*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-2: #f1f5f9;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-light: #eff6ff;
  --text: #0f172a;
  --text-secondary: #64748b;
  --border: #e2e8f0;
  --success: #16a34a;
  --success-light: #f0fdf4;
  --warning: #d97706;
  --warning-light: #fffbeb;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.05);
}
body { font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; background: var(--bg); color: var(--text); line-height: 1.6; font-size: 16px; }
a { text-decoration: none; color: inherit; }

/* ── HEADER ── */
header { background: var(--bg-card); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.header-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; height: 60px; display: flex; align-items: center; justify-content: space-between; }
.logo { font-size: 1.25rem; font-weight: 800; color: var(--text); letter-spacing: -0.02em; }
.logo span { color: var(--accent); }
nav { display: flex; gap: 28px; }
nav a { font-size: 0.88rem; font-weight: 500; color: var(--text-secondary); transition: color 0.15s; }
nav a:hover { color: var(--accent); }

/* ── AD BANNER ── */
.ad-banner-top { background: var(--bg-card-2); border-bottom: 1px solid var(--border); padding: 10px 24px; text-align: center; }
.ad-banner { background: #fff; border: 1px dashed #cbd5e1; border-radius: 6px; display: flex; align-items: center; justify-content: center; color: var(--text-secondary); font-size: 0.75rem; letter-spacing: 0.05em; text-transform: uppercase; }
.ad-banner-top .ad-banner { height: 90px; max-width: 728px; margin: 0 auto; }
.ad-sidebar .ad-banner { width: 100%; min-height: 250px; }
.ad-bottom { margin-top: 24px; text-align: center; }
.ad-bottom .ad-banner { height: 90px; }
.ad-desktop { display: block; }
.ad-mobile { display: none; }
@media (max-width: 768px) { .ad-desktop { display: none; } .ad-mobile { display: block; } }

/* ── HERO ── */
.hero { background: linear-gradient(135deg, #1e40af 0%, #2563eb 50%, #3b82f6 100%); color: white; padding: 64px 24px; text-align: center; }
.hero h1 { font-size: clamp(2rem, 5vw, 3rem); font-weight: 800; letter-spacing: -0.03em; margin-bottom: 16px; }
.hero p { font-size: 1.1rem; opacity: 0.85; max-width: 560px; margin: 0 auto 32px; }
.hero-stats { display: flex; justify-content: center; gap: 40px; flex-wrap: wrap; }
.hero-stat .num { font-size: 1.75rem; font-weight: 800; }
.hero-stat .lbl { font-size: 0.8rem; opacity: 0.75; text-transform: uppercase; letter-spacing: 0.05em; }

/* ── SECTIONS ── */
.section { max-width: 1200px; margin: 0 auto; padding: 56px 24px; }
.section-header { margin-bottom: 32px; }
.section-title { font-size: 1.5rem; font-weight: 700; color: var(--text); letter-spacing: -0.02em; margin-bottom: 6px; }
.section-subtitle { font-size: 0.9rem; color: var(--text-secondary); }

/* ── CALC GRID ── */
.calc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }
.calc-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; display: flex; flex-direction: column; gap: 8px; transition: all 0.2s; box-shadow: var(--shadow); }
.calc-card:hover { border-color: var(--accent); box-shadow: var(--shadow-md); transform: translateY(-2px); }
.calc-card .icon { font-size: 1.75rem; }
.calc-card h3 { font-size: 1rem; font-weight: 700; color: var(--text); }
.calc-card p { font-size: 0.83rem; color: var(--text-secondary); line-height: 1.55; flex: 1; }
.calc-card-arrow { font-size: 0.8rem; color: var(--accent); font-weight: 600; margin-top: 4px; }
.badge { display: inline-block; font-size: 0.7rem; font-weight: 700; padding: 3px 8px; border-radius: 20px; text-transform: uppercase; letter-spacing: 0.04em; margin-top: 4px; }
.badge-hot { background: #fef2f2; color: #dc2626; }
.badge-new { background: #fffbeb; color: #d97706; }
.badge-popular { background: var(--accent-light); color: var(--accent); }

/* ── CALC PAGE ── */
.calc-page-wrapper { max-width: 1200px; margin: 0 auto; padding: 32px 24px; display: grid; grid-template-columns: 1fr 300px; gap: 32px; align-items: start; }
@media (max-width: 900px) { .calc-page-wrapper { grid-template-columns: 1fr; } .calc-sidebar { display: none; } }
.breadcrumb { font-size: 0.8rem; color: var(--text-secondary); margin-bottom: 20px; }
.breadcrumb a { color: var(--accent); }
.breadcrumb span { margin: 0 6px; }
.calc-hero { margin-bottom: 24px; }
.calc-hero h1 { font-size: 1.75rem; font-weight: 800; letter-spacing: -0.02em; margin-bottom: 8px; }
.calc-hero p { color: var(--text-secondary); font-size: 0.95rem; }
.calc-form-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow); margin-bottom: 24px; }
.form-group { margin-bottom: 18px; }
.form-group label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.form-group input, .form-group select { width: 100%; padding: 10px 14px; border: 1px solid var(--border); border-radius: 8px; font-size: 0.95rem; color: var(--text); background: var(--bg-card); transition: border-color 0.15s; }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px rgba(37,99,235,0.1); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.unit-toggle { display: flex; gap: 0; margin-bottom: 20px; border: 1px solid var(--border); border-radius: 8px; overflow: hidden; }
.unit-toggle button { flex: 1; padding: 9px 16px; border: none; background: var(--bg-card); font-size: 0.85rem; font-weight: 500; color: var(--text-secondary); cursor: pointer; transition: all 0.15s; }
.unit-toggle button.active { background: var(--accent); color: white; font-weight: 600; }
.radio-group { display: flex; gap: 16px; flex-wrap: wrap; }
.radio-option { display: flex; align-items: center; gap: 8px; cursor: pointer; font-size: 0.9rem; color: var(--text-secondary); }
.radio-option input { accent-color: var(--accent); width: 16px; height: 16px; margin: 0; flex-shrink: 0; }
.btn-calculate { width: 100%; padding: 14px; background: var(--accent); color: white; border: none; border-radius: 8px; font-size: 1rem; font-weight: 700; cursor: pointer; transition: background 0.2s; letter-spacing: 0.02em; margin-top: 4px; }
.btn-calculate:hover { background: var(--accent-hover); }
.btn-calculate + p.view-results { text-align: center; font-size: 0.78rem; color: var(--text-secondary); margin: 8px 0 0; }

