:root{--bg:#f6f7f9;--card:#fff;--ink:#1b2430;--muted:#5d6b7a;--line:#e3e7ec;--brand:#1d5c63;--accent:#e8452c;--ok:#1a7f4b}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:-apple-system,BlinkMacSystemFont,"Apple SD Gothic Neo","Noto Sans KR",sans-serif;line-height:1.6}
a{color:var(--brand)}
header{background:var(--brand);color:#fff;padding:14px 16px}
header a{color:#fff;text-decoration:none;font-weight:700}
main{max-width:720px;margin:0 auto;padding:16px}
h1{font-size:1.45rem;line-height:1.35;margin:.4em 0}
h2{font-size:1.15rem;margin:1.6em 0 .5em}
.lead{color:var(--muted);margin:0 0 1em}
.card{background:var(--card);border:1px solid var(--line);border-radius:14px;padding:16px;margin:12px 0}
label{display:block;font-weight:600;margin:14px 0 6px}
.hint{font-size:.85rem;color:var(--muted);font-weight:400}
input[type=number],input[type=text],select{width:100%;padding:12px;border:1px solid var(--line);border-radius:10px;font-size:1rem;background:#fff}
.seg{display:flex;gap:8px;flex-wrap:wrap}
.seg label{flex:1;min-width:96px;margin:0;border:1px solid var(--line);border-radius:10px;padding:10px;text-align:center;cursor:pointer;font-weight:500}
.seg input{display:none}
.seg input:checked+span{color:var(--brand);font-weight:700}
.seg label:has(input:checked){border-color:var(--brand);background:#eaf4f4}
button{width:100%;margin-top:18px;padding:14px;border:0;border-radius:12px;background:var(--accent);color:#fff;font-size:1.05rem;font-weight:700;cursor:pointer}
.result{display:none}
.result.show{display:block}
.big{font-size:2rem;font-weight:800;color:var(--ok)}
table{width:100%;border-collapse:collapse;font-size:.92rem}
th,td{border:1px solid var(--line);padding:8px;text-align:left}
th{background:#eef2f5}
.warn{background:#fff7e6;border:1px solid #ffd591;border-radius:10px;padding:10px 12px;font-size:.9rem}
.tools{display:grid;gap:12px}
.tools a{display:block;text-decoration:none;color:inherit}
footer{max-width:720px;margin:24px auto;padding:16px;color:var(--muted);font-size:.85rem}
@media (prefers-color-scheme:dark){:root{--bg:#12161b;--card:#1b2128;--ink:#e8edf2;--muted:#9aa7b4;--line:#2b333d}th{background:#222a33}.seg label:has(input:checked){background:#16302f}.warn{background:#2a2414;border-color:#5c4a1a}input[type=number],input[type=text],select{background:#12161b;color:var(--ink)}}