@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');
        
        * {
            font-family: 'Inter', sans-serif;
        }
        
        :root {
            --bg-primary: #0f172a;
            --bg-secondary: #1e293b;
            --bg-tertiary: #334155;
            --bg-card: rgba(30, 41, 59, 0.9);
            --text-primary: #f8fafc;
            --text-secondary: #cbd5e1;
            --text-muted: #94a3b8;
            --border: rgba(148, 163, 184, 0.15);
            --accent-primary: #2563eb;
            --accent-secondary: #475569;
            --accent-success: #059669;
            --accent-warning: #d97706;
            --accent-error: #dc2626;
            --gradient-primary: linear-gradient(135deg, #2563eb, #1e40af);
            --gradient-secondary: linear-gradient(135deg, #1e293b, #334155);
            --gradient-accent: linear-gradient(135deg, #1e293b, #334155, #475569);
        }
        
        body {
            background: var(--bg-primary);
            background-image: 
                radial-gradient(circle at 50% 50%, rgba(37, 99, 235, 0.05) 0%, transparent 70%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1rem;
        }
        
        .auth-container {
            background: var(--bg-card);
            backdrop-filter: blur(20px);
            border: 1px solid var(--border);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
            border-radius: 16px;
            overflow: hidden;
            max-width: 1000px;
            width: 100%;
            min-height: 600px;
            display: flex;
        }
        
        .auth-side {
            flex: 1;
            padding: 3rem;
            display: flex;
            flex-direction: column;
            justify-content: center;
        }
        
        .brand-side {
            background: var(--gradient-accent);
            color: var(--text-primary);
            position: relative;
            overflow: hidden;
        }
        
        .brand-side::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="20" height="20" patternUnits="userSpaceOnUse"><path d="M 20 0 L 0 0 0 20" fill="none" stroke="rgba(248,250,252,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
            opacity: 0.4;
        }
        
        .floating-shapes {
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            overflow: hidden;
            opacity: 0.3;
        }
        
        .form-container {
            display: none;
        }
        
        .form-container.active {
            display: block;
            animation: slideIn 0.5s ease-out;
        }
        
        @keyframes slideIn {
            from {
                opacity: 0;
                transform: translateX(30px);
            }
            to {
                opacity: 1;
                transform: translateX(0);
            }
        }
        
        .input-group {
            position: relative;
            margin-bottom: 1.5rem;
        }
        
        .input-field {
            width: 100%;
            padding: 1rem 1rem 1rem 3rem;
            border: 1px solid var(--border);
            border-radius: 8px;
            font-size: 1rem;
            transition: all 0.2s ease;
            background: var(--bg-secondary);
            color: var(--text-primary);
        }
        
        .input-field:focus {
            outline: none;
            border-color: var(--accent-primary);
            background: var(--bg-tertiary);
            box-shadow: 0 0 0 2px rgba(37, 99, 235, 0.1);
        }
        
        .input-field::placeholder {
            color: var(--text-muted);
        }
        
        .input-icon {
            position: absolute;
            left: 1rem;
            top: 50%;
            transform: translateY(-50%);
            color: var(--text-muted);
            transition: color 0.3s ease;
        }
        
        .input-field:focus + .input-icon {
            color: var(--accent-primary);
        }
        
        .btn-primary {
            background: var(--gradient-primary);
            color: var(--text-primary);
            padding: 1rem 2rem;
            border-radius: 8px;
            font-weight: 600;
            font-size: 1rem;
            border: none;
            cursor: pointer;
            transition: all 0.2s ease;
            width: 100%;
            box-shadow: 0 2px 8px rgba(37, 99, 235, 0.2);
        }
        
        .btn-primary:hover {
            background: linear-gradient(135deg, #1d4ed8, #1e3a8a);
            box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
        }
        
        .btn-secondary {
            background: transparent;
            color: var(--accent-primary);
            border: 1px solid var(--border);
            padding: 1rem 2rem;
            border-radius: 12px;
            font-weight: 600;
            cursor: pointer;
            transition: all 0.3s ease;
            width: 100%;
        }
        
        .btn-secondary:hover {
            background: var(--bg-tertiary);
            border-color: var(--accent-primary);
            transform: translateY(-2px);
        }
        
        .social-btn {
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 0.75rem;
            border: 1px solid var(--border);
            border-radius: 12px;
            background: var(--bg-secondary);
            color: var(--text-secondary);
            text-decoration: none;
            transition: all 0.3s ease;
            font-weight: 500;
        }
        
        .social-btn:hover {
            border-color: var(--accent-primary);
            background: var(--bg-tertiary);
        }
        
        .divider {
            display: flex;
            align-items: center;
            margin: 2rem 0;
            color: var(--text-muted);
            font-size: 0.875rem;
        }
        
