/* shared.css - 全局共享样式表，提供一致的视觉体验和响应式布局 */

/* 1. 基础重置和盒模型设置，确保跨浏览器一致性 */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth; /* 启用平滑滚动效果 */
    font-size: 16px; /* 基础字体大小，便于REM单位计算 */
    line-height: 1.5; /* 基础行高 */
}

body {
    font-family: 'Roboto', 'Helvetica Neue', 'Arial', sans-serif; /* 优先使用Roboto，提供优雅的字体 */
    color: #333; /* 基础文本颜色 */
    background-color: #f8f9fa; /* 页面背景色 */
    -webkit-font-smoothing: antialiased; /* 字体抗锯齿优化 */
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden; /* 防止横向滚动条 */
}

/* 2. 通用容器和布局辅助类 */
.container {
    max-width: 1200px; /* 页面最大宽度 */
    margin: 0 auto; /* 居中布局 */
    padding: 0 15px; /* 左右内边距 */
}

.main-header, .main-footer {
    background-color: #fff; /* 头部和页脚背景色 */
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08); /* 轻微阴影效果 */
    padding: 20px 0; /* 上下内边距 */
}

/* 3. 头部导航样式 */
.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap; /* 允许元素换行 */
}

.main-header .logo img {
    height: 50px; /* Logo高度 */
    vertical-align: middle;
    transition: transform 0.3s ease; /* 鼠标悬停效果 */
}
.main-header .logo img:hover {
    transform: scale(1.05);
}

.main-nav {
    flex-grow: 1; /* 占据可用空间 */
    text-align: center;
}

.main-nav .nav-list {
    list-style: none;
    display: flex;
    justify-content: center;
    gap: 30px; /* 导航项间距 */
}

.main-nav .nav-item .nav-link {
    text-decoration: none;
    color: #555; /* 导航链接颜色 */
    font-weight: 500;
    padding: 10px 0; /* 上下内边距 */
    position: relative;
    transition: color 0.3s ease; /* 颜色过渡效果 */
}

.main-nav .nav-item .nav-link:hover,
.main-nav .nav-item .nav-link.current {
    color: #007bff; /* 悬停和当前页面的颜色 */
}

.main-nav .nav-item .nav-link::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 3px; /* 下划线高度 */
    background-color: #007bff;
    transform: scaleX(0); /* 默认隐藏 */
    transition: transform 0.3s ease; /* 动画效果 */
}

.main-nav .nav-item .nav-link:hover::after,
.main-nav .nav-item .nav-link.current::after {
    transform: scaleX(1); /* 悬停和当前页面显示下划线 */
}

/* 下拉菜单样式 */
.main-nav .has-dropdown {
    position: relative;
}

.main-nav .dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: #fff;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15); /* 下拉菜单阴影 */
    list-style: none;
    min-width: 200px; /* 最小宽度 */
    z-index: 1000; /* 确保在其他元素之上 */
    opacity: 0;
    visibility: hidden;
    transform: translateY(15px); /* 初始位移 */
    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.3s ease; /* 动画效果 */
    border-radius: 5px;
}

.main-nav .has-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0); /* 悬停时显示 */
}

.main-nav .dropdown-menu li a {
    display: block;
    padding: 12px 20px;
    color: #555;
    text-decoration: none;
    white-space: nowrap;
    transition: background-color 0.2s ease, color 0.2s ease;
}

.main-nav .dropdown-menu li a:hover {
    background-color: #f0f0f0;
    color: #007bff;
}

/* 头部操作区 */
.header-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box input[type="search"] {
    border: 1px solid #ccc;
    padding: 10px 15px; /* 输入框内边距 */
    border-radius: 25px;
    outline: none;
    transition: border-color 0.3s ease, width 0.3s ease;
    width: 200px; /* 默认宽度 */
}

.search-box input[type="search"]:focus {
    border-color: #007bff;
    width: 220px; /* 聚焦时宽度增加 */
}

.search-box button {
    background: none;
    border: none;
    position: absolute;
    right: 10px;
    cursor: pointer;
    color: #555;
    font-size: 18px;
    transition: color 0.3s ease;
}

