:root {
    --primary-color: #09fcfd;
    --secondary-color: #510303;
    --size-unit: 64px;
    --ships-animation-time: 200ms;
    --explosions-animation-time: 600ms;
  }
  
  *,
  *::after,
  *::before {
    margin: 0;
    padding: 0;
    box-sizing: inherit;
  }
  
  body {
    font-family: 'Lato', sans-serif;
    box-sizing: border-box;
  }
  
  .container {
    width: 100vw;
    height: 100vh;
    background-color: #000;
    position: relative;
  }
  
  .information {
    color: #fff;
    display: flex;
    justify-content: space-between;
    padding: 20px;
    font-size: 32px;
    z-index: 2;
    position: relative;
  }
  
  .modal {
    width: 100vw;
    height: 100vh;
    background-color: #000;
    position: absolute;
    top: 0;
    left: 0;
    z-index: 3;
    display: flex;
    color: #fff;
    justify-content: center;
    align-items: center;
  }
  
  .modal__content {
    position: relative;
    display: flex;
    flex-direction: column;
  }
  
  .modal__text {
    font-size: 42px;
    text-align: center;
  }
  
  .modal__button {
    padding: 30px 15px;
    background-color: transparent;
    border: 3px solid var(--primary-color);
    color: var(--primary-color);
    cursor: pointer;
    font-size: 42px;
    margin-top: 20px;
    outline: none;
    transition: box-shadow 0.1s ease-in;
  }
  .modal__button:hover {
    box-shadow: 0px 0px 20px 5px var(--primary-color);
  }
  
  .spaceship {
    width: var(--size-unit);
    height: var(--size-unit);
    background-image: url('../images/ship.png');
    animation: move-8-units-X var(--ships-animation-time) steps(8) infinite;
    left: 0;
    position: fixed;
  }
  .enemy {
    width: var(--size-unit);
    height: var(--size-unit);
    background-image: url('../images/enemy.png');
    animation: move-5-units-X var(--ships-animation-time) steps(5) infinite;
    z-index: 1;
    position: fixed;
  }
  .enemy--big {
    width: calc(var(--size-unit) * 2);
    height: calc(var(--size-unit) * 2);
    background-image: url('../images/enemy-big.png');
    animation: move-16-units-X var(--ships-animation-time) steps(8) infinite;
    position: fixed;
  }
  .explosion {
    width: var(--size-unit);
    height: var(--size-unit);
    background-image: url('../images/explosion.png');
    animation: move-17-units-X var(--explosions-animation-time) steps(17) forwards;
    position: fixed;
  }
  .explosion--big {
    width: calc(var(--size-unit) * 2);
    height: calc(var(--size-unit) * 2);
    background-image: url('../images/explosion-big.png');
    animation: move-34-units-X var(--explosions-animation-time) steps(17) forwards;
    position: fixed;
  }
  
  .missile {
    background-image: url('../images/missile.png');
    background-size: cover;
    width: 12px;
    height: 24px;
    position: absolute;
  }
  
  @keyframes move-8-units-X {
    from {
      background-position-x: 0px;
    }
    to {
      background-position-x: calc(var(--size-unit) * -8);
    }
  }
  @keyframes move-5-units-X {
    from {
      background-position-x: 0px;
    }
    to {
      background-position-x: calc(var(--size-unit) * -5);
    }
  }
  @keyframes move-16-units-X {
    from {
      background-position-x: 0px;
    }
    to {
      background-position-x: calc(var(--size-unit) * -16);
    }
  }
  @keyframes move-17-units-X {
    from {
      background-position-x: 0px;
    }
    to {
      background-position-x: calc(var(--size-unit) * -17);
    }
  }
  @keyframes move-34-units-X {
    from {
      background-position-x: 0px;
    }
    to {
      background-position-x: calc(var(--size-unit) * -34);
    }
  }
  
  .hide {
    display: none;
  }
  
  .hit {
    background-color: var(--secondary-color);
  }