:root { --bg:#1358bf; --card:#ffffff; --text:#0b0d10; --muted:#555; --accent:#57cdff; --ok:#28c76f; }
* { box-sizing: border-box; }
body { margin: 0; font-family: system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, "Helvetica Neue", Arial; background: var(--bg); color: var(--text); }
.have { color: var(--card); }
.wrap { max-width: 980px; margin: 40px auto; padding: 0 16px; }
h1 { font-size: 28px; margin: 0 0 18px; }
.sub { color: var(--card); margin-bottom: 24px; }

.grid { display: grid; grid-template-columns: repeat(12, 1fr); gap: 16px; }

.card { grid-column: span 12; background: var(--card); border: 1px solid #ddd; border-radius: 16px; padding: 18px; box-shadow: 0 6px 24px rgba(0,0,0,.1); }
@media (min-width: 900px) {
  .card.inputs { grid-column: span 7; }
  .card.result { grid-column: span 5; position: sticky; top: 16px; align-self: start; }
}

.row { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; }
.row + .row { margin-top: 12px; }
@media (max-width: 600px) { .row { grid-template-columns: 1fr; } }

label { display: block; font-size: 14px; color: var(--muted); margin: 0 0 6px; }
input[type="number"], select { width: 100%; background: #f7fbff; color: var(--text); border: 1px solid #ccc; border-radius: 12px; padding: 12px 14px; font-size: 16px; outline: none; transition: border-color .2s, box-shadow .2s; }
input[type="number"]:focus, select:focus { border-color: var(--accent); box-shadow: 0 0 0 4px rgba(87,205,255,.25); }

.inline { display:flex; align-items:center; gap:10px; color:var(--muted); font-size:13px; margin-top:6px; }

.result h2 { margin: 0 0 8px; font-size: 22px; }
.sum { font-size: 42px; font-weight: 700; letter-spacing: -.5px; margin: 8px 0 16px; }
.sum.ok { color: var(--ok); }

.btn { display:inline-block; padding:12px 16px; border-radius:10px; border:1px solid #1d242c; background:#1358bf; color:#fff; text-decoration:none; font-weight:600; }
.btn:hover { filter:brightness(1.1); }
.result .actions { margin-top:12px; }

.config-tip { margin-top: 12px; font-size: 12px; color: var(--muted); }