.search-box button:hover {
    color: #007bff;
}

/* 通用按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 25px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 600;
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, transform 0.2s ease;
    cursor: pointer;
    border: 1px solid transparent;
    text-align: center;
    white-space: nowrap;
}

.btn-primary {
    background-color: #007bff;
    color: #fff;
    border-color: #007bff;
}

.btn-primary:hover {
    background-color: #0056b3;
    border-color: #0056b3;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: #6c757d;
    color: #fff;
    border-color: #6c757d;
}

.btn-secondary:hover {
    background-color: #5a6268;
    border-color: #5a6268;
    transform: translateY(-2px);
}

/* 汉堡菜单切换按钮 (移动端可见) */
.menu-toggle {
    display: none; /* 桌面端隐藏 */
    background: none;
    border: none;
    cursor: pointer;
    padding: 10px;
    position: absolute;
    right: 15px;
    top: 25px;
    z-index: 1001;
}

.menu-toggle .icon-bar {
    display: block;
    width: 30px;
    height: 3px;
    background-color: #333;
    margin: 6px 0;
    transition: all 0.3s ease;
    border-radius: 2px;
}

/* 4. 页脚样式 */
.main-footer {
    background-color: #2c3e50; /* 深色背景 */
    color: #ecf0f1; /* 浅色文本 */
    padding-top: 50px;
    font-size: 0.9em;
}

.main-footer .footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); /* 响应式网格布局 */
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.15); /* 分隔线 */
}

.main-footer h3 {
    color: #fff;
    margin-bottom: 20px;
    font-size: 1.2em;
    position: relative;
}

.main-footer h3::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: -8px;
    width: 40px;
    height: 3px;
    background-color: #007bff;
    border-radius: 2px;
}

.main-footer p {
    margin-bottom: 12px;
}

.main-footer ul {
    list-style: none;
}

.main-footer ul li a {
    color: #bdc3c7; /* 链接颜色 */
    text-decoration: none;
    display: block;
    padding: 6px 0;
    transition: color 0.3s ease, transform 0.2s ease;
}

.main-footer ul li a:hover {
    color: #007bff;
    transform: translateX(5px);
}

.main-footer .social-links a {
    color: #ecf0f1;
    font-size: 1.8em;
    margin-right: 18px;
    transition: color 0.3s ease, transform 0.2s ease;
    display: inline-block;
}

.main-footer .social-links a:hover {
    color: #007bff;
    transform: translateY(-3px);
}

.main-footer .contact-info i {
    margin-right: 10px;
    color: #007bff;
    font-size: 1.1em;
}

.main-footer .contact-info a {
    color: #bdc3c7;
    text-decoration: none;
}

.main-footer .contact-info a:hover {
    color: #007bff;
    text-decoration: underline;
}

.main-footer .newsletter-form {
    display: flex;
    margin-top: 20px;
}

.main-footer .newsletter-form input[type="email"] {
    flex-grow: 1;
    padding: 12px;
    border: none;
    border-radius: 5px 0 0 5px;
    outline: none;
    background-color: rgba(255, 255, 255, 0.1);
    color: #fff;
}

.main-footer .newsletter-form input[type="email"]::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

.main-footer .newsletter-form .btn-secondary {
    border-radius: 0 5px 5px 0;
    padding: 12px 20px;
    background-color: #007bff;
    border-color: #007bff;
    font-weight: 500;
}

.main-footer .newsletter-form .btn-secondary:hover {
    background-color: #0056b3;
    border-color: #0056b3;
}

.main-footer .footer-bottom {
    text-align: center;
    padding: 25px 0;
    margin-top: 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
}

.main-footer .footer-bottom p {
    margin: 8px 0;
    color: #bdc3c7;
}

.main-footer .footer-bottom a {
    color: #007bff;
    text-decoration: none;
    margin: 0 8px;
}

.main-footer .footer-bottom a:hover {
    text-decoration: underline;
}

.main-footer .back-to-top a {
    color: #ecf0f1;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.main-footer .back-to-top a:hover {
    color: #007bff;
}

