style.css

:root {
  --borderColor: rgb(33, 57, 167);
  --bgColor: white;
}

body {
  background-color: lightgray;
  width: 100vw;
  height: 100vh;
  margin: 0;
}

.all-content {
  display: grid;
  justify-content: center;
  margin-top: 50px;
}

.container {
  width: 600px;
  height: 500px;
  background-color: var(--bgColor);
  margin-top: 5px;
  border-radius: 5px;
  border: 10px solid var(--borderColor);
}

.main-canvas {
  background-color: var(--bgColor);
  width: 100%;
  height: 100%;
}

.clear-button {
  font-size: 1.5rem;
  font-weight: bold;
  background-color: rgb(38, 255, 129);
  color: rgb(16, 105, 53);
  padding: 5px 12px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
  border: 2px solid rgb(16, 105, 53);
  cursor: pointer;
  border-radius: 5px;
  box-shadow: 0 3px #999;
  margin-bottom: 10px;
}

.clear-button:hover {
  background-color: rgb(165, 252, 201);
}

.clear-button:active {
  box-shadow: 0 1px #666;
  transform: translateY(4px);
}