style.css

*{
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}
html, body {
  height: 100vh;
}

body {
  font-family: 
    ui-sans-serif, 
    system-ui, 
    -system-ui, 
    -apple-system,
    BlinkMacSystemFont,
    Roboto, Helvetica, Arial, 
    sans-serif, 
    "Apple Color Emoji";
  font-size: 14pt;
  background: lightblue;
}

.del {
  color: red;
}

#answer {
  font-size: 144pt;
  font-weight: 700;
}

#equals {
  font-size: 72pt;
  font-weight: 700;
}

#times {
  font-size: 72pt;
  font-weight: 700;
  margin-left: 20px;
  margin-right: 20px;
}

.hidden {
  visibility: hidden;
}

header {
  padding: 30px;
  display: grid;
  grid-template-columns: 150px auto;
  background-color: white;
}

.equation {
  display: grid;
  grid-template-columns: 200px 80px 200px 160px 200px;
}

.equation > div {
  font-size: 72pt;
  font-weight: 700;
  margin: 10px;
  text-align: center;
}

.stats-label {
  font-weight: 600;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
}

footer {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.factors {
  display: flex;
  flex-direction: row;
}

.factor-container {
  display: grid;
  grid-template-columns: auto auto auto;
}

button {
  font-size: 24pt;
}