:root {
    /* 主色调 - 渐变色系 */
    --primary-color: #5e72e4;
    --primary-light: #7b8ff7;
    --primary-dark: #4050c7;
    
    /* 情绪色系 */
    --emotion-happy: #ffdb4d;
    --emotion-sad: #5e91ff;
    --emotion-angry: #ff5c5c;
    --emotion-calm: #6cd4a8;
    --emotion-fear: #c792ea;
    --emotion-surprise: #ff9966;
    
    /* 中性色 */
    --neutral-100: #ffffff;
    --neutral-200: #f5f7fa;
    --neutral-300: #e4e8f0;
    --neutral-400: #ccd4e0;
    --neutral-500: #a0aec0;
    --neutral-600: #718096;
    --neutral-700: #4a5568;
    --neutral-800: #2d3748;
    --neutral-900: #1a202c;
    
    /* 字体 */
    --font-family: 'Poppins', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    
    /* 圆角 */
    --border-radius-sm: 8px;
    --border-radius-md: 12px;
    --border-radius-lg: 20px;
    --border-radius-xl: 30px;
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.12);
    
    /* 间距 */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 48px;
    --spacing-xxxl: 64px;
}

/* 基础重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    color: var(--neutral-800);
    line-height: 1.6;
    background-color: var(--neutral-200);
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: color 0.3s ease;
}

a:hover {
    color: var(--primary-dark);
}

img {
    max-width: 100%;
    height: auto;
}

ul {
    list-style: none;
}

/* 容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: var(--border-radius-md);
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
    box-shadow: 0 4px 14px rgba(94, 114, 228, 0.3);
}

.btn-primary:hover {
    background-color: var(--primary-dark);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 7px 14px rgba(94, 114, 228, 0.4);
}

.btn-secondary {
    background-color: var(--neutral-200);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: white;
    transform: translateY(-2px);
}

/* 头部样式 */
.header {
    background-color: var(--neutral-100);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: var(--spacing-md) 0;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

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

.logo img {
    height: 40px;
    margin-right: var(--spacing-sm);
}

.logo h1 {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    margin: 0;
}

nav ul {
    display: flex;
    align-items: center;
}

nav ul li {
    margin-left: var(--spacing-lg);
}

nav ul li a {
    color: var(--neutral-700);
    font-weight: 500;
    transition: color 0.3s ease;
}

nav ul li a:hover {
    color: var(--primary-color);
}

.language-selector select {
    border: 1px solid var(--neutral-300);
    padding: 8px 12px;
    border-radius: var(--border-radius-sm);
    color: var(--neutral-700);
    font-size: 0.9rem;
    background-color: var(--neutral-100);
    cursor: pointer;
}

/* 英雄区域 */
.hero {
    padding: var(--spacing-xxxl) 0;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
}

.hero .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.hero-content {
    flex: 1;
    padding-right: var(--spacing-xl);
}

.hero-content h1 {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-lg);
    background: linear-gradient(to right, var(--primary-color), var(--emotion-happy));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.hero-content p {
    font-size: 1.2rem;
    color: var(--neutral-700);
    margin-bottom: var(--spacing-xl);
}

.hero-cta {
    display: flex;
    gap: var(--spacing-md);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero-image img {
    max-width: 450px;
    animation: float 6s ease-in-out infinite;
    filter: drop-shadow(0 10px 15px rgba(0, 0, 0, 0.1));
}

@keyframes float {
    0% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-15px);
    }
    100% {
        transform: translateY(0px);
    }
}

/* 功能部分 */
.features {
    padding: var(--spacing-xxxl) 0;
    background-color: var(--neutral-100);
}

.features h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xxl);
    color: var(--neutral-800);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.feature-card {
    background: var(--neutral-100);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    text-align: center;
}

.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
}

.feature-icon img {
    width: 40px;
    height: 40px;
    object-fit: contain;
}

.feature-card h3 {
    margin-bottom: var(--spacing-md);
    font-size: 1.3rem;
    color: var(--primary-dark);
}

