/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #0f1117; --bg-card: #1a1d27; --bg-input: #141722; --border: #2a2e3d;
  --text: #e8eaed; --text-dim: #8b90a4; --accent: #4ecdc4; --accent2: #ff6b6b;
  --safe: #4ecdc4; --warn: #f0a500; --danger: #ff6b6b; --radius: 10px; --radius-sm: 6px;
  --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --max-width: 1200px; --transition: 0.2s ease;
}
html { scroll-behavior: smooth; scroll-padding-top: 70px; }
body { font-family: var(--font); background: var(--bg); color: var(--text); line-height: 1.6; min-height: 100vh; }
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover, a:focus-visible { color: #7ee8e2; text-decoration: underline; }
img, svg { max-width: 100%; height: auto; }
.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 20px; }
.skip-link { position: absolute; top: -100%; left: 0; background: var(--accent); color: #000; padding: 8px 16px; z-index: 100; font-weight: 600; }
.skip-link:focus { top: 0; }

/* ===== Header ===== */
.site-header { position: sticky; top: 0; z-index: 50; background: rgba(15, 17, 23, 0.95); backdrop-filter: blur(10px); border-bottom: 1px solid var(--border); }
.header-inner { display: flex; align-items: center; gap: 24px; height: 56px; }
.logo { display: flex; align-items: center; gap: 8px; font-weight: 700; font-size: 1.1rem; color: var(--text); flex-shrink: 0; }
.logo:hover, .logo:focus-visible { text-decoration: none; color: var(--text); }
.logo .accent { color: var(--accent); }
.header-nav { display: flex; gap: 20px; margin-left: auto; }
.header-nav a { font-size: 0.9rem; color: var(--text-dim); font-weight: 500; }
.header-nav a:hover, .header-nav a:focus-visible { color: var(--text); text-decoration: none; }
.menu-toggle { display: none; flex-direction: column; gap: 4px; background: none; border: none; cursor: pointer; padding: 4px; }
.menu-toggle span { display: block; width: 22px; height: 2px; background: var(--text); border-radius: 2px; }
.mobile-nav { padding: 12px 20px; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 8px; }
.mobile-nav a { padding: 8px 0; color: var(--text-dim); font-weight: 500; }
.mobile-nav a:hover { color: var(--text); }

/* ===== Hero ===== */
.hero { padding: 80px 0 60px; text-align: center; background: radial-gradient(ellipse at 50% 0%, rgba(78, 205, 196, 0.08) 0%, transparent 60%); }
.hero h1 { font-size: clamp(2rem, 5vw, 3rem); font-weight: 800; line-height: 1.2; margin-bottom: 16px; letter-spacing: -0.02em; }
.hero-sub { font-size: 1.1rem; color: var(--text-dim); max-width: 560px; margin: 0 auto 32px; }
.hero-actions { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }

/* ===== Buttons ===== */
.btn { display: inline-flex; align-items: center; justify-content: center; padding: 10px 20px; border-radius: var(--radius-sm); font-weight: 600; font-size: 0.9rem; cursor: pointer; border: 2px solid transparent; transition: all var(--transition); font-family: inherit; }
.btn-primary { background: var(--accent); color: #000; }
.btn-primary:hover, .btn-primary:focus-visible { background: #7ee8e2; color: #000; text-decoration: none; }
.btn-secondary { background: transparent; border-color: var(--border); color: var(--text); }
.btn-secondary:hover, .btn-secondary:focus-visible { border-color: var(--accent); color: var(--accent); text-decoration: none; }
.btn-sm { padding: 6px 14px; font-size: 0.82rem; }
.btn-danger { background: transparent; border-color: var(--danger); color: var(--danger); }
.btn-danger:hover { background: var(--danger); color: #fff; }

/* ===== Calculator Section ===== */
.calculator-section { padding: 60px 0; }
.calc-layout { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
.calc-inputs h2, .calc-results h2 { font-size: 1.3rem; margin-bottom: 24px; }
.input-group { margin-bottom: 20px; }
.input-group label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--text-dim); margin-bottom: 6px; text-transform: uppercase; letter-spacing: 0.04em; }
select, input[type="number"] { width: 100%; padding: 10px 14px; background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text); font-size: 1rem; font-family: inherit; transition: border-color var(--transition); }
select:focus, input[type="number"]:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(78,205,196,0.15); }
.radio-group { display: flex; gap: 8px; flex-wrap: wrap; }
.radio-card { position: relative; }
.radio-card input { position: absolute; opacity: 0; width: 0; height: 0; }
.radio-label { display: block; padding: 8px 16px; border: 1px solid var(--border); border-radius: var(--radius-sm); cursor: pointer; font-size: 0.9rem; font-weight: 500; transition: all var(--transition); }
.radio-card input:checked + .radio-label { border-color: var(--accent); background: rgba(78,205,196,0.1); color: var(--accent); }
.radio-card input:focus-visible + .radio-label { box-shadow: 0 0 0 3px rgba(78,205,196,0.3); }
.speaker-inputs-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 10px; }
.speaker-input { display: flex; flex-direction: column; gap: 4px; }
.speaker-input label { font-size: 0.75rem; color: var(--text-dim); font-weight: 500; }
.speaker-input input { width: 100%; padding: 8px 12px; background: var(--bg-input); border: 1px solid var(--border); border-radius: var(--radius-sm); color: var(--text); font-size: 1rem; font-family: inherit; }
.speaker-input input:focus { outline: none; border-color: var(--accent); }
.presets { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-top: 4px; }
.presets-label { font-size: 0.8rem; color: var(--text-dim); }
.preset-btn { padding: 4px 10px; background: var(--bg-input); border: 1px solid var(--border); border-radius: 20px; color: var(--text-dim); font-size: 0.78rem; cursor: pointer; font-family: inherit; transition: all var(--transition); }
.preset-btn:hover, .preset-btn:focus-visible { border-color: var(--accent); color: var(--accent); }

