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

/* CSS变量定义 */
:root {
    --primary-color: #3A8FE6;
    --primary-dark: #2D7FD6;
    --secondary-color: #4CAF50;
    --accent-color: #FF6B6B;
    --text-primary: #2C3E50;
    --text-secondary: #7F8C8D;
    --text-light: #BDC3C7;
    --bg-primary: #FFFFFF;
    --bg-secondary: #F8F9FA;
    --bg-dark: #2C3E50;
    --border-color: #E9ECEF;
    --shadow-light: 0 2px 10px rgba(0, 0, 0, 0.1);
    --shadow-medium: 0 4px 20px rgba(0, 0, 0, 0.15);
    --shadow-heavy: 0 8px 30px rgba(0, 0, 0, 0.2);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-secondary: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --border-radius: 12px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 基础样式 */
html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-light);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.nav-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-logo i {
    margin-right: 10px;
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-link {
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover::after {
    width: 100%;
}

.hamburger {
    display: none;
    flex-direction: column;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-primary);
    margin: 3px 0;
    transition: var(--transition);
}

/* 英雄区域 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('img/back.png');
    background-size: cover;
    background-position: center;
    z-index: 1;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.8), rgba(118, 75, 162, 0.8));
    z-index: 2;
}

.hero-content {
    position: relative;
    z-index: 3;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    text-align: center;
    color: white;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 700;
    margin-bottom: 1rem;
    opacity: 0;
    animation: fadeInUp 1s ease-out 0.5s forwards;
}

.gradient-text {
    background: linear-gradient(45deg, #fff, #f0f0f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 1rem;
    opacity: 0;
    animation: fadeInUp 1s ease-out 0.7s forwards;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    opacity: 0;
    animation: fadeInUp 1s ease-out 0.9s forwards;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
    opacity: 0;
    animation: fadeInUp 1s ease-out 1.1s forwards;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
    opacity: 0;
    animation: fadeInUp 1s ease-out 1.3s forwards;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

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

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

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    border-color: rgba(255, 255, 255, 0.5);
}

.btn-disabled {
    background: #ccc;
    color: #666;
    cursor: not-allowed;
}

/* 视频区域 */
.video-section {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

.video-container {
    max-width: 900px;
    margin: 0 auto;
}

.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-heavy);
}

.video-wrapper video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.3);
    opacity: 1;
    transition: var(--transition);
}

.video-wrapper:hover .video-overlay {
    opacity: 0;
}

.play-button {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--primary-color);
    cursor: pointer;
    transition: var(--transition);
}

.play-button:hover {
    transform: scale(1.1);
    background: white;
}

/* 功能特色区域 */
.features-section {
    padding: 100px 0;
    background: var(--bg-primary);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    transition: var(--transition);
    border: 1px solid var(--border-color);
    text-align: center;
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: white;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.feature-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 下载区域 */
.download-section {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.download-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.download-card.available:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-heavy);
}

.download-card.coming-soon {
    opacity: 0.7;
}

.download-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.download-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

.download-info {
    margin-bottom: 1.5rem;
}

.version, .size {
    display: inline-block;
    background: var(--bg-secondary);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.9rem;
    margin: 0.25rem;
    color: var(--text-secondary);
}

.status {
    color: var(--accent-color);
    font-weight: 500;
}

/* 团队区域 */
.team-section {
    padding: 100px 0;
    background: var(--bg-primary);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1000px;
    margin: 0 auto;
}

.team-card {
    background: white;
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-light);
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

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

.team-avatar {
    position: relative;
    width: 120px;
    height: 120px;
    margin: 0 auto 1.5rem;
    border-radius: 50%;
    overflow: hidden;
}

.team-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.avatar-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: var(--transition);
}

.team-avatar:hover .avatar-overlay {
    opacity: 1;
}

.social-links {
    display: flex;
    gap: 1rem;
}

.social-links a {
    color: white;
    font-size: 1.2rem;
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--primary-color);
    transform: scale(1.2);
}

.team-card h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.team-role {
    color: var(--primary-color);
    font-weight: 500;
    margin-bottom: 1rem;
}

.team-bio {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* 关于我们区域 */
.about-section {
    padding: 100px 0;
    background: var(--bg-secondary);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.about-text h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
}

.about-text p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 2rem;
}

.about-features {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.about-feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--primary-color);
    font-weight: 500;
}

.about-stats {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat .stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat .stat-label {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.about-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.image-placeholder {
    width: 300px;
    height: 300px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 6rem;
    color: white;
    box-shadow: var(--shadow-heavy);
}

/* 页脚 */
.footer {
    background: var(--bg-dark);
    color: white;
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-logo i {
    margin-right: 10px;
    color: var(--primary-color);
}

.footer-section p {
    color: var(--text-light);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.footer-section h4 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: white;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section ul li a {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--primary-color);
}

.footer .social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1rem;
}

.footer .social-links a {
    color: var(--text-light);
    font-size: 1.5rem;
    transition: var(--transition);
}

.footer .social-links a:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

.contact-info p {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.2rem;
    cursor: pointer;
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 1000;
}

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

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

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        justify-content: flex-start;
        align-items: center;
        padding-top: 2rem;
        transition: var(--transition);
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-stats {
        gap: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }
    
    .about-features {
        flex-direction: column;
        gap: 1rem;
    }
    
    .about-stats {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-header h2 {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .feature-card {
        padding: 1.5rem;
    }
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-color);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--primary-dark);
}

/* 选择文本样式 */
::selection {
    background: var(--primary-color);
    color: white;
}

/* 焦点样式 */
button:focus,
a:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}