styles.css

/*
      SPACE SIZE SYSTEM (px)
      2 / 4 / 8 / 12 / 16 / 24 / 32 / 48 / 64 /
      80 / 96 / 128

      FONT SIZE SYSTEM (px)
      10 / 12 / 14 / 16 / 18 / 20 / 24 / 30 /
      36 / 44 / 52 / 62 / 74 / 86 / 98
      */

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 62.5%;
}

body {
  background-color: #001b39;
  color: #fff;
}

.heading-primary {
  color: #fff;
  background-color: #001524;
  font-family: 'Press Start 2P', sans-serif;
  font-size: 2.8rem;
  text-align: center;
  padding: 4rem;
  margin-bottom: 4rem;
}

.heading-secondary {
  color: #ffd35b;
  font-family: 'Press Start 2P', sans-serif;
  font-size: 2rem;
  text-align: center;
  margin-bottom: 2rem;
}

.btn {
  color: #fff;
  width: 18rem;
  padding: 1.8rem 2rem;
  font-size: 1, 4rem;
  font-family: 'Press Start 2P', sans-serif;
  text-align: center;
  margin: 0 auto;
  margin-bottom: 4rem;
  cursor: pointer;
  background-color: #002f5d;
  display: flex;
  justify-content: center;
  text-transform: uppercase;
}

.btn:hover {
  background-color: #033d78;
}

.main {
  display: flex;
  justify-content: center;
}

.grid {
  position: absolute;
  background-color: #fff;
  width: 564px;
  height: 300px;
  border: solid black 1px;
  margin: 0 auto;
}

.block {
  position: absolute;
  width: 100px;
  height: 20px;
  background-color: #e8b423;
}

.user {
  position: absolute;
  width: 100px;
  height: 20px;
  background-color: #c39004;
}

.ball {
  position: absolute;
  width: 20px;
  height: 20px;
  border-radius: 10px;
  background-color: #001524;
}

.footer {
  position: absolute;
  bottom: 0;
  width: 100%;
  height: 100px;
  background-color: #001524;
  display: flex;
  justify-content: center;
  align-items: center;
}

.copyright {
  color: #fff;
  font-family: 'Press Start 2P', sans-serif;
  font-size: 1.2rem;
  text-align: center;
  margin-top: 4rem;
}

.link {
  color: #fff;
  text-decoration: none;
  cursor: pointer;
}

.hidden {
  display: none;
}