:root {
    --primary-color: #005b96;
    --secondary-color: #ff6f61;
    --background-color: #f4f4f9;
    --text-color: #333;
    --input-background: #fff;
    --input-border: #ddd;
    --error-color: #e63946;
    --transition-speed: 0.3s;
}

@media (prefers-color-scheme: dark) {
    :root {
        --background-color: #1e1e1e;
        --text-color: #f1f1f1;
        --input-background: #333;
        --input-border: #555;
    }
}

body {
    font-family: 'Arial', sans-serif;
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    color: var(--text-color);
    transition: background-color var(--transition-speed), color var(--transition-speed);
}

.container {
    display: flex;
    flex-direction: column;
    padding: 1rem;
    max-width: 600px;
    margin: auto;
}

h1 {
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 1rem;
}

.description {
    text-align: center;
    margin-bottom: 2rem;
}

form {
    display: grid;
    gap: 1rem;
    grid-template-columns: 1fr;
}

input[type="text"],
input[type="number"],
select,
button {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--input-border);
    border-radius: 5px;
    background-color: var(--input-background);
    color: var(--text-color);
    transition: border-color var(--transition-speed), background-color var(--transition-speed);
}

input:focus,
select:focus,
button:focus {
    border-color: var(--primary-color);
    outline: none;
}

button {
    background-color: var(--primary-color);
    color: #fff;
    cursor: pointer;
    font-weight: bold;
    text-transform: uppercase;
    transition: background-color var(--transition-speed);
}

button:hover,
button:active {
    background-color: var(--secondary-color);
}

.error-message {
    color: var(--error-color);
    font-size: 0.875rem;
    margin-top: -0.5rem;
    margin-bottom: 0.5rem;
}

.results {
    margin-top: 2rem;
    padding: 1rem;
    border: 1px solid var(--input-border);
    border-radius: 5px;
    background-color: var(--input-background);
}

@media (min-width: 768px) {
    form {
        grid-template-columns: repeat(2, 1fr);
        gap: 1.5rem;
    }
}

@media print {
    body {
        color: #000;
    }
    .container {
        max-width: 100%;
        padding: 0;
    }
    button {
        display: none;
    }
}