* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #202124;
    background-color: #ffffff;
    overflow-x: hidden;
}

/* 顶部导航 */
header {
    position: sticky;
    top: 0;
    background: #ffffff;
    border-bottom: 1px solid #dadce0;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 40px;
    height: 70px;
    max-width: 1400px;
    margin: 0 auto;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: #202124;
    font-size: 24px;
    font-weight: 600;
    transition: opacity 0.3s;
}

.logo:hover {
    opacity: 0.8;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, #4285F4 0%, #34A853 50%, #EA4335 100%);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 20px;
}

.nav-links {
    display: flex;
    gap: 40px;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: #5f6368;
    font-size: 16px;
    font-weight: 500;
    transition: color 0.3s;
    position: relative;
}

.nav-links a:hover {
    color: #4285F4;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #4285F4;
    transition: width 0.3s;
}

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

/* Banner轮播 */
.banner-section {
    position: relative;
    height: 600px;
    overflow: hidden;
    background: #f8f9fa;
}

.banner-container {
    position: relative;
    width: 100%;
    height: 100%;
}

.banner-slide {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
}

.banner-slide.active {
    opacity: 1;
}

.banner-slide-1 {
    background: linear-gradient(135deg, #4285F4 0%, #1e88e5 100%);
}

.banner-slide-2 {
    background: linear-gradient(135deg, #34A853 0%, #1b8e47 100%);
}

.banner-slide-3 {
    background: linear-gradient(135deg, #EA4335 0%, #c5221f 100%);
}

.banner-content {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 100%;
    text-align: center;
    color: white;
}

.banner-text {
    max-width: 600px;
    animation: slideUp 0.8s ease-out;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.banner-text h1 {
    font-size: 56px;
    font-weight: 700;
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.banner-text p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
    font-weight: 300;
}

.banner-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.btn {
    padding: 14px 32px;
    font-size: 16px;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    text-decoration: none;
    display: inline-block;
}

.btn-primary {
    background: #ffffff;
    color: #4285F4;
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

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

.btn-secondary:hover {
    background: rgba(255,255,255,0.3);
    transform: translateY(-2px);
}

.btn-download-group {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-small {
    padding: 10px 18px;
    font-size: 14px;
    font-weight: 500;
    background: rgba(255,255,255,0.15);
    color: #ffffff;
    border: 1px solid rgba(255,255,255,0.4);
}

.btn-small:hover {
    background: rgba(255,255,255,0.25);
    transform: translateY(-2px);
}

/* 平台专用按钮样式 */
.btn-android {
    background: #34A853 !important;
    color: #ffffff !important;
}

.btn-android:hover {
    background: #1b8e47 !important;
    box-shadow: 0 4px 12px rgba(26, 142, 71, 0.3) !important;
}

.btn-ios {
    background: #000000 !important;
    color: #ffffff !important;
}

.btn-ios:hover {
    background: #1a1a1a !important;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4) !important;
}

.banner-indicators {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
    z-index: 10;
}

.indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255,255,255,0.5);
    cursor: pointer;
    transition: all 0.3s;
}

.indicator.active {
    background: #ffffff;
    width: 32px;
    border-radius: 6px;
}

/* 功能介绍 */
.features-section {
    padding: 80px 40px;
    background: #ffffff;
}

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

.section-title {
    text-align: center;
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 20px;
    color: #202124;
}

.section-subtitle {
    text-align: center;
    font-size: 18px;
    color: #5f6368;
    margin-bottom: 60px;
    font-weight: 300;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.feature-card {
    padding: 40px;
    border-radius: 12px;
    background: #f8f9fa;
    transition: all 0.3s;
    text-align: center;
    border: 1px solid #dadce0;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
    background: #ffffff;
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #4285F4 0%, #34A853 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 40px;
    margin: 0 auto 20px;
}

.feature-card h3 {
    font-size: 22px;
    font-weight: 600;
    margin-bottom: 12px;
    color: #202124;
}

.feature-card p {
    font-size: 16px;
    color: #5f6368;
    font-weight: 300;
    line-height: 1.8;
}

/* FAQ 部分 */
.faq-section {
    padding: 80px 40px;
    background: #f8f9fa;
}

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

.faq-item {
    background: #ffffff;
    border: 1px solid #dadce0;
    border-radius: 8px;
    margin-bottom: 12px;
    overflow: hidden;
    transition: all 0.3s;
}

.faq-item:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.faq-question {
    padding: 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 18px;
    font-weight: 600;
    color: #202124;
    background: #ffffff;
    transition: background 0.3s;
}

.faq-item:hover .faq-question {
    background: #f8f9fa;
}

.faq-toggle {
    font-size: 24px;
    transition: transform 0.3s;
}

.faq-item.active .faq-toggle {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background: #f8f9fa;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    transition: max-height 0.3s ease-in;
}

.faq-answer-content {
    padding: 0 24px 24px 24px;
    font-size: 16px;
    color: #5f6368;
    font-weight: 300;
    line-height: 1.8;
}

/* 页脚 */
footer {
    background: #202124;
    color: #e8eaed;
    padding: 40px;
    text-align: center;
    font-size: 14px;
}

.footer-links {
    margin-bottom: 20px;
    display: flex;
    gap: 30px;
    justify-content: center;
    flex-wrap: wrap;
}

.footer-links a {
    color: #e8eaed;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-links a:hover {
    color: #4285F4;
}

.footer-bottom {
    border-top: 1px solid #5f6368;
    padding-top: 20px;
    margin-top: 20px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .navbar {
        padding: 0 20px;
        height: 60px;
    }
    
    .nav-links {
        gap: 20px;
    }
    
    .nav-links a {
        font-size: 14px;
    }
    
    .banner-text h1 {
        font-size: 36px;
    }
    
    .banner-text p {
        font-size: 16px;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .feature-card {
        padding: 30px 20px;
    }
    
    .banner-buttons {
        flex-direction: column;
    }
    
    .btn-download-group {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .btn-small {
        width: 100%;
    }
    
    .faq-container {
        padding: 0 20px;
    }
    
    .footer-links {
        gap: 15px;
        font-size: 12px;
    }
}

/* 加载优化 */
img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* 无障碍访问 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}