:root {
    --primary-color: #ffffff;
    --secondary-color: #3498db;
    --background-color: #f5f6fa;
    --box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--background-color);
    color: var(--primary-color);
    line-height: 1.6;

    background-image: url('img/background_copia.jpg');
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center;
}

.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1rem;
}

h1 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--primary-color);
}

.calculator {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    margin-bottom: 2rem;
}

.input-group {
    margin-bottom: 1.5rem;
}

label {
    color: #2980b9;
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

input, select {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 1rem;
}

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

button {
    width: 100%;
    padding: 1rem;
    background-color: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 5px;
    font-size: 1.1rem;
    cursor: pointer;
    transition: background-color 0.3s;
}

button:hover {
    background-color: #2980b9;
}

.results {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.result-box {
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    text-align: center;
}

.result-box h3 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.result-box p {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--secondary-color);
}

.chart-container {
    background: white;
    padding: 1rem;
    border-radius: 10px;
    box-shadow: var(--box-shadow);
    margin-top: 2rem;
}

@media (max-width: 768px) {
    .container {
        margin: 1rem auto;
    }
    
    .calculator {
        padding: 1rem;
    }
    
    .results {
        grid-template-columns: 1fr;
    }
}