/* 通用样式 */
:root {
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

html {
    scroll-behavior: smooth;
}

body {
    background-color: #f9f9f9;
    color: #333;
    line-height: 1.6;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 5%;
}

.nav-logo a {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--secondary-color);
    text-decoration: none;
    transition: var(--transition);
}

.nav-logo a:hover {
    color: var(--primary-color);
}

.nav-menu {
    display: flex;
}

.nav-list {
    display: flex;
    list-style: none;
}

.nav-item {
    position: relative;
    margin-left: 1.5rem;
}

.nav-link {
    color: var(--dark-color);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 0;
    position: relative;
    transition: var(--transition);
    display: flex;
    align-items: center;
}

.nav-link:hover {
    color: var(--primary-color);
}

.nav-link.active {
    color: var(--primary-color);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* 下拉菜单 */
.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    background-color: white;
    min-width: 200px;
    box-shadow: var(--shadow);
    border-radius: 5px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: var(--transition);
    list-style: none;
    padding: 0.5rem 0;
    z-index: 1001;
}

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

.dropdown-menu li {
    padding: 0;
}

.dropdown-menu a {
    display: block;
    padding: 0.7rem 1.5rem;
    color: var(--dark-color);
    text-decoration: none;
    transition: var(--transition);
}

.dropdown-menu a:hover {
    background-color: #f5f5f5;
    color: var(--primary-color);
}

/* 移动端导航切换按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background-color: var(--dark-color);
    margin: 3px 0;
    transition: var(--transition);
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background-color: #2980b9;
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.btn-secondary {
    background-color: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

/* 页脚样式 */
.footer {
    background-color: var(--secondary-color);
    color: white;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--light-color);
}

.footer-section p {
    margin-bottom: 1rem;
    opacity: 0.8;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background-color: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    color: white;
    transition: var(--transition);
}

.social-links a:hover {
    background-color: var(--primary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 1.5rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    opacity: 0.7;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        background-color: white;
        flex-direction: column;
        text-align: center;
        transition: var(--transition);
        box-shadow: 0 10px 10px rgba(0, 0, 0, 0.1);
        padding: 2rem 0;
    }

    .nav-menu.active {
        left: 0;
    }

    .nav-list {
        flex-direction: column;
    }

    .nav-item {
        margin: 0.5rem 0;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active .bar:nth-child(1) {
        transform: rotate(-45deg) translate(-5px, 6px);
    }

    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active .bar:nth-child(3) {
        transform: rotate(45deg) translate(-5px, -6px);
    }

    .dropdown-menu {
        position: static;
        opacity: 1;
        visibility: visible;
        transform: none;
        box-shadow: none;
        background-color: transparent;
        padding-left: 1rem;
        display: none;
    }

    .dropdown.active .dropdown-menu {
        display: block;
    }
}

.social-links a {
    text-decoration: none; /* 移除下划线 */
}