html {
  height: 100%;
  background: lightcyan;
  font-family: "Verdana", sans-serif;
}
.card-container {
  display: inline-grid;
  grid-gap: 0px;
  grid-template-rows: repeat(1, 110px);
  grid-template-columns: repeat(5, 100px);
}

.card-grid-item {
  padding: 1em;
  border: 1px solid green;
  text-align: center;
  font-size: 80px;
  color: black;
  background: goldenrod;
  margin: 0;
  padding: 0;
}
.start_button {
  background-color: darkgreen;
  border: 2px solid black;
  color: white;
  padding: 12px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  font-size: 20px;
}