/* ========== 全局样式 ========== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0066ff;
    --primary-dark: #0052cc;
    --text-color: #333;
    --text-light: #666;
    --bg-light: #f5f5f5;
    --border-color: #ddd;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    color: var(--text-color);
    line-height: 1.6;
    background-color: #fff;
}

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

/* ========== 按钮样式 ========== */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 16px;
}

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

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

.btn-download {
    background-color: var(--primary-color);
    color: white;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 20px 30px;
    font-size: 18px;
    border-radius: 8px;
}

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

.download-icon {
    font-size: 28px;
}

/* ========== 顶部导航 ========== */
.header {
    background-color: white;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

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

.logo h1 {
    font-size: 24px;
    color: var(--primary-color);
    margin: 0;
}

.logo p {
    font-size: 12px;
    color: var(--text-light);
    margin: 0;
}

.nav-desktop {
    display: flex;
    gap: 30px;
    align-items: center;
}

.nav-desktop a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-color);
}

/* ========== 移动端菜单 ========== */
.nav-mobile {
    position: fixed;
    right: -300px;
    top: 0;
    width: 300px;
    height: 100vh;
    background-color: white;
    box-shadow: -2px 0 8px rgba(0, 0, 0, 0.1);
    z-index: 200;
    transition: right 0.3s ease;
    overflow-y: auto;
    padding-top: 60px;
}

.nav-mobile.active {
    right: 0;
}

.nav-mobile a {
    display: block;
    padding: 15px 20px;
    text-decoration: none;
    color: var(--text-color);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s ease;
}

.nav-mobile a:hover {
    background-color: var(--bg-light);
    color: var(--primary-color);
}

.close-menu {
    position: absolute;
    top: 15px;
    right: 15px;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-color);
}

.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    z-index: 150;
    display: none;
}

.overlay.active {
    display: block;
}

/* ========== Banner ========== */
.banner {
    background: linear-gradient(135deg, var(--primary-color) 0%, #0052cc 100%);
    color: white;
    padding: 80px 20px;
    text-align: center;
}

.banner-content h2 {
    font-size: 48px;
    margin-bottom: 20px;
    font-weight: 700;
}

.banner-content p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
}

.banner .btn {
    font-size: 18px;
    padding: 15px 40px;
}

/* ========== 核心功能模块 ========== */
.features {
    padding: 80px 20px;
    background-color: #f9f9f9;
}

.features h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.feature-card {
    background-color: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.feature-card h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ========== 下载模块 ========== */
.download {
    padding: 80px 20px;
    background-color: white;
}

.download h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 15px;
    color: var(--text-color);
}

.download-subtitle {
    text-align: center;
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 40px;
}

.download-buttons {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.download-info {
    text-align: center;
    padding: 20px;
    background-color: var(--bg-light);
    border-radius: 6px;
    color: var(--text-light);
    font-size: 16px;
}

/* ========== 应用场景模块 ========== */
.scenes {
    padding: 80px 20px;
    background-color: #f9f9f9;
}

.scenes h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-color);
}

.scenes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.scene-card {
    background-color: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.scene-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.scene-card h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--text-color);
}

.scene-card p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ========== 系统要求模块 ========== */
.requirements {
    padding: 80px 20px;
    background-color: white;
}

.requirements h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-color);
}

.requirements-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.requirement-item {
    background-color: var(--bg-light);
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

.requirement-item h3 {
    font-size: 20px;
    margin-bottom: 15px;
    color: var(--text-color);
}

.requirement-item ul {
    list-style: none;
}

.requirement-item li {
    padding: 8px 0;
    color: var(--text-light);
    line-height: 1.8;
}

.requirement-item li:before {
    content: "✓ ";
    color: var(--primary-color);
    font-weight: bold;
    margin-right: 8px;
}

/* ========== 常见问题模块 ========== */
.faq {
    padding: 80px 20px;
    background-color: #f9f9f9;
}

