html{
  min-width: 300px;
}

header{
  display: flex;
  justify-content: center;
  align-items: center;
}

header .logo{
  width: 200px;
  height: 80px;
  background-color: green;
}

.contenido{
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: 2%;
}

.contenido p{
  display: flex;
  justify-content: center;
  font-size: 1.04em;
}

.contenido form{
  margin-top: 4%;
}

#login_contra, #login_nick{
  padding: 5px;
  font-size: 1.02em;
}

#login_nick{
  margin-bottom: 3%;
}

label{
  font-size: 1.02em;
}

#acceder{
  display:block;
  margin-left: auto;
  margin-right: auto;
  font-size: 1.02em;
}

@media screen and (max-width: 768px){
  header .logo{
    width: 160px;
    height: 60px;
  }
}