/* 全局样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", sans-serif;
}

/* 颜色变量定义 */
:root {
    --sky-blue: #87CEEB;      /* 天空蓝 */
    --milk-white: #F5F5F5;    /* 奶白色 */
    --deep-blue: #4169E1;     /* 深蓝（辅助色） */
    --text-color: #333333;    /* 文字颜色 */
    --light-gray: #E0E0E0;    /* 浅灰色 */
}

/* 页面基础样式 */
body {
    background-color: var(--milk-white);
    color: var(--text-color);
    line-height: 1.6;
}

/* 容器居中 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 头部样式 */
header {
    background-color: white;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    padding: 15px 0;
}

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

.logo {
    display: flex;
    align-items: center;
}

.logo img {
    height: 50px;
    margin-right: 10px;
}

.logo-text {
    font-size: 24px;
    font-weight: bold;
    color: var(--deep-blue);
}

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

nav ul li {
    margin-left: 30px;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-color);
    font-size: 16px;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: var(--deep-blue);
}

/* 主要内容区样式 */
main {
    padding: 50px 0;
}

.section-title {
    font-size: 32px;
    color: var(--deep-blue);
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

.section-title::after {
    content: "";
    display: block;
    width: 80px;
    height: 3px;
    background-color: var(--sky-blue);
    margin: 10px auto;
}

/* 首页banner */
.banner {
    background: linear-gradient(135deg, var(--sky-blue), var(--deep-blue));
    color: white;
    padding: 80px 0;
    text-align: center;
    border-radius: 10px;
    margin-bottom: 60px;
}

.banner h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.banner p {
    font-size: 18px;
    max-width: 800px;
    margin: 0 auto 30px;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    background-color: white;
    color: var(--deep-blue);
    text-decoration: none;
    border-radius: 50px;
    font-weight: bold;
    transition: all 0.3s;
    border: 2px solid white;
}

.btn:hover {
    background-color: transparent;
    color: white;
}

/* 产品介绍样式 */
.product-intro {
    margin-bottom: 60px;
}

.intro-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.intro-item {
    background-color: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s;
}

.intro-item:hover {
    transform: translateY(-5px);
}

.intro-item h3 {
    color: var(--deep-blue);
    margin-bottom: 15px;
    font-size: 20px;
}

/* 下载页样式 */
.download-section {
    background-color: white;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.05);
    text-align: center;
    margin-bottom: 40px;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
    position: relative;
    z-index: 2;
}

.download-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 10px 25px;
    background-color: var(--sky-blue);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: background-color 0.3s;
}

.download-btn i {
    margin-right: 8px;
    font-size: 18px;
}

.download-btn:hover {
    background-color: var(--deep-blue);
}

.product-image {
    width: 100%;
    max-width: 800px;
    height: auto;
    border-radius: 10px;
    margin: -40px auto 30px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    position: relative;
    z-index: 1;
}

/* 版本更新样式 */
.version-update {
    margin-bottom: 60px;
}

.version-list {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0,0,0,0.05);
    overflow: hidden;
}

.version-item {
    padding: 20px;
    border-bottom: 1px solid var(--light-gray);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.version-number {
    font-weight: bold;
    color: var(--deep-blue);
}

.version-date {
    color: #999;
    font-size: 14px;
}

/* 短文章样式 */
.articles {
    margin-bottom: 60px;
}

.article-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.article-item {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}

.article-item h4 {
    color: var(--deep-blue);
    margin-bottom: 10px;
    font-size: 16px;
}

.article-item p {
    font-size: 14px;
    color: #666;
}

/* 404页面样式 */
.error-page {
    text-align: center;
    padding: 80px 0;
}

.error-page h1 {
    font-size: 120px;
    color: var(--deep-blue);
    margin-bottom: 20px;
}

.error-page h2 {
    font-size: 36px;
    margin-bottom: 30px;
}

.error-page p {
    font-size: 18px;
    margin-bottom: 40px;
    color: #666;
}

/* 页脚样式 */
footer {
    background-color: var(--deep-blue);
    color: white;
    padding: 40px 0 20px;
    margin-top: 60px;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    margin-bottom: 30px;
}

.footer-col {
    flex: 1;
    min-width: 200px;
    margin-bottom: 20px;
    padding-right: 20px;
}

.footer-col h3 {
    font-size: 18px;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h3::after {
    content: "";
    display: block;
    width: 40px;
    height: 2px;
    background-color: var(--sky-blue);
    position: absolute;
    bottom: 0;
    left: 0;
}

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

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

.footer-col ul li a {
    color: #ddd;
    text-decoration: none;
    transition: color 0.3s;
}

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

.copyright {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid rgba(255,255,255,0.2);
    font-size: 14px;
    color: #ccc;
}

/* 响应式适配 */
@media (max-width: 992px) {
    .intro-list {
        grid-template-columns: 1fr;
    }
    .article-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 20px;
    }
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    nav ul li {
        margin: 10px 15px;
    }
    .banner h1 {
        font-size: 36px;
    }
    .download-buttons {
        flex-wrap: wrap;
    }
    .article-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 576px) {
    .section-title {
        font-size: 24px;
    }
    .banner {
        padding: 50px 0;
    }
    .error-page h1 {
        font-size: 80px;
    }
    .error-page h2 {
        font-size: 28px;
    }
}