* {
  margin: 0;
  padding: 0;
  text-decoration: none;
  list-style: none;
  font-family: Arial, Helvetica, sans-serif;
}
/*HEADER*/
#header {
  background-color: white;
  height: 57px;
}
#header-logo {
  width: 20px;
}
/*SECCION CLASES*/
#clases {
  background-image: linear-gradient(
      rgba(255, 255, 255, 0.8),
      rgba(255, 255, 255, 0.7)
    ),
    url(../imagenes/clases/fondo.jpeg);
  background-position: center center;
  background-repeat: no-repeat;
  background-attachment: fixed;
  background-size: cover;
  margin-top: 56px;
}
/*#clases{
    background-color: #f2f3f4;
}*/
#clases h1 {
  text-decoration: underline;
}