:root {
    --primary-color: #007fff;
    --secondary-color: #333;
    --bg-color: #f4f7f9;
    --text-color: #444;
    --container-width: 1000px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    margin: 0;
    padding: 0;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 20px;
}

header {
    background: #fff;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    padding: 15px 0;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 24px;
    font-weight: bold;
    color: var(--primary-color);
}

nav ul {
    list-style: none;
    display: flex;
    margin: 0;
    padding: 0;
}

nav ul li {
    margin-left: 20px;
}

nav ul li a {
    text-decoration: none;
    color: #666;
    font-weight: 500;
}

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

.hero, .hero-sub {
    background: linear-gradient(135deg, #007fff 0%, #0059b2 100%);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}

.hero h1 { font-size: 42px; margin-bottom: 10px; }
.hero p { font-size: 20px; opacity: 0.9; }

.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: bold;
    transition: all 0.3s;
    cursor: pointer;
}

.btn-primary { background: #fff; color: var(--primary-color); }
.btn-primary:hover { background: #f0f0f0; transform: translateY(-2px); }
.btn-secondary { background: rgba(255,255,255,0.2); color: #fff; border: 1px solid #fff; margin-left: 10px; }

.grid, .download-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin: 40px 0;
}

.card {
    background: #fff;
    padding: 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(0,0,0,0.05);
}

.card h3 { color: var(--primary-color); margin-top: 0; }
.card.highlight { border: 2px solid var(--primary-color); }

.content-rich {
    background: #fff;
    padding: 40px;
    border-radius: 10px;
    margin-bottom: 40px;
}

.faq { margin-bottom: 60px; }
.faq-item { margin-bottom: 20px; background: #fff; padding: 20px; border-radius: 5px; }
.faq-item h4 { margin-top: 0; color: var(--primary-color); }

footer {
    background: #333;
    color: #ccc;
    padding: 40px 0;
    text-align: center;
    font-size: 14px;
}

.timeline { margin: 40px 0; }
.update-item { background: #fff; padding: 20px; border-left: 4px solid var(--primary-color); margin-bottom: 20px; }
.update-item .version { font-weight: bold; font-size: 18px; margin-bottom: 10px; }

@media (max-width: 768px) {
    .grid, .download-grid { grid-template-columns: 1fr; }
    .hero h1 { font-size: 32px; }
}