:root {
    /* 浅色主题变量 */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --accent-color: #4361ee;
    --accent-secondary: #7209b7;
    --border-color: #e9ecef;
    --card-bg: #ffffff;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
    --hover-bg: rgba(0, 0, 0, 0.03);
    --hero-gradient: linear-gradient(135deg, #4361ee, #3a0ca3);
}

.dark-theme {
    /* 深色主题变量 */
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --accent-color: #5a7dff;
    --accent-secondary: #9d4edd;
    --border-color: #2d2d2d;
    --card-bg: #1e1e1e;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.25);
    --hover-bg: rgba(255, 255, 255, 0.05);
    --hero-gradient: linear-gradient(135deg, #3a0ca3, #7209b7);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    transition: background-color 0.3s ease, color 0.2s ease, border-color 0.3s ease;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
header {
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    padding: 0 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent-color);
    text-decoration: none;
}

.logo i {
    color: var(--accent-secondary);
}

.nav-links {
    display: flex;
    gap: 30px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 500;
    position: relative;
    padding: 5px 0;
}

.nav-links a:after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--accent-color);
    transition: width 0.3s ease;
}

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

.theme-toggle {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.3rem;
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--hover-bg);
    transform: rotate(15deg);
}

/* 英雄区域 */
.hero {
    padding: 100px 0;
    text-align: center;
    background: var(--hero-gradient);
    color: white;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml;utf8,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><polygon points="0,100 100,0 100,100" opacity="0.1"/></svg>');
    background-size: cover;
    opacity: 0.2;
}

.hero h1 {
    font-size: 4rem;
    margin-bottom: 20px;
    letter-spacing: 2px;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero h2 {
    font-size: 2.5rem;
    margin-bottom: 30px;
    font-weight: 300;
}

.hero p {
    font-size: 1.3rem;
    max-width: 700px;
    margin: 0 auto 40px;
    opacity: 0.9;
}

.btn-container {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    background-color: white;
    color: var(--accent-secondary);
    padding: 14px 32px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    min-width: 200px;
}

.btn:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 25px rgba(0, 0, 0, 0.3);
}

.btn-outline {
    background-color: transparent;
    border: 2px solid white;
    color: white;
}

/* 功能区域 */
.section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    position: relative;
}

.section-title:after {
    content: '';
    position: absolute;
    bottom: -15px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: linear-gradient(to right, var(--accent-color), var(--accent-secondary));
    border-radius: 2px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 40px;
    margin-top: 50px;
}

.feature-card {
    background-color: var(--card-bg);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    padding: 30px;
    text-align: center;
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 12px 20px rgba(0, 0, 0, 0.1);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 25px;
    color: white;
    font-size: 2rem;
}

.feature-title {
    font-size: 1.8rem;
    margin-bottom: 15px;
    color: var(--text-primary);
}

.feature-desc {
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.divider {
    height: 1px;
    background: var(--border-color);
    margin: 40px 0;
}

/* 技术优势部分 */
.tech-section {
    background-color: var(--bg-secondary);
}

.tech-container {
    display: flex;
    flex-wrap: wrap;
    gap: 50px;
    align-items: center;
}

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

.tech-image {
    flex: 1;
    min-width: 300px;
    height: 400px;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 5rem;
    box-shadow: var(--shadow);
}

/* 团队部分 */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.team-card {
    background-color: var(--card-bg);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    text-align: center;
    padding: 30px 20px;
    border: 1px solid var(--border-color);
}

.team-avatar {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-color), var(--accent-secondary));
    margin: 0 auto 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 3rem;
}

.team-name {
    font-size: 1.5rem;
    margin-bottom: 5px;
}

.team-role {
    color: var(--accent-color);
    margin-bottom: 15px;
    font-weight: 500;
}

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

/* 用户服务部分 */
.service-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.service-card {
    background-color: var(--card-bg);
    border-radius: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    padding: 30px;
    border: 1px solid var(--border-color);
    transition: transform 0.3s ease;
}

.service-card:hover {
    transform: translateY(-10px);
}

.service-icon {
    font-size: 2.5rem;
    color: var(--accent-color);
    margin-bottom: 20px;
}

/* 下载区域 */
.download-section {
    padding: 100px 0;
    text-align: center;
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), var(--hero-gradient);
    color: white;
}

.download-title {
    font-size: 3rem;
    margin-bottom: 20px;
}

.download-subtitle {
    font-size: 1.5rem;
    margin-bottom: 40px;
    font-weight: 300;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* 页脚样式 */
footer {
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    padding: 50px 0 30px;
    margin-top: auto;
}

.footer-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand {
    flex: 1;
    min-width: 300px;
}

.footer-logo {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-about {
    color: var(--text-secondary);
    margin-bottom: 20px;
    max-width: 400px;
}

.social-links {
    display: flex;
    gap: 15px;
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--hover-bg);
    color: var(--text-primary);
    transition: all 0.3s ease;
    text-decoration: none;
}

.social-links a:hover {
    background-color: var(--accent-color);
    color: white;
    transform: translateY(-5px);
}

.footer-links {
    flex: 1;
    min-width: 200px;
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-links h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
    color: var(--accent-color);
}

.footer-links a {
    text-decoration: none;
    color: var(--text-secondary);
    transition: color 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

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

.copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.9rem;
}

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

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero h2 {
        font-size: 1.8rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .btn-container {
        flex-direction: column;
        align-items: center;
    }
}