css body{margin:0;font-family:system-ui;background:#0f0f0f;color:#fff}.container{max-width:480px;margin:0 auto;padding:20px}.btn{background:#1877f2;color:#fff;padding:12px 24px;border-radius:24px;border:none;width:100%;font-weight:700}.card{background:#1c1c1c;padding:16px;border-radius:16px;margin-top:16px}input{width:100%;padding:12px;border-radius:12px;border:1px solid #333;background:#222;color:#fff;margin:8px 0}