/* ── RESULTS ── */
.results-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; margin-bottom: 24px; display: none; box-shadow: var(--shadow); }
.results-card.visible { display: block; }
.results-card h2 { font-size: 1.2rem; font-weight: 700; margin-bottom: 20px; color: var(--text); }
.result-primary { background: var(--accent-light); border: 1px solid rgba(37,99,235,0.15); border-radius: 10px; padding: 24px; text-align: center; margin-bottom: 20px; }
.result-value { font-size: 2.8rem; font-weight: 800; color: var(--accent); letter-spacing: -0.03em; line-height: 1; }
.result-label { font-size: 0.82rem; color: var(--text-secondary); margin-top: 4px; text-transform: uppercase; letter-spacing: 0.05em; }
.result-category { font-size: 1rem; font-weight: 600; color: var(--text); margin-top: 8px; }
.results-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr)); gap: 12px; margin-bottom: 16px; }
.result-item { background: var(--bg-card-2); border: 1px solid var(--border); border-radius: 8px; padding: 14px; text-align: center; }
.result-item .val { font-size: 1.2rem; font-weight: 700; color: var(--text); }
.result-item .lbl { font-size: 0.72rem; color: var(--text-secondary); margin-top: 3px; text-transform: uppercase; letter-spacing: 0.04em; }
.result-info { background: var(--accent-light); border: 1px solid rgba(37,99,235,0.2); border-radius: 8px; padding: 14px 16px; font-size: 0.875rem; color: var(--text); line-height: 1.65; }
.percentile-bar-wrap { margin: 16px 0; }
.percentile-bar-track { height: 10px; background: var(--bg-card-2); border-radius: 5px; overflow: hidden; margin-bottom: 6px; }
.percentile-bar-fill { height: 100%; background: linear-gradient(90deg, #3b82f6, #2563eb); border-radius: 5px; transition: width 0.6s ease; }
.percentile-labels { display: flex; justify-content: space-between; font-size: 0.72rem; color: var(--text-secondary); }

/* ── SIDEBAR ── */
.calc-sidebar { display: flex; flex-direction: column; gap: 20px; }
.sidebar-card { background: var(--bg-card); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; box-shadow: var(--shadow); }
.sidebar-card h3 { font-size: 0.9rem; font-weight: 700; margin-bottom: 14px; color: var(--text); }
.related-links { display: flex; flex-direction: column; gap: 8px; }
.related-links a { font-size: 0.85rem; color: var(--accent); padding: 8px 10px; background: var(--accent-light); border-radius: 6px; transition: background 0.15s; }
.related-links a:hover { background: #dbeafe; }

/* ── FOOTER ── */
footer { background: var(--text); color: #94a3b8; margin-top: 48px; }
.footer-inner { max-width: 1200px; margin: 0 auto; padding: 32px 24px; }
.footer-disclaimer { font-size: 0.78rem; margin-bottom: 16px; line-height: 1.6; }
.footer-bottom { display: flex; justify-content: space-between; align-items: center; font-size: 0.8rem; flex-wrap: wrap; gap: 12px; }
.footer-bottom a { color: #94a3b8; margin-left: 16px; }
.footer-bottom a:hover { color: white; }

/* ── QUIZ ── */
.quiz-progress { height: 4px; background: var(--border); border-radius: 2px; margin-bottom: 24px; overflow: hidden; }
.quiz-progress-fill { height: 100%; background: var(--accent); border-radius: 2px; transition: width 0.3s ease; }
.quiz-question { font-size: 1.05rem; font-weight: 600; color: var(--text); margin-bottom: 16px; line-height: 1.5; }
.quiz-options { display: flex; flex-direction: column; gap: 10px; }
.quiz-option { padding: 12px 16px; border: 1px solid var(--border); border-radius: 8px; background: var(--bg-card); font-size: 0.9rem; cursor: pointer; text-align: left; transition: all 0.15s; color: var(--text); }
.quiz-option:hover { border-color: var(--accent); background: var(--accent-light); }
.quiz-option.selected { border-color: var(--accent); background: var(--accent-light); color: var(--accent); font-weight: 600; }
.btn-next { padding: 10px 24px; background: var(--accent); color: white; border: none; border-radius: 8px; font-size: 0.9rem; font-weight: 600; cursor: pointer; transition: background 0.2s; }
.btn-next:hover { background: var(--accent-hover); }
.btn-next:disabled { background: var(--border); color: var(--text-secondary); cursor: not-allowed; }
.quiz-step-label { font-size: 0.75rem; font-weight: 700; color: var(--accent); text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 8px; }

@media (max-width: 600px) {
  .hero { padding: 40px 16px; }
  .hero-stats { gap: 24px; }
  .form-row { grid-template-columns: 1fr; }
  .calc-page-wrapper { padding: 20px 16px; }
}