body, html
{
  height:100%;
}
body
{
  margin: 0;
  padding: 0;
  background: linear-gradient(to right, #00AAFF, #00FF6C);
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
}
.calc-container
{
  display: grid;
  justify-content: center;
  height:100%;
  align-content:center;
  grid-template-columns: repeat(4, 100px);
  grid-template-rows: minmax(100px, auto) repeat(5, 100px);
}

.ac
{
  /* grid-area: 1/1/span 1/ span 2; */
  grid-column: 1/span 2;
}
.equal
{
  grid-column: span 2;
}
.output
{
  grid-column: 1/-1;
  word-break: break-all;
  background-color: rgba(0, 0, 0, .75);
  color: white;
  display: flex;
  flex-direction: column;
  align-items: end;
  gap: 20px;
  padding: 15px;
}
.number
{
  columns: black;
}
button
{
  border: 1px solid rgb(255, 255, 255);
  outline:none;
  font-size: 2rem;
  background-color:rgba(255, 255, 255, .75);
  cursor:pointer;
}
button:hover
{
  background: white;
}
.output > .previous-number-entiry
{
  font-size: 1.5rem;
  color: rgba(255, 255, 255, .75);
}
.output > .current-number-entiry
{
  font-size: 2.5rem;
  color: white;
}