.main-footer .back-to-top i {
    margin-right: 8px;
    font-size: 1.1em;
}

/* 5. 响应式设计 - 针对不同屏幕尺寸进行调整 */
@media (max-width: 992px) {
    .main-nav .nav-list {
        gap: 20px;
    }
    .main-header .search-box {
        width: 150px;
    }
    .main-header .search-box input[type="search"] {
        width: 100%;
    }
    .main-header .header-actions {
        gap: 10px;
    }
}

@media (max-width: 768px) {
    .main-header .container {
        flex-direction: column;
        align-items: flex-start;
    }

    .main-header .logo {
        width: 100%;
        text-align: center;
        margin-bottom: 20px;
    }

    .main-nav {
        order: 3; /* 导航在移动端移到下方 */
        width: 100%;
        text-align: left;
        position: relative;
    }

    .main-nav .menu-toggle {
        display: block;
        position: absolute;
        right: 15px;
        top: 0px; /* 调整位置 */
        transform: translateY(-50%);
    }

    .main-nav .nav-list {
        flex-direction: column;
        width: 100%;
        display: none; /* 默认隐藏 */
        background-color: #f8f9fa;
        border-top: 1px solid #eee;
        padding: 10px 0;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.05);
    }

    .main-nav .nav-list.active {
        display: flex; /* 激活时显示 */
    }

    .main-nav .nav-item {
        width: 100%;
        border-bottom: 1px solid #eee;
    }

    .main-nav .nav-item:last-child {
        border-bottom: none;
    }

    .main-nav .nav-item .nav-link {
        padding: 15px 25px;
        display: block;
        width: 100%;
    }

    .main-nav .nav-item .nav-link::after {
        display: none; /* 移动端不显示下划线动画 */
    }

    .main-nav .dropdown-menu {
        position: static;
        box-shadow: none;
        transform: none;
        opacity: 1;
        visibility: visible;
        background-color: #e9ecef;
        padding-left: 30px;
        border-radius: 0;
    }

    .main-nav .dropdown-menu li a {
        padding: 10px 15px;
    }

    .header-actions {
        order: 2;
        width: 100%;
        justify-content: center;
        margin-bottom: 20px;
    }

    .search-box {
        width: calc(100% - 100px);
        margin-right: 10px;
    }
    .search-box input[type="search"] {
        width: 100%;
    }

    .main-footer .footer-grid {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .main-footer h3::after {
        left: 50%;
        transform: translateX(-50%);
    }

    .main-footer .social-links {
        margin-top: 20px;
    }

    .main-footer .newsletter-form {
        flex-direction: column;
        align-items: center;
    }

    .main-footer .newsletter-form input[type="email"] {
        border-radius: 5px;
        margin-bottom: 15px;
        width: 90%;
    }

    .main-footer .newsletter-form .btn-secondary {
        border-radius: 5px;
        width: 90%;
    }

    .main-footer .footer-bottom {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .main-header .logo img {
        height: 45px;
    }
    .btn {
        padding: 10px 20px;
        font-size: 0.9em;
    }
    .main-nav .menu-toggle {
        top: 15px;
    }
    .search-box input[type="search"] {
        width: 100%;
    }
}

/* 更多通用样式，例如表格、卡片、提示框等，可根据项目需求添加 */
/*
.card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
    padding: 25px;
    margin-bottom: 30px;
    transition: transform 0.3s ease;
}
.card:hover {
    transform: translateY(-5px);
}
.alert {
    padding: 18px;
    border-radius: 6px;
    margin-bottom: 25px;
    font-weight: 500;
}
.alert-success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}
.alert-error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}
*/
/* 移动端内容区防溢出（系统追加，请勿删除） */
@media (max-width: 768px) {
  .page-content img {
    max-width: 100% !important;
    height: auto !important;
    display: block;
  }
  .page-content {
    overflow-x: hidden;
    max-width: 100%;
  }
  body {
    overflow-x: hidden;
  }
}