:root{--blue:#0b5ed7;--purple:#6f42c1;--ink:#1d2733;--bg:#f2f6fb;--muted:#5b6776}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font-family:system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;background:var(--bg);color:var(--ink);line-height:1.65}
a{color:var(--blue)}
.topbar{position:sticky;top:0;z-index:10;background:#fff;box-shadow:0 1px 8px rgba(0,0,0,.08);display:flex;align-items:center;justify-content:space-between;padding:12px 20px;flex-wrap:wrap}
.brand{font-weight:700;font-size:1.2rem;text-decoration:none;color:var(--blue)}
.links{display:flex;gap:6px;flex-wrap:wrap}
.links a{text-decoration:none;color:var(--ink);padding:8px 12px;border-radius:8px}
.links a:hover{background:#e8f0fe;color:var(--blue)}
.menu-btn{display:none;background:none;border:1px solid #ccd;border-radius:8px;font-size:1.3rem;padding:2px 10px;cursor:pointer}
@media(max-width:700px){.menu-btn{display:block}.links{display:none;width:100%;flex-direction:column;margin-top:10px}.links.open{display:flex}}
.hero{background:linear-gradient(135deg,var(--blue),var(--purple));color:#fff;text-align:center;padding:80px 20px}
.hero h1{font-size:clamp(2rem,5vw,3.2rem);margin-bottom:12px}
.hero p{max-width:640px;margin:0 auto 24px;font-size:1.15rem;opacity:.95}
.pagehead{background:linear-gradient(135deg,var(--blue),var(--purple));color:#fff;text-align:center;padding:48px 20px}
.pagehead p{opacity:.92;margin-top:6px}
.container{max-width:960px;margin:32px auto;padding:0 16px}
.article h2{color:var(--blue);margin:28px 0 10px}
.article h3{margin:16px 0 6px}
.article p,.article ul{margin-bottom:12px}
.article ul{margin-left:22px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(240px,1fr));gap:18px;margin:18px 0}
.card{background:#fff;border-radius:12px;padding:22px 24px;box-shadow:0 2px 10px rgba(0,0,0,.07);margin-bottom:18px}
.grid .card{margin-bottom:0}
.card h3{color:var(--blue);margin-bottom:6px}
.card.link{text-decoration:none;color:inherit;display:block;transition:transform .15s}
.card.link:hover{transform:translateY(-4px)}
.icon{font-size:2.2rem}
.btn{display:inline-block;background:var(--blue);color:#fff;padding:11px 22px;border-radius:8px;text-decoration:none;border:0;font-size:1rem;cursor:pointer}
.btn:hover{background:#084298}
.btn.light{background:#fff;color:var(--blue)}
.btn.light:hover{background:#e8f0fe}
.stats{display:flex;flex-wrap:wrap;justify-content:center;gap:34px;padding:26px 16px;background:#fff}
.stats div{text-align:center}
.stats b{display:block;font-size:1.8rem;color:var(--blue)}
table{width:100%;border-collapse:collapse;background:#fff;margin:12px 0 18px;box-shadow:0 2px 10px rgba(0,0,0,.07)}
th,td{padding:10px 12px;border-bottom:1px solid #e6ebf2;text-align:left}
th{background:#e8f0fe;color:var(--blue)}
.fact{border-left:5px solid var(--purple);background:#fff;padding:14px 18px;border-radius:8px;margin-bottom:12px}
.videos{display:grid;grid-template-columns:repeat(auto-fit,minmax(260px,1fr));gap:16px;margin-top:14px}
.video{position:relative;padding-bottom:56.25%;height:0;overflow:hidden;border-radius:10px;background:#000}
.video iframe{position:absolute;inset:0;width:100%;height:100%;border:0}
.quiz .opt{display:block;width:100%;text-align:left;padding:12px 14px;margin:8px 0;border:2px solid #d6deea;border-radius:10px;background:#fff;font-size:1rem;cursor:pointer}
.quiz .opt:hover:not(:disabled){border-color:var(--blue)}
.quiz .opt.good{background:#d1f2dc;border-color:#2e9e57}
.quiz .opt.bad{background:#fbd5d5;border-color:#d64545}
.muted{color:var(--muted);font-size:.9rem}
.center{text-align:center}
footer{background:#14202e;color:#cbd5e1;text-align:center;padding:28px 16px;margin-top:40px}
footer a{color:#9ec5fe}