:root { --border:#e5e5e5; --fg:#111; --muted:#666; --bg:#fafafa; }
* { box-sizing:border-box; }
body { margin:0; font-family:system-ui, Arial, sans-serif; color:var(--fg); background:white; }
.container { max-width:800px; margin:40px auto; padding:0 16px; }
.card { border:1px solid var(--border); border-radius:14px; padding:18px; background:white; }
h1 { margin:0 0 12px; font-size:1.4rem; }
.grid { display:grid; grid-template-columns:1fr 1fr; gap:12px; margin:12px 0; }
.field { display:flex; flex-direction:column; gap:6px; }
.field > span { font-size:.9rem; }
.field > small { color:var(--muted); }
input, select { padding:10px; border:1px solid #ccc; border-radius:8px; font:inherit; }
.btn { margin-top:4px; padding:10px 14px; border:0; border-radius:10px; background:#111; color:#fff; cursor:pointer; }
.error { color:#b00020; margin-top:10px; }
.hidden { display:none; }
.result { margin-top:16px; }
.summary { font-weight:600; margin-bottom:6px; }
.meta { color:var(--muted); font-size:.9rem; margin-bottom:8px; }
.spark { width:100%; height:60px; background:var(--bg); border:1px solid var(--border); border-radius:6px; }
@media (max-width:640px){ .grid { grid-template-columns:1fr; } }