:root { --bg: #0f172a; --card: #1e293b; --accent: #38bdf8; --text: #f8fafc; --sub: #94a3b8; }
        * { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', system-ui, sans-serif; }
        body { background: var(--bg); color: var(--text); min-height: 100vh; display: flex; flex-direction: column; align-items: center; }

     /* Responsive Navigation Header with Dropdown */
        .site-header { width: 100%; max-width: 1100px; display: flex; justify-content: space-between; align-items: center; padding: 20px 30px; margin-bottom: 20px; position: relative; }
        .logo-container { width: 150px; height: 60px; display: flex; align-items: center; z-index: 10; }
        .logo-placeholder { width: 150px; height: 50px; border-radius: 8px; display: flex; align-items: center; justify-content: center; color: var(--accent); font-size: 0.8rem; font-weight: 600; }
        
        .nav-menu { display: flex; gap: 28px; list-style: none; align-items: center; }
    .nav-menu > li { position: relative; }
    .nav-menu a { color: var(--sub); text-decoration: none; font-size: 0.95rem; font-weight: 500; transition: color 0.2s; display: flex; align-items: center; gap: 10px; }
    .nav-menu a:hover { color: var(--accent); }

    /* Polished Desktop Dropdown */
    .dropdown { position: absolute; top: 100%; left: 0; background: var(--card); min-width: 240px; border-radius: 12px; border: 1px solid rgba(255,255,255,0.08); box-shadow: 0 14px 30px rgba(0,0,0,0.5); padding: 12px 0; opacity: 0; visibility: hidden; transform: translateY(10px); transition: all 0.2s ease-in-out; z-index: 60; }
    .nav-menu > li.has-dropdown:hover .dropdown { opacity: 1; visibility: visible; transform: translateY(0); }
    .dropdown li { list-style: none; width: 100%; }
    .dropdown a { padding: 12px 24px; color: var(--sub); width: 100%; font-size: 0.9rem; display: block; }
    .dropdown a:hover { background: rgba(56, 189, 248, 0.1); color: var(--accent); }

    /* Clean Arrow Indicator */
    .arrow { border: solid var(--sub); border-width: 0 2px 2px 0; display: inline-block; padding: 3px; transform: rotate(45deg); transition: transform 0.2s; margin-top: -2px; }
    .has-dropdown:hover .arrow { transform: rotate(-135deg); border-color: var(--accent); }

    /* Hamburger Toggle Button */
    .menu-toggle { display: none; background: none; border: none; cursor: pointer; flex-direction: column; gap: 6px; z-index: 50; padding: 6px; }
    .menu-toggle span { display: block; width: 28px; height: 2.5px; background: var(--text); border-radius: 2px; transition: 0.3s; }

    /* Mobile Styles Overhaul */
    @media (max-width: 768px) {
        .site-header { padding: 15px 20px; }
        .menu-toggle { display: flex; }
        .nav-menu { position: absolute; top: 100%; left: 0; width: 100%; background: #162032; flex-direction: column; align-items: flex-start; gap: 0; max-height: 0; overflow: hidden; transition: max-height 0.35s ease-in-out; border-bottom: 1px solid rgba(255,255,255,0.08); box-shadow: 0 15px 30px rgba(0,0,0,0.4); }
        .nav-menu.active { max-height: 600px; overflow-y: auto; }
        .nav-menu li { width: 100%; border-top: 1px solid rgba(255,255,255,0.05); }
        .nav-menu > li > a { display: flex; justify-content: space-between; padding: 18px 24px; width: 100%; font-size: 1rem; }
        
        .dropdown { position: static; opacity: 1; visibility: visible; transform: none; box-shadow: none; border: none; background: rgba(15, 23, 42, 0.7); max-height: 0; overflow: hidden; transition: max-height 0.3s ease-in-out; padding: 0; border-radius: 0; }
        .nav-menu li.dropdown-open .dropdown { max-height: 450px; padding: 8px 0; }
        .dropdown a { padding: 14px 24px 14px 38px; font-size: 0.95rem; }
        .arrow { transform: rotate(45deg); padding: 4px; }
        .nav-menu li.dropdown-open .arrow { transform: rotate(-135deg); border-color: var(--accent); }
    }


