.hero{
      background-image:url('asset/co2.jpg');
      background-size: cover;
      background-position: center;
    }
    
    .custom-border th,
    .custom-border td{
      border: 2px solid black;
    }
    
html, body {
  height: 100%;
  margin: 0;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container.my-5 {
  flex: 1;
}