html {
    height: 100%; }
  
  body {
    margin: 0;
    height: 100%; }
  
  a {
    text-decoration: none; }
  
  ul {
    list-style: none; }
  
  ul, li, p, h1, h2, h3 {
    padding: 0;
    margin: 0; }
  
  * {
    box-sizing: border-box; }