:root {
    --bg-dark: #07111F;
    --bg-card: #0D1B2A;
    --bg-section: #091522;
    --primary: #39C6B3;
    --secondary: #5B8CFF;
    --text-main: #F5F8FC;
    --text-muted: #B9C5D3;
    --border: rgba(255,255,255,0.08);
    --border-hover: rgba(57,198,179,0.3);
    --radius: 18px;
    --shadow: 0 10px 30px rgba(0,0,0,0.5);
}
* {
    margin: 0; padding: 0; box-sizing: border-box;
}
html { scroll-behavior: smooth; font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; }
body { background: var(--bg-dark); color: var(--text-main); line-height: 1.6; font-size: 16px; -webkit-font-smoothing: antialiased; }
a { color: var(--primary); text-decoration: none; transition: 0.3s; }
a:hover { color: var(--secondary); }
img { max-width: 100%; height: auto; display: block; }
ul { list-style: none; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.top-notice { background: var(--bg-section); text-align: center; font-size: 14px; padding: 10px; color: var(--text-muted); border-bottom: 1px solid var(--border); }
header { background: rgba(7, 17, 31, 0.9); backdrop-filter: blur(10px); position: sticky; top: 0; z-index: 1000; border-bottom: 1px solid var(--border); }
.header-inner { display: flex; justify-content: space-between; align-items: center; height: 70px; }
.logo a { font-size: 24px; font-weight: 700; color: var(--text-main); }
.logo span { color: var(--primary); }
.logo-sub { display: block; font-size: 12px; color: var(--text-muted); margin-top: -4px; }
#main-nav ul { display: flex; gap: 20px; }
#main-nav a { color: var(--text-muted); font-weight: 500; font-size: 15px; }
#main-nav a:hover, #main-nav a.active { color: var(--primary); }
.btn-primary { background: linear-gradient(135deg, var(--primary), #2D9B8C); color: #fff; padding: 10px 24px; border-radius: 8px; font-weight: 600; box-shadow: 0 4px 15px rgba(57,198,179,0.2); border: none; cursor: pointer; transition: 0.3s; display: inline-block; text-align: center; }
.btn-primary:hover, .btn-primary:focus { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(57,198,179,0.4); color: #fff; }
.btn-secondary { background: transparent; border: 1px solid var(--primary); color: var(--primary); padding: 10px 24px; border-radius: 8px; font-weight: 600; transition: 0.3s; display: inline-block; text-align: center; }
.btn-secondary:hover { background: rgba(57,198,179,0.1); }
#menu-toggle { display: none; background: none; border: none; cursor: pointer; width: 30px; height: 24px; position: relative; }
#menu-toggle span { display: block; width: 100%; height: 2px; background: var(--text-main); position: absolute; transition: 0.3s; }
#menu-toggle span:nth-child(1) { top: 0; }
#menu-toggle span:nth-child(2) { top: 11px; }
#menu-toggle span:nth-child(3) { top: 22px; }

/* Hero */
.hero { padding: 80px 0; text-align: center; background: radial-gradient(circle at top, var(--bg-section), var(--bg-dark)); }
.hero h1 { font-size: 48px; margin-bottom: 20px; background: -webkit-linear-gradient(45deg, var(--text-main), var(--primary)); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero p { font-size: 18px; color: var(--text-muted); max-width: 800px; margin: 0 auto 40px; }
.hero-btns { display: flex; gap: 20px; justify-content: center; }
.service-panel { margin-top: 60px; background: var(--bg-card); padding: 30px; border-radius: var(--radius); border: 1px solid var(--border); box-shadow: var(--shadow); display: flex; justify-content: space-around; flex-wrap: wrap; gap: 20px;}
.panel-item h3 { font-size: 16px; color: var(--primary); margin-bottom: 5px; }
.panel-item p { font-size: 14px; color: var(--text-muted); }

/* Sections */
.section { padding: 80px 0; }
.section-header { text-align: center; margin-bottom: 50px; }
.section-header h2 { font-size: 32px; margin-bottom: 15px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 30px; }
.card { background: var(--bg-card); padding: 30px; border-radius: var(--radius); border: 1px solid var(--border); transition: 0.3s; display: block; }
.card:hover { transform: translateY(-5px); border-color: var(--border-hover); box-shadow: var(--shadow); }
.card h3 { font-size: 20px; margin-bottom: 15px; color: var(--text-main); }
.card p { color: var(--text-muted); font-size: 15px; margin-bottom: 20px; }

/* Article & Content */
.article-container { max-width: 860px; margin: 0 auto; padding: 40px 20px; }
.article-header { margin-bottom: 40px; text-align: center; }
.article-header h1 { font-size: 36px; margin-bottom: 20px; }
.article-meta { color: var(--text-muted); font-size: 14px; }
.article-content { margin-top: 30px; }
.article-content h2 { font-size: 28px; margin: 40px 0 20px; border-bottom: 1px solid var(--border); padding-bottom: 10px; color: var(--primary); }
.article-content h3 { font-size: 22px; margin: 30px 0 15px; }
.article-content p { margin-bottom: 20px; font-size: 17px; color: var(--text-muted); }
.article-content ul, .article-content ol { margin: 0 0 20px 20px; color: var(--text-muted); font-size: 17px; }
.article-content li { margin-bottom: 10px; }
.article-content .warning, .article-content .note { padding: 20px; border-radius: 12px; margin-bottom: 20px; font-size: 16px; }
.article-content .warning { background: rgba(255, 99, 71, 0.1); border-left: 4px solid #ff6347; }
.article-content .note { background: rgba(57, 198, 179, 0.1); border-left: 4px solid var(--primary); }
.toc { background: var(--bg-card); border: 1px solid var(--border); padding: 20px; border-radius: 12px; margin-bottom: 30px; }
.toc h3 { margin-bottom: 15px; font-size: 18px; }
.toc ul { list-style: none; margin: 0; }
.toc ul li { margin-bottom: 8px; }

