body {
  margin: 0;
  background: #ddd;
  display: flex;
  flex-direction: column;
  align-items: center;
  font-family: sans-serif;
}

h1 {
  margin: 10px 0;
}

#color-bar {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}

.color {
  width: 24px;
  height: 24px;
  border: 2px solid #000;
  cursor: pointer;
}

.color.selected {
  outline: 3px solid red;
}

#viewport {
  width: 800px;
  height: 800px;
  overflow: hidden;
  background: white;
  border: 2px solid #000;
  box-sizing: border-box;
  position: relative;
}