/* 全局样式 */
:root {
    --primary-color: #4a90e2;    /* 主色调 */
    --secondary-color: #2c3e50;  /* 次要色调 */
    --accent-color: #e74c3c;     /* 强调色 */
    --text-color: #333;          /* 文本颜色 */
    --light-bg: #f5f6fa;         /* 浅色背景 */
    --white: #ffffff;            /* 白色 */
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1); /* 阴影效果 */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--light-bg);
}

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

/* 导航栏样式 */
.navbar {
    background-color: var(--white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-list {
    display: flex;
    list-style: none;
    padding: 0;
    margin: 0;
}

.nav-list li {
    margin: 0;
    padding: 0;
}

.nav-list a {
    display: block;
    padding: 20px;
    color: var(--secondary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-list a:hover,
.nav-list a.active {
    color: var(--primary-color);
}

/* 按钮样式 */
.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 12px 24px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: background-color 0.3s ease, transform 0.2s ease;
    border: none;
    cursor: pointer;
    text-align: center;
}

.btn:hover {
    background-color: #3a7bc8;
    transform: translateY(-2px);
}

.btn:active {
    transform: translateY(0);
}

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

.btn-secondary:hover {
    background-color: rgba(74, 144, 226, 0.1);
}

/* 标题样式 */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 15px;
}

.page-title {
    font-size: 2em;
    color: var(--secondary-color);
    text-align: center;
    margin-bottom: 40px;
    position: relative;
    padding-bottom: 15px;
}

.page-title::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background-color: var(--primary-color);
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-list {
        flex-direction: column;
    }
    
    .nav-list a {
        padding: 15px;
    }
    
    .btn {
        padding: 10px 20px;
    }
    
    .page-title {
        font-size: 1.8em;
    }
}

/* 辅助类 */
.text-center {
    text-align: center;
}

.mt-20 {
    margin-top: 20px;
}

.mb-20 {
    margin-bottom: 20px;
}

.p-20 {
    padding: 20px;
}

/* 卡片样式 */
.card {
    background: white;
    border-radius: 10px;
    box-shadow: var(--shadow);
    padding: 20px;
    margin-bottom: 20px;
}

/* 表单样式 */
input, textarea, select {
    font-family: inherit;
    font-size: inherit;
}

/* 图片样式 */
img {
    max-width: 100%;
    height: auto;
}

/* 链接样式 */
a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #3a7bc8;
}

/* 页脚样式 */
footer {
    background: var(--secondary-color);
    color: white;
    padding: 50px 0 20px;
    margin-top: 50px;
}

.footer-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-links h3 {
    margin-bottom: 20px;
    color: #fff;
}

.footer-links ul {
    list-style: none;
    padding: 0;
}

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

.footer-links a {
    color: rgba(255,255,255,0.8);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.6);
}