:root {
            --primary: #ff4d94;
            --secondary: #bc51ea;
            --dark: #0f172a;
            --gray: #64748b;
            --light-bg: #f8fafc;
            --border-color: #e2e8f0;
            --transition: all 0.25s ease;
        }

        /* Sử dụng System Font Stack để tối ưu tốc độ tải và trông chuyên nghiệp/native hơn */
        * { 
            margin: 0; 
            padding: 0; 
            box-sizing: border-box; 
            font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; 
        }

        body, html { 
            height: 100%; 
            overflow: hidden; 
            background: #fff; 
            color: #334155;
            line-height: 1.5;
        }

        .split-container {
            display: grid;
            grid-template-columns: 45% 55%;
            height: 100vh;
            width: 100vw;
        }

        /* --- LEFT SIDE: AUTH --- */
        .auth-side {
            padding: 60px;
            display: flex;
            flex-direction: column;
            justify-content: center;
            background: #fff;
            position: relative;
        }

        .brand-top {
            font-size: 24px;
            font-weight: 700;
            color: var(--dark);
            text-decoration: none;
            margin-bottom: 60px;
            text-align: center;
            letter-spacing: -0.5px;
        }
        .brand-top span { 
            font-weight: 400; 
            color: var(--gray);
        }

        .auth-content { 
            max-width: 380px; 
            margin: 0 auto; 
            width: 100%; 
        }
        
        .auth-content h2 { 
            font-size: 30px; 
            font-weight: 700; 
            color: var(--dark);
            margin-bottom: 16px; 
            letter-spacing: -0.5px; 
        }
        
        .auth-content p { 
            color: var(--gray); 
            margin-bottom: 40px; 
            line-height: 1.6; 
            font-size: 15px;
        }

        /* Social Buttons */
        .social-group { 
            display: flex; 
            flex-direction: column; 
            gap: 16px; 
            margin-bottom: 32px; 
        }
        
        .btn-social {
            width: 100%;
            padding: 12px 16px;
            border-radius: 12px;
            border: 1px solid var(--border-color);
            background: #fff;
            color: var(--dark);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 12px;
            font-weight: 600;
            font-size: 14px;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .btn-social:hover { 
            background: var(--light-bg); 
            border-color: #cbd5e1; 
        }

        .divider {
            text-align: center;
            margin: 32px 0;
            color: #94a3b8;
            font-size: 12px;
            font-weight: 500;
            position: relative;
            letter-spacing: 0.5px;
        }
        .divider::before, .divider::after { 
            content: ""; 
            position: absolute; 
            top: 50%; 
            width: 32%; 
            height: 1px; 
            background: var(--border-color); 
        }
        .divider::before { left: 0; } 
        .divider::after { right: 0; }

        /* OTP Input Flow */
        .input-wrapper { 
            position: relative; 
            margin-bottom: 20px; 
        }
        
        .input-wrapper input {
            width: 100%;
            padding: 16px 20px;
            border-radius: 12px;
            border: 1px solid var(--border-color);
            background: var(--light-bg);
            outline: none;
            font-size: 15px;
            color: var(--dark);
            transition: var(--transition);
        }
        
        .input-wrapper input::placeholder {
            color: #94a3b8;
        }
        
        .input-wrapper input:focus {
            background: #fff;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(255, 77, 148, 0.1);
        }

        .btn-continue {
            width: 100%;
            padding: 16px;
            border-radius: 12px;
            border: none;
            background: var(--dark);
            color: white;
            font-weight: 600;
            font-size: 15px;
            cursor: pointer;
            transition: var(--transition);
        }
        
        .btn-continue:hover { 
            background: #1e293b; 
            transform: translateY(-1px); 
            box-shadow: 0 4px 12px rgba(15, 23, 42, 0.15); 
        }

        .terms-text {
            margin-top: 32px; 
            font-size: 13px; 
            text-align: center; 
            color: #94a3b8;
            line-height: 1.5;
        }
        .terms-text a {
            color: var(--dark);
            text-decoration: none;
            font-weight: 500;
        }
        .terms-text a:hover {
            text-decoration: underline;
        }

        /* --- RIGHT SIDE: CREATIVE INFO --- */
        .info-side {
            background: var(--dark);
            position: relative;
            display: flex;
            align-items: center;
            justify-content: center;
            overflow: hidden;
            color: white;
        }

        /* Abstract Background Decor */
        .blob {
            position: absolute;
            width: 600px;
            height: 600px;
            background: linear-gradient(135deg, var(--primary), var(--secondary));
            filter: blur(80px);
            border-radius: 50%;
            opacity: 0.3;
            animation: move 20s infinite alternate;
        }

        @keyframes move {
            from { transform: translate(-10%, -10%) rotate(0deg); }
            to { transform: translate(20%, 20%) rotate(360deg); }
        }

        .info-card {
            position: relative;
            z-index: 10;
            text-align: left;
            padding: 60px;
            max-width: 540px;
        }

        .badge {
            color: var(--primary); 
            font-weight: 700; 
            text-transform: uppercase; 
            letter-spacing: 1.5px; 
            font-size: 13px;
            display: block;
            margin-bottom: 16px;
        }

        .info-card h1 {
            font-size: 48px;
            font-weight: 800;
            line-height: 1.15;
            margin-bottom: 32px;
            letter-spacing: -1.5px;
        }

        .feature-list { 
            list-style: none; 
            margin-top: 32px; 
        }
        
        .feature-item {
            display: flex;
            align-items: center;
            gap: 16px;
            margin-bottom: 24px;
            font-size: 16px;
            font-weight: 500;
            opacity: 0.9;
        }
        
        .feature-item i {
            width: 36px;
            height: 36px;
            background: rgba(255,255,255,0.08);
            border-radius: 10px;
            display: flex;
            align-items: center;
            justify-content: center;
            color: var(--primary);
            font-size: 14px;
        }

        .testimonial-card {
            margin-top: 56px; 
            padding: 24px; 
            background: rgba(255,255,255,0.03); 
            border-radius: 16px; 
            border: 1px solid rgba(255,255,255,0.05);
            backdrop-filter: blur(10px);
        }

        .testimonial-card p.quote {
            font-style: italic; 
            opacity: 0.8;
            line-height: 1.6;
            font-size: 15px;
        }

        .testimonial-author {
            margin-top: 20px; 
            display: flex; 
            align-items: center; 
            gap: 12px;
        }

        .testimonial-author img {
            border-radius: 50%;
            width: 40px;
            height: 40px;
        }

        .testimonial-author-info p.name {
            font-weight: 600; 
            font-size: 14px;
        }

        .testimonial-author-info p.title {
            font-size: 13px; 
            opacity: 0.6;
            margin-top: 2px;
        }

        /* Responsive */
        @media (max-width: 1024px) {
            .split-container { grid-template-columns: 1fr; overflow-y: auto; }
            .info-side { display: none; }
            .auth-side { padding: 40px 24px; height: 100vh; }
        }