/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", sans-serif;
}

:root {
    --primary: #409eff;
    --primary-dark: #337ecc;
    --light: #f5f7fa;
    --dark: #333;
    --gray: #666;
}

body {
    color: var(--dark);
    line-height: 1.6;
}

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

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

ul {
    list-style: none;
}

.btn {
    display: inline-block;
    padding: 12px 30px;
    background: var(--primary);
    color: white;
    border-radius: 50px;
    font-size: 16px;
    transition: 0.3s;
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

.section {
    padding: 80px 0;
}

.bg-light {
    background: var(--light);
}

.section-title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 50px;
    color: var(--dark);
    position: relative;
}

.section-title::after {
    content: "";
    width: 60px;
    height: 4px;
    background: var(--primary);
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

/* 导航栏 */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: white;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    z-index: 999;
    padding: 15px 0;
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.logo h1 {
    font-size: 24px;
    color: var(--primary);
}

.nav {
    display: flex;
    gap: 25px;
}

.nav-link {
    font-size: 16px;
    color: var(--dark);
    transition: 0.3s;
}

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

/* 横幅 */
.banner {
    margin-top: 80px;
    padding: 100px 0;
    background: linear-gradient(135deg, #f0f9ff 0%, #e6f7ff 100%);
}

.banner .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 30px;
}

.banner-content {
    flex: 1;
    min-width: 300px;
}

.banner-content h2 {
    font-size: 42px;
    margin-bottom: 20px;
    line-height: 1.3;
}

.banner-content p {
    font-size: 18px;
    color: var(--gray);
    margin-bottom: 30px;
}

.banner-img {
    flex: 1;
    min-width: 300px;
}

.banner-img img {
    width: 100%;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

/* 产品介绍 */
.product-wrap {
    display: flex;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
}

.product-img {
    flex: 1;
    min-width: 300px;
}

.product-img img {
    width: 100%;
    border-radius: 10px;
}

.product-text {
    flex: 1;
    min-width: 300px;
    font-size: 16px;
    color: var(--gray);
    line-height: 1.8;
}

.product-text p {
    margin-bottom: 15px;
}

/* 功能亮点 */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 3px 15px rgba(0,0,0,0.05);
    transition: 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.feature-card img {
    width: 80px;
    height: 80px;
    margin-bottom: 20px;
    object-fit: contain;
}

.feature-card h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.feature-card p {
    color: var(--gray);
}

/* 使用教程 */
.tutorial-step {
    display: flex;
    justify-content: center;
    gap: 40px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.step {
    text-align: center;
}

.step span {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    line-height: 40px;
    font-size: 18px;
    margin-bottom: 10px;
}

.tutorial-img {
    text-align: center;
}

.tutorial-img img {
    max-width: 600px;
    width: 100%;
    border-radius: 10px;
}

/* 关于我们 */
.about-text {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
    font-size: 17px;
    color: var(--gray);
    line-height: 1.8;
}

/* 联系我们 */
.contact-info {
    text-align: center;
    font-size: 18px;
    color: var(--gray);
}

.contact-info p {
    margin-bottom: 10px;
}

/* 下载中心 */
.download-main {
    margin-top: 120px;
    padding: 60px 0;
}

.download-desc {
    text-align: center;
    color: var(--gray);
    margin-bottom: 40px;
    font-size: 17px;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-bottom: 60px;
}

.download-card {
    background: white;
    padding: 40px 20px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 3px 15px rgba(0,0,0,0.08);
}

.card-icon {
    font-size: 40px;
    margin-bottom: 20px;
}

.download-card h3 {
    font-size: 20px;
    margin-bottom: 10px;
}

.download-card p {
    color: var(--gray);
    margin-bottom: 25px;
    font-size: 14px;
}

.download-btn {
    padding: 10px 25px;
    background: var(--primary);
    color: white;
    border-radius: 50px;
    transition: 0.3s;
}

.download-btn:hover {
    background: var(--primary-dark);
}

.update-log {
    background: var(--light);
    padding: 30px;
    border-radius: 10px;
}

.update-log h3 {
    margin-bottom: 20px;
    color: var(--dark);
}

.update-log li {
    margin-bottom: 8px;
    color: var(--gray);
    position: relative;
    padding-left: 15px;
}

.update-log li::before {
    content: "•";
    color: var(--primary);
    position: absolute;
    left: 0;
}

/* 页脚 */
.footer {
    background: var(--dark);
    color: white;
    text-align: center;
    padding: 30px 0;
    margin-top: 50px;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav {
        gap: 15px;
    }
    .banner-content h2 {
        font-size: 32px;
    }
    .section-title {
        font-size: 26px;
    }
}