/* ===== Results ===== */
.result-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; margin-bottom: 20px; }
.result-card h3 { font-size: 0.8rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--text-dim); margin-bottom: 8px; }
.result-value { font-size: 2.5rem; font-weight: 800; color: var(--accent); letter-spacing: -0.02em; }
.result-detail { font-size: 0.9rem; color: var(--text-dim); margin-top: 4px; }
.amp-check { border-left: 3px solid var(--safe); transition: border-color var(--transition); }
.amp-check.warn { border-left-color: var(--warn); }
.amp-check.danger { border-left-color: var(--danger); }
.amp-status { display: flex; align-items: center; gap: 8px; margin-bottom: 8px; }
.status-icon { width: 10px; height: 10px; border-radius: 50%; background: var(--safe); flex-shrink: 0; transition: background var(--transition); }
.warn .status-icon { background: var(--warn); }
.danger .status-icon { background: var(--danger); }
.status-text { font-weight: 600; font-size: 1rem; }
.amp-note { font-size: 0.85rem; color: var(--text-dim); }
.diagram-container { min-height: 120px; display: flex; align-items: center; justify-content: center; }
.diagram-container svg { width: 100%; max-width: 400px; }
.result-actions { display: flex; gap: 8px; flex-wrap: wrap; }
.toast { margin-top: 12px; padding: 10px 16px; background: var(--bg-card); border: 1px solid var(--accent); border-radius: var(--radius-sm); font-size: 0.85rem; color: var(--accent); text-align: center; }

/* ===== Guide Section ===== */
.guide-section { padding: 60px 0; background: var(--bg-card); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.guide-section h2 { font-size: 1.6rem; margin-bottom: 32px; text-align: center; }
.guide-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
.guide-card { background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; }
.guide-card h3 { font-size: 1rem; margin-bottom: 12px; color: var(--accent); }
.guide-card p { font-size: 0.9rem; color: var(--text-dim); margin-bottom: 8px; }
.guide-card p:last-child { margin-bottom: 0; }
.guide-card .formula { font-family: 'SF Mono', SFMono-Regular, Consolas, monospace; background: var(--bg-input); padding: 8px 12px; border-radius: var(--radius-sm); font-size: 0.85rem; color: var(--text); display: inline-block; margin: 8px 0; }
.guide-card ul { padding-left: 20px; font-size: 0.9rem; color: var(--text-dim); }
.guide-card li { margin-bottom: 6px; }

/* ===== FAQ Section ===== */
.faq-section { padding: 60px 0; }
.faq-section h2 { font-size: 1.6rem; margin-bottom: 32px; text-align: center; }
.faq-list { max-width: 720px; margin: 0 auto; display: flex; flex-direction: column; gap: 4px; }
.faq-item { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden; }
.faq-item summary { padding: 16px 20px; font-weight: 600; cursor: pointer; list-style: none; display: flex; justify-content: space-between; align-items: center; }
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after { content: '+'; font-size: 1.2rem; color: var(--text-dim); transition: transform var(--transition); }
.faq-item[open] summary::after { content: '−'; color: var(--accent); }
.faq-item p { padding: 0 20px 16px; font-size: 0.9rem; color: var(--text-dim); line-height: 1.7; }

/* ===== Saved Section ===== */
.saved-section { padding: 40px 0; background: var(--bg-card); border-top: 1px solid var(--border); }
.saved-section h2 { font-size: 1.3rem; margin-bottom: 20px; }
.saved-list { display: flex; flex-direction: column; gap: 8px; margin-bottom: 16px; max-width: 600px; }
.saved-item { display: flex; align-items: center; justify-content: space-between; background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius-sm); padding: 12px 16px; }
.saved-item .saved-info { font-size: 0.85rem; }
.saved-item .saved-info strong { color: var(--accent); }
.saved-item .saved-actions { display: flex; gap: 8px; }

/* ===== Footer ===== */
.site-footer { padding: 40px 0; border-top: 1px solid var(--border); }
.footer-inner { display: flex; flex-direction: column; align-items: center; gap: 16px; text-align: center; }
.logo-mark { font-weight: 700; font-size: 1.1rem; }
.footer-tagline { font-size: 0.85rem; color: var(--text-dim); }
.footer-nav { display: flex; gap: 20px; flex-wrap: wrap; justify-content: center; }
.footer-nav a { font-size: 0.85rem; color: var(--text-dim); }
.footer-nav a:hover { color: var(--text); }
.footer-copy { font-size: 0.78rem; color: var(--text-dim); }

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .calc-layout { grid-template-columns: 1fr; }
  .header-nav { display: none; }
  .menu-toggle { display: flex; margin-left: auto; }
  .hero { padding: 60px 0 40px; }
}
@media (max-width: 480px) {
  .speaker-inputs-grid { grid-template-columns: 1fr 1fr; }
  .radio-group { flex-direction: column; }
  .result-value { font-size: 2rem; }
}

/* ===== Print Styles ===== */
@media print {
  .site-header, .hero, .site-footer, .presets, .result-actions, .saved-section { display: none; }
  body { background: #fff; color: #000; }
  .result-card, .guide-card { border: 1px solid #ccc; break-inside: avoid; }
}

/* ===== Focus ===== */
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }



/* 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;
}