/* 闪连VPN SEO Optimized CSS */

:root {
    --primary-color: #0d6efd;
    --secondary-color: #6c757d;
    --bg-color: #f8f9fa;
    --text-color: #333;
    --heading-color: #212529;
    --white: #fff;
    --border-color: #e9ecef;
}

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

body {
    font-family: "Helvetica Neue", Helvetica, Arial, "Microsoft YaHei", sans-serif;
    color: var(--text-color);
    background-color: var(--bg-color);
    line-height: 1.6;
}

a {
    text-decoration: none;
    color: var(--primary-color);
    transition: color 0.3s;
}

a:hover {
    color: #0b5ed7;
}

h1, h2, h3, h4, h5, h6 {
    color: var(--heading-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
}

/* Header */
.header {
    background: var(--white);
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo h1 a {
    color: var(--primary-color);
    font-size: 1.8rem;
    font-weight: 700;
}

.nav ul {
    list-style: none;
    display: flex;
    gap: 20px;
}

.nav a {
    color: var(--text-color);
    font-weight: 500;
}

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

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: 4px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    border: 1px solid transparent;
}

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

.btn-primary:hover {
    background-color: #0b5ed7;
    color: var(--white);
}

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

.btn-secondary:hover {
    background-color: #e9ecef;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #e0f2fe 0%, #bae6fd 100%);
    padding: 5rem 0;
    text-align: center;
}

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

.hero p {
    font-size: 1.2rem;
    color: var(--secondary-color);
    margin-bottom: 2rem;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.download-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
}

/* Features Section */
.features {
    padding: 4rem 0;
    background: var(--white);
}

.features h3 {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 2rem;
}

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

.feature-card {
    padding: 2rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    background: var(--bg-color);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.05);
}

.feature-card h4 {
    font-size: 1.25rem;
    color: var(--primary-color);
}

/* Download Section */
.download-section {
    padding: 4rem 0;
    text-align: center;
}

.download-section h3 {
    font-size: 2rem;
}

.download-section > p {
    margin-bottom: 3rem;
    color: var(--secondary-color);
}

.platforms {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.platform-card {
    background: var(--white);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.platform-card h4 {
    margin-bottom: 0.5rem;
}

.platform-card p {
    color: var(--secondary-color);
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}

.btn-download {
    background: var(--primary-color);
    color: var(--white);
    display: block;
    width: 100%;
}

/* SEO Content */
.seo-content {
    padding: 4rem 0;
    background: var(--white);
}

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

.seo-content h3 {
    font-size: 1.8rem;
}

.seo-content p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

.seo-content strong {
    color: var(--heading-color);
}

/* Footer */
.footer {
    background: #212529;
    color: #adb5bd;
    padding: 2rem 0;
    text-align: center;
}

.footer-links {
    margin-bottom: 1rem;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.footer-links a {
    color: #adb5bd;
}

.footer-links a:hover {
    color: var(--white);
}

/* Responsive */
@media (max-width: 768px) {
    .nav ul {
        flex-direction: column;
        gap: 10px;
        align-items: center;
    }
    
    .header .container {
        flex-direction: column;
        gap: 15px;
    }

    .download-buttons {
        flex-direction: column;
    }
}