.feature-card p {
    color: var(--neutral-600);
    font-size: 1rem;
}

/* 如何使用部分 */
.how-it-works {
    padding: var(--spacing-xxxl) 0;
    background-color: var(--neutral-200);
}

.how-it-works h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xxl);
    color: var(--neutral-800);
}

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

.step {
    display: flex;
    margin-bottom: var(--spacing-xxl);
    position: relative;
}

.step:last-child {
    margin-bottom: 0;
}

.step:not(:last-child)::after {
    content: '';
    position: absolute;
    left: 24px;
    top: 60px;
    bottom: -60px;
    width: 2px;
    background-color: var(--primary-light);
}

.step-number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-light) 0%, var(--primary-color) 100%);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 600;
    margin-right: var(--spacing-lg);
    flex-shrink: 0;
    z-index: 1;
}

.step-content {
    flex: 1;
}

.step-content h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--primary-dark);
}

.step-content p {
    color: var(--neutral-600);
    margin-bottom: var(--spacing-lg);
}

.step-content img {
    width: 100%;
    max-width: 500px;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
}

/* 应用预览 */
.app-preview {
    padding: var(--spacing-xxxl) 0;
    background-color: var(--neutral-100);
}

.app-preview h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
    color: var(--neutral-800);
}

.app-preview p {
    text-align: center;
    color: var(--neutral-600);
    margin-bottom: var(--spacing-xxl);
    font-size: 1.2rem;
}

.preview-tabs {
    display: flex;
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.tab-btn {
    background: var(--neutral-200);
    border: none;
    padding: 12px 24px;
    margin: 0 var(--spacing-sm);
    border-radius: var(--border-radius-md);
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    color: var(--neutral-600);
}

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

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.phone-mockups {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.phone-mockup {
    width: 280px;
    position: relative;
    text-align: center;
}

.phone-mockup iframe {
    width: 100%;
    height: 580px;
    border-radius: var(--border-radius-lg);
    border: 10px solid var(--neutral-800);
    box-shadow: var(--shadow-lg);
    background-color: white;
}

.phone-mockup p {
    margin-top: var(--spacing-md);
    font-size: 1rem;
    color: var(--neutral-700);
}

.preview-cta {
    text-align: center;
    margin-top: var(--spacing-xl);
}

/* 用户评价部分 */
.testimonials {
    padding: var(--spacing-xxxl) 0;
    background-color: var(--neutral-200);
}

.testimonials h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xxl);
    color: var(--neutral-800);
}

.testimonial-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.testimonial-card {
    background: var(--neutral-100);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    transition: transform 0.3s ease;
}

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

.testimonial-avatar {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    overflow: hidden;
    margin-bottom: var(--spacing-md);
}

.testimonial-avatar img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.testimonial-text {
    color: var(--neutral-700);
    font-size: 1rem;
    margin-bottom: var(--spacing-md);
    position: relative;
    padding-left: var(--spacing-md);
}

.testimonial-text::before {
    content: """;
    position: absolute;
    left: -10px;
    top: -15px;
    font-size: 3rem;
    color: var(--primary-light);
    opacity: 0.3;
}

.testimonial-author {
    color: var(--primary-dark);
    font-weight: 600;
    font-size: 1rem;
}

/* 下载部分 */
.download {
    padding: var(--spacing-xxxl) 0;
    background: linear-gradient(135deg, var(--neutral-800) 0%, var(--neutral-900) 100%);
    color: white;
}

.download h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: var(--spacing-md);
}

.download p {
    text-align: center;
    color: var(--neutral-400);
    margin-bottom: var(--spacing-xxl);
    font-size: 1.2rem;
}

.download-options {
    display: flex;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xxl);
}

.download-btn {
    transition: transform 0.3s ease;
}

.download-btn:hover {
    transform: translateY(-5px);
}

.download-btn img {
    height: 50px;
}

.subscription-info {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xxl);
}

.subscription-plan {
    background: var(--neutral-800);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    width: 300px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    position: relative;
    transition: transform 0.3s ease;
}

