/* ==========================================================================
   全局样式
   ========================================================================== */

:root {
    --primary-color: #0066cc;
    --primary-dark: #004999;
    --primary-light: #3385d6;
    --secondary-color: #00a8e8;
    --accent-color: #00d4ff;
    --text-dark: #1a1a1a;
    --text-light: #666666;
    --text-white: #ffffff;
    --bg-light: #f5f9ff;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;
    --shadow: 0 4px 6px rgba(0, 102, 204, 0.1);
    --shadow-hover: 0 8px 15px rgba(0, 102, 204, 0.2);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
}

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

/* ==========================================================================
   导航栏
   ========================================================================== */

.navbar {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow);
}

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

.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--text-white);
}

.nav-brand i {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    color: var(--text-white);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    padding: 0.5rem 1rem;
    border-radius: 5px;
}

.nav-menu a:hover,
.nav-menu a.active {
    background-color: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

/* ==========================================================================
   英雄区
   ========================================================================== */

.hero {
    position: relative;
    background: linear-gradient(135deg, #0066cc, #00a8e8);
    color: var(--text-white);
    padding: 120px 0;
    text-align: center;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,186.7C384,213,480,235,576,213.3C672,192,768,128,864,128C960,128,1056,192,1152,197.3C1248,203,1344,149,1392,122.7L1440,96L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat;
    background-size: cover;
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3rem;
    font-weight: bold;
    margin-bottom: 1rem;
    animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.95;
    animation: fadeInUp 0.8s ease 0.2s both;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 0.8s ease 0.4s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================================================
   按钮
   ========================================================================== */

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background-color: var(--accent-color);
    color: var(--text-white);
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-white);
    border: 2px solid var(--text-white);
}

.btn-secondary:hover {
    background-color: var(--text-white);
    color: var(--primary-color);
    transform: translateY(-3px);
}

.btn-large {
    padding: 15px 40px;
    font-size: 1.1rem;
}

/* ==========================================================================
   功能特色
   ========================================================================== */

.features {
    padding: 80px 0;
    background-color: var(--bg-white);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.section-subtitle {
    text-align: center;
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 3rem;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    transition: all 0.3s ease;
    border: 2px solid var(--border-color);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary-color);
}

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 1.5rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: 2rem;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--primary-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ==========================================================================
   优势展示
   ========================================================================== */

.advantages {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--bg-light), var(--bg-white));
}

.advantages-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.advantage-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
}

.advantage-number {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    opacity: 0.3;
    line-height: 1;
}

.advantage-text h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    color: var(--primary-dark);
}

.advantage-text p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ==========================================================================
   关于我们
   ========================================================================== */

.about {
    padding: 80px 0;
    background-color: var(--bg-white);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    margin-top: 3rem;
}

.about-text p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1.5rem;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 2rem;
}

.stat-item {
    text-align: center;
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: 10px;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-light);
    font-size: 0.9rem;
}

.about-image-placeholder {
    height: 400px;
    background: linear-gradient(135deg, var(--primary-light), var(--secondary-color));
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-white);
    font-size: 5rem;
}

/* ==========================================================================
   联系我们
   ========================================================================== */

.contact {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--bg-light), var(--bg-white));
}

.contact-content {
    margin-top: 3rem;
}

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

.contact-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.contact-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.contact-card i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.contact-card h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--primary-dark);
}

.contact-card p {
    color: var(--text-light);
    word-break: break-word;
}

/* ==========================================================================
   CTA区域
   ========================================================================== */

.cta {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: var(--text-white);
    padding: 80px 0;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.cta p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

/* ==========================================================================
   页脚
   ========================================================================== */

.footer {
    background: linear-gradient(135deg, var(--primary-dark), #001a33);
    color: var(--text-white);
    padding: 3rem 0 1rem;
}

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

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: var(--accent-color);
}

.footer-section p,
.footer-section li {
    margin-bottom: 0.5rem;
    opacity: 0.9;
    line-height: 1.8;
}

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

.footer-section a {
    color: var(--text-white);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: var(--accent-color);
}

.footer-section i {
    margin-right: 0.5rem;
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    margin: 0.5rem 0;
    opacity: 0.8;
}

.footer-bottom a {
    color: var(--text-white);
    text-decoration: none;
}

.footer-bottom a:hover {
    color: var(--accent-color);
}

/* ==========================================================================
   内容页面（隐私政策、服务条款）
   ========================================================================== */

.page-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: var(--text-white);
    padding: 80px 0 60px;
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.page-header p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.content-section {
    padding: 60px 0;
}

.content-box {
    background: var(--bg-white);
    padding: 3rem;
    border-radius: 15px;
    box-shadow: var(--shadow);
    max-width: 900px;
    margin: 0 auto;
}

.content-box h2 {
    color: var(--primary-color);
    font-size: 1.8rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-light);
}

.content-box h2:first-child {
    margin-top: 0;
}

.content-box h3 {
    color: var(--primary-dark);
    font-size: 1.3rem;
    margin-top: 1.5rem;
    margin-bottom: 0.8rem;
}

.content-box p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.content-box ul {
    margin: 1rem 0 1rem 2rem;
}

.content-box li {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 0.5rem;
}

.content-box strong {
    color: var(--primary-dark);
}

.terms-footer {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
    text-align: center;
}

.terms-footer p {
    color: var(--primary-color);
    font-size: 1.2rem;
}

/* ==========================================================================
   404错误页面
   ========================================================================== */

.error-page {
    padding: 100px 0;
    text-align: center;
}

.error-content {
    max-width: 600px;
    margin: 0 auto;
}

.error-code {
    font-size: 8rem;
    font-weight: bold;
    color: var(--primary-color);
    line-height: 1;
    margin-bottom: 1rem;
}

.error-content h2 {
    font-size: 2rem;
    color: var(--primary-dark);
    margin-bottom: 1rem;
}

.error-content p {
    color: var(--text-light);
    margin-bottom: 2rem;
    font-size: 1.1rem;
}

/* ==========================================================================
   响应式设计
   ========================================================================== */

@media (max-width: 768px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .content-box {
        padding: 1.5rem;
    }
    
    .page-header h1 {
        font-size: 2rem;
    }
    
    .error-code {
        font-size: 5rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .hero {
        padding: 80px 0;
    }
    
    .hero-title {
        font-size: 1.5rem;
    }
    
    .features,
    .advantages,
    .about,
    .contact,
    .cta {
        padding: 50px 0;
    }
}