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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #fff;
}

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

/* 导航栏 */
.header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-logo {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    object-fit: cover;
}

.nav-brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #007AFF;
}

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

.nav-links a {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav-links a:hover {
    color: #007AFF;
}

/* 主要内容区域 */
main {
    margin-top: 80px;
}

/* 英雄区域 */
.hero {
    padding: 4rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    min-height: 80vh;
    display: flex;
    align-items: center;
}

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

.hero-title-container {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1rem;
}

.hero-logo {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    object-fit: cover;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin: 0;
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: 1rem;
    opacity: 0.9;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.8;
    line-height: 1.6;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: #fff;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

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

.btn-secondary:hover {
    background: #fff;
    color: #667eea;
}

/* 应用模型 */
.app-mockup {
    display: flex;
    justify-content: center;
    align-items: center;
}

.phone-frame {
    width: 280px;
    height: 560px;
    background: #000;
    border-radius: 40px;
    padding: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.screen {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 25px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.app-interface {
    text-align: center;
    color: #333;
    padding: 1rem;
}

.app-header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

.app-icon {
    width: 24px;
    height: 24px;
    border-radius: 6px;
    object-fit: cover;
}

.app-name {
    font-size: 1rem;
    font-weight: 600;
    color: #007AFF;
}

.card-preview {
    background: #fff;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.card-preview h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: #007AFF;
}

.card-preview p {
    margin-bottom: 1rem;
    color: #666;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: #e0e0e0;
    border-radius: 4px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #007AFF, #667eea);
    border-radius: 4px;
    transition: width 0.3s ease;
}

/* 功能特色区域 */
.features {
    padding: 6rem 0;
    background: #f8f9fa;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: #333;
}

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

.feature-card {
    background: #fff;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.feature-card p {
    color: #666;
    line-height: 1.6;
}

/* 算法区域 */
.algorithm {
    padding: 6rem 0;
    background: #fff;
}

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

.algorithm-text h3 {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.algorithm-text p {
    color: #666;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.interval-list {
    list-style: none;
    margin: 2rem 0;
}

.interval-list li {
    padding: 0.5rem 0;
    color: #007AFF;
    font-weight: 500;
}

.interval-list li:before {
    content: "✓ ";
    color: #28a745;
    font-weight: bold;
}

.chart-container {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 15px;
    height: 300px;
    position: relative;
}

.curve-visualization {
    position: relative;
    height: 100%;
}

.curve-line {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #007AFF, #667eea);
    border-radius: 2px;
    transform: translateY(-50%);
}

.review-points {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
}

.point {
    position: absolute;
    top: 45%;
    transform: translateX(-50%);
    background: #007AFF;
    color: #fff;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 500;
}

.point:before {
    content: "";
    position: absolute;
    top: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 16px;
    height: 16px;
    background: #007AFF;
    border-radius: 50%;
}

/* 使用场景区域 */
.use-cases {
    padding: 6rem 0;
    background: #f8f9fa;
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.use-case-card {
    background: #fff;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    text-align: center;
    transition: transform 0.3s ease;
}

.use-case-card:hover {
    transform: translateY(-5px);
}

.use-case-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.use-case-card h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.use-case-card p {
    color: #666;
    line-height: 1.6;
}

/* 下载区域 */
.download {
    padding: 6rem 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    text-align: center;
}

.download .section-title {
    color: #fff;
}

.download-description {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.download-btn img {
    height: 60px;
    transition: transform 0.3s ease;
}

.download-btn:hover img {
    transform: scale(1.05);
}

.system-requirements {
    opacity: 0.8;
    font-size: 0.9rem;
}

/* 页脚 */
.footer {
    background: #2c3e50;
    color: #fff;
    padding: 3rem 0 1rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 1rem;
}

.footer-logo {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    object-fit: cover;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #fff;
}

.footer-brand h3 {
    margin-bottom: 0;
}

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

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

.footer-section a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #34495e;
    color: #bdc3c7;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    
    .nav-links {
        gap: 1rem;
    }
    
    .hero .container {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 2rem;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-title-container {
        flex-direction: column;
        text-align: center;
        gap: 0.75rem;
    }
    
    .hero-logo {
        width: 48px;
        height: 48px;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .use-cases-grid {
        grid-template-columns: 1fr;
    }
    
    .algorithm-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .phone-frame {
        width: 240px;
        height: 480px;
    }
    
    .download-buttons {
        flex-direction: column;
        align-items: center;
    }
}

/* 内页样式 */
.page-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 6rem 0 4rem;
    text-align: center;
}

.page-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.page-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
}

.page-content {
    padding: 4rem 0;
    max-width: 800px;
    margin: 0 auto;
}

.content-section {
    margin-bottom: 3rem;
}

.content-section h2 {
    font-size: 1.8rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #333;
}

.content-section h3 {
    font-size: 1.4rem;
    font-weight: 600;
    margin-bottom: 0.8rem;
    color: #007AFF;
}

.content-section p {
    color: #666;
    line-height: 1.8;
    margin-bottom: 1rem;
}

.content-section ul {
    color: #666;
    line-height: 1.8;
    margin-left: 2rem;
    margin-bottom: 1rem;
}

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

.contact-info {
    background: #f8f9fa;
    padding: 2rem;
    border-radius: 10px;
    margin: 2rem 0;
}

.contact-info h3 {
    color: #333;
    margin-bottom: 1rem;
}

.contact-info p {
    margin-bottom: 0.5rem;
}

.contact-info a {
    color: #007AFF;
    text-decoration: none;
}

.contact-info a:hover {
    text-decoration: underline;
}

.back-link {
    display: inline-block;
    margin-top: 2rem;
    color: #007AFF;
    text-decoration: none;
    font-weight: 500;
}

.back-link:hover {
    text-decoration: underline;
}

.back-link:before {
    content: "← ";
}