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

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

header {
    background: linear-gradient(135deg, #1E88E5 0%, #42A5F5 100%);
    color: white;
    padding: 1rem 0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    text-decoration: none;
    color: white;
}

nav {
    display: flex;
    gap: 30px;
}

nav a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s;
}

nav a:hover {
    opacity: 0.8;
}

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

.hero {
    background: linear-gradient(135deg, #1E88E5 0%, #42A5F5 100%);
    color: white;
    padding: 80px 20px;
    text-align: center;
    border-radius: 10px;
    margin: 40px 0;
}

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

.hero-subtitle {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 15px 40px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
    cursor: pointer;
    border: none;
    font-size: 16px;
}

.btn-primary {
    background: white;
    color: #1E88E5;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 20px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: rgba(255,255,255,0.2);
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #1E88E5;
}

.advantages {
    margin: 80px 0;
}

.advantages h2,
.features-section h2,
.stats h2,
.download-guide h2,
.faq h2 {
    font-size: 36px;
    margin-bottom: 50px;
    text-align: center;
    color: #1E88E5;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.advantage-card {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
    transition: all 0.3s;
}

.advantage-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}

.icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.advantage-card h3 {
    color: #1E88E5;
    margin-bottom: 15px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
}

.feature-item {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid #1E88E5;
}

.feature-item h3 {
    color: #1E88E5;
    margin-bottom: 10px;
}

.stats {
    background: linear-gradient(135deg, #1E88E5 0%, #42A5F5 100%);
    color: white;
    padding: 60px 20px;
    border-radius: 10px;
    margin: 60px 0;
}

.stats h2 {
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 30px;
    text-align: center;
}

.stat-card {
    background: rgba(255,255,255,0.1);
    padding: 30px;
    border-radius: 8px;
}

.stat-number {
    font-size: 36px;
    font-weight: bold;
    margin-bottom: 10px;
}

.download-guide {
    margin: 60px 0;
}

.download-options {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.download-option {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
    border-top: 4px solid #1E88E5;
}

.download-option h3 {
    color: #1E88E5;
    margin-bottom: 15px;
}

.faq-list {
    display: grid;
    gap: 20px;
}

.faq-item {
    background: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    border-left: 4px solid #1E88E5;
}

.faq-item h3 {
    color: #1E88E5;
    margin-bottom: 10px;
    cursor: pointer;
}

footer {
    background: #2c3e50;
    color: white;
    padding: 40px 20px;
    margin-top: 80px;
    text-align: center;
}

.download-main {
    padding: 40px 0;
}

.download-main h1 {
    font-size: 40px;
    color: #1E88E5;
    margin-bottom: 15px;
}

.subtitle {
    font-size: 18px;
    color: #666;
    margin-bottom: 40px;
}

.download-versions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 40px 0;
}

.version-card {
    background: white;
    padding: 40px 25px;
    border-radius: 10px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    text-align: center;
    border-top: 5px solid #1E88E5;
}

.version-card:hover {
    transform: translateY(-10px);
}

.os-icon {
    font-size: 64px;
    margin-bottom: 15px;
}

.version-card h2 {
    color: #1E88E5;
}

.download-instructions {
    background: #f8f9fa;
    padding: 30px;
    border-radius: 10px;
    margin: 40px 0;
}

.download-instructions h2 {
    color: #1E88E5;
    margin-bottom: 20px;
}

.system-requirements {
    margin: 40px 0;
}

.requirements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-top: 25px;
}

.requirement {
    background: white;
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
    border-left: 4px solid #1E88E5;
}

.requirement h3 {
    color: #1E88E5;
    margin-bottom: 15px;
}

.features-main h1,
.download-main h1,
.about-main h1 {
    font-size: 40px;
    color: #1E88E5;
    margin-bottom: 15px;
}

.feature-category {
    margin: 40px 0;
}

.feature-category h2 {
    color: #1E88E5;
    margin-bottom: 25px;
    border-bottom: 2px solid #1E88E5;
    padding-bottom: 15px;
}

.feature-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.feature-detail {
    background: #f8f9fa;
    padding: 25px;
    border-radius: 8px;
    border-left: 4px solid #1E88E5;
}

.feature-detail h3 {
    color: #1E88E5;
    margin-bottom: 10px;
}

.about-content {
    padding: 40px 0;
}

.about-section {
    margin-bottom: 50px;
}

.about-section h2 {
    color: #1E88E5;
    margin-bottom: 20px;
    border-bottom: 2px solid #1E88E5;
    padding-bottom: 10px;
}

.values-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.value-card {
    background: linear-gradient(135deg, #1E88E5 0%, #42A5F5 100%);
    color: white;
    padding: 25px;
    border-radius: 8px;
    text-align: center;
}

.value-card h3 {
    margin-bottom: 10px;
}

@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 32px;
    }

    nav {
        display: none;
    }

    .advantages-grid,
    .features-grid,
    .download-versions {
        grid-template-columns: 1fr;
    }
}