html {
    scroll-behavior: smooth;
}

:root {
    --primary-color: #333333;
    --text-main: #333333;
    --text-secondary: #666666;
    --bg-light: #FAFAFA;
    --bg-white: #FFFFFF;
    --border-color: #E8E8E8;
    --font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--bg-white);
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.navbar {
    height: 64px;
    display: flex;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    width: 100%;
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    font-size: 20px;
    font-weight: 600;
    letter-spacing: 1px;
}

nav ul {
    display: flex;
    list-style: none;
}

nav ul li {
    margin: 0 20px;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-main);
    font-size: 15px;
    transition: color 0.3s;
}

nav ul li a:hover {
    color: #000;
}

.auth-buttons {
    display: flex;
    align-items: center;
}

.btn-text {
    text-decoration: none;
    color: var(--text-main);
    margin-right: 20px;
    font-size: 15px;
}

.btn-primary {
    text-decoration: none;
    background-color: var(--primary-color);
    color: #fff;
    padding: 8px 20px;
    border-radius: 4px;
    font-size: 15px;
    transition: background-color 0.3s;
}

.btn-primary:hover {
    background-color: #000;
}

/* Sections with scroll margin for fixed header */
section[id] {
    scroll-margin-top: 64px;
}

/* Hero Section */
.hero {
    padding: 120px 0 60px;
    text-align: center;
    background-color: var(--bg-white);
}

.hero h1 {
    font-size: 48px;
    font-weight: 500;
    margin-bottom: 16px;
    letter-spacing: -0.5px;
}

.hero .subtitle {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 32px;
}

.hero-actions {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 60px;
}

.hero-image {
    max-width: 900px;
    margin: 0 auto;
    box-shadow: 0 20px 50px rgba(0,0,0,0.1);
    border-radius: 8px;
    overflow: hidden;
}

.hero-image img {
    width: 100%;
    display: block;
}

/* Products Section */
.products {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.section-title {
    text-align: center;
    font-size: 32px;
    margin-bottom: 48px;
    font-weight: 500;
}

.product-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
}

.product-card {
    height: 240px;
    background-size: cover;
    background-position: center;
    border-radius: 12px;
    position: relative;
    overflow: hidden;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

.card-content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 24px;
    background: linear-gradient(transparent, rgba(0,0,0,0.6));
    color: #fff;
}

.card-content h3 {
    font-size: 20px;
    margin-bottom: 4px;
}

.card-content p {
    font-size: 14px;
    opacity: 0.9;
}

/* Collaboration Section */
.collaboration {
    padding: 120px 0;
    background-size: cover;
    background-position: center;
    color: #fff;
    text-align: center;
    position: relative;
}

.collaboration::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.4);
}

.collab-content {
    position: relative;
    z-index: 1;
    max-width: 600px;
    margin: 0 auto;
}

.collab-content h2 {
    font-size: 36px;
    margin-bottom: 20px;
}

.collab-content p {
    font-size: 18px;
    margin-bottom: 32px;
}

/* Scenarios Section */
.scenarios {
    padding: 80px 0;
}

.scenario-item {
    display: flex;
    align-items: center;
    gap: 60px;
}

.scenario-text {
    flex: 1;
}

.scenario-text h2 {
    font-size: 32px;
    margin-bottom: 20px;
}

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

.scenario-image {
    flex: 1.2;
}

.scenario-image img {
    width: 100%;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
}

/* Pricing Section */
.pricing {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.pricing-card {
    background: var(--bg-white);
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    border: 1px solid var(--border-color);
    transition: all 0.3s ease;
    position: relative;
    display: flex;
    flex-direction: column;
}

.pricing-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.05);
}

.pricing-card.featured {
    border: 2px solid var(--primary-color);
}

.pricing-card .badge {
    position: absolute;
    top: 0;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--primary-color);
    color: #fff;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
}

.pricing-card h3 {
    font-size: 24px;
    margin-bottom: 20px;
}

.pricing-card .price {
    font-size: 36px;
    font-weight: 600;
    margin-bottom: 30px;
}

.pricing-card ul {
    list-style: none;
    margin-bottom: 40px;
    text-align: left;
    flex-grow: 1;
}

.pricing-card ul li {
    margin-bottom: 12px;
    color: var(--text-secondary);
    padding-left: 24px;
    position: relative;
}

.pricing-card ul li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

.btn-outline {
    text-decoration: none;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    padding: 10px 20px;
    border-radius: 4px;
    font-size: 15px;
    transition: all 0.3s;
}

.btn-outline:hover {
    background: var(--primary-color);
    color: #fff;
}

/* Download Section */
.download {
    padding: 100px 0;
    background-color: var(--bg-white);
    text-align: center;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 40px;
    margin-top: 50px;
}

.download-item {
    padding: 40px 20px;
    border-radius: 12px;
    transition: all 0.3s;
}

.download-item:hover {
    background-color: var(--bg-light);
}

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

.download-item h3 {
    font-size: 22px;
    margin-bottom: 10px;
}

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

.download-btns {
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
}

.download-btns .btn-outline {
    width: 100%;
    max-width: 200px;
}

/* Footer */
footer {
    padding: 60px 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
}

footer .logo {
    margin-bottom: 16px;
    opacity: 0.6;
}

footer p {
    color: var(--text-secondary);
    font-size: 14px;
}

@media (max-width: 768px) {
    .navbar nav, .auth-buttons {
        display: none;
    }
    
    .hero h1 {
        font-size: 32px;
    }
    
    .scenario-item {
        flex-direction: column;
        text-align: center;
    }
}