style.css

* {
  margin: 0;
  padding: 0;
}
body {
  display: flex;
  justify-content: center;
  align-content: center;
  flex-direction: column;
}

button {
  padding: 8px 24px;
  margin-bottom: 20px;
}
.header {
  height: 72px;
  background-color: #EEEEEE;
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 32px;
  color: #3D2C8D;
}

.content {
  display: flex;
  flex-direction: column;
  align-items: center;
  margin: 25px 0;
}
.row {
  display: flex;
  height: 100%;
}
.row >*{
  flex: 1 1 0;
}
.grid {
  height: 100%;
  /* border: 1px solid black; */
}
.active {
  background-color: aqua;
}
 
.container {
  border: 10px outset gray;
   width: 400px;
   height: 400px;
   display: flex;
   flex-direction: column;
}
.buttons {
   width: 400px;
  display: flex;
  justify-content: space-between;
}
.footer {
  height: 72px;
  background-color: #DED9C4;
  display: flex;
  justify-content: center;
  align-items: center;
}