.main-container {
    width: 600px;
    margin: 50px auto;
    background: #eee;
    padding: 20px;
    border-radius: 10px;
}
.display {
    width: 100%;
    height: 40px;
    font-size: 1.5em;
    margin-bottom: 10px;
    box-sizing: border-box;
}
.contenedor {
    background-color: #b3d9ea;
    padding: 20px 0;
    margin-bottom: 0;
}
.teclado {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 15px;
    justify-items: center;
    margin: 0 auto 20px auto;
    width: 80%;
}
.teclado button {
    width: 100px;
    height: 40px;
    font-size: 1.2em;
    background: #f5f5fa;
    border: 1px solid #ccc;
    border-radius: 5px;
}
.acciones {
    background: #ffffe0;
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    padding: 20px;
    margin-top: 0;
}
.acciones button {
    width: 100%;
    height: 40px;
    font-size: 1.1em;
    border-radius: 5px;
    border: 1px solid #ccc;
    background: #fff;
}