/* ============================================
   公共样式表 - common.css
   包含所有页面共用的导航栏、页脚、基础样式
   所有HTML页面需首先引用此文件
   ============================================ */

/* ============================================
   全局重置与基础样式
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Microsoft YaHei', 'PingFang SC', 'Helvetica Neue', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background: #fff;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

a {
    text-decoration: none;
    color: inherit;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ============================================
   导航栏样式
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(26, 42, 74, 0.97);
    padding: 14px 0;
    transition: all 0.3s ease;
    border-bottom: 1px solid rgba(255,255,255,0.06);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: 700;
    color: #fff;
    letter-spacing: 2px;
    display: inline-block;
    position: relative;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.logo::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, #f5a623, transparent);
    opacity: 0.6;
}

.logo span {
    color: #f5a623;
    font-weight: 800;
    position: relative;
}

.logo span::before {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 50%;
    transform: translateX(-50%);
    width: 80%;
    height: 2px;
    background: #f5a623;
    border-radius: 1px;
}

/* 导航电话 */
.nav-phone {
    display: flex;
    align-items: center;
}

.phone-link {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #fff;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.3s;
    padding: 8px 16px;
    border-radius: 50px;
    background: rgba(255,255,255,0.1);
}

.phone-link:hover {
    background: rgba(245,166,35,0.9);
    color: #fff;
    transform: translateY(-2px);
}

.phone-icon {
    width: 18px;
    height: 18px;
    color: currentColor;
}

/* 桌面导航 */
.nav {
    display: flex;
    list-style: none;
    gap: 24px;
}

.nav a {
    color: rgba(255,255,255,0.8);
    font-size: 14px;
    transition: color 0.3s;
    position: relative;
    padding: 4px 0;
}

.nav a::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background: #f5a623;
    transition: width 0.3s;
}

.nav a:hover {
    color: #f5a623;
}

.nav a:hover::after {
    width: 100%;
}

/* 移动端汉堡菜单按钮 */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 28px;
    height: 20px;
    cursor: pointer;
    z-index: 1001;
}

.menu-toggle span {
    display: block;
    width: 100%;
    height: 3px;
    background: #fff;
    border-radius: 2px;
    transition: all 0.3s;
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(6px, 6px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(6px, -6px);
}

/* 移动端导航遮罩层 */
.nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 999;
}

.nav-overlay.active {
    display: block;
}

/* ============================================
   下拉菜单样式
   ============================================ */
.dropdown {
    position: relative;
}

.dropdown-toggle {
    cursor: pointer;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 600px;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
    padding: 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.25s ease;
    z-index: 1001;
}

.dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

/* 两列布局 */
.dropdown-menu.two-columns {
    display: flex;
    gap: 0;
}

.dropdown-column {
    flex: 1;
    padding: 16px 20px;
    background: #fff;
    border-radius: 0;
}

.dropdown-column:first-child {
    border-right: 1px solid #eee;
    border-radius: 8px 0 0 8px;
}

.dropdown-column:last-child {
    border-radius: 0 8px 8px 0;
}

.column-title {
    font-size: 14px;
    font-weight: 700;
    color: #1a2a4a;
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid #f5a623;
}

.column-list {
    list-style: none;
}

.column-list li {
    margin-bottom: 0;
}

.column-list a {
    display: block;
    padding: 8px 12px;
    color: #555;
    font-size: 13px;
    line-height: 1.5;
    transition: all 0.2s;
    border-radius: 4px;
}

.column-list a:hover {
    background: #f8f9fc;
    color: #f5a623;
}

/* 单列下拉菜单（默认） */
.dropdown-menu:not(.two-columns) a {
    display: block;
    padding: 10px 20px;
    color: #333;
    font-size: 14px;
    line-height: 1.5;
    transition: all 0.2s;
}

.dropdown-menu:not(.two-columns) a:hover {
    background: #f8f9fc;
    color: #f5a623;
}

/* 二级子菜单 */
.dropdown-submenu {
    position: relative;
}

.dropdown-submenu > a::after {
    content: '›';
    position: absolute;
    right: 15px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 16px;
    color: #888;
}