        /* Hero Header */
        header { text-align: center; margin: 20px 0 40px; padding: 0 20px; }
        header h1 { font-size: 2.5rem; color: var(--accent); margin-bottom: 10px; }
        header p { color: var(--sub); font-size: 1.1rem; }
		
		.headerp1 { color: var(--sub); font-size: 1.1rem; max-width: 100%; padding: 0px 50px 0px 50px; margin-top: 15px; margin-bottom: 15px;}
        
        .grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; width: 100%; max-width: 900px; margin-bottom: 50px; padding: 0 20px; }
        .card { background: var(--card); border-radius: 20px; padding: 30px; border: 1px solid rgba(255,255,255,0.05); display: flex; flex-direction: column; gap: 16px; text-decoration: none; color: inherit; transition: transform 0.2s, border-color 0.2s; }
        .card:hover { transform: translateY(-4px); border-color: var(--accent); }
        .card h2 { font-size: 1.5rem; color: var(--accent); }
        .card p { color: var(--sub); font-size: 0.95rem; line-height: 1.5; }
        .badge-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
        .badge { background: #0f172a; color: var(--accent); padding: 4px 10px; border-radius: 6px; font-size: 0.8rem; border: 1px solid #334155; }
        
        /* main-content Section */
        .comprehensive-guide { width: 100%; max-width: 1150px; margin-bottom: 60px; margin-top: 60px; padding: 0 20px; }
        .guide-container { background: var(--card); border-radius: 20px; padding: 40px; border: 1px solid rgba(255,255,255,0.05); }
        .comprehensive-guide h2 { font-size: 2rem; color: var(--accent); margin-bottom: 20px; text-align: left; }
        .comprehensive-guide h3 { font-size: 1.35rem; color: var(--text); margin-top: 30px; margin-bottom: 15px; border-bottom: 1px solid rgba(255,255,255,0.05); padding-bottom: 8px; }
        .comprehensive-guide h4 { font-size: 1.1rem; color: var(--accent); margin-top: 20px; margin-bottom: 8px; }
        .comprehensive-guide p { color: var(--sub); font-size: 0.95rem; line-height: 1.7; margin-bottom: 16px; }
        .comprehensive-guide ul, .comprehensive-guide ol { color: var(--sub); font-size: 0.95rem; line-height: 1.7; padding-left: 20px; margin-bottom: 20px; }
        .comprehensive-guide li { margin-bottom: 10px; }
        .definition-box { background: #0f172a; border-left: 4px solid var(--accent); padding: 20px; border-radius: 0 12px 12px 0; margin: 20px 0; }
        .definition-box p { margin-bottom: 0; color: var(--text); font-style: italic; }

		/* Guide Section Styles */
        .guide-section { width: 100%; max-width: 900px; margin-bottom: 50px; margin-top: 50px; }
        .guide-section h2 { font-size: 1.8rem; color: var(--accent); margin-bottom: 24px; text-align: center; }
        .guide-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 20px; }
        .guide-card { background: var(--card); border-radius: 16px; padding: 24px; border: 1px solid rgba(255,255,255,0.05); }
        .guide-card h3 { font-size: 1.15rem; color: var(--text); margin-bottom: 10px; display: flex; align-items: center; gap: 8px; }
        .guide-card p, .guide-card ul { color: var(--sub); font-size: 0.9rem; line-height: 1.6; }
        .guide-card ul { padding-left: 18px; margin-top: 8px; }
        .guide-card li { margin-bottom: 6px; }

        /* FAQ Section */
        .faq-section { width: 100%; max-width: 900px; margin-bottom: 60px; padding: 0 20px; }
        .faq-section h2 { font-size: 1.8rem; color: var(--accent); margin-bottom: 20px; text-align: center; }
        .faq-grid { display: grid; grid-template-columns: 1fr; gap: 16px; }
        .faq-card { background: var(--card); border-radius: 16px; padding: 24px; border: 1px solid rgba(255,255,255,0.05); }
        .faq-card h3 { font-size: 1.1rem; color: var(--text); margin-bottom: 8px; }
        .faq-card p { color: var(--sub); font-size: 0.9rem; line-height: 1.5; }

