/* === 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);
  --shadow-lg: 0 2px 6px rgba(0,0,0,0.06), 0 10px 30px rgba(0,0,0,0.1);
  --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-logo svg { vertical-align: middle; margin-right: 6px; }
.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; text-align: center; }
.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(--google-blue);
}
.hero-sub { color: var(--text-muted); font-size: 1.05rem; line-height: 1.6; max-width: 640px; margin: 0 auto; }
.hero-actions { margin-top: 1.5rem; display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* === Typography === */
h2 { font-family: 'Google Sans', sans-serif; font-size: 1.3rem; 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; color: var(--text); }
p { margin-bottom: 1rem; }
a { color: var(--google-blue); text-decoration: none; }
a:hover { text-decoration: underline; }

/* === Code === */
pre {
  background: #1e1e1e; border: 1px solid #333;
  border-radius: var(--radius); padding: 1rem 1.2rem;
  overflow-x: auto; font-size: .88rem; line-height: 1.55;
  margin: .8rem 0 1.2rem;
}
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;
  cursor: pointer;
}
.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); }
.btn-accent { background: var(--google-green); color: #fff; border: none; }
.btn-accent:hover { background: #2d8f47; box-shadow: var(--shadow); }
.btn-lg { padding: 14px 36px; font-size: 1.05rem; }

/* === 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); }

/* === 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; }

/* === Overview Grid (homepage cards) === */
.overview-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px; margin: 24px 0;
}
.overview-card {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 20px;
  text-decoration: none; display: block; transition: border-color .15s, box-shadow .15s;
  box-shadow: var(--shadow-sm);
}
.overview-card:hover { border-color: var(--google-blue); box-shadow: var(--shadow); text-decoration: none; }
.overview-card h3 { color: var(--google-blue); margin: 0 0 8px; font-size: 1rem; }
.overview-card p { color: var(--text-muted); font-size: .87rem; margin: 0; }

/* === Step Number (deployment) === */
.step-number {
  display: inline-block; background: var(--google-blue); color: #fff;
  border-radius: 50%; width: 28px; height: 28px; line-height: 28px;
  text-align: center; font-size: .85rem; font-weight: 600;
  margin-right: .5rem; flex-shrink: 0;
}

/* === Tier Card (hardware) === */
.tier-card {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 24px; margin: 20px 0;
  box-shadow: var(--shadow-sm);
}
.tier-card h3 { margin-top: 0; }
.tier-label {
  display: inline-block; padding: 3px 12px; border-radius: 12px;
  font-size: .78rem; font-weight: 600; margin-bottom: 12px;
}
.tier-label.green { background: #e6f4ea; color: #137333; }
.tier-label.blue { background: #e8f0fe; color: #1a56db; }
.tier-label.purple { background: #f3e8fd; color: #7627b7; }

/* === Spec Grid (hardware) === */
.spec-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: 12px; margin: 16px 0;
}
.spec-item {
  background: var(--gray-50); border-radius: var(--radius-sm);
  padding: 14px 16px; text-align: center;
}
.spec-value { font-size: 1.2rem; font-weight: 600; color: var(--text); }
.spec-label { font-size: .78rem; color: var(--text-muted); margin-top: 4px; }

/* === Combo Card (models) === */
.combo-card {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 24px; margin: 20px 0;
  box-shadow: var(--shadow-sm);
}
.combo-card h3 { margin-top: 0; }
.combo-label {
  display: inline-block; padding: 3px 12px; border-radius: 12px;
  font-size: .78rem; font-weight: 600; margin-bottom: 12px;
}
.combo-label.gold { background: #fef7e0; color: #b06000; }
.combo-label.green { background: #e6f4ea; color: #137333; }
.combo-label.blue { background: #e8f0fe; color: #1a56db; }

/* === Verdict Card (vs-notebooklm) === */
.verdict-card {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius); padding: 24px; margin: 16px 0;
  box-shadow: var(--shadow-sm);
}
.verdict-card h3 { margin-top: 0; }
.win { color: var(--google-green); font-weight: 600; }
.lose { color: var(--warn); font-weight: 600; }

/* === Module List (production-guide) === */
.module-list { list-style: none; padding: 0; }
.module-list li {
  background: var(--gray-50); border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm); padding: 14px 18px; margin-bottom: 8px;
  font-size: .93rem;
}
.module-list li strong { color: var(--google-blue); }

/* === Pricing Box === */
.pricing-box {
  background: #fff; border: 2px solid var(--google-green);
  border-radius: var(--radius); padding: 36px 24px;
  text-align: center; margin: 32px 0;
  box-shadow: var(--shadow);
}
.price { font-size: 3rem; font-weight: 700; color: var(--text); }
.price sub { font-size: 1rem; color: var(--text-muted); font-weight: 400; }
.guarantee { font-size: .88rem; color: var(--text-muted); margin-top: 12px; }

/* === Badge (production-guide) === */
.badge-rec {
  display: inline-block; padding: 3px 10px;
  background: var(--google-green); color: #fff;
  font-size: .75rem; font-weight: 600; border-radius: 12px;
  position: absolute; top: -14px; left: 24px;
}

/* === FAQ (details/summary) === */
details {
  background: #fff; border: 1px solid var(--gray-200);
  border-radius: var(--radius-sm); padding: .8rem 1rem; margin: .5rem 0;
}
details summary { cursor: pointer; font-weight: 500; }
details[open] { border-color: var(--google-blue); }
.faq-answer { padding-top: .6rem; color: var(--text-muted); font-size: .93rem; }
.faq-answer p { margin-bottom: 10px; }
.faq-answer p:last-child { margin-bottom: 0; }

/* === Download Button (thanks) === */
.btn-dl {
  display: inline-block; padding: 14px 36px; font-size: 1.05rem; font-weight: 600;
  background: var(--google-green); color: #fff; border-radius: 24px;
  text-decoration: none; transition: all .15s;
  box-shadow: 0 2px 10px rgba(52,168,83,.3);
}
.btn-dl:hover { transform: translateY(-1px); box-shadow: 0 4px 18px rgba(52,168,83,.4); text-decoration: none; color: #fff; }

/* === Who Grid (production-guide) === */
.who-grid {
  display: grid; grid-template-columns: 1fr 1fr; gap: 12px;
}
.who-yes { background: var(--gray-50); border: 1px solid var(--google-green); border-radius: var(--radius-sm); padding: 16px 18px; }
.who-no { background: var(--gray-50); border: 1px solid var(--gray-200); border-radius: var(--radius-sm); padding: 16px 18px; }

/* === 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; }

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

/* === 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); }
.footer p { margin-bottom: .3rem; }

/* === Responsive === */
@media (max-width: 768px) {
  .nav { flex-direction: column; align-items: flex-start; }
  .nav-links { margin-top: 4px; }
  .hero { padding: 2rem 0 1.5rem; }
  .who-grid { grid-template-columns: 1fr; }
  .overview-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .overview-grid { grid-template-columns: 1fr; }
  .spec-grid { grid-template-columns: 1fr 1fr; }
  h1 { font-size: 1.5rem; }
  pre { font-size: .8rem; padding: .8rem; }
}