body {
    font-family: 'Inter', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #eef2f5; 
    color: #333;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
}

.container {
    background-color: #ffffff; 
    padding: 30px;
    /* 修改 margin-top 为 85px，防止被顶部固定的通知栏遮挡 (原为30px) */
    margin: 85px 20px 30px 20px;
    border-radius: 16px; 
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08); 
    width: 100%;
    max-width: 450px; 
    box-sizing: border-box;
    position: relative;
    z-index: 1;
}

h2 {
    color: #1a73e8; 
    text-align: center;
    margin-bottom: 30px;
    font-weight: 700;
    border-bottom: 2px solid #f0f4f7;
    padding-bottom: 15px;
}

/* 统一输入控件样式 */
input[type="text"],
input[type="password"],
select {
    width: 100%;
    padding: 14px 12px;
    margin-bottom: 20px;
    border: 1px solid #dcdfe6;
    border-radius: 10px;
    box-sizing: border-box;
    font-size: 16px;
    background-color: #f7f9fb; 
    transition: all 0.3s;
}

input:focus,
select:focus {
    border-color: #1a73e8;
    background-color: #fff;
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
    outline: none;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: #555;
    font-size: 0.95em;
}

/* 按钮样式 - 纵向分布 */
.btn-primary {
    background-color: #1a73e8;
    color: white;
    padding: 15px 20px;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    width: 100%; 
    font-size: 18px;
    font-weight: 600;
    transition: background-color 0.3s, transform 0.1s;
    margin-top: 10px; 
    text-decoration: none; 
    display: block;
}

.btn-primary:hover {
    background-color: #1558b3;
}

.btn-primary:active {
    transform: translateY(1px);
}

/* 课程列表样式 (Card 优化) */
#courseList {
    margin-top: 30px;
}

.course-item {
    padding: 18px;
    margin-bottom: 12px;
    border-left: 5px solid #4285f4; 
    border-radius: 8px;
    background-color: #ffffff;
    box-shadow: 0 3px 10px rgba(0, 0, 0, 0.05);
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.course-item:hover {
    background-color: #f6f8fa;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transform: translateY(-2px);
}

.course-name {
    font-weight: 600;
    color: #333;
    flex-grow: 1;
}

.course-state {
    font-size: 0.85em;
    color: #34a853; 
    padding: 4px 8px;
    border-radius: 5px;
    background-color: #e6f4ea;
    font-weight: 500;
}

/* 订单信息样式 */
.order-detail {
    margin-bottom: 20px;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    background-color: #f8f9fa;
}

.order-detail p {
    margin: 8px 0;
    line-height: 1.6;
}

.order-detail strong {
    color: #007bff;
}

/* 消息提示 */
#message, #orderMessage, #successMessage {
    text-align: center;
    margin-top: 20px;
    padding: 12px;
    border-radius: 8px;
    font-weight: 500;
}

.error {
    background-color: #fde2e6;
    color: #a7223b;
    border: 1px solid #f5c6cb;
}

.success {
    background-color: #e6f4ea;
    color: #1e8e3e;
    border: 1px solid #c3e6cb;
}

/* --- [新增] 顶部通知栏样式 --- */
.notification-bar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: #e8f0fe; /* 浅蓝背景，呼应主色调 */
    color: #1967d2;            /* 深蓝文字 */
    padding: 12px 20px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    box-sizing: border-box;
    font-size: 14px;
    line-height: 1.5;
    animation: slideDown 0.5s ease-out;
}

.notification-content {
    display: flex;
    align-items: center;
    text-align: center;
    margin-right: 15px;
    font-weight: 500;
}

.notification-icon {
    margin-right: 8px;
    font-size: 16px;
}

.close-notification {
    background: transparent;
    border: none;
    color: #1967d2;
    font-size: 20px;
    cursor: pointer;
    padding: 0 8px;
    line-height: 1;
    opacity: 0.6;
    transition: opacity 0.3s;
    display: flex;
    align-items: center;
}

.close-notification:hover {
    opacity: 1;
}

@keyframes slideDown {
    from { transform: translateY(-100%); }
    to { transform: translateY(0); }
}

/* 适配移动端：防止文字太长换行 */
@media (max-width: 480px) {
    .notification-bar {
        padding: 10px 15px;
        align-items: flex-start;
    }
    .notification-content {
        text-align: left;
        font-size: 13px;
        flex: 1;
    }
}