html, body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
}

html {
  --alien-bounce-speed: 2s;
  --alien-speed: 10s;
}

body {
  background: url("/sprites/space.gif");
  font-family: 'MS Gothic', sans-serif;
  font-style: italic;
}

h1, h2, h3, h4, h5, h6 {
  margin: 0;
}

/* Alien */
#alien_container {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;

  overflow: hidden;
}

#alien {
  position: absolute;
  width: fit-content;
}

#alien.flyRight {
  animation: float var(--alien-bounce-speed) infinite ease-in-out, flyRight var(--alien-speed) linear;
}

#alien.flyLeft {
  animation: float var(--alien-bounce-speed) infinite ease-in-out, flyLeft var(--alien-speed) linear;
}

@keyframes float {
  0% {
    margin-top: 0;
  }
  50% {
    margin-top: 5vw;
  }
  100% {
    margin-top: 0;
  }
}

@keyframes flyRight {
  0% {
    transform: translateX(-100px);
  }
  100% {
    transform: translateX(100vw);
  }
}

@keyframes flyLeft {
  0% {
    transform: translateX(100vw) scaleX(-1);
  }
  100% {
    transform: translateX(-100px) scaleX(-1);
  }
}

/* Content */
#content_container {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  min-height: 50%;

  margin: 20px;
  padding: 5%;

  text-align: center;
  border: 1px dashed white;
  color: white;

  display: flex;
  flex-direction: column;
  align-items: center;
}

.align {
  display: flex;
  align-items: center;
}