/* ==== 基础样式重置 ==== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

body {
    font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
    color: #333;
    line-height: 1.6;
    background-color: #fff;
}

a {
    text-decoration: none;
    color: #333;
    transition: color 0.3s;
}

a:hover {
    color: #1890ff;
}

ul, ol {
    list-style: none;
}

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

/* ==== 布局 ==== */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

.section {
    padding: 80px 0;
}

.bg-light {
    background-color: #f8f9fa;
}

/* ==== 标题样式 ==== */
.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-title {
    position: relative;
    font-size: 2.5rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: #222;
}

.section-subtitle {
    font-size: 1.1rem;
    color: #777;
    max-width: 600px;
    margin: 0 auto;
}

.section-footer {
    text-align: center;
    margin-top: 40px;
}

/* ==== 按钮样式 ==== */
.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 4px;
    font-weight: 500;
    font-size: 1rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn--primary {
    background-color: #1890ff;
    color: #fff;
}

.btn--primary:hover {
    background-color: #0c7cd5;
    color: #fff;
}

.btn--secondary {
    background-color: transparent;
    color: #1890ff;
    border: 1px solid #1890ff;
}

.btn--secondary:hover {
    background-color: #1890ff;
    color: #fff;
}

.btn--large {
    padding: 14px 32px;
    font-size: 1.1rem;
}

/* ==== 卡片样式 ==== */
.card {
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.05);
    overflow: hidden;
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

/* ==== 动画效果 ==== */
[data-aos] {
    opacity: 0;
    transition-property: opacity, transform;
    transition-duration: 0.8s;
}

[data-aos="fade-up"] {
    transform: translateY(50px);
}

[data-aos="fade-up"].aos-animate {
    opacity: 1;
    transform: translateY(0);
}

/* ==== 返回顶部按钮 ==== */
.back-to-top {
    position: fixed;
    right: 30px;
    bottom: 30px;
    width: 40px;
    height: 40px;
    background-color: #1890ff;
    color: #fff;
    text-align: center;
    line-height: 40px;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 99;
}

.back-to-top.show {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: #0c7cd5;
}

/* ==== 响应式设计 ==== */
@media (max-width: 992px) {
    .section {
        padding: 60px 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .section {
        padding: 50px 0;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .btn--large {
        padding: 12px 28px;
        font-size: 1rem;
    }
}

@media (max-width: 576px) {
    .section {
        padding: 40px 0;
    }
    
    .section-title {
        font-size: 1.6rem;
    }
    
    .section-subtitle {
        font-size: 1rem;
    }
}