* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body, html {
  margin: 0;
  padding: 0;
  overflow: hidden;
  width: 100%;
  height: 100%;
}

#c {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}