:root {
            --primary: #ff4646;
            --secondary: #ff9000;
            --bg: #0b0c10;
            --card: #1f2833;
            --text: #c5c6c7;
        }
        * { box-sizing: border-box; }
        body { font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; background-color: var(--bg); color: var(--text); margin: 0; line-height: 1.8; scroll-behavior: smooth; }
        header { background: linear-gradient(90deg, #000 0%, #440000 100%); padding: 25px; text-align: center; border-bottom: 3px solid var(--primary); position: sticky; top: 0; z-index: 100; }
        .logo { font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; font-size: 28px; color: var(--primary); text-decoration: none; text-transform: uppercase; letter-spacing: 2px; }
        .container { max-width: 1000px; margin: 30px auto; padding: 0 15px; }
        .tool-card { background: var(--card); border-radius: 20px; padding: 40px; border: 1px solid #333; box-shadow: 0 20px 50px rgba(0,0,0,0.7); margin-bottom: 40px; }
        h1 { font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; font-size: 38px; text-align: center; color: #fff; text-transform: uppercase; margin-bottom: 25px; }
        input[type="text"] { width: 100%; padding: 20px; border: 2px solid #444; border-radius: 10px; font-size: 18px; outline: none; margin-bottom: 20px; background: #0b0c10; color: #fff; }
        .amount-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(180px, 1fr)); gap: 15px; margin-bottom: 25px; }
        .amount-item { padding: 20px; border: 2px solid #333; border-radius: 12px; text-align: center; cursor: pointer; transition: 0.3s; background: #161b22; }
        .amount-item.active { border-color: var(--primary); background: rgba(255,70,70,0.15); }
        .amount-item .num { display: block; font-size: 28px; font-weight: 900; color: #fff; font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; }
        .btn-youtube { display: inline-block; width: 100%; background: var(--primary); color: #fff; text-decoration: none; padding: 18px 40px; border-radius: 8px; font-weight: 900; margin-top: 15px; text-transform: uppercase; }
        .btn-launch { width: 100%; padding: 22px; border: none; border-radius: 10px; font-size: 22px; font-weight: 900; background: #333; color: #666; cursor: not-allowed; font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; }
        .btn-launch.active { background: linear-gradient(180deg, #ff4646, #b30000); color: #fff; cursor: pointer; }
        .progress-area { display: none; margin-top: 30px; }
        .bar-bg { width: 100%; height: 45px; background: #000; border-radius: 10px; overflow: hidden; border: 1px solid #444; }
        .bar-fill { height: 100%; width: 0%; background: linear-gradient(90deg, var(--primary), var(--secondary)); }
        .seo-content { background: var(--card); padding: 50px; border-radius: 20px; border: 1px solid #333; }
        .seo-figure img {display: block; width: 100%; height: auto; border-radius: 10px; }
        .toc-box { background: #161b22; padding: 30px; border-radius: 15px; border-left: 6px solid var(--primary); margin-bottom: 40px; }
        .toc-title { font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; font-size: 24px; color: var(--primary); margin-bottom: 20px; text-transform: uppercase; display: block; }
        .toc-box ul { list-style: none; padding: 0; }
        .toc-box li { margin-bottom: 12px; border-bottom: 1px solid #2d3436; padding-bottom: 8px; }
        .toc-box a { color: #fff; text-decoration: none; font-weight: 700; transition: 0.3s; }
        .toc-box a:hover { color: var(--primary); padding-left: 10px; }
        .seo-content h2 { font-size: 32px; color: var(--primary); font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif; border-left: 8px solid var(--primary); padding-left: 20px; margin-top: 60px; text-transform: uppercase; scroll-margin-top: 100px; }
        .seo-content p { margin-bottom: 25px; font-size: 18px; color: #d1d1d1; }
        footer { background: #000; padding: 50px; text-align: center; font-size: 14px; color: #555; margin-top: 60px; }
        #maintenance-overlay { display: none; position: fixed; top: 0; left: 0; width: 100%; height: 100%; background: rgba(0,0,0,0.98); z-index: 1000; justify-content: center; align-items: center; }
        .maintenance-modal { background: var(--card); border: 2px solid var(--primary); width: 95%; max-width: 450px; padding: 40px; border-radius: 15px; text-align: center; }
    
/* SEO cluster additions */
.site-nav{display:flex;gap:12px;justify-content:center;flex-wrap:wrap;margin-top:12px}.site-nav a,.footer-links a{color:#fff;text-decoration:none;font-weight:700}.site-nav a:hover,.footer-links a:hover{color:var(--secondary)}
.guide-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(230px,1fr));gap:12px;margin-top:24px}.guide-card{display:block;background:#161b22;border:1px solid #333;border-radius:12px;padding:16px;color:#fff;text-decoration:none;font-weight:800;line-height:1.35}.guide-card:hover{border-color:var(--primary);transform:translateY(-1px)}
.breadcrumb{font-size:14px;margin:0 0 18px}.breadcrumb a,.context-link{color:#ffb04a;text-decoration:none;font-weight:800}.breadcrumb a:hover,.context-link:hover{text-decoration:underline}.related{margin-top:40px;padding-top:24px;border-top:1px solid #333}.related h2{margin-top:0}.footer-links{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;margin-bottom:15px}
.article-hero{background:linear-gradient(135deg,#1f2833,#12151b);border:1px solid #333;border-radius:20px;padding:34px;margin-bottom:25px}.article-hero h1{text-align:left;margin:0 0 12px;font-size:36px}.article-hero p{margin:0;color:#ddd;font-size:17px}.seo-content h3{color:#fff;font-size:23px;margin-top:34px}.seo-content ul{padding-left:22px}.seo-content li{margin-bottom:10px}.notice{background:#161b22;border-left:5px solid var(--secondary);padding:18px;border-radius:10px;margin:24px 0}
@media(max-width:640px){header{padding:16px}.container{margin:18px auto}.tool-card,.seo-content{padding:24px}.article-hero{padding:24px}.article-hero h1,h1{font-size:29px}.seo-content h2{font-size:25px;padding-left:14px;margin-top:42px}.seo-content p{font-size:16px}.guide-grid{grid-template-columns:1fr}}