/* ===== RESET & BASE ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #0f0f13;
  --bg-elevated: #18181f;
  --bg-card: #1e1e28;
  --bg-input: #141420;
  --border: #2a2a3a;
  --border-light: #3a3a50;
  --text: #e8e8f0;
  --text-muted: #9090a8;
  --text-dim: #6a6a80;
  --accent: #6C3AED;
  --accent-light: #8b5cf6;
  --accent-bg: rgba(108,58,237,0.12);
  --accent-border: rgba(108,58,237,0.35);
  --amber: #F59E0B;
  --amber-bg: rgba(245,158,11,0.1);
  --green: #10B981;
  --green-bg: rgba(16,185,129,0.1);
  --red: #EF4444;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(0,0,0,0.3);
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
}
html { font-size: 16px; scroll-behavior: smooth; }
body { font-family: var(--font); background: var(--bg); color: var(--text); line-height: 1.6; -webkit-font-smoothing: antialiased; }
a { color: var(--accent-light); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }

/* ===== HEADER ===== */
.site-header { background: var(--bg-elevated); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; backdrop-filter: blur(12px); }
.site-header .container { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.logo { display: flex; align-items: center; gap: 10px; color: var(--text); text-decoration: none; }
.logo:hover { text-decoration: none; }
.logo-text { font-size: 1.1rem; font-weight: 600; letter-spacing: -0.01em; }
.logo-text strong { color: var(--accent-light); }
.site-nav { display: flex; gap: 24px; }
.site-nav a { color: var(--text-muted); font-size: 0.9rem; font-weight: 500; text-decoration: none; transition: color 0.15s; }
.site-nav a:hover { color: var(--text); text-decoration: none; }

/* ===== HERO ===== */
.hero-section { padding: 80px 0 60px; text-align: center; }
.hero-label { display: inline-block; background: var(--accent-bg); color: var(--accent-light); border: 1px solid var(--accent-border); padding: 4px 14px; border-radius: 20px; font-size: 0.8rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.06em; margin-bottom: 20px; }
.hero-content h1 { font-size: clamp(1.8rem, 4vw, 2.8rem); font-weight: 700; line-height: 1.2; letter-spacing: -0.02em; margin-bottom: 16px; background: linear-gradient(135deg, var(--text) 0%, var(--accent-light) 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }
.hero-sub { font-size: 1.1rem; color: var(--text-muted); max-width: 600px; margin: 0 auto 32px; line-height: 1.7; }
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ===== BUTTONS ===== */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 24px; border-radius: var(--radius-sm); font-size: 0.95rem; font-weight: 600; cursor: pointer; border: none; transition: all 0.15s; text-decoration: none; }
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-light); transform: translateY(-1px); }
.btn-ghost { background: transparent; color: var(--text-muted); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--text-muted); color: var(--text); }

/* ===== CALCULATOR ===== */
.calculator-section { padding: 20px 0 80px; }
.calc-layout { display: grid; grid-template-columns: 340px 1fr; gap: 32px; align-items: start; }
.calc-inputs { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; position: sticky; top: 80px; }
.calc-inputs h2 { font-size: 1.2rem; margin-bottom: 20px; }
.input-group { margin-bottom: 20px; }
.input-group label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--text-muted); margin-bottom: 6px; text-transform: uppercase; letter-spacing: 0.04em; }
.length-inputs { display: flex; align-items: center; gap: 12px; }
.length-field { display: flex; align-items: center; flex: 1; }
.length-field input { width: 100%; }
.length-or { color: var(--text-dim); font-size: 0.85rem; font-weight: 500; flex-shrink: 0; }
input[type="number"], select { width: 100%; padding: 10px 14px; background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text); font-size: 0.95rem; font-family: var(--font); outline: none; transition: border-color 0.15s; appearance: auto; }
input[type="number"]:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-bg); }
.input-suffix { padding: 10px 12px; background: var(--bg-input); border: 1px solid var(--border); border-left: none; border-radius: 0 var(--radius-sm) var(--radius-sm) 0; color: var(--text-dim); font-size: 0.85rem; white-space: nowrap; }
.length-field input { border-radius: var(--radius-sm) 0 0 var(--radius-sm); }
.hint { font-size: 0.8rem; color: var(--text-dim); margin-top: 4px; line-height: 1.4; }
.presets { display: flex; flex-wrap: wrap; gap: 8px; }
.preset-btn { padding: 6px 14px; background: var(--bg-input); border: 1px solid var(--border); border-radius: 20px; color: var(--text-muted); font-size: 0.85rem; cursor: pointer; transition: all 0.15s; }
.preset-btn:hover { border-color: var(--text-muted); color: var(--text); }
.preset-btn.active { background: var(--accent-bg); border-color: var(--accent-border); color: var(--accent-light); }
.calc-actions { display: flex; gap: 10px; margin-top: 24px; padding-top: 20px; border-top: 1px solid var(--border); }
.calc-actions .btn { flex: 1; padding: 10px 16px; font-size: 0.85rem; }

