Centering error with CSS [closed]

My class .contenido is not focused, how can I solve it?

This is my code:

body{
  font-family: sans-serif;
  text-align: center;
  font-size: 22px;
}
.portada{
  padding: 5% 5% 0 5%;
  font-size: 30px;
}
.Logotipo{
  width: 90%;
}

.contenido{
  text-align: center;
}
.texto{
  width: 60%;
  margin-bottom: 50px;
  text-align: center;
}

.microfonos{
  display: inline-block;
  width: 60%;
  display: flex;
  flex-flow: wrap;
  justify-content: space-around;
}
.microfono{
  border: 2px solid black;
  margin: 50px 50px;
  width: 250px;
  padding: 20px;
  transition: .2s;
}
.microfono:hover{
  transform: scale(1.1);
  background: #F0F0F0;
}
.microfono a{
  color: black;
  text-decoration: none;
}
.microfono p{
  border-top: 1px solid black;
  padding-top: 10px;
}

.footer{
  border-top: 4px solid black;
  font-size: 20px;
  margin: 100px;
  padding: 50px 100px;
}
.footer ul{
  text-align: left;
}
.footer a{
  color: black;
}
.fondo{
  background: black;
  width: 100%;
  height: 20px;
}