* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
        }

        :root {
            --primary: #4361ee;
            --primary-dark: #3a56d4;
            --secondary: #7209b7;
            --success: #4cc9f0;
            --danger: #f72585;
            --warning: #f8961e;
            --light: #f8f9fa;
            --dark: #212529;
            --gray: #6c757d;
            --gray-light: #e9ecef;
            --premium-gold: #ffd700;
            --premium-gradient: linear-gradient(135deg, #4361ee, #3a0ca3, #7209b7);
            --shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
            --shadow-lg: 0 15px 30px rgba(0, 0, 0, 0.15);
            --radius: 16px;
            --transition: all 0.3s ease;
        }

        body {
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            color: var(--dark);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: 20px;
            line-height: 1.6;
        }

        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
        }

        header {
            text-align: center;
            margin-bottom: 40px;
            width: 100%;
        }

        .logo {
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 15px;
            margin-bottom: 15px;
        }

        .logo-icon {
            background: var(--premium-gradient);
            width: 60px;
            height: 60px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 28px;
            box-shadow: var(--shadow);
        }

        .logo-text {
            font-size: 32px;
            font-weight: 800;
            background: var(--premium-gradient);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
            letter-spacing: -0.5px;
        }

        .tagline {
            color: var(--gray);
            font-size: 18px;
            max-width: 600px;
            margin: 0 auto;
        }

        .premium-badge {
            display: inline-flex;
            align-items: center;
            gap: 8px;
            background: linear-gradient(135deg, #ffd700, #ffed4e);
            color: #8a6d00;
            padding: 8px 20px;
            border-radius: 50px;
            font-weight: 700;
            margin-top: 10px;
            box-shadow: 0 4px 10px rgba(255, 215, 0, 0.3);
        }

        .main-content {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 40px;
            margin-bottom: 40px;
        }

        @media (max-width: 992px) {
            .main-content {
                grid-template-columns: 1fr;
            }
        }

        .calculator-card {
            background: white;
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow-lg);
            transition: var(--transition);
        }

        .calculator-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
        }

        .card-title {
            font-size: 24px;
            font-weight: 700;
            margin-bottom: 25px;
            color: var(--primary);
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .card-title i {
            color: var(--secondary);
        }

        .input-group {
            margin-bottom: 25px;
        }

        .input-label {
            display: flex;
            justify-content: space-between;
            margin-bottom: 10px;
            font-weight: 600;
            color: var(--dark);
        }

        .unit-toggle {
            display: flex;
            background: var(--gray-light);
            border-radius: 50px;
            padding: 4px;
            width: fit-content;
            margin-bottom: 20px;
        }

        .unit-toggle button {
            border: none;
            background: transparent;
            padding: 8px 20px;
            border-radius: 50px;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
        }

        .unit-toggle button.active {
            background: white;
            color: var(--primary);
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }

        .input-with-unit {
            position: relative;
        }

        .input-with-unit input {
            width: 100%;
            padding: 16px 20px;
            border: 2px solid var(--gray-light);
            border-radius: var(--radius);
            font-size: 18px;
            font-weight: 600;
            transition: var(--transition);
        }

        .input-with-unit input:focus {
            border-color: var(--primary);
            outline: none;
            box-shadow: 0 0 0 3px rgba(67, 97, 238, 0.2);
        }

        .unit {
            position: absolute;
            right: 20px;
            top: 50%;
            transform: translateY(-50%);
            font-weight: 600;
            color: var(--gray);
        }

        .slider-container {
            margin-top: 15px;
        }

        .slider {
            width: 100%;
            height: 10px;
            border-radius: 5px;
            background: var(--gray-light);
            outline: none;
            -webkit-appearance: none;
        }

        .slider::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 24px;
            height: 24px;
            border-radius: 50%;
            background: var(--primary);
            cursor: pointer;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
        }

        .slider::-moz-range-thumb {
            width: 24px;
            height: 24px;
            border-radius: 50%;
            background: var(--primary);
            cursor: pointer;
            border: none;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
        }

        .gender-buttons {
            display: flex;
            gap: 15px;
            margin-top: 10px;
        }

        .gender-btn {
            flex: 1;
            padding: 15px;
            border: 2px solid var(--gray-light);
            background: white;
            border-radius: var(--radius);
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
        }

        .gender-btn:hover {
            border-color: var(--primary);
        }

        .gender-btn.active {
            border-color: var(--primary);
            background: rgba(67, 97, 238, 0.1);
            color: var(--primary);
        }