.faq h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-color);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: 15px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: white;
    overflow: hidden;
}

.faq-question {
    width: 100%;
    padding: 20px;
    background-color: white;
    border: none;
    text-align: left;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--text-color);
}

.faq-question:hover {
    background-color: var(--bg-light);
    color: var(--primary-color);
}

.faq-answer {
    display: none;
    padding: 20px;
    background-color: var(--bg-light);
    border-top: 1px solid var(--border-color);
    color: var(--text-light);
    line-height: 1.8;
}

.faq-answer.active {
    display: block;
}

/* ========== 使用教程模块 ========== */
.tutorial {
    padding: 80px 20px;
    background-color: white;
}

.tutorial h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-color);
}

.tutorial-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.step {
    background-color: var(--bg-light);
    padding: 30px;
    border-radius: 8px;
    text-align: center;
    transition: all 0.3s ease;
}

.step:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}

.step-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: white;
    border-radius: 50%;
    font-size: 24px;
    font-weight: bold;
    margin-bottom: 15px;
}

.step h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--text-color);
}

.step p {
    color: var(--text-light);
    line-height: 1.7;
}

/* ========== 友情链接模块 ========== */
.links {
    padding: 80px 20px;
    background-color: #f9f9f9;
}

.links h2 {
    text-align: center;
    font-size: 36px;
    margin-bottom: 50px;
    color: var(--text-color);
}

.links-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    max-width: 900px;
    margin: 0 auto;
}

.link-item {
    display: block;
    padding: 15px;
    text-align: center;
    background-color: white;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 500;
    transition: all 0.3s ease;
}

.link-item:hover {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

/* ========== 底部 ========== */
.footer {
    background-color: #2c3e50;
    color: white;
    padding: 60px 20px 20px;
}

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

.footer-section h4 {
    font-size: 18px;
    margin-bottom: 15px;
    color: white;
}

.footer-section p {
    color: #bbb;
    line-height: 1.8;
    margin-bottom: 10px;
}

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

.footer-section ul li {
    margin-bottom: 8px;
}

.footer-section a {
    color: #bbb;
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #444;
    color: #999;
}

.footer-bottom a {
    color: #999;
    text-decoration: none;
}

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

/* ========== 返回顶部按钮 ========== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background-color: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 24px;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 99;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-lg);
}

.back-to-top:hover {
    background-color: var(--primary-dark);
    transform: translateY(-3px);
}

.back-to-top.show {
    display: flex;
}

/* ========== 响应式设计 ========== */
@media (max-width: 768px) {
    .nav-desktop {
        display: none;
    }

    .menu-toggle {
        display: block;
    }

    .banner-content h2 {
        font-size: 32px;
    }

    .banner-content p {
        font-size: 16px;
    }

    .features h2,
    .scenes h2,
    .requirements h2,
    .faq h2,
    .tutorial h2,
    .links h2 {
        font-size: 28px;
    }

    .features-grid,
    .scenes-grid,
    .requirements-content,
    .tutorial-steps {
        grid-template-columns: 1fr;
    }

    .download-buttons {
        grid-template-columns: 1fr;
    }

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
        font-size: 20px;
    }

    .logo h1 {
        font-size: 20px;
    }

    .header .container {
        padding: 12px 15px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .banner-content h2 {
        font-size: 24px;
    }

    .banner-content p {
        font-size: 14px;
    }

    .btn {
        padding: 10px 20px;
        font-size: 14px;
    }

    .btn-download {
        padding: 15px 20px;
        font-size: 14px;
    }

    .features h2,
    .scenes h2,
    .requirements h2,
    .faq h2,
    .tutorial h2,
    .links h2 {
        font-size: 22px;
        margin-bottom: 30px;
    }

    .feature-card,
    .scene-card,
    .step {
        padding: 20px;
    }

    .links-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .nav-mobile {
        width: 100%;
        right: -100%;
    }
}