/* PC端样式文件 */
/* 主要定义桌面电脑屏幕下的页面布局和外观 */

/* 导入Google字体 */
@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@300;400;500&display=swap');

/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 页面基础样式 */
body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: #000000;
    background-color: white;
}

/* 主头部样式 - 天蓝色渐变背景 */
.main-header {
    /* 从上到下、由深到浅的天蓝色渐变 */
    background: linear-gradient(180deg, #4a90e2 0%, #7bb3f0 100%);
    padding: 15px 0;
    box-shadow: 0 2px 10px rgba(74, 144, 226, 0.3);
}

/* 头部容器布局 */
.header-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 20px;
}

/* 左侧Logo区域 */
.header-left .logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    /* 移除边框 */
    border: none;
}

/* Logo图片样式 */
.logo-img {
    width: 60px;
    height: 60px;
    /* 背景透明 */
    background: transparent;
    /* 无边框 */
    border: none;
    margin-right: 15px;
}

/* 网站名称样式 */
.site-name {
    color: white;
    font-size: 28px;
    font-weight: 500;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

/* 右侧公告区域 */
.header-right .announcement {
    color: white;
    font-size: 18px;
    font-weight: 300;
    text-align: right;
}

/* 主要内容区域 */
.main-content {
    min-height: calc(100vh - 200px);
    padding: 40px 20px;
}

/* 容器样式 */
.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* 首页网格布局 */
.home-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

/* 年级卡片样式 */
.grade-card {
    background: white;
    border-radius: 15px;
    padding: 40px 30px;
    text-align: center;
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

/* 年级卡片悬停效果 */
.grade-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.15);
}

/* 年级标题 */
.grade-title {
    font-size: 32px;
    color: #4a90e2;
    margin-bottom: 15px;
    font-weight: 500;
}

/* 年级描述 */
.grade-desc {
    font-size: 16px;
    color: #666;
    margin-bottom: 25px;
}

/* 进入按钮 */
.enter-btn {
    background: linear-gradient(45deg, #4a90e2, #7bb3f0);
    color: white;
    border: none;
    padding: 12px 30px;
    border-radius: 25px;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.3s ease;
}

/* 进入按钮悬停效果 */
.enter-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 5px 15px rgba(74, 144, 226, 0.4);
}

/* 列表页样式 */
.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding: 20px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* 返回按钮 */
.back-btn {
    background: #6c757d;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}

/* 批量下载区域 */
.batch-download {
    margin-bottom: 20px;
    padding: 15px;
    background: #e3f2fd;
    border-radius: 8px;
}

/* 下载按钮 */
.download-selected {
    background: #28a745;
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    cursor: pointer;
}

/* 试题列表 */
.exam-list {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* 列表项 */
.exam-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid #eee;
    transition: background-color 0.3s ease;
}

/* 列表项悬停效果 */
.exam-item:hover {
    background-color: #f8f9fa;
}

/* 列表项最后一项去掉下边框 */
.exam-item:last-child {
    border-bottom: none;
}

/* 试题信息 */
.exam-info h3 {
    color: #4a90e2;
    margin-bottom: 5px;
}

.exam-info p {
    color: #666;
    font-size: 14px;
}

/* 详情按钮 */
.detail-btn {
    background: #4a90e2;
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
}

/* 复选框样式 */
.exam-checkbox {
    margin-right: 15px;
    transform: scale(1.2);
}

/* 详情页样式 */
.detail-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding: 15px;
    background: white;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

/* 双按钮布局 */
.detail-nav {
    display: flex;
    gap: 10px;
}

/* 操作按钮通用样式 */
.action-btn {
    padding: 8px 8px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    margin: 0 5px;
}

/* 预览按钮 */
.preview-btn {
    background: #17a2b8;
    color: white;
}

/* 打印按钮 */
.print-btn {
    background: #ffc107;
    color: #212529;
}

/* 全屏按钮 */
.fullscreen-btn {
    background: #6f42c1;
    color: white;
}

/* PDF预览容器 */
.pdf-preview {
    background: white;
    border-radius: 10px;
    padding: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

/* iframe样式 */
.pdf-frame {
    width: 100%;
    height: 600px;
    border: 1px solid #ddd;
    border-radius: 5px;
}

/* 全屏模态框 */
.fullscreen-modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.9);
    z-index: 9999;
}

/* 全屏内容 */
.fullscreen-content {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
}

/* 全屏头部 */
.fullscreen-header {
    background: #333;
    color: white;
    padding: 15px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* 关闭按钮 */
.close-btn {
    background: #8B8B83;
    color: white;
    border: none;
    padding: 8px 15px;
    border-radius: 5px;
    cursor: pointer;
    font-size: 16px;
}

/* 全屏iframe */
.fullscreen-frame {
    flex: 1;
    border: none;
}

/* 底部样式 */
.main-footer {
    background: #343a40;
    color: white;
    padding: 20px 0 10px;
}

/* 底部容器 */
.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 5px;
    padding: 0 15px;
}

/* 底部区块 */
.footer-section h4 {
    margin-bottom: 15px;
    color: #4a90e2;
}

/* 响应式设计 - 平板设备 */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 5px;
    }
    
    .home-grid {
        grid-template-columns: 1fr;
    }
}