:root {
  --primary: #059669;
  --primary-dark: #047857;
  --primary-light: #d1fae5;
  --accent: #f59e0b;
  --text: #111827;
  --text-light: #6b7280;
  --bg: #ffffff;
  --bg-light: #f9fafb;
  --border: #e5e7eb;
  --shadow: 0 4px 24px rgba(0,0,0,0.08);
  --radius: 12px;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Inter', -apple-system, sans-serif; color: var(--text); background: var(--bg); line-height: 1.6; }
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 24px; }
/* Header */
header { background: #fff; border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 100; }
.header-inner { max-width: 1200px; margin: 0 auto; padding: 0 24px; display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-size: 1.3rem; font-weight: 800; color: var(--text); }
.logo span { color: var(--primary); }
nav { display: flex; gap: 24px; }
nav a { color: var(--text-light); font-size: 0.9rem; font-weight: 500; }
nav a:hover { color: var(--primary); text-decoration: none; }
.nav-cta { background: var(--primary); color: #fff !important; padding: 8px 16px; border-radius: 8px; }
.nav-cta:hover { background: var(--primary-dark); }
/* Hero */
.hero { background: linear-gradient(135deg, #064e3b 0%, #065f46 50%, #047857 100%); color: #fff; padding: 80px 24px; text-align: center; }
.hero h1 { font-size: clamp(1.8rem, 4vw, 3rem); font-weight: 800; line-height: 1.2; margin-bottom: 16px; }
.hero p { font-size: 1.15rem; opacity: 0.9; max-width: 600px; margin: 0 auto 32px; }
.btn-primary { display: inline-block; background: var(--accent); color: #1f2937; padding: 14px 28px; border-radius: var(--radius); font-weight: 700; font-size: 1rem; margin: 0 8px 8px; }
.btn-primary:hover { background: #d97706; text-decoration: none; }
.btn-secondary { display: inline-block; background: rgba(255,255,255,0.15); color: #fff; padding: 14px 28px; border-radius: var(--radius); font-weight: 600; font-size: 1rem; margin: 0 8px 8px; border: 1px solid rgba(255,255,255,0.3); }
.btn-secondary:hover { background: rgba(255,255,255,0.25); text-decoration: none; }
/* Trust bar */
.trust-bar { background: var(--primary-dark); color: rgba(255,255,255,0.85); padding: 14px 24px; display: flex; justify-content: center; gap: 32px; flex-wrap: wrap; font-size: 0.9rem; }
/* Cards */
.cards-section { padding: 60px 0; background: var(--bg-light); }
.cards-section h2 { text-align: center; font-size: 1.8rem; font-weight: 800; margin-bottom: 8px; }
.cards-section .subtitle { text-align: center; color: var(--text-light); margin-bottom: 40px; }
.cards-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 24px; max-width: 1200px; margin: 0 auto; padding: 0 24px; }
.card { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; transition: transform 0.2s, box-shadow 0.2s; }
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card-badge { display: inline-block; background: var(--primary); color: #fff; font-size: 0.75rem; font-weight: 700; padding: 3px 10px; border-radius: 20px; margin-bottom: 12px; }
.card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--text-light); font-size: 0.9rem; margin-bottom: 16px; }
.card .commission { color: var(--primary); font-weight: 700; font-size: 0.9rem; }
.card .card-link { display: block; text-align: center; background: var(--primary); color: #fff; padding: 10px; border-radius: var(--radius); font-weight: 600; margin-top: 16px; }
.card .card-link:hover { background: var(--primary-dark); text-decoration: none; }
.rating { color: var(--accent); font-size: 1.1rem; margin-bottom: 8px; }
/* Stats bar */
.stats-bar { background: var(--primary-dark); color: #fff; padding: 40px 24px; }
.stats-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; text-align: center; }
@media(max-width:600px) { .stats-grid { grid-template-columns: repeat(2,1fr); } }
.stat-number { font-size: 2.2rem; font-weight: 800; color: var(--accent); }
.stat-label { font-size: 0.9rem; opacity: 0.8; margin-top: 4px; }
/* Tool CTA */
.tool-cta { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%); color: #fff; padding: 60px 24px; text-align: center; }
.tool-cta h2 { font-size: 2rem; font-weight: 800; margin-bottom: 12px; }
.tool-cta p { font-size: 1.1rem; opacity: 0.9; max-width: 560px; margin: 0 auto 28px; }
.tool-cta .btn-tool { display: inline-block; background: #fff; color: var(--primary-dark); padding: 16px 36px; border-radius: var(--radius); font-weight: 800; font-size: 1.05rem; }
.tool-cta .btn-tool:hover { background: #f0fdf4; text-decoration: none; }
/* Blog grid */
.blog-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 24px; }
/* Article */
.content-grid { display: grid; grid-template-columns: 1fr 300px; gap: 40px; padding: 40px 0; }
@media(max-width:900px) { .content-grid { grid-template-columns: 1fr; } }
.article-body h2 { font-size: 1.4rem; font-weight: 700; margin: 32px 0 12px; color: var(--text); }
.article-body h3 { font-size: 1.15rem; font-weight: 700; margin: 24px 0 10px; }
