:root{--ink:#172033;--muted:#667085;--bg:#f7f8fc;--card:#fff;--line:#e6e8ef;--accent:#4f46e5;--soft:#eef2ff}
*{box-sizing:border-box}body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,Arial;color:var(--ink);background:var(--bg);line-height:1.5}
header{background:#fff;border-bottom:1px solid var(--line)}nav{max-width:1100px;margin:auto;padding:16px 22px;display:flex;justify-content:space-between}.brand{font-size:21px;font-weight:800}.brand b{color:var(--accent)}nav a{margin-left:18px;color:var(--muted);text-decoration:none}
.hero,.wrap{max-width:1100px;margin:auto;padding-left:22px;padding-right:22px}.hero{padding-top:55px;padding-bottom:30px}.eyebrow{color:var(--accent);font-weight:800;font-size:12px;text-transform:uppercase;letter-spacing:.1em}.hero h1{font-size:clamp(40px,6vw,62px);line-height:1.02;letter-spacing:-.04em;max-width:760px;margin:12px 0}.hero p{max-width:680px;color:var(--muted);font-size:18px}.section{margin:25px 0 15px}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:16px}.card{background:#fff;border:1px solid var(--line);border-radius:16px;padding:19px;box-shadow:0 4px 18px #1018280a}.card h3{margin:0 0 6px}.card p{font-size:14px;color:var(--muted);margin:0 0 14px}button,.btn{background:var(--accent);color:#fff;border:0;border-radius:9px;padding:10px 14px;font-weight:700;cursor:pointer}.tool{display:none;border-top:1px solid var(--line);margin-top:14px;padding-top:14px}.tool.open{display:block}label{display:block;font-size:13px;font-weight:650;margin:9px 0 4px}input{width:100%;padding:10px;border:1px solid #d7dbe5;border-radius:8px;font:inherit}.result{background:var(--soft);padding:12px;border-radius:9px;margin-top:12px;font-weight:750}.formgrid{display:grid;grid-template-columns:1fr 1fr;gap:10px}.preview{background:#fff;border:1px solid var(--line);padding:20px;margin-top:15px;border-radius:10px}.preview-head{display:flex;justify-content:space-between;border-bottom:2px solid var(--ink);padding-bottom:12px}.table{width:100%;border-collapse:collapse;margin-top:15px}.table td,.table th{padding:8px;border-bottom:1px solid var(--line);text-align:left}.total{text-align:right;font-weight:800;margin-top:12px}.about{margin:30px 0;background:#fff;border:1px solid var(--line);border-radius:16px;padding:22px;color:var(--muted)}footer{background:#fff;border-top:1px solid var(--line);padding:22px;color:var(--muted);font-size:13px}
@media(max-width:750px){.grid{grid-template-columns:1fr 1fr}}@media(max-width:560px){.grid,.formgrid{grid-template-columns:1fr}.hero{padding-top:40px}.hero h1{font-size:43px}}
.itemrow{display:grid;grid-template-columns:2fr 1fr 1fr;gap:10px;margin-top:10px}.formgrid{display:grid;grid-template-columns:1fr 1fr;gap:10px}textarea{width:100%;padding:10px;border:1px solid #d7dbe5;border-radius:8px;font:inherit}@media(max-width:560px){.itemrow,.formgrid{grid-template-columns:1fr}}