/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f9f9f9;
}

a {
    text-decoration: none;
    color: #007bff;
    transition: color 0.3s;
}

a:hover {
    color: #0056b3;
}

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

/* Header & Navigation */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
}

.logo a {
    font-size: 24px;
    color: #333;
}

.nav-links a {
    margin-left: 20px;
    color: #666;
    font-weight: 500;
}

.nav-links a.active, .nav-links a:hover {
    color: #007bff;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #007bff 0%, #6610f2 100%);
    color: #fff;
    padding: 80px 0;
    text-align: center;
}

.hero h1 {
    font-size: 48px;
    margin-bottom: 20px;
}

.hero .subtitle {
    font-size: 20px;
    margin-bottom: 40px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.download-buttons {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 20px;
}

.btn {
    padding: 15px 30px;
    border-radius: 8px;
    font-size: 18px;
    font-weight: bold;
    cursor: pointer;
    display: inline-block;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

.btn-primary {
    background: #fff;
    color: #007bff;
}

.btn-secondary {
    background: rgba(255,255,255,0.2);
    color: #fff;
    border: 1px solid #fff;
}

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

/* Features Section */
.features {
    padding: 60px 0;
    background: #fff;
}

.features h2 {
    text-align: center;
    font-size: 32px;
    margin-bottom: 40px;
}

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

.feature-card {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    transition: transform 0.3s;
}

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

.feature-card h3 {
    font-size: 24px;
    margin-bottom: 15px;
    color: #333;
}

/* Download Section */
.download-section {
    padding: 60px 0;
}

.bg-light {
    background-color: #f1f3f5;
}

.download-section h2 {
    text-align: center;
    font-size: 32px;
    margin-bottom: 15px;
}

.section-desc {
    text-align: center;
    margin-bottom: 40px;
    color: #666;
    font-size: 18px;
}

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

.os-card {
    background: #fff;
    padding: 40px 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

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

.os-card h3 {
    font-size: 24px;
    margin-bottom: 10px;
}

.os-card p {
    color: #666;
    margin-bottom: 25px;
}

.btn-download {
    display: block;
    background: #28a745;
    color: #fff;
    margin-bottom: 10px;
    padding: 12px;
    font-size: 16px;
}

.btn-outline {
    display: block;
    background: transparent;
    color: #007bff;
    border: 1px solid #007bff;
    padding: 12px;
    font-size: 16px;
}

.btn-outline:hover {
    background: #007bff;
    color: #fff;
}

/* SEO Content & Article Pages */
.seo-content, .page-content {
    padding: 60px 0;
    background: #fff;
}

.seo-content h2 {
    font-size: 28px;
    margin-bottom: 20px;
    border-bottom: 2px solid #007bff;
    padding-bottom: 10px;
    display: inline-block;
}

.seo-content h3 {
    font-size: 22px;
    margin-top: 25px;
    margin-bottom: 10px;
}

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

.page-title {
    font-size: 36px;
    margin-bottom: 20px;
    color: #222;
}

.lead {
    font-size: 18px;
    color: #555;
    margin-bottom: 40px;
}

.text-center {
    text-align: center;
}

/* Step Guide (Tutorial) */
.step-guide h2 {
    font-size: 24px;
    margin-top: 30px;
    margin-bottom: 15px;
    color: #007bff;
}

.step-card {
    background: #f8f9fa;
    padding: 20px;
    border-left: 4px solid #007bff;
    border-radius: 4px;
    margin-bottom: 20px;
}

.step-card ol {
    margin-left: 20px;
    margin-top: 10px;
}

.step-card li {
    margin-bottom: 10px;
}

.notice-box {
    background: #e1f5fe;
    padding: 15px;
    border-radius: 6px;
    margin-top: 30px;
    color: #0277bd;
}

/* FAQ List */
.faq-list {
    margin-top: 30px;
}

.faq-item {
    background: #fff;
    border: 1px solid #e9ecef;
    border-radius: 8px;
    padding: 25px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.02);
}

.faq-question {
    font-size: 20px;
    color: #333;
    margin-bottom: 15px;
}

.faq-answer {
    color: #555;
    line-height: 1.8;
}

/* Footer */
.footer {
    background: #343a40;
    color: #fff;
    padding: 40px 0;
    text-align: center;
}

.footer-links {
    margin-bottom: 20px;
}

.footer-links a {
    color: #adb5bd;
    margin: 0 15px;
}

.footer-links a:hover {
    color: #fff;
}

.copyright {
    color: #6c757d;
    font-size: 14px;
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 { font-size: 32px; }
    .hero .subtitle { font-size: 16px; }
    .download-buttons { flex-direction: column; }
    .nav-links { display: none; /* Simple mobile hide */ }
}