		/* Grid Panel section */
       
		.grid-panel { display: grid; grid-template-columns: repeat(auto-fit, minmax(320px, 1fr)); gap: 24px; width: 100%; max-width: 1150px; margin-bottom: 50px; margin-top: 50px; padding: 0 20px; }

        /* 4-Column Footer */
        .site-footer { width: 100%; background: #090d16; border-top: 1px solid rgba(255,255,255,0.05); padding: 50px 20px 30px; display: flex; justify-content: center; }
        .footer-container { width: 100%; max-width: 1100px; display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 30px; margin-bottom: 40px; }
        .footer-col h4 { font-size: 1rem; color: var(--text); margin-bottom: 16px; }
        .footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 10px; }
        .footer-col ul a { color: var(--sub); text-decoration: none; font-size: 0.85rem; transition: color 0.2s; }
        .footer-col ul a:hover { color: var(--accent); }
        .footer-col p { color: var(--sub); font-size: 0.85rem; line-height: 1.5; }
        .footer-bottom { width: 100%; max-width: 1100px; border-top: 1px solid rgba(255,255,255,0.05); padding-top: 20px; text-align: center; color: var(--sub); font-size: 0.8rem; }
		
		/* Main FAQ Content Layout */
        header { text-align: center; margin: 20px 0 30px; padding: 0 20px; }
        header h1 { font-size: 2.3rem; color: var(--accent); margin-bottom: 10px; }
        header p { color: var(--sub); font-size: 1.05rem; max-width: 700px; margin: 0 auto; line-height: 1.5; }

        .faq-container { width: 100%; max-width: 900px; margin-bottom: 60px; padding: 0 20px; display: flex; flex-direction: column; gap: 20px; }
        .faq-card { background: var(--card); border-radius: 16px; padding: 30px; border: 1px solid rgba(255,255,255,0.05); box-shadow: 0 4px 15px rgba(0,0,0,0.2); }
        .faq-card h2 { font-size: 1.25rem; color: var(--accent); margin-bottom: 12px; display: flex; align-items: center; gap: 10px; }
        .faq-card p { color: var(--sub); font-size: 0.95rem; line-height: 1.7; margin-bottom: 12px; }
        .faq-card ul { color: var(--sub); font-size: 0.95rem; line-height: 1.7; padding-left: 20px; }
        .faq-card li { margin-bottom: 8px; }
		
		/* ipone17/18 Layout */
		 .container { width: 100%; max-width: 500px; display: flex; flex-direction: column; gap: 20px; margin-bottom: 40px; }
        .card { background: var(--card); border-radius: 16px; padding: 20px; border: 1px solid rgba(255,255,255,0.05); }
        .model-select { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-bottom: 16px; }
        .m-btn { background: #0f172a; color: var(--sub); border: 1px solid #334155; padding: 10px; border-radius: 10px; font-size: 0.85rem; cursor: pointer; text-align: center; }
        .m-btn.active { color: var(--accent); border-color: var(--accent); background: rgba(56,189,248,0.1); }
        .visualizer { position: relative; height: 160px; background: #090d16; border-radius: 12px; display: flex; align-items: center; justify-content: center; overflow: hidden; }
        canvas { position: absolute; width: 100%; height: 100%; }
        .btn-primary { background: var(--accent); color: #0f172a; font-size: 1.1rem; padding: 16px; width: 100%; border-radius: 12px; border: none; font-weight: 700; cursor: pointer; margin-top: 15px; }
        .info { font-size: 0.85rem; color: var(--sub); line-height: 1.5; }
        .faq-section { width: 100%; max-width: 500px; }
        .faq-section h2 { font-size: 1.4rem; color: var(--accent); margin-bottom: 16px; text-align: center; }
        .faq-grid { display: grid; grid-template-columns: 1fr; gap: 12px; }
        .faq-card { background: var(--card); border-radius: 14px; padding: 18px; border: 1px solid rgba(255,255,255,0.05); }
        .faq-card h3 { font-size: 1rem; color: var(--text); margin-bottom: 6px; }
        .faq-card p { color: var(--sub); font-size: 0.85rem; line-height: 1.4; }