body{
    padding: 0px;
    margin: 0px;
    background: white;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen,
      Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}

header {
    z-index: 50;
    padding: 0px;
    margin: 0px;
    padding-left: 10px;
    padding-top: 10px;
    position: sticky;
    min-width: 1000px;
    top: 0;
    background-color: #ffffff;
}

.center {
  display: block;
  margin-left: 18px;
}

#btn1 {
    position: absolute;
    top: 136px;
    left: 47px;
    background-color: #1b1b1b;
    color: #1b1b1b;
    font-size: 25px;
    padding: 73px 24px;
    border: none;
    cursor: pointer;
    border-radius: 1px;
  }
  
#btn1:hover {
    background-color: rgb(151, 70, 158);
  }

#btn2 {
    position: absolute;
    top: 354.5px;
    left: 268.5px;
    background-color: #1b1b1b;
    color: #1b1b1b;
    font-size: 25px;
    padding: 58.5px 19.5px;
    border: none;
    cursor: pointer;
    border-radius: 1px;
  }
  
#btn2:hover {
    background-color: rgb(110, 219, 79);
  }

#btn3 {
    position: absolute;
    top: 575px;
    left: 491px;
    background-color: #1b1b1b;
    color: #1b1b1b;
    font-size: 25px;
    padding: 58px 25px;
    border: none;
    cursor: pointer;
    border-radius: 1px;
  }
  
#btn3:hover {
    background-color: rgb(70, 152, 207);
  }

#btn4 {
    position: absolute;
    top: 793.5px;
    left: 713px;
    background-color: #1b1b1b;
    color: #1b1b1b;
    font-size: 25px;
    padding: 73px 30.5px;
    border: none;
    cursor: pointer;
    border-radius: 1px;
  }
  
#btn4:hover {
    background-color: rgb(194, 50, 50);
  }