/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --success-color: #10b981;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "微软雅黑", sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-white);
}

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

/* 导航栏 */
.navbar {
    background: var(--bg-white);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
}

.logo {
    flex-shrink: 0;
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 600;
    transition: all 0.2s;
    padding: 8px 16px;
    border-radius: 6px;
}

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

/* 按钮样式 */
.btn-primary {
    background: var(--primary-color);
    color: white;
    padding: 10px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    display: inline-block;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    padding: 10px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    display: inline-block;
    border: 2px solid var(--primary-color);
}

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

.btn-large {
    padding: 14px 32px;
    font-size: 18px;
}

/* Hero 区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 100px 0;
    text-align: center;
}

.hero-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 20px;
    backdrop-filter: blur(10px);
}

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

.hero-title {
    font-size: 48px;
    font-weight: 800;
    margin-bottom: 24px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 32px;
    opacity: 0.95;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.feature-tag {
    background: rgba(255, 255, 255, 0.2);
    padding: 8px 20px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
    backdrop-filter: blur(10px);
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
    margin-bottom: 24px;
}

.hero-version {
    font-size: 14px;
    opacity: 0.8;
}

/* 区块标题 */
.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 60px;
    color: var(--text-primary);
}

/* 产品价值 */
.value-props {
    padding: 80px 0;
    background: var(--bg-light);
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 32px;
}

.value-card {
    background: var(--bg-white);
    padding: 40px 32px;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s;
    border: 1px solid var(--border-color);
}

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

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

.value-card h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

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

/* 核心功能 */
.features {
    padding: 80px 0;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 40px;
}

.feature-item {
    position: relative;
    padding-left: 80px;
}

.feature-number {
    position: absolute;
    left: 0;
    top: 0;
    font-size: 48px;
    font-weight: 800;
    color: var(--primary-color);
    opacity: 0.2;
}

.feature-item h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

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

/* 适用场景 */
.scenarios {
    padding: 80px 0;
    background: var(--bg-light);
}

.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.scenario-card {
    background: var(--bg-white);
    padding: 40px;
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.scenario-card h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.scenario-card ul {
    list-style: none;
}

.scenario-card li {
    padding: 10px 0 10px 28px;
    position: relative;
    color: var(--text-secondary);
    line-height: 1.6;
}

.scenario-card li:before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* 下载区域 */
.download {
    padding: 80px 0;
}

.download-content {
    max-width: 900px;
    margin: 0 auto;
}

.download-info {
    background: var(--bg-light);
    padding: 32px;
    border-radius: 12px;
    margin-bottom: 40px;
}

.download-info h3 {
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--primary-color);
}

.download-info ul {
    list-style: none;
    margin-top: 12px;
}

.download-info li {
    padding: 8px 0;
    color: var(--text-secondary);
}

.download-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.download-card {
    background: var(--bg-white);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 32px;
    text-align: center;
    transition: all 0.3s;
}

.download-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.download-card.recommended {
    position: relative;
    border-color: var(--primary-color);
    background: linear-gradient(to bottom, #f0f7ff, var(--bg-white));
}

.recommended-badge {
    position: absolute;
    top: -12px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}

.download-card.seller-version {
    border-color: #f59e0b;
    background: linear-gradient(to bottom, #fffbeb, var(--bg-white));
}

.download-card.seller-version h4 {
    color: #f59e0b;
}

.download-card h4 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.download-card p {
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.download-size {
    font-size: 14px;
    color: var(--text-secondary);
    margin-bottom: 24px !important;
}

.btn-download {
    background: var(--primary-color);
    color: white;
    padding: 12px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    display: inline-block;
    transition: all 0.2s;
}

.btn-download:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

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

.download-notice {
    background: #fef3c7;
    border: 1px solid #fbbf24;
    border-radius: 8px;
    padding: 20px;
    text-align: center;
}

.download-notice p {
    margin: 8px 0;
    color: var(--text-primary);
}

/* 常见问题 */
.faq {
    padding: 80px 0;
    background: var(--bg-light);
}

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

.faq-item {
    background: var(--bg-white);
    padding: 32px;
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
}

.faq-item h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

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

/* 联系申请 */
.contact {
    padding: 80px 0;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 60px;
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-primary);
}

.contact-info ul {
    list-style: none;
    margin-bottom: 32px;
}

.contact-info li {
    padding: 8px 0;
    padding-left: 24px;
    position: relative;
    color: var(--text-secondary);
}

.contact-info li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: bold;
}

.contact-methods {
    background: var(--bg-light);
    padding: 24px;
    border-radius: 8px;
    margin-top: 24px;
}

.contact-methods p {
    margin: 8px 0;
    color: var(--text-secondary);
}

/* 表单 */
.contact-form {
    background: var(--bg-light);
    padding: 40px;
    border-radius: 12px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.btn-submit {
    width: 100%;
    background: var(--primary-color);
    color: white;
    padding: 14px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-submit:hover {
    background: var(--secondary-color);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

/* 页脚 */
.footer {
    background: var(--text-primary);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 60px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-brand p {
    color: #9ca3af;
    line-height: 1.6;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

.footer-section h4 {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-section a {
    display: block;
    color: #9ca3af;
    text-decoration: none;
    margin-bottom: 12px;
    transition: color 0.2s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    border-top: 1px solid #374151;
    padding-top: 24px;
    text-align: center;
    color: #9ca3af;
    font-size: 14px;
}

.footer-bottom p {
    margin: 4px 0;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .hero-title {
        font-size: 32px;
    }

    .hero-subtitle {
        font-size: 18px;
    }

    .section-title {
        font-size: 28px;
    }

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

    .contact-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .footer-links {
        grid-template-columns: 1fr;
        gap: 30px;
    }
}

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

.value-card,
.feature-item,
.scenario-card,
.faq-item {
    animation: fadeIn 0.6s ease-out;
}