/* ===== RESULTS ===== */
.calc-results { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.results-header { display: flex; align-items: center; justify-content: space-between; padding: 20px 24px; border-bottom: 1px solid var(--border); }
.results-header h2 { font-size: 1.2rem; }
.results-meta { font-size: 0.85rem; color: var(--text-dim); }
.beat-table-wrap { max-height: 420px; overflow-y: auto; }
.beat-table { width: 100%; border-collapse: collapse; }
.beat-table th { text-align: left; padding: 10px 16px; font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-dim); background: var(--bg-elevated); border-bottom: 1px solid var(--border); position: sticky; top: 0; }
.beat-table td { padding: 12px 16px; border-bottom: 1px solid var(--border); font-size: 0.9rem; cursor: pointer; transition: background 0.1s; }
.beat-table td:first-child { font-weight: 600; }
.beat-table td:nth-child(2), .beat-table td:nth-child(3) { font-family: var(--font-mono); font-size: 0.85rem; }
.beat-table td:last-child { color: var(--text-dim); font-size: 0.85rem; }
.beat-table tbody tr:hover td { background: var(--accent-bg); }
.beat-table tbody tr.active td { background: var(--accent-bg); }
.beat-table tbody tr.active td:first-child { color: var(--accent-light); }

/* ===== BEAT DETAIL ===== */
.beat-detail { padding: 24px; border-top: 1px solid var(--border); min-height: 160px; }
.beat-detail-empty { display: flex; flex-direction: column; align-items: center; justify-content: center; gap: 12px; color: var(--text-dim); text-align: center; padding: 20px; }
.beat-detail-empty p { font-size: 0.9rem; }
.beat-detail-card h3 { font-size: 1.1rem; margin-bottom: 4px; }
.beat-detail-card .detail-range { font-family: var(--font-mono); color: var(--accent-light); font-size: 0.9rem; margin-bottom: 12px; }
.beat-detail-card .detail-purpose { color: var(--text-muted); font-size: 0.95rem; margin-bottom: 16px; line-height: 1.6; }
.detail-tips { background: var(--amber-bg); border: 1px solid rgba(245,158,11,0.2); border-radius: var(--radius-sm); padding: 14px 18px; }
.detail-tips h4 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--amber); margin-bottom: 6px; }
.detail-tips p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.5; }

/* ===== INFO SECTIONS ===== */
.info-section { padding: 64px 0; }
.info-section.alt-section { background: var(--bg-elevated); }
.info-section h2 { font-size: 1.6rem; font-weight: 700; margin-bottom: 12px; letter-spacing: -0.01em; }
.section-intro { color: var(--text-muted); font-size: 1rem; max-width: 640px; margin-bottom: 36px; line-height: 1.7; }
.info-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 24px; }
.info-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.info-step { width: 36px; height: 36px; background: var(--accent-bg); color: var(--accent-light); border: 1px solid var(--accent-border); border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: 700; font-size: 0.9rem; margin-bottom: 14px; }
.info-card h3 { font-size: 1rem; margin-bottom: 8px; }
.info-card p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.6; }

/* ===== COMPARISON ===== */
.comparison-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
.comparison-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; }
.comparison-card h3 { font-size: 1rem; margin-bottom: 8px; color: var(--text); }
.comparison-card p { font-size: 0.9rem; color: var(--text-muted); line-height: 1.6; }

