html,body {
    margin: 0;
    padding-top: 25px;/* Add padding to prevent content from being hidden under the fixed div */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}
.fixed-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 15px;
    text-align: center;
    background: #e0e0e0;
    z-index: 1000; /* Ensure it stays on top */
    display: flex;
    justify-content: flex-start;
    align-items: center;
    gap: 15px;
}
.form-container {
    background: #f9f9f9;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 400px;
    text-align: center;
    display: flex;
    flex-direction: column;
}
h2 {
    margin-bottom: 5px;
    font-size: 20px;
    color: #333;
}
form {
    display: flex;
    flex-direction: column;
}
label {
    font-size: 14px;
    color: #555;
    margin-bottom: 5px;
    text-align: left;
}
input {
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    font-size: 14px;
    outline: none;
    transition: border-color 0.3s ease;
}
input:focus {
    border-color: #6a11cb;
}
#checkcode {
    width: 200px; /* 固定寬度 */
    height: 200px; /* 固定高度 */
    border-radius: 8px;
    border: 1px solid #ddd;
    object-fit: cover; /* 確保圖片比例不變形 */
}
a {
    color: #6a11cb;
    text-decoration: none;
    font-size: 14px;
    margin-bottom: 15px;
    transition: color 0.3s ease;
}
a:hover {
    color: #2575fc;
}
button {
    padding: 12px;
    background: #6a11cb;
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background 0.3s ease;
}
button:hover {
    background: #2575fc;
}
#message {
    margin-top: 15px;
    font-size: 14px;
    color: red;
}