:root{--bg:#f6f7fb;--ink:#1d2433;--mut:#5b6478;--acc:#2f5bea;--card:#fff;--bd:#dde1ee}
*{box-sizing:border-box}body{margin:0;font:16px/1.6 system-ui,Segoe UI,Roboto,sans-serif;background:var(--bg);color:var(--ink)}
header{background:#101828;color:#fff;padding:14px 20px;display:flex;gap:20px;align-items:center;flex-wrap:wrap}
header a{color:#fff;text-decoration:none}header .logo{font-weight:700;font-size:20px}header nav a{margin-right:14px;opacity:.85;font-size:15px}
main{max-width:860px;margin:24px auto;padding:0 16px}h1{font-size:30px;margin:.2em 0}
.card{background:var(--card);border:1px solid var(--bd);border-radius:12px;padding:20px;margin:16px 0}
label{display:block;font-weight:600;margin:10px 0 4px;font-size:14px}
input,select,textarea{width:100%;padding:9px 10px;border:1px solid var(--bd);border-radius:8px;font:inherit;background:#fff}
textarea{min-height:140px;font-family:ui-monospace,Menlo,monospace;font-size:14px}
button{background:var(--acc);color:#fff;border:0;border-radius:8px;padding:10px 18px;font:inherit;font-weight:600;cursor:pointer;margin:12px 8px 0 0}
button.sec{background:#e8ecfb;color:var(--acc)}
.out{margin-top:14px;padding:14px;background:#f1f4ff;border-radius:8px;white-space:pre-wrap;word-break:break-word}
.row{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:12px}
.list{columns:2;padding-left:18px}.list a{color:var(--acc)}
footer{text-align:center;color:var(--mut);padding:30px 16px;font-size:14px}
.note{color:var(--mut);font-size:14px}

.answer{font-size:18px;background:#eef2ff;border-left:4px solid var(--acc);padding:12px 14px;border-radius:6px}
h2{font-size:21px;margin:.2em 0 .5em}h3{font-size:17px;margin:1em 0 .2em}
input,select,textarea{font-size:16px}
@media(max-width:600px){h1{font-size:25px}main{margin:14px auto}.card{padding:14px}button{width:100%;margin:10px 0 0;min-height:46px}.list{columns:1}header{padding:10px 14px}header nav a{display:inline-block;padding:6px 0}.out{font-size:15px}}
button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,a:focus-visible{outline:3px solid #9db4ff;outline-offset:2px}