-section { margin-top: 3rem; text-align: center; }
.cta-section h2 { border: none; margin-bottom: .5rem; }

/* === Comparison Table (vs-npm-11) === */
.compare-table {
  width: 100%; border-collapse: collapse; margin: 1rem 0 1.5rem; font-size: .9rem;
}
.compare-table th {
  background: var(--gray-900); color: #fff; text-align: left; padding: .65rem .8rem;
  border: 1px solid var(--gray-200); font-weight: 600;
}
.compare-table th:first-child { width: 35%; }
.compare-table td {
  padding: .55rem .8rem; border: 1px solid var(--gray-200); vertical-align: top;
}
.compare-table td:first-child { font-weight: 500; }
.compare-table .v11 { color: var(--text-muted); }
.compare-table .v12 { color: var(--text); }
.compare-table code { font-size: .8rem; }

/* === Tags (vs-npm-11) === */
.tag-yes { color: var(--ok); }
.tag-no { color: var(--danger); }
.tag-warn { color: var(--warn); }
.tag-new {
  display: inline-block; background: #f0fdf4; color: var(--ok);
  padding: .1rem .4rem; border-radius: 3px; font-size: .75rem; font-weight: 600; margin-left: .3rem;
}

/* === Verdict Card (vs-npm-11) === */
.verdict {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 1.2rem 1.4rem; margin: 1rem 0;
  box-shadow: var(--shadow-sm);
}
.verdict h3 { margin-top: 0; display: flex; align-items: center; gap: .5rem; }

/* === Decision Card (vs-npm-11, rollback) === */
.decision {
  background: var(--gray-50); border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 1rem 1.3rem; margin: .8rem 0;
}
.decision h3 { margin-top: 0; }
.decision code { font-size: .82rem; }

/* === Error Block (errors) === */
.error-block {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); margin: 1.2rem 0; overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.error-msg {
  background: #fef2f2; border-bottom: 1px solid #fecaca;
  padding: .8rem 1.2rem; font-family: 'Roboto Mono', monospace;
  font-size: .85rem; color: var(--danger);
}
.error-body { padding: 1rem 1.2rem; }
.error-body h4 { font-size: .95rem; margin-bottom: .4rem; }
.error-body p { color: var(--text-muted); font-size: .9rem; margin-bottom: .6rem; }
.error-body pre { margin: .6rem 0 0; }

/* === Bench Numbers (performance) === */
.bench-number {
  font-family: 'Google Sans', sans-serif;
  font-size: 1.8rem; font-weight: 700; color: var(--ok);
}
.bench-label { color: var(--text-muted); font-size: .85rem; }

/* === Highlight Box (privacy, terms) === */
.highlight {
  background: var(--gray-50); border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 1.2rem 1.4rem; margin: 1.5rem 0;
}

/* === Back Link === */
.back-link {
  display: inline-block; margin: 2rem 0 1rem;
  padding: .5rem 1rem; border: 1px solid var(--gray-200);
  border-radius: var(--radius); color: var(--text-muted); font-size: .9rem; text-decoration: none;
}
.back-link:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* === Responsive === */
@media (max-width: 768px) {
  .nav { flex-direction: column; align-items: flex-start; }
  .nav-links { margin-top: 4px; }
  .hero { padding: 2rem 0 1.5rem; }
}
@media (max-width: 480px) {
  h1 { font-size: 1.5rem; }
  pre { font-size: .8rem; padding: .8rem; }
  .breaking-change { padding: .9rem 1rem; }
  .compare-table { font-size: .78rem; }
  .compare-table td, .compare-table th { padding: .4rem .5rem; }
}