.article-body p { margin-bottom: 16px; color: var(--text); line-height: 1.75; }
.article-body ul, .article-body ol { margin: 0 0 16px 24px; }
.article-body li { margin-bottom: 8px; line-height: 1.7; }
.article-body table { width: 100%; border-collapse: collapse; margin: 24px 0; font-size: 0.9rem; }
.article-body th { background: var(--primary); color: #fff; padding: 12px; text-align: left; }
.article-body td { padding: 10px 12px; border-bottom: 1px solid var(--border); }
.article-body tr:nth-child(even) td { background: var(--bg-light); }
.cta-box { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%); color: #fff; border-radius: var(--radius); padding: 32px; margin: 40px 0; text-align: center; }
.cta-box h3 { font-size: 1.4rem; margin-bottom: 12px; }
.cta-box p { opacity: 0.9; margin-bottom: 24px; }
/* Sidebar */
.sidebar-card { background: var(--bg-light); border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; margin-bottom: 24px; }
.sidebar-card h3 { font-size: 1rem; font-weight: 700; margin-bottom: 16px; color: var(--primary-dark); }
/* Breadcrumb */
.breadcrumb { padding: 16px 0; font-size: 0.85rem; color: var(--text-light); }
.breadcrumb a { color: var(--text-light); }
.breadcrumb span { margin: 0 6px; }
/* Newsletter */
.newsletter { background: var(--bg-light); padding: 60px 24px; text-align: center; border-top: 1px solid var(--border); }
.newsletter h2 { font-size: 1.8rem; font-weight: 800; margin-bottom: 8px; }
.newsletter p { color: var(--text-light); margin-bottom: 24px; }
.newsletter-form { display: flex; gap: 12px; max-width: 480px; margin: 0 auto; }
.newsletter-form input { flex: 1; padding: 12px 16px; border: 1px solid var(--border); border-radius: var(--radius); font-size: 1rem; }
.newsletter-form button { background: var(--primary); color: #fff; border: none; padding: 12px 24px; border-radius: var(--radius); font-weight: 700; cursor: pointer; }
@media(max-width:500px) { .newsletter-form { flex-direction: column; } }
/* Footer */
footer { background: #111827; color: rgba(255,255,255,0.7); padding: 48px 24px 24px; }
.footer-grid { max-width: 1200px; margin: 0 auto; display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
@media(max-width:700px) { .footer-grid { grid-template-columns: 1fr; } }
.footer-brand { font-size: 1.3rem; font-weight: 800; color: #fff; margin-bottom: 12px; }
.footer-brand span { color: var(--accent); }
.footer-desc { font-size: 0.9rem; line-height: 1.6; }
footer h4 { color: #fff; font-size: 0.9rem; font-weight: 700; margin-bottom: 12px; text-transform: uppercase; letter-spacing: 0.5px; }
footer ul { list-style: none; }
footer ul li { margin-bottom: 8px; }
footer ul li a { color: rgba(255,255,255,0.6); font-size: 0.9rem; }
footer ul li a:hover { color: #fff; text-decoration: none; }
.footer-bottom { max-width: 1200px; margin: 0 auto; padding-top: 24px; border-top: 1px solid rgba(255,255,255,0.1); display: flex; justify-content: space-between; font-size: 0.85rem; }
.disclaimer { max-width: 1200px; margin: 16px auto 0; font-size: 0.8rem; opacity: 0.5; }
/* Biological Age Calculator */
.bio-age-calculator { background: #fff; border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; max-width: 700px; margin: 0 auto; box-shadow: var(--shadow); }
.bio-age-calculator h2 { font-size: 1.6rem; font-weight: 800; margin-bottom: 8px; color: var(--text); }
.bio-age-calculator .subtitle { color: var(--text-light); margin-bottom: 28px; }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 20px; }
@media(max-width:600px) { .form-grid { grid-template-columns: 1fr; } }
.form-group label { display: block; font-size: 0.85rem; font-weight: 600; margin-bottom: 6px; color: var(--text); }
.form-group input, .form-group select { width: 100%; padding: 10px 14px; border: 1px solid var(--border); border-radius: 8px; font-size: 0.95rem; background: var(--bg-light); }
.form-group input:focus, .form-group select:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 3px rgba(5,150,105,0.12); }
.calc-btn { width: 100%; background: var(--primary); color: #fff; border: none; padding: 14px; border-radius: var(--radius); font-size: 1rem; font-weight: 700; cursor: pointer; margin-top: 8px; }
.calc-btn:hover { background: var(--primary-dark); }
.result-box { display: none; margin-top: 24px; padding: 24px; background: var(--primary-light); border-radius: var(--radius); text-align: center; }
.result-box.show { display: block; }
.result-age { font-size: 3rem; font-weight: 800; color: var(--primary-dark); }
.result-label { font-size: 1rem; color: var(--primary-dark); font-weight: 600; margin-bottom: 12px; }
.result-tips { text-align: left; margin-top: 16px; }
.result-tips li { margin-bottom: 8px; font-size: 0.9rem; color: var(--text); }
.result-cta { margin-top: 20px; background: var(--primary); color: #fff; display: inline-block; padding: 12px 24px; border-radius: var(--radius); font-weight: 700; }