/* 通用样式 */
body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    color: #333;
    background-color: #f8f9fa;
}

.container {
    max-width: 1200px;
}

/* 导航栏样式 */
.navbar {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    background-color: #fff;
}

.navbar-brand {
    font-weight: bold;
    font-size: 1.5rem;
    color: #0056b3;
}

.nav-link {
    color: #333;
    font-weight: 500;
    margin: 0 10px;
    transition: color 0.2s ease;
}

.nav-link:hover, .nav-link:focus {
    color: #0056b3;
}

.dropdown-menu {
    border: none;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
}

.dropdown-item:hover {
    background-color: #f1f8ff;
    color: #0056b3;
}

/* 页脚样式 */
.footer {
    background-color: #343a40;
    color: #fff;
    padding: 2rem 0;
    margin-top: 3rem;
}

.footer a {
    color: #adb5bd;
    transition: color 0.2s ease;
}

.footer a:hover {
    color: #fff;
    text-decoration: none;
}

/* 轮播图样式 */
.carousel-item {
    height: 400px;
}

.carousel-caption {
    background-color: rgba(0, 0, 0, 0.5);
    border-radius: 5px;
    padding: 20px;
}

/* 占位色块样式 */
.placeholder-img {
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 2rem;
}

.placeholder-1 {
    background-color: #007bff;
}

.placeholder-2 {
    background-color: #28a745;
}

.placeholder-3 {
    background-color: #dc3545;
}

/* 学科卡片样式 */
.subject-card {
    transition: all 0.3s ease;
    margin-bottom: 20px;
    border: none;
    box-shadow: 0 0 15px rgba(0, 0, 0, 0.1);
}

.subject-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.card-title {
    font-weight: bold;
    color: #0056b3;
}

/* 页面标题样式 */
.page-header {
    padding: 2rem 0;
    margin-bottom: 2rem;
    background-color: #f1f8ff;
    border-bottom: 1px solid #e7f1fd;
}

.page-title {
    font-weight: bold;
    color: #0056b3;
}

/* 内容区样式 */
.content-section {
    padding: 3rem 0;
}

/* 联系信息样式 */
.contact-info i {
    color: #0056b3;
    font-size: 1.2rem;
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

.contact-item {
    margin-bottom: 15px;
}