body {
    font-family: "SF Pro Display", -apple-system, BlinkMacSystemFont, sans-serif;
    margin: 0;
    padding: 0;
    background: #f5f5f7;
    color: #1d1d1f;
}

.login-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    padding: 20px;
}

/* ... 將 index.html 中 <style> 標籤內的其他樣式移到這裡 ... */