body { font-family: system-ui, sans-serif; max-width: 760px; margin: 0 auto; padding: 24px; line-height: 1.6; }
h1 { margin-top: 0; }
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
input[type="number"] { width: 80px; padding: 6px 8px; }
button { padding: 8px 12px; border-radius: 10px; border: 1px solid #ccc; background: #fff; cursor: pointer; }
button:disabled { opacity: 0.5; cursor: default; }
.card { border: 1px solid #e6e6e6; border-radius: 12px; padding: 12px 14px; margin: 10px 0; }
.id { color: #777; font-size: 12px; }
.result { padding: 10px; border-radius: 10px; background: #f5f7ff; margin: 10px 0 0; }
.ok { color: #0b7; }
.ng { color: #d33; }