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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 
                 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: #2c3e50;
    background-color: #fafbfc;
    padding-top: 70px; /* 为固定导航栏留出空间 */
}

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

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: #fff;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.12);
}

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

.nav-logo {
    display: flex;
    align-items: center;
}

.logo-text {
    font-size: 24px;
    font-weight: 600;
    color: #5a7a9e;
    letter-spacing: 1px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 40px;
    margin: 0;
    padding: 0;
}

.nav-link {
    color: #2c3e50;
    text-decoration: none;
    font-size: 15px;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #5a7a9e;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: #5a7a9e;
    transition: width 0.3s ease;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background-color: #2c3e50;
    margin: 3px 0;
    transition: all 0.3s ease;
    border-radius: 3px;
}

.nav-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(8px, 8px);
}

.nav-toggle.active span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -7px);
}

/* 按钮样式 */
.btn {
    padding: 14px 32px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: 500;
}

.btn-primary {
    background-color: #5a7a9e;
    color: #fff;
}

.btn-primary:hover {
    background-color: #4a6a8e;
    transform: translateY(-2px);
}

.btn-secondary {
    background-color: #fff;
    color: #5a7a9e;
    border: 2px solid #5a7a9e;
}

.btn-secondary:hover {
    background-color: #f5f7fa;
    transform: translateY(-2px);
}

.btn-download {
    background-color: #5a7a9e;
    color: #fff;
    width: 100%;
    margin-top: 16px;
}

.btn-download:hover {
    background-color: #4a6a8e;
}

/* Hero 区 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #5a7a9e 100%);
    color: #fff;
    padding: 120px 0 100px;
    text-align: center;
}

.hero-title {
    font-size: 48px;
    font-weight: 500;
    margin-bottom: 20px;
    letter-spacing: 1px;
}

.hero-subtitle {
    font-size: 24px;
    font-weight: 400;
    margin-bottom: 16px;
    opacity: 0.95;
}

.hero-desc {
    font-size: 16px;
    opacity: 0.85;
    margin-bottom: 40px;
}

.hero-cta {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* 通用 Section 样式 */
section {
    padding: 80px 0;
}

.section-title {
    font-size: 36px;
    font-weight: 500;
    text-align: center;
    margin-bottom: 50px;
    color: #2c3e50;
}

/* 产品定位说明 */
.about {
    background-color: #fff;
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    font-size: 18px;
    line-height: 1.8;
    color: #5a6c7d;
    margin-bottom: 20px;
}

/* 核心功能 */
.features {
    background-color: #fafbfc;
}

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

.feature-card {
    background-color: #fff;
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid #e8ecef;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(90, 122, 158, 0.1);
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-title {
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 12px;
    color: #2c3e50;
}

.feature-desc {
    font-size: 15px;
    color: #5a6c7d;
    line-height: 1.6;
}

/* 适用人群 */
.target-users {
    background-color: #fff;
}

.users-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    max-width: 900px;
    margin: 0 auto;
}

.user-card {
    background-color: #f5f7fa;
    padding: 30px 24px;
    border-radius: 8px;
    text-align: center;
    border: 1px solid #e8ecef;
}

.user-card p {
    font-size: 16px;
    color: #2c3e50;
    font-weight: 400;
}

/* 下载方式 */
.download {
    background-color: #fafbfc;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 40px;
    max-width: 800px;
    margin: 0 auto;
}

.download-card {
    background-color: #fff;
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    border: 1px solid #e8ecef;
}

.download-platform {
    font-size: 24px;
    font-weight: 500;
    margin-bottom: 16px;
    color: #2c3e50;
}

.download-desc {
    font-size: 16px;
    color: #5a6c7d;
    margin-bottom: 8px;
}

.download-note {
    font-size: 13px;
    color: #8892a0;
    margin-top: 16px;
    line-height: 1.5;
}

/* 免责声明 */
.disclaimer {
    background-color: #f5f7fa;
    border-top: 1px solid #e8ecef;
    border-bottom: 1px solid #e8ecef;
}

.disclaimer-content {
    max-width: 900px;
    margin: 0 auto;
    background-color: #fff;
    padding: 40px;
    border-radius: 8px;
    border: 1px solid #e8ecef;
}

.disclaimer-content p {
    font-size: 15px;
    line-height: 1.8;
    color: #5a6c7d;
    margin-bottom: 16px;
}

.disclaimer-content p:last-child {
    margin-bottom: 0;
}

/* 页脚 */
.footer {
    background-color: #2c3e50;
    color: #fff;
    padding: 30px 0;
    text-align: center;
}

.footer p {
    font-size: 14px;
    opacity: 0.8;
}

/* 下载悬浮按钮 */
.floating-download {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 999;
    opacity: 0;
    transform: translateY(100px);
    transition: all 0.3s ease;
}

.floating-download.show {
    opacity: 1;
    transform: translateY(0);
}

.floating-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    background: linear-gradient(135deg, #667eea 0%, #5a7a9e 100%);
    color: #fff;
    border: none;
    padding: 16px 24px;
    border-radius: 50px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(90, 122, 158, 0.3);
    transition: all 0.3s ease;
}

.floating-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 28px rgba(90, 122, 158, 0.4);
}

.floating-btn:active {
    transform: translateY(-1px);
}

.download-icon {
    width: 20px;
    height: 20px;
}

.floating-text {
    white-space: nowrap;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background-color: #fff;
        flex-direction: column;
        gap: 0;
        padding: 20px 0;
        box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
        transform: translateX(-100%);
        transition: transform 0.3s ease;
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .nav-menu li {
        padding: 12px 30px;
        border-bottom: 1px solid #f0f0f0;
    }
    
    .nav-menu li:last-child {
        border-bottom: none;
    }
    
    .nav-link::after {
        display: none;
    }
    
    .floating-download {
        bottom: 20px;
        right: 20px;
    }
    
    .floating-btn {
        padding: 14px 20px;
        font-size: 14px;
    }
    
    .download-icon {
        width: 18px;
        height: 18px;
    }
    
    .hero-title {
        font-size: 36px;
    }
    
    .hero-subtitle {
        font-size: 20px;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .features-grid,
    .users-grid,
    .download-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
    }
}

@media (max-width: 480px) {
    body {
        padding-top: 60px;
    }
    
    .nav-content {
        height: 60px;
    }
    
    .nav-menu {
        top: 60px;
    }
    
    .logo-text {
        font-size: 20px;
    }
    
    .floating-btn {
        padding: 12px 16px;
        font-size: 13px;
    }
    
    .floating-text {
        display: none;
    }
    
    .floating-btn {
        border-radius: 50%;
        width: 50px;
        height: 50px;
        padding: 0;
        justify-content: center;
    }
    
    .download-icon {
        width: 22px;
        height: 22px;
    }
    
    .hero {
        padding: 80px 0 60px;
    }
    
    section {
        padding: 60px 0;
    }
    
    .hero-title {
        font-size: 28px;
    }
    
    .hero-subtitle {
        font-size: 18px;
    }
    
    .about-content p {
        font-size: 16px;
    }
    
    .disclaimer-content {
        padding: 30px 20px;
    }
}