        .divider::before,
        .divider::after {
            content: '';
            flex: 1;
            height: 1px;
            background: var(--border);
        }
        
        .divider span {
            padding: 0 1rem;
        }
        
        .toggle-link {
            color: var(--accent-primary);
            text-decoration: none;
            font-weight: 600;
            transition: color 0.3s ease;
        }
        
        .toggle-link:hover {
            color: var(--accent-secondary);
        }
        
        .success-message {
            background: linear-gradient(135deg, var(--accent-success), #059669);
            color: var(--text-primary);
            padding: 1rem;
            border-radius: 12px;
            margin-bottom: 1rem;
            display: none;
            border: 1px solid rgba(16, 185, 129, 0.3);
        }
        
        .error-message {
            background: linear-gradient(135deg, var(--accent-error), #dc2626);
            color: var(--text-primary);
            padding: 1rem;
            border-radius: 12px;
            margin-bottom: 1rem;
            display: none;
            border: 1px solid rgba(239, 68, 68, 0.3);
        }
        
        .features-list {
            list-style: none;
            padding: 0;
            margin: 2rem 0;
        }
        
        .features-list li {
            display: flex;
            align-items: center;
            margin-bottom: 1rem;
            color: rgba(248, 250, 252, 0.9);
        }
        
        .features-list li i {
            margin-right: 0.75rem;
            color: var(--accent-success);
            font-size: 1.1rem;
        }
        
        .stats-grid {
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 1.5rem;
            margin-top: 2rem;
        }
        
        .stat-item {
            text-align: center;
            padding: 1rem;
            background: rgba(248, 250, 252, 0.1);
            border-radius: 12px;
            backdrop-filter: blur(10px);
            border: 1px solid rgba(248, 250, 252, 0.1);
        }
        
        .stat-number {
            font-size: 1.5rem;
            font-weight: 800;
            color: var(--text-primary);
            display: block;
        }
        
        .stat-label {
            font-size: 0.875rem;
            color: rgba(248, 250, 252, 0.8);
            margin-top: 0.25rem;
        }
        
        .password-strength {
            margin-top: 0.5rem;
            display: none;
        }
        
        .strength-bar {
            height: 4px;
            background: #e5e7eb;
            border-radius: 2px;
            overflow: hidden;
            margin-bottom: 0.5rem;
        }
        
        .strength-fill {
            height: 100%;
            transition: all 0.3s ease;
            border-radius: 2px;
        }
        
        .strength-text {
            font-size: 0.75rem;
            color: #6b7280;
        }
        
        @media (max-width: 768px) {
            .auth-container {
                flex-direction: column;
                max-width: 400px;
                min-height: auto;
            }
            
            .brand-side {
                padding: 2rem;
                min-height: 200px;
            }
            
            .auth-side {
                padding: 2rem;
            }
            
            .stats-grid {
                grid-template-columns: repeat(2, 1fr);
                gap: 1rem;
            }
        }
        
        .loading-spinner {
            border: 2px solid rgba(255, 255, 255, 0.3);
            border-top: 2px solid white;
            border-radius: 50%;
            width: 20px;
            height: 20px;
            animation: spin 1s linear infinite;
            display: none;
            margin-right: 0.5rem;
        }
        
        @keyframes spin {
            0% { transform: rotate(0deg); }
            100% { transform: rotate(360deg); }
        }
        
        .checkbox-container {
            display: flex;
            align-items: center;
            margin: 1rem 0;
        }
        
        .checkbox-container input[type="checkbox"] {
            margin-right: 0.5rem;
            transform: scale(1.2);
        }
        
        .checkbox-container label {
            font-size: 0.875rem;
            color: var(--text-secondary);
            cursor: pointer;
        }
        
        .referral-input {
            background: linear-gradient(135deg, #f0f9ff, #e0f2fe);
            border: 2px solid #0ea5e9;
        }
        
        .level-badge {
            display: inline-block;
            padding: 0.25rem 0.75rem;
            border-radius: 20px;
            font-size: 0.75rem;
            font-weight: 600;
            text-transform: uppercase;
            letter-spacing: 0.5px;
        }
        
        .level-bronze { background: linear-gradient(135deg, #cd7f32, #b8860b); color: white; }
        .level-silver { background: linear-gradient(135deg, #c0c0c0, #a8a8a8); color: white; }
        .level-gold { background: linear-gradient(135deg, #ffd700, #ffb347); color: #1a1a1a; }
        .level-platinum { background: linear-gradient(135deg, #e5e4e2, #b8b8b8); color: #1a1a1a; }
        .level-diamond { background: linear-gradient(135deg, #b9f2ff, #87ceeb); color: #1a1a1a; }
        .level-elite { background: linear-gradient(135deg, #1a1a2e, #16213e); color: white; }