:root{
  --bg:#f7f8fb; --card:#fff; --text:#111827; --muted:#6b7280; --line:#e5e7eb;
  --accent:#111827;
}
*{box-sizing:border-box}
body{margin:0;font-family:Arial,Helvetica,sans-serif;background:var(--bg);color:var(--text);line-height:1.55}
a{color:inherit}
.container{max-width:1100px;margin:0 auto;padding:24px}
header,footer{background:#fff;border-bottom:1px solid var(--line)}
footer{border-top:1px solid var(--line);border-bottom:none;margin-top:40px}
.brand{font-weight:700;text-decoration:none}
.nav{display:flex;gap:16px;flex-wrap:wrap;margin-top:10px}
.nav a{text-decoration:none;color:#374151}
.hero{padding:32px 0}
.grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:16px}
.card,.panel{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:18px;box-shadow:0 2px 8px rgba(0,0,0,.03)}
.btn{display:inline-block;background:var(--accent);color:#fff;text-decoration:none;border:none;border-radius:10px;padding:10px 14px;cursor:pointer}
.btn.secondary{background:#fff;color:#111827;border:1px solid var(--line)}
.lead{color:#374151;max-width:850px}
.value-strip{margin:14px 0;padding:12px;background:#fff;border:1px solid var(--line);border-radius:12px;color:#374151}
.section-title{margin:28px 0 12px}
label{display:block;font-weight:700;margin-bottom:10px}
input,select,textarea{width:100%;padding:10px;border:1px solid #d1d5db;border-radius:10px;margin-top:6px;background:#fff}
.results{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:12px;margin-top:14px}
.result{background:#f9fafb;border:1px solid var(--line);border-radius:12px;padding:12px}
.small{font-size:.92rem;color:var(--muted)}
ul.clean{padding-left:18px;margin:8px 0}
code.box{display:block;background:#f9fafb;border:1px solid var(--line);padding:12px;border-radius:12px;white-space:pre-wrap}
table{width:100%;border-collapse:collapse;background:#fff}
th,td{padding:10px;border-bottom:1px solid var(--line);text-align:left}
.badge{display:inline-block;padding:4px 10px;border-radius:999px;background:#eef2ff;font-size:.85rem}
.math{background:#f9fafb;border:1px solid var(--line);border-radius:12px;padding:12px;font-weight:700}
footer .cols{display:grid;grid-template-columns:repeat(auto-fit,minmax(180px,1fr));gap:16px}
canvas{max-width:100%;background:#fff;border:1px solid var(--line);border-radius:12px}

.notice{padding:12px;border:1px solid var(--line);background:#fff;border-radius:12px}
table button.btn{padding:8px 10px}