:root {
    --primary: #2c3e50;
    --secondary: #3498db;
    --accent: #2980b9;
    --light: #ecf0f1;
    --dark: #34495e;
    --success: #27ae60;
    --border-radius: 8px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7fa;
    color: var(--primary);
    line-height: 1.6;
    padding: 20px;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.container {
    max-width: 1000px;
    width: 100%;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px;
}

h1 {
    color: var(--primary);
    margin-bottom: 10px;
    font-weight: 600;
}

.subtitle {
    color: var(--dark);
    font-size: 1.1rem;
}

.calculator {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 30px;
    margin-bottom: 40px;
}

@media (max-width: 768px) {
    .calculator {
        grid-template-columns: 1fr;
    }
}

.input-section, .results-section {
    background: white;
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--shadow);
}

.section-title {
    font-size: 1.3rem;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--light);
    color: var(--primary);
}

.form-group {
    margin-bottom: 20px;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark);
}

input, select {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid #ddd;
    border-radius: var(--border-radius);
    font-size: 1rem;
    transition: var(--transition);
}

input:focus, select:focus {
    outline: none;
    border-color: var(--secondary);
    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
}

.unit-toggle {
    display: flex;
    margin-bottom: 20px;
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 5px;
}

.unit-toggle button {
    flex: 1;
    padding: 10px;
    border: none;
    background: transparent;
    cursor: pointer;
    border-radius: calc(var(--border-radius) - 2px);
    transition: var(--transition);
    font-weight: 500;
}

.unit-toggle button.active {
    background: var(--secondary);
    color: white;
}

.dimension-toggle {
    display: flex;
    gap: 10px;
    margin-bottom: 15px;
}

.dimension-toggle button {
    flex: 1;
    padding: 10px;
    border: 1px solid #ddd;
    background: white;
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.dimension-toggle button.active {
    background: var(--secondary);
    color: white;
    border-color: var(--secondary);
}

.dimension-inputs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.results-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.result-card {
    background: var(--light);
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
}

.result-value {
    font-size: 1.5rem;
    font-weight: 600;
    margin: 10px 0;
    color: var(--primary);
}

.result-label {
    font-size: 0.9rem;
    color: var(--dark);
}

.result-unit {
    font-size: 0.9rem;
    color: var(--dark);
    margin-left: 5px;
}

.compression-section {
    margin-top: 25px;
    padding-top: 20px;
    border-top: 1px solid #eee;
}

.compression-slider {
    width: 100%;
    margin: 15px 0;
}

.compression-value {
    text-align: center;
    font-weight: 600;
    color: var(--secondary);
    margin-top: 10px;
}

.explanation {
    background: white;
    border-radius: var(--border-radius);
    padding: 25px;
    box-shadow: var(--shadow);
    margin-top: 30px;
}

.explanation h2 {
    margin-bottom: 15px;
    color: var(--primary);
}

.formula {
    background: #f8f9fa;
    padding: 15px;
    border-radius: var(--border-radius);
    margin: 15px 0;
    font-family: monospace;
    border-left: 4px solid var(--secondary);
}

footer {
    text-align: center;
    margin-top: 40px;
    padding: 20px;
    color: var(--dark);
    font-size: 0.9rem;
}

.highlight {
    color: var(--secondary);
    font-weight: 600;
}