        .btn-calculate {
            width: 100%;
            padding: 18px;
            background: var(--premium-gradient);
            color: white;
            border: none;
            border-radius: var(--radius);
            font-size: 18px;
            font-weight: 700;
            cursor: pointer;
            transition: var(--transition);
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            margin-top: 10px;
        }

        .btn-calculate:hover {
            transform: translateY(-3px);
            box-shadow: 0 10px 20px rgba(67, 97, 238, 0.3);
        }

        .result-card {
            background: white;
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow-lg);
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            text-align: center;
        }

        .bmi-value {
            font-size: 72px;
            font-weight: 900;
            margin: 20px 0;
            background: var(--premium-gradient);
            -webkit-background-clip: text;
            background-clip: text;
            color: transparent;
        }

        .bmi-category {
            font-size: 28px;
            font-weight: 700;
            margin-bottom: 30px;
            padding: 10px 30px;
            border-radius: 50px;
        }

        .underweight { background: #cfe2ff; color: #084298; }
        .normal { background: #d1e7dd; color: #0a3622; }
        .overweight { background: #fff3cd; color: #664d03; }
        .obese { background: #f8d7da; color: #842029; }

        .bmi-scale {
            width: 100%;
            margin: 30px 0;
        }

        .scale-bar {
            height: 20px;
            background: linear-gradient(to right, #4cc9f0, #b5e48c, #ffd166, #ef476f);
            border-radius: 10px;
            position: relative;
            margin-bottom: 10px;
        }

        .scale-marker {
            position: absolute;
            top: 25px;
            transform: translateX(-50%);
            font-weight: 600;
            font-size: 14px;
        }

        .scale-marker.active {
            color: var(--primary);
            font-weight: 800;
            font-size: 16px;
        }

        .user-marker {
            position: absolute;
            top: -30px;
            transform: translateX(-50%);
            color: var(--primary);
            font-weight: 800;
        }

        .user-marker i {
            font-size: 24px;
        }

        .ai-insights {
            background: white;
            border-radius: var(--radius);
            padding: 40px;
            box-shadow: var(--shadow-lg);
            margin-top: 40px;
        }

        .ai-header {
            display: flex;
            align-items: center;
            gap: 15px;
            margin-bottom: 25px;
        }

        .ai-icon {
            background: var(--premium-gradient);
            width: 50px;
            height: 50px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            font-size: 24px;
        }

        .insight-item {
            display: flex;
            align-items: flex-start;
            gap: 15px;
            margin-bottom: 25px;
            padding-bottom: 25px;
            border-bottom: 1px solid var(--gray-light);
        }

        .insight-item:last-child {
            border-bottom: none;
            margin-bottom: 0;
            padding-bottom: 0;
        }

        .insight-icon {
            width: 40px;
            height: 40px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            flex-shrink: 0;
        }

        .insight-icon.nutrition { background: #e7f5ff; color: #0c63e4; }
        .insight-icon.exercise { background: #e7f8e9; color: #0f6e2a; }
        .insight-icon.health { background: #fef7e6; color: #b37b00; }
        .insight-icon.tips { background: #f9e6ff; color: #8a2be2; }

        .premium-features {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 25px;
            margin-top: 40px;
        }

        .feature-card {
            background: white;
            border-radius: var(--radius);
            padding: 25px;
            box-shadow: var(--shadow);
            transition: var(--transition);
        }

        .feature-card:hover {
            transform: translateY(-5px);
            box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
        }

        .feature-icon {
            width: 60px;
            height: 60px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            margin-bottom: 20px;
            background: var(--premium-gradient);
            color: white;
        }

        footer {
            text-align: center;
            margin-top: 60px;
            padding-top: 30px;
            border-top: 1px solid var(--gray-light);
            width: 100%;
            color: var(--gray);
            font-size: 15px;
        }

        @media (max-width: 768px) {
            .main-content {
                gap: 25px;
            }
            
            .calculator-card, .result-card, .ai-insights {
                padding: 30px 25px;
            }
            
            .bmi-value {
                font-size: 60px;
            }
            
            .card-title {
                font-size: 22px;
            }
            
            .gender-buttons {
                flex-direction: column;
            }
        }

        @media (max-width: 480px) {
            body {
                padding: 15px;
            }
            
            .calculator-card, .result-card, .ai-insights {
                padding: 25px 20px;
            }
            
            .bmi-value {
                font-size: 48px;
            }
            
            .logo-text {
                font-size: 28px;
            }
        }