.subscription-plan:hover {
    transform: translateY(-8px);
}

.subscription-plan.popular {
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary-color) 100%);
    transform: scale(1.05);
}

.subscription-plan.popular:hover {
    transform: scale(1.05) translateY(-8px);
}

.popular-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--emotion-happy);
    color: var(--neutral-800);
    padding: 5px 15px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.8rem;
}

.subscription-plan h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-md);
}

.price {
    margin-bottom: var(--spacing-lg);
}

.amount {
    font-size: 2.5rem;
    font-weight: 700;
}

.period {
    font-size: 1rem;
    color: var(--neutral-400);
}

.features-list {
    margin-bottom: var(--spacing-lg);
    text-align: left;
}

.features-list li {
    margin-bottom: var(--spacing-sm);
    padding-left: var(--spacing-md);
    position: relative;
}

.features-list li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--emotion-happy);
}

.download-guarantee {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.download-guarantee img {
    width: 80px;
    margin-bottom: var(--spacing-md);
}

.download-guarantee p {
    color: var(--neutral-400);
    font-size: 1rem;
    margin-bottom: 0;
}

/* 页脚 */
.footer {
    background-color: var(--neutral-900);
    color: var(--neutral-400);
    padding: var(--spacing-xxl) 0 var(--spacing-md);
}

.footer-logo {
    display: flex;
    align-items: center;
    margin-bottom: var(--spacing-xl);
}

.footer-logo img {
    height: 30px;
    margin-right: var(--spacing-sm);
}

.footer-logo h3 {
    color: white;
    font-size: 1.2rem;
    margin: 0;
}

.footer-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    margin-bottom: var(--spacing-xxl);
}

.footer-nav-column {
    min-width: 160px;
    margin-bottom: var(--spacing-lg);
}

.footer-nav-column h4 {
    color: white;
    margin-bottom: var(--spacing-md);
    font-size: 1rem;
}

.footer-nav-column ul li {
    margin-bottom: var(--spacing-sm);
}

.footer-nav-column ul li a {
    color: var(--neutral-500);
    font-size: 0.9rem;
    transition: color 0.3s ease;
}

.footer-nav-column ul li a:hover {
    color: white;
}

.social-links {
    display: flex;
    gap: var(--spacing-md);
}

.social-links a {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--neutral-800);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color 0.3s ease;
}

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

.social-links a img {
    width: 18px;
    height: 18px;
    filter: brightness(0) invert(1);
}

.footer-bottom {
    border-top: 1px solid var(--neutral-800);
    padding-top: var(--spacing-lg);
    text-align: center;
}

.footer-bottom p {
    font-size: 0.9rem;
    color: var(--neutral-600);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero .container {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-content {
        padding-right: 0;
        margin-bottom: var(--spacing-xxl);
    }
    
    .hero-cta {
        justify-content: center;
    }
    
    .step {
        flex-direction: column;
    }
    
    .step-number {
        margin-bottom: var(--spacing-md);
        margin-right: 0;
    }
    
    .step:not(:last-child)::after {
        left: 24px;
        top: 50px;
        height: calc(100% - 50px);
        width: 2px;
    }
    
    .subscription-info {
        flex-direction: column;
        align-items: center;
    }
    
    .subscription-plan.popular {
        order: -1;
    }
}

@media (max-width: 768px) {
    .header .container {
        flex-direction: column;
    }
    
    .logo {
        margin-bottom: var(--spacing-md);
    }
    
    nav ul {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    nav ul li {
        margin: 0 var(--spacing-sm) var(--spacing-sm);
    }
    
    .features-grid,
    .testimonial-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .download-options {
        flex-direction: column;
        align-items: center;
    }
    
    .footer-nav {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .footer-nav-column {
        margin-bottom: var(--spacing-xl);
    }
    
    .social-links {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .features h2,
    .how-it-works h2,
    .app-preview h2,
    .testimonials h2,
    .download h2 {
        font-size: 2rem;
    }
    
    .phone-mockups {
        flex-direction: column;
        align-items: center;
    }
    
    .tab-btn {
        padding: 8px 16px;
        font-size: 0.9rem;
    }
}