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

body {
    font-family: Arial, sans-serif;
    background-color: #f0f8ff;
    color: #333;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

header h1 {
    color: #2c3e50;
    margin-bottom: 10px;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.input-panel, .results-panel {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

section {
    margin-bottom: 20px;
}

h2 {
    color: #2c3e50;
    margin-bottom: 15px;
}

.data-input-methods {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

button {
    background: #3498db;
    color: white;
    border: none;
    padding: 8px 12px;
    border-radius: 4px;
    cursor: pointer;
}

button:hover {
    background: #2980b9;
}

.calculate-btn {
    background: #27ae60;
    width: 100%;
    padding: 10px;
}

.calculate-btn:hover {
    background: #219a52;
}

table {
    width: 100%;
    border-collapse: collapse;
}

th, td {
    padding: 8px;
    border: 1px solid #ddd;
    text-align: left;
}

th {
    background: #34495e;
    color: white;
}

input[type="number"] {
    width: 100%;
    padding: 6px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.model-selection {
    margin-bottom: 15px;
}

select {
    width: 100%;
    padding: 8px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.report-container {
    background: #f8f9fa;
    padding: 15px;
    border-radius: 4px;
    min-height: 200px;
    display: flex;
    flex-direction: column;
}

.no-results {
    text-align: center;
    color: #666;
    font-style: italic;
    margin: auto;
}

.chart-container {
    height: 300px;
    margin-bottom: 20px;
}

.report-content h3 {
    margin-bottom: 15px;
    color: #2c3e50;
}

.report-content p {
    margin-bottom: 8px;
}

.validation-message {
    padding: 8px;
    border-radius: 4px;
    margin-top: 10px;
}

.validation-message.error {
    background: #ffeaa7;
    color: #d63031;
}

@media (max-width: 768px) {
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .data-input-methods {
        flex-direction: column;
    }
    
    button {
        width: 100%;
    }
}