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

:root {
    --primary: #4b7bec;
    --primary-dark: #3a6bd6;
    --primary-light: #e8f0fe;
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --text-primary: #1f2a3a;
    --text-secondary: #5e6f8d;
    --text-tertiary: #8e9db1;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --border-light: #edf0f5;
    --border-medium: #d0d7e5;
    --card-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    --hover-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
}

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

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--border-light);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    color: var(--primary);
}

.logo-text {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
    align-items: center;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    transition: color 0.2s;
}

.nav-menu a:hover {
    color: var(--primary);
}

.nav-download {
    background: var(--primary);
    color: white !important;
    padding: 8px 20px;
    border-radius: 30px;
}

.nav-download:hover {
    background: var(--primary-dark);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 6px;
    background: none;
    border: none;
    cursor: pointer;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    transition: 0.3s;
}

/* 英雄区域 */
.hero {
    padding: 140px 20px 80px;
    background: linear-gradient(135deg, #f5f7fa 0%, #ffffff 100%);
    overflow: hidden;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-title {
    font-size: 56px;
    line-height: 1.2;
    margin-bottom: 24px;
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, #8e6eff 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 32px;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: 40px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: var(--primary);
    color: white;
    box-shadow: 0 10px 20px rgba(75, 123, 236, 0.3);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 15px 30px rgba(75, 123, 236, 0.4);
}

.btn-outline {
    background: transparent;
    color: var(--text-primary);
    border: 2px solid var(--border-medium);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.hero-stats {
    display: flex;
    gap: 40px;
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 14px;
    color: var(--text-tertiary);
}

/* 英雄区域图片 - 拉大预览图 */
.hero-image {
    position: relative;
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-app-preview {
    position: relative;
    width: 100%;
    max-width: 1000px; /* 增大预览图最大宽度 */
    aspect-ratio: 4/3; /* 保持4:3比例，更宽更高 */
    background: white;
    border-radius: 24px;
    box-shadow: var(--hover-shadow);
    overflow: hidden;
    margin: 0 auto;
}

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

/* 特性区域 */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 40px;
    margin-bottom: 16px;
}

.section-header p {
    font-size: 18px;
    color: var(--text-secondary);
}

.features {
    padding: 100px 20px;
    background: white;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    padding: 40px 30px;
    background: var(--bg-secondary);
    border-radius: 24px;
    border: 1px solid var(--border-light);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--hover-shadow);
    border-color: var(--primary-light);
}

.feature-icon {
    width: 64px;
    height: 64px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.feature-icon.blue {
    background: rgba(75, 123, 236, 0.1);
    color: var(--primary);
}

.feature-icon.green {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
}

.feature-icon.purple {
    background: rgba(139, 92, 246, 0.1);
    color: #8b5cf6;
}

.feature-icon.orange {
    background: rgba(245, 158, 11, 0.1);
    color: var(--warning);
}

.feature-icon.red {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
}

.feature-icon.teal {
    background: rgba(20, 184, 166, 0.1);
    color: #14b8a6;
}

.feature-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
}

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

/* 语速范围 */
.speed-range {
    padding: 80px 20px;
    background: var(--bg-secondary);
}

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

.speed-range h2 {
    font-size: 36px;
    margin-bottom: 16px;
}

.speed-range p {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.speed-meter {
    background: white;
    padding: 40px;
    border-radius: 32px;
    box-shadow: var(--card-shadow);
}

.speed-meter-scale {
    display: flex;
    justify-content: space-between;
    margin-bottom: 20px;
}

.speed-label {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
}

.speed-label span {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    display: block;
    margin-top: 4px;
}

.speed-meter-bar {
    display: flex;
    height: 40px;
    border-radius: 40px;
    overflow: hidden;
    margin-bottom: 30px;
}

.speed-range-slow {
    background: #f59e0b;
    opacity: 0.3;
}

.speed-range-normal {
    background: #10b981;
    opacity: 0.5;
}

.speed-range-fast {
    background: #ef4444;
    opacity: 0.3;
}

.speed-examples {
    display: flex;
    justify-content: space-around;
}

.example-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.example-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.slow-dot {
    background: #f59e0b;
}

.normal-dot {
    background: #10b981;
}

.fast-dot {
    background: #ef4444;
}

/* 工作原理 */
.how-it-works {
    padding: 100px 20px;
    background: white;
}

.steps {
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 30px;
    margin-bottom: 40px;
    align-items: flex-start;
}

