.loader {
    position: absolute;
    border: 10px solid #f3f3f3;
    border-radius: 50%;
    border-top: 10px solid #006699;
    width: 60px;
    height: 60px;
    left:calc(50% - 30px);
    top:calc(50% - 30px);
    -webkit-animation: spin 2s linear infinite; /* Safari */
    animation: spin 2s linear infinite;
  }
  
  /* Safari */
  @-webkit-keyframes spin {
    0% { -webkit-transform: rotate(0deg); }
    100% { -webkit-transform: rotate(360deg); }
  }
  
  @keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
  }

  #contenedor_loader{
    position:fixed;
    top:0;
    left:0;
    z-index:9999;
    background-color:rgba(0, 0, 0, 0.5);
    width:100%; 
    height:100%;
    display: none;
  }
  
  #loader_text{
      position:absolute;
      width:200px;
      height:20px;
      top: 50%;
      left:calc(50% - 90px);
      color:#FFFFFF;
      text-align: center;
      font:14px Arial;
  }