:root{--bg:#f7f8fa;--card:#fff;--text:#1f2937;--muted:#6b7280;--primary:#2563eb;--border:#e5e7eb;--radius:12px}
*{box-sizing:border-box}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Noto Sans KR",sans-serif;background:var(--bg);color:var(--text);line-height:1.6}
a{color:var(--primary);text-decoration:none}
.container{max-width:960px;margin:0 auto;padding:20px}
header{background:#fff;border-bottom:1px solid var(--border);position:sticky;top:0;z-index:10}
nav{display:flex;gap:12px;flex-wrap:wrap;align-items:center;padding:12px 20px}
nav a{font-weight:600;font-size:14px}
.hero{padding:40px 20px;text-align:center}
.hero h1{font-size:28px;margin:0 0 8px}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:20px;transition:transform .15s}
.card:hover{transform:translateY(-2px)}
.card h3{margin:0 0 6px;font-size:16px}
.card p{margin:0;color:var(--muted);font-size:13px}
.calc{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:24px;margin:20px 0}
.calc h2{margin-top:0}
label{display:block;margin:12px 0 4px;font-weight:600;font-size:14px}
input,select{width:100%;padding:10px 12px;border:1px solid var(--border);border-radius:8px;font-size:16px}
button{background:var(--primary);color:#fff;border:none;padding:12px 20px;border-radius:8px;font-size:16px;font-weight:600;cursor:pointer;margin-top:16px;width:100%}
button:hover{opacity:.9}
.result{margin-top:20px;padding:16px;background:#f0f6ff;border-radius:8px;font-size:15px}
.result strong{color:var(--primary)}
footer{margin-top:40px;padding:20px;text-align:center;color:var(--muted);font-size:13px;border-top:1px solid var(--border)}
@media(max-width:600px){.hero h1{font-size:22px}}