.step-number {
    width: 60px;
    height: 60px;
    background: var(--primary-light);
    color: var(--primary);
    font-size: 24px;
    font-weight: 700;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.step-content h3 {
    font-size: 24px;
    margin-bottom: 8px;
}

.step-content p {
    color: var(--text-secondary);
    font-size: 16px;
}

/* 展示区域 */
.showcase {
    padding: 100px 20px;
    background: var(--bg-secondary);
}

.showcase-tabs {
    display: flex;
    justify-content: center;
    gap: 16px;
    margin-bottom: 40px;
}

.tab-btn {
    padding: 12px 30px;
    border: 2px solid var(--border-light);
    background: white;
    border-radius: 40px;
    font-size: 16px;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.tab-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.tab-btn.active {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.showcase-content {
    max-width: 1000px;
    margin: 0 auto;
}

.showcase-panel {
    display: none;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: center;
    background: white;
    border-radius: 24px;
    padding: 40px;
    box-shadow: var(--card-shadow);
}

.showcase-panel.active {
    display: grid;
}

.showcase-img {
    width: 100%;
    border-radius: 16px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
}

.showcase-desc h3 {
    font-size: 28px;
    margin-bottom: 16px;
}

.showcase-desc p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.showcase-desc ul {
    list-style: none;
}

.showcase-desc li {
    margin-bottom: 12px;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
}

/* 下载区域 */
.download {
    padding: 100px 20px;
    background: white;
}

.download-card {
    max-width: 600px;
    margin: 0 auto;
    background: var(--bg-secondary);
    border-radius: 40px;
    padding: 60px 40px;
    text-align: center;
    border: 1px solid var(--border-light);
}

.download-icon {
    width: 120px;
    height: 120px;
    background: var(--primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 30px;
    color: var(--primary);
}

.download-card h2 {
    font-size: 32px;
    margin-bottom: 16px;
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.download-info {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
}

.info-item {
    display: flex;
    flex-direction: column;
}

.info-label {
    font-size: 12px;
    color: var(--text-tertiary);
}

.info-value {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.btn-download {
    background: var(--primary);
    color: white;
    font-size: 18px;
    padding: 16px 48px;
    margin-bottom: 16px;
}

.btn-download:hover {
    background: var(--primary-dark);
}

.download-note {
    font-size: 14px;
    color: var(--text-tertiary);
}

/* 常见问题 */
.faq {
    padding: 80px 20px;
    background: var(--bg-secondary);
}

.faq-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    padding: 30px;
    border-radius: 24px;
    border: 1px solid var(--border-light);
}

.faq-item h3 {
    font-size: 18px;
    margin-bottom: 12px;
    color: var(--primary);
}

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

/* 页脚 */
.footer {
    padding: 60px 20px;
    background: #1a1a1a;
    color: white;
}

.footer-content {
    text-align: center;
}

.footer-logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-bottom: 16px;
}

.footer-logo span {
    font-size: 20px;
    font-weight: 600;
}

.footer-tagline {
    color: #808080;
    margin-bottom: 30px;
}

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

.footer-links a {
    color: #b0b0b0;
    text-decoration: none;
    transition: color 0.2s;
}

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

.footer-copyright {
    color: #606060;
    font-size: 14px;
}

/* 响应式设计 */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 48px;
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .nav-toggle {
        display: flex;
    }
    
    .hero-container {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-subtitle {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-buttons {
        justify-content: center;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .showcase-panel {
        grid-template-columns: 1fr;
    }
    
    .faq-grid {
        grid-template-columns: 1fr;
    }
    
    .step {
        flex-direction: column;
        text-align: center;
        gap: 16px;
    }
    
    .step-number {
        margin: 0 auto;
    }
    
    .hero-app-preview {
        max-width: 100%;
        aspect-ratio: 4/3;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 36px;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 20px;
    }
    
    .download-info {
        flex-direction: column;
        gap: 15px;
    }
    
    .speed-meter-scale {
        flex-direction: column;
        gap: 10px;
    }
    
    .speed-examples {
        flex-direction: column;
        gap: 10px;
        align-items: center;
    }
    
    .hero-app-preview {
        aspect-ratio: 4/3;
    }
}