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

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --bg: #ffffff;
    --bg-secondary: #f8fafc;
    --border: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 1px 3px 0 rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========== 导航栏 ========== */
.nav {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.nav-menu {
    display: flex;
    gap: 3rem;
    list-style: none;
}

.nav-item {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: color 0.2s;
    position: relative;
}

.nav-item::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary);
    transition: width 0.3s;
}

.nav-item:hover,
.nav-item.active {
    color: var(--text-primary);
}

.nav-item.active::after {
    width: 100%;
}

/* ========== 主要内容 ========== */
.main {
    min-height: calc(100vh - 70px);
}

.page {
    display: none;
    animation: fadeIn 0.5s;
}

.page.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ========== 英雄区 ========== */
.hero {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem 3rem;
    text-align: center;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 1rem;
    line-height: 1.1;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    font-weight: 400;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

/* ========== 按钮 ========== */
.btn {
    padding: 0.875rem 2rem;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    text-decoration: none;
    display: inline-block;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

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

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

.btn-outline {
    background: transparent;
    color: var(--primary);
    border: 1px solid var(--primary);
}

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

.btn-large {
    padding: 1.125rem 2.5rem;
    font-size: 1.125rem;
}

/* ========== 区块 ========== */
.section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 2rem;
    letter-spacing: -0.02em;
}

.section-dark {
    background: var(--text-primary);
    color: white;
    width: 100%;
    max-width: 100%;
}

.section-dark .content-block {
    max-width: 800px;
    margin: 0 auto;
}

/* ========== 价格卡片 ========== */
.price-card {
    max-width: 400px;
    margin: 0 auto;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: 1rem;
    text-align: center;
    border: 1px solid var(--border);
}

.price-badge {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--primary);
    color: white;
    border-radius: 2rem;
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.price-main {
    margin-bottom: 1.5rem;
}

.price-amount {
    font-size: 4rem;
    font-weight: 700;
    color: var(--primary);
}

.price-unit {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-left: 0.5rem;
}

.price-divider {
    width: 50%;
    height: 1px;
    background: var(--border);
    margin: 1.5rem auto;
}

.price-yearly {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.price-note {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* ========== 功能卡片 ========== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.feature-card {
    padding: 2rem 1.5rem;
    text-align: center;
    border: 1px solid var(--border);
    border-radius: 1rem;
    transition: all 0.3s;
}

.feature-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

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

.feature-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.feature-desc {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* ========== 文本样式 ========== */
.text-lead {
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: 1rem;
    color: rgba(255, 255, 255, 0.9);
}

.text-muted {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.link-text {
    color: var(--primary);
    cursor: pointer;
    text-decoration: underline;
    font-weight: 600;
}

/* ========== 页面标题 ========== */
.page-header {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem 1rem;
}

.page-title {
    font-size: 2.5rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

/* ========== 视频容器 ========== */
.video-container {
    max-width: 900px;
    margin: 0 auto;
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    aspect-ratio: 16 / 9;
}

.video-container iframe {
    width: 100%;
    height: 100%;
    border: none;
}

/* ========== 图库 ========== */
.gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.gallery-item {
    border-radius: 1rem;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

.gallery-item:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

/* ========== 选项卡 ========== */
.tabs {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem 1rem;
    display: flex;
    gap: 0.5rem;
    border-bottom: 1px solid var(--border);
}

.tab {
    padding: 1rem 2rem;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

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

.tab.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
}

.tab-content {
    display: none;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 2rem;
}

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

/* ========== 步骤 ========== */
.steps {
    max-width: 800px;
    margin: 0 auto;
}

.step {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.step-number {
    flex-shrink: 0;
    width: 60px;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    font-size: 1.25rem;
    font-weight: 700;
}

.step-content {
    flex: 1;
}

.step-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.step-desc {
    color: var(--text-secondary);
    margin-bottom: 1rem;
    font-size: 1rem;
    line-height: 1.6;
}

.step-link {
    margin-bottom: 1rem;
}

.step-link a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
}

.step-link a:hover {
    text-decoration: underline;
}

.step-list {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.step-list li {
    margin-bottom: 0.25rem;
    line-height: 1.6;
}

