:root { --primary-color: rgb(0,0,0); --text-main: #1a1a1a; --text-muted: #666; --bg-body: #f4f5f7; --bg-card: #ffffff; --border-color: #e5e7eb; --container-width: 1200px; }
        * { box-sizing: border-box; margin: 0; padding: 0; }
        body { font-family: -apple-system, BlinkMacSystemFont, sans-serif; background-color: var(--bg-body); color: var(--text-main); line-height: 1.6; }
        a { text-decoration: none; color: inherit; }
        ul { list-style: none; }
        img { max-width: 100%; height: auto; }
        .container { max-width: var(--container-width); margin: 0 auto; padding: 0 15px; }
        
        
        .site-header { background: var(--primary-color); color: #fff; position: sticky; top: 0; z-index: 100; box-shadow: 0 2px 10px rgba(0,0,0,0.1); }
        .header-inner { display: flex; justify-content: space-between; align-items: center; height: 64px; }
        .logo { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; }
        .logo img { display: block; height: 36px; width: auto; max-width: 160px; object-fit: contain; }
        .logo span { display: inline-block; font-size: 20px; font-weight: 700; color: #fff; white-space: nowrap; }
        .pc-nav { display: flex; gap: 24px; }
        .pc-nav a { font-size: 15px; color: #e5e5e5; font-weight: 500; }
        .pc-nav a:hover { color: #fff; }
        .mobile-menu-btn { display: none; cursor: pointer; font-size: 24px; }

        
        .dl-hero { background: var(--bg-card); padding: 80px 0; border-bottom: 1px solid var(--border-color); text-align: center; }
        .dl-hero h1 { font-size: 32px; margin-bottom: 15px; color: var(--primary-color); }
        .dl-hero p { font-size: 16px; color: var(--text-muted); max-width: 600px; margin: 0 auto 30px; }
        .dl-btn { display: inline-block; background: var(--primary-color); color: #fff; padding: 15px 40px; border-radius: 4px; font-size: 18px; font-weight: 600; }
        
        .dl-content { padding: 60px 0; }
        .dl-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 40px; }
        .dl-card { background: var(--bg-card); padding: 30px; border: 1px solid var(--border-color); border-radius: 8px; }
        .dl-card h3 { font-size: 20px; border-bottom: 1px solid var(--border-color); padding-bottom: 10px; margin-bottom: 20px; }
        .dl-list li { margin-bottom: 15px; display: flex; gap: 10px; }
        .dl-list li::before { content: '✓'; color: var(--primary-color); font-weight: bold; }

        
        .site-footer { background: #111; color: #999; padding: 60px 0 20px; font-size: 14px; }
        .footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr; gap: 40px; margin-bottom: 40px; }
        .footer-logo .logo span { color: #fff; }
        .footer-links li { margin-bottom: 10px; }
        .friend-links { border-top: 1px solid #333; padding-top: 20px; margin-bottom: 30px; }
        .friend-title { color: #fff; margin-bottom: 15px; font-weight: 600;}
        .friend-content { display: flex; gap: 15px; font-size: 13px; flex-wrap: wrap;}
        .footer-bottom { border-top: 1px solid #333; padding-top: 20px; text-align: center; }

        
        .drawer-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.5); z-index: 999; display: none; opacity: 0; transition: 0.3s; }
        .drawer-menu { position: fixed; top: 0; left: -300px; bottom: 0; width: 280px; background: #fff; z-index: 1000; transition: 0.3s; }
        .drawer-header { padding: 20px; background: var(--primary-color); display: flex; justify-content: space-between; }
        .drawer-header .logo span, .drawer-close { color: #fff; }
        .drawer-nav a { display: block; padding: 15px 20px; border-bottom: 1px solid #eee; color: #333; }
        
        @media (max-width: 992px) { .dl-grid { grid-template-columns: 1fr; } .footer-grid { grid-template-columns: 1fr; } }
        @media (max-width: 768px) { .pc-nav { display: none; } .mobile-menu-btn { display: block; } }