:root {
    --primary-color: #0066ff;
    --secondary-color: #0052cc;
    --text-color: #333;
    --light-bg: #f5f7fa;
    --border-color: #e2e8f0;
}
* { margin: 0; padding: 0; box-sizing: border-box; font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; }
body { color: var(--text-color); line-height: 1.6; background-color: #fff; }
a { text-decoration: none; color: inherit; }
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.text-center { text-align: center; }

/* Header & Nav */
.header { border-bottom: 1px solid var(--border-color); background: #fff; padding: 15px 0; position: sticky; top: 0; z-index: 100; }
.header .container { display: flex; justify-content: space-between; align-items: center; }
.logo h1, .logo h2 { font-size: 24px; color: var(--primary-color); font-weight: bold; margin: 0;}
.nav ul { list-style: none; display: flex; gap: 30px; align-items: center; }
.nav a { font-size: 16px; font-weight: 500; transition: color 0.3s; }
.nav a:hover, .nav a.active { color: var(--primary-color); }
.btn-download-nav { background: var(--primary-color); color: #fff !important; padding: 8px 20px; border-radius: 4px; }
.btn-download-nav:hover { background: var(--secondary-color); }

/* Buttons */
.btn { display: inline-block; padding: 10px 24px; border-radius: 4px; font-weight: bold; text-align: center; cursor: pointer; transition: 0.3s; }
.btn-primary { background: var(--primary-color); color: #fff; border: none; }
.btn-primary:hover { background: var(--secondary-color); }
.btn-outline { background: transparent; color: var(--primary-color); border: 2px solid var(--primary-color); }
.btn-outline:hover { background: var(--primary-color); color: #fff; }
.btn-large { padding: 15px 40px; font-size: 18px; }

/* Hero Section */
.hero { background: var(--light-bg); padding: 80px 0; }
.hero-content { display: flex; align-items: center; justify-content: space-between; gap: 50px; }
.hero-text { flex: 1; }
.hero-text h2 { font-size: 36px; margin-bottom: 20px; color: #111; }
.hero-text p { font-size: 18px; color: #555; margin-bottom: 30px; }
.hero-image { flex: 1; text-align: right; }
.hero-image img { max-width: 100%; border-radius: 8px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); }

/* Grid Layouts */
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; margin-top: 40px; }
.grid-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 40px; margin-top: 40px; }

/* Feature Cards */
.features-summary { padding: 80px 0; text-align: center; }
.features-summary h3 { font-size: 28px; margin-bottom: 10px; }
.feature-card { padding: 30px; border: 1px solid var(--border-color); border-radius: 8px; 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: 20px; margin-bottom: 15px; color: var(--primary-color); }

/* SEO Content / FAQ */
.seo-content { padding: 60px 0; background: #fafafa; }
.seo-content h3 { font-size: 24px; margin-bottom: 30px; text-align: center; }
.faq-item { max-width: 800px; margin: 0 auto 25px; background: #fff; padding: 20px; border-radius: 8px; box-shadow: 0 2px 10px rgba(0,0,0,0.03); }
.faq-item h4 { font-size: 18px; margin-bottom: 10px; }
.faq-item p { color: #666; }

/* Download Page */
.page-header { padding: 60px 0; background: var(--primary-color); color: #fff; }
.page-header h1 { font-size: 36px; margin-bottom: 15px; }
.page-header p { font-size: 18px; opacity: 0.9; }
.download-card { border: 1px solid var(--border-color); border-radius: 8px; padding: 40px; text-align: center; background: #fff; }
.download-card h3 { font-size: 24px; margin-bottom: 10px; }
.version-info { color: #888; font-size: 14px; margin-bottom: 20px; }
.sys-req { text-align: left; margin: 0 auto 30px; max-width: 250px; color: #555; padding-left: 20px; }
.sys-req li { margin-bottom: 10px; }

/* Features Page */
.features-detail { padding: 60px 0; }
.feature-row { display: flex; align-items: center; gap: 50px; margin-bottom: 60px; padding: 40px; background: var(--light-bg); border-radius: 12px; }
.feature-row.reverse { flex-direction: row-reverse; background: #fff; border: 1px solid var(--border-color); }
.feature-text h2 { font-size: 28px; margin-bottom: 20px; color: var(--primary-color); }
.feature-text p { font-size: 16px; color: #555; line-height: 1.8; }

/* Footer */
.footer { background: #1a1a1a; color: #aaa; text-align: center; padding: 40px 0; margin-top: 40px; }
.footer-links { margin-bottom: 20px; }
.footer-links a { color: #ddd; margin: 0 10px; }
.footer-links a:hover { color: #fff; }
.footer p { margin-bottom: 10px; font-size: 14px; }