*{box-sizing:border-box}
:root{--bg:#f6f8fb;--card:#fff;--text:#172033;--muted:#697386;--line:#e5e9f0;--primary:#2563eb;--primary-dark:#1d4ed8;--soft:#eff6ff;--danger:#b42318}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.55}
.container{width:min(1080px,calc(100% - 32px));margin:auto}
.topbar{background:#fff;border-bottom:1px solid var(--line);position:sticky;top:0;z-index:10}
.nav{height:68px;display:flex;align-items:center;justify-content:space-between}
.brand{font-weight:800;font-size:21px;color:var(--text);text-decoration:none;letter-spacing:-.5px}
.brand span{color:var(--primary)}
nav{display:flex;gap:26px}nav a{color:var(--muted);text-decoration:none;font-size:14px;font-weight:600}nav a:hover{color:var(--primary)}
.hero{text-align:center;padding:58px 0 34px}
.eyebrow{font-size:12px;font-weight:800;letter-spacing:1.5px;color:var(--primary);margin-bottom:8px}
h1{font-size:clamp(34px,5vw,50px);line-height:1.08;letter-spacing:-1.8px;margin:0 0 12px}
.hero p{margin:0;color:var(--muted);font-size:17px}
.main-grid{display:grid;grid-template-columns:minmax(0,2fr) minmax(260px,1fr);gap:22px;align-items:start}
.card{background:var(--card);border:1px solid var(--line);border-radius:18px;box-shadow:0 8px 28px rgba(16,24,40,.05)}
.calculator-card{padding:28px}
.card-title h2,.info h2{margin:0;font-size:23px;letter-spacing:-.5px}
.card-title p{margin:6px 0 24px;color:var(--muted);font-size:14px}
.form-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}
label span{display:block;font-size:13px;font-weight:700;margin-bottom:8px}
input{width:100%;height:48px;border:1px solid #d6dce6;border-radius:10px;padding:0 13px;font:inherit;color:var(--text);background:#fff;outline:none}
input:focus{border-color:var(--primary);box-shadow:0 0 0 3px rgba(37,99,235,.12)}
.actions{display:flex;gap:10px;margin-top:20px}
button{font:inherit;cursor:pointer;border-radius:10px;padding:12px 18px;font-weight:750}
.primary{border:1px solid var(--primary);background:var(--primary);color:#fff}.primary:hover{background:var(--primary-dark)}
.secondary{border:1px solid var(--line);background:#fff;color:var(--text)}.secondary:hover{background:#f8fafc}
.error{display:none;margin-top:16px;padding:11px 13px;background:#fff1f0;color:var(--danger);border:1px solid #ffd5d2;border-radius:9px;font-size:14px}
.result{margin-top:28px;border-top:1px solid var(--line);padding-top:25px}.hidden{display:none}
.result-head{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:13px;font-weight:750;text-transform:uppercase;letter-spacing:.6px}
.copy-btn{padding:7px 10px;background:#fff;border:1px solid var(--line);color:var(--muted);font-size:12px}
.headline-age{font-size:32px;font-weight:850;letter-spacing:-1px;margin:10px 0 18px}
.stats-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}
.stat{background:var(--soft);border:1px solid #dbeafe;border-radius:13px;text-align:center;padding:16px 8px}
.stat strong{display:block;font-size:29px;line-height:1.1}.stat span{font-size:12px;color:var(--muted);font-weight:700}
.details{display:grid;grid-template-columns:1fr 1fr;gap:1px;background:var(--line);border:1px solid var(--line);border-radius:12px;overflow:hidden;margin-top:16px}
.details div{background:#fff;padding:12px 14px;display:flex;justify-content:space-between;gap:10px;font-size:13px}
.details span,.birthday span{color:var(--muted)}.details strong{font-weight:750}
.birthday{margin-top:16px;padding:16px;border-radius:12px;background:#fafbfc;border:1px solid var(--line);display:grid;grid-template-columns:1fr 1fr;gap:15px}
.birthday strong{display:block;margin-top:3px}.side-card{padding:24px;position:sticky;top:92px}.side-card h3{margin:0 0 8px;font-size:19px}.side-card p{font-size:14px;color:var(--muted);margin:0 0 16px}.side-card ul{padding-left:19px;margin:0;color:var(--muted);font-size:14px}.side-card li{margin:8px 0}
.info{margin-top:22px;margin-bottom:50px}.info .card{padding:28px}.info h2{margin-bottom:12px}.info p{color:var(--muted);font-size:14px}
footer{border-top:1px solid var(--line);background:#fff}.footer-inner{height:70px;display:flex;align-items:center;justify-content:space-between;color:var(--muted);font-size:12px}
@media(max-width:760px){nav{display:none}.hero{padding:42px 0 25px}.main-grid{grid-template-columns:1fr}.side-card{position:static}.form-grid,.birthday{grid-template-columns:1fr}.calculator-card,.info .card{padding:20px}.headline-age{font-size:27px}.details{grid-template-columns:1fr}.footer-inner{height:auto;padding:18px 0;gap:8px;align-items:flex-start;flex-direction:column}}