/* ===== MISTAKES ===== */
.mistakes-list { display: flex; flex-direction: column; gap: 12px; }
mistake-item, .faq-item { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
mistake-item summary, .faq-item summary { padding: 18px 22px; cursor: pointer; font-weight: 600; font-size: 0.95rem; list-style: none; display: flex; align-items: center; justify-content: space-between; transition: background 0.15s; }
mistake-item summary:hover, .faq-item summary:hover { background: var(--bg-elevated); }
mistake-item summary::after, .faq-item summary::after { content: '+'; font-size: 1.2rem; color: var(--text-dim); flex-shrink: 0; margin-left: 12px; }
mistake-item[open] summary::after, .faq-item[open] summary::after { content: '−'; }
mistake-item p, .faq-item p { padding: 0 22px 18px; color: var(--text-muted); font-size: 0.95rem; line-height: 1.7; }

/* ===== FAQ ===== */
.faq-list { display: flex; flex-direction: column; gap: 12px; }

/* ===== FOOTER ===== */
.site-footer { background: var(--bg-elevated); border-top: 1px solid var(--border); padding: 40px 0 24px; }
.footer-top { display: flex; justify-content: space-between; align-items: flex-start; flex-wrap: wrap; gap: 24px; margin-bottom: 24px; }
.footer-brand .logo-text { font-size: 1rem; margin-bottom: 6px; display: inline-block; }
.footer-brand p { color: var(--text-dim); font-size: 0.85rem; }
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-links a { color: var(--text-muted); font-size: 0.85rem; text-decoration: none; }
.footer-links a:hover { color: var(--text); }
.footer-bottom { border-top: 1px solid var(--border); padding-top: 20px; }
.footer-bottom p { color: var(--text-dim); font-size: 0.8rem; }
.footer-bottom a { color: var(--text-muted); }

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
  .calc-layout { grid-template-columns: 1fr; }
  .calc-inputs { position: static; }
  .hero-section { padding: 48px 0 40px; }
  .info-section { padding: 48px 0; }
}
@media (max-width: 600px) {
  .site-header .container { flex-direction: column; height: auto; padding: 12px 24px; gap: 8px; }
  .site-nav { gap: 16px; }
  .hero-actions { flex-direction: column; align-items: center; }
  .length-inputs { flex-direction: column; align-items: stretch; }
  .length-or { text-align: center; }
  .calc-actions { flex-direction: column; }
  .results-header { flex-direction: column; align-items: flex-start; gap: 4px; }
  .beat-table th, .beat-table td { padding: 8px 10px; font-size: 0.8rem; }
  .info-grid { grid-template-columns: 1fr; }
  .comparison-grid { grid-template-columns: 1fr; }
  .footer-top { flex-direction: column; }
}

/* ===== PRINT ===== */
@media print {
  .site-header, .hero-section, .calc-inputs, .site-footer, .info-section, .hero-actions { display: none !important; }
  body { background: #fff; color: #000; }
  .calculator-section { padding: 0; }
  .calc-results { border: none; }
  .beat-detail { display: none; }
  .beat-table th, .beat-table td { color: #000; border-color: #ccc; }
  .results-meta { color: #444; }
}

/* ===== SCROLLBAR ===== */
.beat-table-wrap::-webkit-scrollbar { width: 6px; }
.beat-table-wrap::-webkit-scrollbar-track { background: var(--bg); }
.beat-table-wrap::-webkit-scrollbar-thumb { background: var(--border-light); border-radius: 3px; }
.beat-table-wrap::-webkit-scrollbar-thumb:hover { background: var(--text-dim); }



/* Factory-injected deployment helpers. The AI owns the site design above this block. */
.ad-unit {
  width: min(100%, 720px);
  min-height: 120px;
  margin: 24px auto;
  display: block;
}

.legal-page {
  width: min(900px, calc(100% - 32px));
  margin: 40px auto;
}

.factory-fallback-nav {
  width: min(900px, calc(100% - 32px));
  margin: 24px auto 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  font-size: 0.95rem;
}

.factory-fallback-nav a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}