* {
  box-sizing: border-box;
  user-select: none;
  margin: 0;
  padding: 0;
}

:root {
	--main-color: #0095dd;
	--canvas-bg-color: #f0f0f0;
	--btn-color: #000;
	--text-color: #fff;
	--btn-hover-color: #222;
	--rules-bg-color: #333;
}

body {
  background-color: var(--main-color);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  font-family: Arial, Helvetica, sans-serif;
  min-height: 100vh;
  margin: 0;
}

.title {
  font-size: 55px;
  color: var(--text-color);
}

canvas {
  background: var(--canvas-bg-color);
  display: block;
  border-radius: 5px;
}

.btn {
  cursor: pointer;
  border: 0;
  padding: 10px 20px;
  background: var(--btn-color);
  color: var(--text-color);
  border-radius: 5px;
}

.btn:focus {
  outline: 0;
}

.btn:hover {
  background: var(--btn-hover-color);
}

.btn:active {
  transform: scale(0.98);
}

.rules-btn {
  position: absolute;
  top: 30px;
  left: 30px;
}

.rules {
  position: absolute;
  top: 0;
  left: 0;
  background: var(--rules-bg-color);
  color: var(--text-color);
  min-height: 100vh;
  width: 400px;
  padding: 20px;
  line-height: 1.5;
  transform: translateX(-400px);
  transition: transform 1s ease-in-out;
}

.rules.show {
  transform: translateX(0);
  user-select: none;
}

.rules h2 {
  font-size: 47px;
  user-select: text;
}

.rules p {
  margin: 25px 0px;
  user-select: text;
}