/* FAQ */
.faq-item { background: var(--bg-card); border: 1px solid var(--border); border-radius: 12px; margin-bottom: 15px; overflow: hidden; }
.faq-question { padding: 20px; cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; font-size: 17px; }
.faq-question:hover { background: rgba(255,255,255,0.02); }
.faq-answer { padding: 0 20px; max-height: 0; overflow: hidden; transition: max-height 0.3s ease-out; color: var(--text-muted); font-size: 16px; }
.faq-item.active .faq-answer { padding: 20px; max-height: 500px; border-top: 1px solid var(--border); }
.faq-icon { transition: transform 0.3s ease; }
.faq-item.active .faq-icon { transform: rotate(180deg); color: var(--primary); }

/* Footer */
footer { background: var(--bg-section); padding: 60px 0 20px; border-top: 1px solid var(--border); margin-top: 60px; }
.footer-inner { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 40px; margin-bottom: 40px; }
.footer-col h3 { font-size: 18px; margin-bottom: 20px; color: var(--text-main); }
.footer-col p, .footer-col a { color: var(--text-muted); font-size: 14px; }
.footer-col ul li { margin-bottom: 10px; }
.footer-bottom { text-align: center; border-top: 1px solid var(--border); padding-top: 20px; color: var(--text-muted); font-size: 13px; }

/* Utilities */
.text-center { text-align: center; }
.mt-40 { margin-top: 40px; }
.mb-40 { margin-bottom: 40px; }
.step-list { counter-reset: step; list-style: none !important; margin-left: 0 !important; }
.step-list li { position: relative; padding-left: 40px; margin-bottom: 20px; }
.step-list li::before { counter-increment: step; content: counter(step); position: absolute; left: 0; top: 0; width: 28px; height: 28px; background: var(--primary); color: #07111F; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-weight: bold; font-size: 14px; }

/* Final Action */
.final-action { text-align: center; padding: 60px 20px; background: var(--bg-card); border-radius: var(--radius); margin: 60px 0; border: 1px solid var(--border); }
.final-action h2 { margin-bottom: 15px; font-size: 28px; }
.final-action p { margin-bottom: 30px; color: var(--text-muted); }

/* SVG Icon alignment */
.icon-inline { display: inline-block; vertical-align: middle; width: 24px; height: 24px; fill: currentColor; }

/* Friend Links Section */
.friend-links-section { margin-top: 50px; }
.friend-links-title { font-size: 20px; font-weight: 700; color: var(--text-main); margin-bottom: 20px; padding-left: 12px; border-left: 4px solid var(--primary); line-height: 1.2; }
.friend-links-box { border: 1px dashed var(--primary); padding: 25px; border-radius: 12px; background: rgba(57, 198, 179, 0.03); }
.friend-links-box h3 { font-size: 18px; color: var(--primary); margin-bottom: 15px; margin-top: 0; }
.friend-links-box p { font-size: 15px; margin-bottom: 15px; color: var(--text-muted); }
.friend-links-code { background: var(--bg-section); padding: 15px; border-radius: 8px; font-family: monospace; font-size: 14px; color: var(--text-muted); margin-bottom: 15px; border: 1px solid var(--border); overflow-x: auto; white-space: pre-wrap; line-height: 1.8; }
.friend-links-box a { text-decoration: underline; }

.friend-links-list { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 20px; margin-bottom: 30px; }
.friend-link-card { display: flex; align-items: flex-start; gap: 15px; background: var(--bg-card); padding: 20px; border-radius: 12px; border: 1px solid var(--border); transition: 0.3s; text-decoration: none !important; }
.friend-link-card:hover { transform: translateY(-3px); border-color: var(--border-hover); box-shadow: var(--shadow); }
.friend-link-logo { width: 50px; height: 50px; border-radius: 50%; object-fit: cover; background: var(--bg-section); flex-shrink: 0; }
.friend-link-info h4 { margin: 0 0 5px 0; font-size: 16px; color: var(--text-main); line-height: 1.4; }
.friend-link-info p { margin: 0; font-size: 13px; color: var(--text-muted); line-height: 1.5; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; }

/* Responsive */
@media (max-width: 900px) {
    .header-action .btn-primary { display: none; }
    #main-nav { position: absolute; top: 70px; left: 0; right: 0; background: var(--bg-section); padding: 20px; border-bottom: 1px solid var(--border); display: none; flex-direction: column; box-shadow: var(--shadow); }
    #main-nav.active { display: flex; }
    #main-nav ul { flex-direction: column; gap: 15px; }
    #menu-toggle { display: block; }
    .hero h1 { font-size: 32px; }
    .article-container { padding: 20px 15px; }
    .grid { grid-template-columns: 1fr; }
    body { font-size: 16px; }
    .article-content p, .article-content ul, .article-content ol { font-size: 16px; }
}
@media (prefers-reduced-motion: reduce) {
    * { animation: none !important; transition: none !important; }
}