* {
    box-sizing: border-box;
    font-family: Segoe UI, Verdana, Geneva, Tahoma, sans-serif;
}

.header-container {
  display: flex;
  flex-flow: row wrap;
  justify-content: space-between;
  padding: 0;
  margin: 20px;
  list-style: none;
  height: auto;
  align-items: center;
}

.box-container {
  display: flex;
  flex-flow: row wrap;
  justify-content: flex-start;  
  padding: 0;
  margin: 0;
  list-style: none;
}

.box {
    padding: 15px;
    margin: 20px;
    width: calc(33% - 40px);
    min-width: 400px;
    height: auto;
}

.cabecera-logo {
  flex: 0.3;
  height: auto;
}

.cabecera-titulo {
  flex: 0.7;
  text-align: center;
  font-size:x-large;
  vertical-align:middle;

}

.opcion {
    background-color: rgb(240,240,240);
    border: 2px solid  rgba(167,0,84); 
    border-radius: 10px;
    text-align: center;
}
.opcion > a > img{
    max-width: 100%;
    max-height: 100%;
}


@media only screen and (max-width: 1400px) {
    .box  {
        width: calc(50% - 40px);
    }
    .header-container {
        height: 100px;
      }
    
}

@media only screen and (max-width: 920px) {
    .box  {
        width: calc(100% - 40px);
    }
    .cabecera-titulo {
        font-size: large;
    }
}