* {
    box-sizing: border-box;
    transition: all 0.2s ease;
}

body {
    font-family: Arial;
    background: linear-gradient(135deg, #121212, #1a1a2e);
    color: #e0e0e0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.contenedor {
    background: #1e1e1e;
    padding: 25px;
    border-radius: 12px;
    width: 400px;
}

input, select, button {
    width: 100%;
    padding: 10px;
    margin: 5px 0 10px;
}

input, select {
    background: #2c2c2c;
    color: white;
}

button {
    background: #3f51b5;
    color: white;
    cursor: pointer;
}

#resultado {
    margin-top: 15px;
    padding: 10px;
    background: #2c2c2c;
    white-space: pre-line;
}

/* Colores */
.resultado-bajo { border-left: 5px solid #2196f3; }
.resultado-normal { border-left: 5px solid #4caf50; }
.resultado-sobrepeso { border-left: 5px solid #ff9800; }
.resultado-obesidad { border-left: 5px solid #f44336; }

/* Barra */
.barra-imc {
    height: 10px;
    background: #333;
    margin-top: 10px;
}

#barraProgreso {
    height: 100%;
    width: 0%;
    background: linear-gradient(to right, blue, green, orange, red);
}

/* Historial */
#historial {
    margin-top: 10px;
    font-size: 0.9em;
}