*{
    margin: 0;
    padding:0;
    box-sizing: border-box;
    background-color: #647ec5;
  }
  .contenedor{
    padding: 60px 0;
    width: 90%;
    max-width: 1000px;
    margin: auto;
    overflow: hidden;
  }
  .titulo{
    color: rgb(12, 112, 112);
    font-size: 30px;
    text-align: center;
    align-content: center;
    margin-bottom: 60px;  
  }
  /*Header*/
  header{
    width: 100%;
    height: 600px;
    background: #1b1e24; 
     /* fallback for old browsers */
    background: -webkit-inear-gradient(to right, hsla(217, 89%, 61%, 0.5), hsla(222, 11%, 24%, 0.5)),url(https://www.elsevier.com/__data/assets/image/0004/710149/human-skeleton-1637151280.jpg);
      /* Chrome 10-25, Safari 5.1-6 */
    background: linear-gradient(to right, hsla(217, 89%, 61%, 0.5), hsla(222, 11%, 24%, 0.5)),url(https://www.elsevier.com/__data/assets/image/0004/710149/human-skeleton-1637151280.jpg);
     /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */
     /*background-size: cover;*/
    background-attachment: fixed;
    position: relative;
    
  }
  .wave{
    position: absolute;
    bottom: 0;
    width: 100%;
  }