*{box-sizing:border-box}
body{margin:0;font:16px/1.7 -apple-system,"PingFang SC","Microsoft YaHei",sans-serif;color:#1a2233}
.top{display:flex;align-items:center;justify-content:space-between;padding:14px 5vw;border-bottom:1px solid #e3e8f0}
.brand{font-weight:700;font-size:20px;color:#0b5fff;text-decoration:none}
nav a{margin-left:18px;color:#334;text-decoration:none}
a.cta{background:#0b5fff;color:#fff;padding:8px 16px;border-radius:8px}
a.cta.big{display:inline-block;padding:14px 28px;font-size:18px;margin-top:8px}
a:focus-visible{outline:3px solid #8fb4ff;outline-offset:2px}
.hero{padding:10vh 5vw;background:linear-gradient(135deg,#eef3ff,#fff)}
.hero h1{font-size:clamp(28px,5vw,44px);margin:0 0 12px;max-width:16em}
.hero p{max-width:34em;color:#445}
section{padding:40px 5vw}
h2{margin:0 0 16px}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:16px}
.box{border:1px solid #e3e8f0;border-radius:12px;padding:16px}
.box h3{margin:0 0 6px}
footer{padding:24px 5vw;color:#667;border-top:1px solid #e3e8f0;font-size:14px}