:root {
  --primary-color: steelblue;
}

* {
  box-sizing: border-box;
}

body {
  display: grid;
  place-content: center;
  min-height: 100vh;
  margin: 0;
  background-color: #f5f5f5;
}

.board {
  width: 404px;
  background-color: #fff;
  border: 2px solid var(--primary-color);
  border-radius: 10px;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.3);
  overflow: hidden;
}

canvas {
  display: block;
  margin: 0;
}

button,
input {
  appearance: none;
  cursor: pointer;
}

.toolbox {
  display: flex;
  padding: 1rem;
  border-top: 2px solid var(--primary-color);
  > * {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 50px;
    height: 50px;
    margin: 0.25rem;
    padding: 0.25rem;
    font-size: 2rem;
    background-color: #fff;
    border: none;
    box-shadow: 0 0 2px var(--primary-color);
    &:last-child {
      margin-left: auto;
    }
  }
}