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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f9fafb;
}

a {
    text-decoration: none;
    color: #0052d9;
}

/* 布局容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}
.text-center {
    text-align: center;
}

/* 导航栏 */
.header {
    background-color: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
}
.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}
.logo strong {
    font-size: 24px;
    color: #d32f2f;
}
.nav-links a {
    margin: 0 15px;
    color: #4b5563;
    font-weight: 500;
    transition: color 0.3s;
}
.nav-links a:hover, .nav-links a.active {
    color: #d32f2f;
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 4px;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s ease;
    cursor: pointer;
}
.btn-primary {
    background-color: #d32f2f;
    color: #fff;
    border: 1px solid #d32f2f;
}
.btn-primary:hover {
    background-color: #b71c1c;
    color: #fff;
}
.btn-secondary {
    background-color: #fff;
    color: #d32f2f;
    border: 1px solid #d32f2f;
}
.btn-secondary:hover {
    background-color: #fce4e4;
}
.btn-large {
    padding: 14px 32px;
    font-size: 18px;
    margin: 10px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #fce4e4 0%, #fff 100%);
    padding: 80px 0;
    text-align: center;
}
.hero h1 {
    font-size: 42px;
    color: #111827;
    margin-bottom: 20px;
}
.hero p {
    font-size: 18px;
    color: #4b5563;
    max-width: 800px;
    margin: 0 auto 40px;
}
.stats {
    margin-top: 50px;
    display: flex;
    justify-content: center;
    gap: 40px;
    color: #6b7280;
}
.stats strong {
    font-size: 24px;
    color: #111827;
    display: block;
}

/* Download Section */
.download-section {
    padding: 80px 0;
    background-color: #fff;
}
.download-section h2, .features-preview h2 {
    text-align: center;
    font-size: 32px;
    margin-bottom: 10px;
}
.section-desc {
    text-align: center;
    color: #6b7280;
    margin-bottom: 50px;
}
.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}
.download-card {
    background: #f9fafb;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
    padding: 40px 30px;
    text-align: center;
    transition: transform 0.3s;
}
.download-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}
.download-card h3 {
    font-size: 22px;
    margin-bottom: 15px;
}
.download-card p {
    color: #6b7280;
    margin-bottom: 25px;
    min-height: 48px;
}

/* Features */
.features-preview {
    padding: 80px 0;
}
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}
.feature-item {
    background: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.02);
}
.feature-item h3 {
    margin-bottom: 15px;
    color: #111827;
}
.feature-item p {
    color: #4b5563;
    font-size: 15px;
}

/* Inner Pages Header */
.page-header {
    background-color: #f3f4f6;
    padding: 60px 0;
    border-bottom: 1px solid #e5e7eb;
}
.page-header h1 {
    font-size: 36px;
    margin-bottom: 10px;
}
.page-header p {
    font-size: 18px;
    color: #6b7280;
}

/* Content Section */
.content-section {
    padding: 60px 0;
    background: #fff;
}
.feature-detail {
    margin-bottom: 50px;
    padding-bottom: 30px;
    border-bottom: 1px solid #f3f4f6;
}
.feature-detail:last-child {
    border-bottom: none;
}
.feature-detail h2 {
    font-size: 26px;
    margin-bottom: 20px;
    color: #1f2937;
}
.feature-detail p {
    font-size: 16px;
    margin-bottom: 15px;
    color: #4b5563;
}
.feature-detail ul {
    margin-left: 20px;
    color: #4b5563;
}
.feature-detail li {
    margin-bottom: 10px;
}

/* FAQ */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}
.faq-item {
    margin-bottom: 30px;
}
.faq-item h3 {
    font-size: 20px;
    color: #111827;
    margin-bottom: 10px;
    padding-left: 15px;
    border-left: 4px solid #d32f2f;
}
.faq-item p {
    color: #4b5563;
    padding-left: 19px;
}

/* Footer */
.footer {
    background-color: #1f2937;
    color: #9ca3af;
    padding: 40px 0;
    text-align: center;
}
.footer-links {
    margin-bottom: 20px;
}
.footer-links a {
    color: #e5e7eb;
    margin: 0 15px;
}
.footer-links a:hover {
    color: #fff;
}

/* 响应式 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    .hero h1 {
        font-size: 32px;
    }
    .stats {
        flex-direction: column;
        gap: 20px;
    }
}