.dropdown-submenu > a {
    padding-right: 35px !important;
}

.dropdown-submenu .dropdown-submenu {
    top: 0;
    left: 100%;
    margin-left: 4px;
}

.dropdown-submenu:hover > .dropdown-submenu {
    opacity: 1;
    visibility: visible;
    transform: translateX(0);
}

.dropdown-submenu .dropdown-submenu {
    opacity: 0;
    visibility: hidden;
    transform: translateX(-10px);
    transition: all 0.25s ease;
}

/* ============================================
   页脚样式
   ============================================ */
.footer {
    background: #1a2a4a;
    color: rgba(255,255,255,0.7);
    padding: 60px 0 0;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-col h4 {
    color: #fff;
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 18px;
}

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

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: rgba(255,255,255,0.55);
    font-size: 13px;
    transition: color 0.3s;
}

.footer-col ul li a:hover {
    color: #f5a623;
}

.footer-bottom {
    padding: 20px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    font-size: 13px;
    color: rgba(255,255,255,0.4);
}

.footer-bottom-links {
    display: flex;
    gap: 20px;
}

.footer-bottom-links a {
    color: rgba(255,255,255,0.4);
    font-size: 13px;
    transition: color 0.3s;
}

.footer-bottom-links a:hover {
    color: #f5a623;
}

/* ============================================
   移动端响应式样式（导航+页脚）
   ============================================ */
@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }
    
    .nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 320px;
        height: 100vh;
        background: #1a2a4a;
        flex-direction: column;
        gap: 0;
        padding: 70px 0 20px;
        transition: right 0.3s ease;
        overflow-y: auto;
        box-shadow: -4px 0 20px rgba(0,0,0,0.2);
    }
    
    .nav.active {
        right: 0;
    }
    
    .nav li {
        border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    
    .nav a {
        display: block;
        padding: 16px 24px;
        font-size: 15px;
        color: rgba(255,255,255,0.9);
    }
    
    .nav a::after {
        display: none;
    }
    
    /* 移动端下拉菜单 */
    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background: #fff;
        padding: 0;
        min-width: 100%;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }
    
    .dropdown-menu.active {
        max-height: 1000px;
    }
    
    .dropdown-menu.two-columns {
        flex-direction: column;
        gap: 0;
    }
    
    .dropdown-column {
        padding: 12px 16px;
        border-right: none;
        border-bottom: 1px solid #eee;
    }
    
    .dropdown-column:first-child,
    .dropdown-column:last-child {
        border-radius: 0;
    }
    
    .column-title {
        font-size: 13px;
        color: #f5a623;
        margin-bottom: 8px;
    }
    
    .column-list a {
        padding: 10px 16px;
        font-size: 14px;
        color: #333333;
        background: #f8f9fc;
        border-radius: 4px;
    }
    
    .column-list a:hover {
        background: rgba(245,166,35,0.1);
        color: #f5a623;
    }
    
    /* 移动端导航电话 */
    .nav-phone {
        display: flex;
        align-items: center;
        padding: 16px 24px;
        border-top: 1px solid rgba(255,255,255,0.06);
    }
    
    .phone-link {
        width: 100%;
        justify-content: center;
    }
    
    /* 移动端页脚 */
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 30px 20px;
    }
    
    .footer-col h4 {
        font-size: 15px;
        margin-bottom: 12px;
    }
    
    .footer-col ul li {
        margin-bottom: 8px;
    }
    
    .footer-col ul li a {
        font-size: 12px;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
        padding: 15px 0;
    }
    
    .footer-bottom-links {
        gap: 15px;
    }
}

@media (max-width: 480px) {
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px 10px;
    }
    
    .footer-col h4 {
        font-size: 14px;
        margin-bottom: 10px;
    }
    
    .footer-col ul li {
        margin-bottom: 6px;
    }
    
    .footer-col ul li a {
        font-size: 12px;
    }
    
    .footer-bottom-links {
        justify-content: center;
    }
}