:root {
            --primary: #2b6cb0;
            --primary-light: #4299e1;
            --secondary: #38b2ac;
            --dark: #2d3748;
            --light: #f7fafc;
            --gray: #e2e8f0;
        }
        
        body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            line-height: 1.6;
            color: var(--dark);
            background-color: var(--light);
            margin: 0;
            padding: 0;
        }
        
        .container {
            max-width: 900px;
            margin: 0 auto;
            padding: 2rem;
        }
        
        header {
            text-align: center;
            margin-bottom: 2rem;
            padding-bottom: 1rem;
            border-bottom: 2px solid var(--gray);
        }
        
        h1 {
            color: var(--primary);
            margin-bottom: 0.5rem;
        }
        
        .description {
            color: var(--dark);
            font-size: 1.1rem;
            max-width: 700px;
            margin: 0 auto;
        }
        
        .calculator {
            display: flex;
            flex-wrap: wrap;
            gap: 2rem;
            margin-bottom: 2rem;
        }
        
        .inputs {
            flex: 1;
            min-width: 300px;
        }
        
        .visualizations {
            flex: 1;
            min-width: 300px;
        }
        
        .form-group {
            margin-bottom: 1.5rem;
        }
        
        label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
        }
        
        .slider-container {
            display: flex;
            align-items: center;
            gap: 1rem;
        }
        
        input[type="range"] {
            flex: 1;
            height: 8px;
            -webkit-appearance: none;
            appearance: none;
            width: 100%;
            background: var(--gray);
            border-radius: 5px;
            outline: none;
        }
        
        input[type="range"]::-webkit-slider-thumb {
            -webkit-appearance: none;
            appearance: none;
            width: 20px;
            height: 20px;
            border-radius: 50%;
            background: var(--primary);
            cursor: pointer;
            transition: background 0.15s ease;
        }
        
        input[type="range"]::-webkit-slider-thumb:hover {
            background: var(--primary-light);
        }
        
        input[type="number"] {
            width: 60px;
            padding: 0.5rem;
            border: 1px solid var(--gray);
            border-radius: 4px;
            font-size: 1rem;
            text-align: center;
        }
        
        .result-container {
            background-color: white;
            border-radius: 8px;
            padding: 1.5rem;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            text-align: center;
            margin-bottom: 2rem;
        }
        
        .tip-amount {
            font-size: 3rem;
            font-weight: bold;
            color: var(--primary);
            margin: 1rem 0;
        }
        
        .tip-label {
            font-size: 1.2rem;
            color: var(--dark);
        }
        
        .fuzzy-visualization {
            background-color: white;
            border-radius: 8px;
            padding: 1.5rem;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            margin-bottom: 1rem;
        }
        
        .fuzzy-title {
            font-size: 1.2rem;
            margin-bottom: 1rem;
            font-weight: 600;
        }
        
        .fuzzy-bars {
            display: flex;
            flex-direction: column;
            gap: 0.5rem;
        }
        
        .fuzzy-bar {
            display: flex;
            align-items: center;
            gap: 1rem;
        }
        
        .bar-label {
            width: 80px;
            text-align: right;
            font-size: 0.9rem;
        }
        
        .bar-container {
            flex: 1;
            height: 20px;
            background-color: var(--gray);
            border-radius: 4px;
            overflow: hidden;
        }
        
        .bar-fill {
            height: 100%;
            background-color: var(--secondary);
            width: 0%;
            transition: width 0.3s ease;
        }
        
        .bar-value {
            width: 40px;
            text-align: left;
            font-size: 0.9rem;
        }
        
        .info-section {
            background-color: white;
            border-radius: 8px;
            padding: 1.5rem;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            margin-top: 2rem;
        }
        
        .fuzzy-explanation {
            margin-bottom: 1.5rem;
        }
        
        @media (max-width: 768px) {
            .calculator {
                flex-direction: column;
            }
        }