/* Reset some default styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* Body & Page Background */
body {
    font-family: 'Arial', sans-serif;
    background-color: #f5f5f5;
    padding: 20px;
}

/* 页眉导航栏 */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background-color: #2575fc;
    padding: 10px 30px;
    color: white;
    border-radius: 10px;
    margin-bottom: 30px;
}

.navbar .logo h1 {
    font-size: 24px;
    font-weight: bold;
}

.navbar-links a {
    color: white;
    text-decoration: none;
    margin: 0 15px;
    font-size: 16px;
    transition: color 0.3s;
}

.navbar-links a:hover {
    color: #f1c40f;
}

.navbar .avatar img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    border: 2px solid white;
}

/* 课程详情页面主体部分 */
.course-details {
    max-width: 1200px;
    margin: 0 auto;

}

/* 上半部分：课程封面和课程详情 */
.course-overview {
    display: flex;
    justify-content: space-between;
    margin-bottom: 30px;
    max-height: 200px;
    height: 30%;
}

.course-cover {
    width: 40%;
    text-align: center;
}

.cover-image {
    
    height: 100%;
    width: auto;
    border-radius: 10px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
}

.course-info {
    width: 55%;
    padding-left: 20px;
}

.course-title {
    font-size: 32px;
    font-weight: bold;
    margin-bottom: 10px;
    color: #333;
}

.course-author {
    font-size: 16px;
    color: #777;
    margin-bottom: 20px;
}

.course-description {
    font-size: 16px;
    color: #555;
}

/* 下半部分：课程教案列表 */
.lesson-plans {
    margin-top: 30px;
}

.lesson-plans h3 {
    font-size: 24px;
    font-weight: bold;
    margin-bottom: 20px;
    color: #333;
}

/* 课程教案卡片容器 */
.lesson-cards {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: space-around;
}

/* 课程教案卡片 */
.lesson-card {
    width: 200px;
    height: 300px;
    background-color: white;
    border-radius: 15px;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: transform 0.3s;
}

.lesson-card:hover {
    transform: translateY(-10px); /* 提升效果 */
}

.lesson-image {
    width: 100%;
    height: 150px;
    object-fit: cover;
}

.lesson-info {
    padding: 15px;
}

.lesson-title {
    font-size: 18px;
    font-weight: bold;
    color: #333;
    margin-bottom: 10px;
}

.lesson-description {
    font-size: 14px;
    color: #777;
}