body { font: 15px/1.5 system-ui, sans-serif; margin: 0; color: #1a1a1a; background: #fafafa; }
header, section, footer { max-width: 720px; margin: 0 auto; padding: 16px 20px; }
header { display: flex; justify-content: space-between; align-items: center; }
nav a { margin-left: 12px; }
.card { background: #fff; border: 1px solid #e3e3e3; border-radius: 12px; padding: 16px; display: grid; gap: 8px; }
input, textarea, select { padding: 8px 10px; border: 1px solid #ccc; border-radius: 8px; font: inherit; }
button, .btn { padding: 10px 14px; border: 0; border-radius: 8px; background: #111; color: #fff; font: inherit; cursor: pointer; text-decoration: none; text-align: center; }
.done { color: #15803d; font-weight: 600; }