:root {
            --background-start: #1a202c;
            --background-end: #2d3748;
            --card-background: #4a5568;
            --text-primary: #edf2f7;
            --text-secondary: #a0aec0;
            --accent-color: #4299e1;
            --border-color: #718096;
            --shadow-color: rgba(0, 0, 0, 0.4);
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

body {
            font-family: 'Poppins', sans-serif;
            background-image: linear-gradient(to right top, var(--background-start), var(--background-end));
            color: var(--text-primary);
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            padding: 40px 20px;
        }

.container {
            max-width: 700px;
            width: 100%;
            background-color: var(--card-background);
            padding: 30px;
            border-radius: 15px;
            box-shadow: 0 10px 30px var(--shadow-color);
        }

        h1, h2, h3 {
            text-align: center;
            font-weight: 600;
        }
        
h1 {
            color: var(--accent-color);
            margin-bottom: 30px;
        }

h2 { margin-bottom: 20px; }

.calculator-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 20px;
            margin-bottom: 30px;
        }

@media (min-width: 600px) {
            .calculator-grid { grid-template-columns: repeat(3, 1fr); }
            .calculator-grid .form-group:nth-child(1) { grid-column: 1 / 4; }
            .calculator-grid .form-group:nth-child(2) { grid-column: 1 / 3; }
        }

.form-group {
            display: flex;
            flex-direction: column;
        }

.form-group label {
            margin-bottom: 8px;
            font-weight: 400;
            color: var(--text-secondary);
        }

.form-group input, .form-group select, .form-group button {
            width: 100%;
            padding: 12px;
            border-radius: 8px;
            border: 1px solid var(--border-color);
            background-color: var(--background-end);
            color: var(--text-primary);
            font-family: 'Poppins', sans-serif;
            font-size: 1rem;
            transition: all 0.2s ease-in-out;
        }

.form-group input:focus, .form-group select:focus {
            outline: none;
            border-color: var(--accent-color);
            box-shadow: 0 0 0 3px rgba(66, 153, 225, 0.5);
        }

.form-group button {
            background-color: var(--accent-color);
            border-color: var(--accent-color);
            cursor: pointer;
            font-weight: 600;
        }

.form-group button:hover {
            background-color: #3182ce;
        }

.result-container {
            margin-top: 20px;
            padding: 20px;
            background-color: var(--background-start);
            border-radius: 10px;
            text-align: center;
        }
        
.result-container h3 {
            margin-bottom: 15px;
            color: var(--text-secondary);
            font-weight: 400;
        }

.result-values {
            display: flex;
            justify-content: space-around;
            gap: 20px;
        }
        
.result-item { display: flex; flex-direction: column; }
.result-item .label { font-size: 0.9rem; color: var(--text-secondary); }
.result-item .value { font-size: 1.8rem; font-weight: 600; color: var(--accent-color); }

.table-container { margin-top: 40px; }
        table { width: 100%; border-collapse: collapse; }
        th, td { padding: 12px; text-align: center; border: 1px solid var(--border-color); }
        thead { background-color: var(--background-end); }
        tbody tr:nth-child(even) { background-color: var(--background-start); }

.divider {
            height: 1px;
            background-color: var(--border-color);
            margin: 40px 0;
        }
        
        
.info-section {
            margin-top: 40px;
            padding: 20px;
            background-color: var(--background-start);
            border-radius: 10px;
            text-align: left;
            line-height: 1.6;
        }
.info-section h2 {
            text-align: center;
        }
        .info-section a {
            color: var(--accent-color);
            text-decoration: none;
        }
        .info-section a:hover {
            text-decoration: underline;
        }
        

.pdf-generator-section { text-align: center; }

        #pdf-form-container {
            display: none;
            grid-template-columns: 1fr;
            gap: 20px;
            margin-top: 20px;
            text-align: left;
            transition: opacity 0.3s ease-in-out;
        }

        @media (min-width: 600px) {
            #pdf-form-container { grid-template-columns: 1fr 1fr; }
            #pdf-form-container .form-group:nth-child(1) { grid-column: 1 / 3; }
            #pdf-form-container .form-group:nth-child(5) { grid-column: 1 / 3; }
            #pdf-form-container .form-group:nth-child(6) { grid-column: 1 / 3; }
        }

        #pdf-form-container.visible { display: grid; }

        .checkbox-group {
            display: flex;
            justify-content: center;
            align-items: center;
            gap: 10px;
            cursor: pointer;
        }