.step-image {
    margin: 1rem 0;
    border-radius: 0.5rem;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.step-image img {
    width: 100%;
    height: auto;
    display: block;
}

.step-note {
    margin-top: 1rem;
    padding: 1rem;
    background: var(--bg-secondary);
    border-left: 4px solid var(--primary);
    border-radius: 0.5rem;
}

.step-note p {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ========== 时间线 ========== */
.timeline {
    max-width: 800px;
    margin: 0 auto;
}

.timeline-item {
    display: flex;
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding-bottom: 2rem;
    border-bottom: 1px solid var(--border);
}

.timeline-item:last-child {
    border-bottom: none;
}

.timeline-date {
    flex-shrink: 0;
    width: 120px;
    font-weight: 700;
    color: var(--primary);
}

.timeline-content ul {
    margin-left: 1.5rem;
    color: var(--text-secondary);
}

.timeline-content li {
    margin-bottom: 0.5rem;
    line-height: 1.7;
}

/* ========== 下载卡片 ========== */
.download-card {
    max-width: 600px;
    margin: 0 auto;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: 1rem;
    border: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.download-info h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.download-info p {
    color: var(--text-secondary);
}

.download-links {
    max-width: 600px;
    margin: 2rem auto 0;
    text-align: center;
}

.download-link {
    display: inline-flex;
    flex-direction: column;
    gap: 0.25rem;
    padding: 1rem 2rem;
    color: var(--primary);
    text-decoration: none;
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    transition: all 0.2s;
}

.download-link:hover {
    border-color: var(--primary);
    background: var(--bg-secondary);
}

/* ========== 联系网格 ========== */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    max-width: 800px;
    margin: 0 auto;
}

.contact-card {
    text-align: center;
    padding: 1.5rem;
    border: 1px solid var(--border);
    border-radius: 1rem;
    transition: all 0.3s;
}

.contact-card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.contact-card img {
    width: 180px;
    height: 180px;
    margin: 0 auto 1rem;
    border-radius: 0.5rem;
    object-fit: contain;
}

.contact-card p {
    font-weight: 600;
    color: var(--text-secondary);
}

.contact-info {
    max-width: 600px;
    margin: 2rem auto;
    padding: 1.5rem;
    background: var(--bg-secondary);
    border-radius: 1rem;
    text-align: center;
}

.contact-email {
    display: flex;
    gap: 1rem;
    justify-content: center;
    align-items: center;
    font-size: 1.125rem;
}

.contact-label {
    color: var(--text-secondary);
    font-weight: 600;
}

.contact-links {
    max-width: 800px;
    margin: 1.5rem auto;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    justify-content: center;
}

/* ========== 页脚 ========== */
.footer {
    border-top: 1px solid var(--border);
    padding: 2rem 2rem;
    text-align: center;
    color: var(--text-muted);
}

/* ========== 响应式 ========== */
@media (max-width: 768px) {
    .nav-container {
        padding: 0 1rem;
        height: 60px;
    }

    .nav-menu {
        gap: 1.5rem;
        font-size: 0.875rem;
    }

    .hero {
        padding: 3rem 1rem 2rem;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .hero-actions {
        flex-direction: column;
    }

    .section {
        padding: 2rem 1rem;
    }

    .section-title {
        font-size: 1.75rem;
    }

    .page-header {
        padding: 2rem 1rem 0.5rem;
    }

    .page-title {
        font-size: 1.75rem;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .gallery {
        grid-template-columns: 1fr;
    }

    .tabs {
        overflow-x: auto;
        padding: 0 1rem 1rem;
    }

    .tab {
        white-space: nowrap;
        padding: 0.75rem 1.5rem;
    }

    .tab-content {
        padding: 2rem 1rem;
    }

    .step {
        flex-direction: column;
        gap: 1rem;
    }

    .timeline-item {
        flex-direction: column;
        gap: 0.5rem;
    }

    .download-card {
        flex-direction: column;
        gap: 2rem;
        text-align: center;
    }

    .contact-grid {
        grid-template-columns: 1fr;
    }

    .contact-links {
        flex-direction: column;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .price-amount {
        font-size: 2.5rem;
    }

    .btn {
        width: 100%;
    }
    
    .section {
        padding: 1.5rem 1rem;
    }
}