body {
  margin: 0;
  font-family: 'Verdana', sans-serif;
  background: #1e1e1e;
  color: #eee;
  display: flex;
  flex-direction: column;
  align-items: center;
}

header, footer {
  text-align: center;
  padding: 20px;
  background: #2a2a2a;
  width: 100%;
}

main {
  margin: 20px;
}

canvas {
  border: 2px solid #3a3a3a;
  background: #87ceeb; /* небо */
}