:root{color-scheme:light;font-family:Inter,Arial,sans-serif}body{margin:0;background:#f8fafc;color:#0f172a}main{max-width:980px;margin:0 auto;padding:24px}.card{background:white;border:1px solid #e2e8f0;border-radius:12px;padding:16px;margin-bottom:16px}button{border:1px solid #1d4ed8;background:#2563eb;color:white;border-radius:8px;padding:8px 12px;cursor:pointer}