index.css

@import url("https://fonts.googleapis.com/css2?family=Montserrat:wght@900&display=swap");

body {
  margin: 0;
  color: white;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  cursor: pointer;
}

#instructions {
  display: none;
}

#results,
body:hover #instructions {
  position: absolute;
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
  width: 100%;
  background-color: rgba(20, 20, 20, 0.75);
}

a:visited {
  color: inherit;
}

#results {
  display: none;
  cursor: default;
}

#results .content,
#instructions .content {
  max-width: 300px;
  padding: 50px;
  border-radius: 20px;
}

#results {}

#score {
  position: absolute;
  color: white;
  font-size: 3em;
  font-weight: bold;
  top: 30px;
  right: 30px;
}

#youtube,
#skillshare,
#youtube-card,
#skillshare-card {
  display: none;
  color: black;
}

@media (min-height: 425px) {

  /** Youtube logo by https://codepen.io/alvaromontoro */
  #youtube,
  #skillshare {
    z-index: 50;
    width: 100px;
    height: 70px;
    position: fixed;
    bottom: 20px;
    transform: scale(0.8);
    transition: transform 0.5s;
  }

  #youtube {
    display: block;
    background: red;
    right: 20px;
    border-radius: 50% / 11%;
  }

  #skillshare {
    display: block;
    left: 20px;
    color: white;
    font-size: 1.8em;
    font-weight: extra-bold;
    font-family: "Montserrat", sans-serif;
    text-decoration: none;
  }

  #youtube:hover,
  #youtube:focus {
    transform: scale(0.9);
    color: black;
  }

  #skillshare:hover,
  #skillshare:focus {
    transform: scale(0.9);
    color: #002333;
  }

  #youtube::before {
    content: "";
    display: block;
    position: absolute;
    top: 7.5%;
    left: -6%;
    width: 112%;
    height: 85%;
    background: red;
    border-radius: 9% / 50%;
  }

  #youtube::after {
    content: "";
    display: block;
    position: absolute;
    top: 20px;
    left: 40px;
    width: 45px;
    height: 30px;
    border: 15px solid transparent;
    box-sizing: border-box;
    border-left: 30px solid white;
  }

  #youtube span {
    font-size: 0;
    position: absolute;
    width: 0;
    height: 0;
    overflow: hidden;
  }

  #youtube:hover+#youtube-card,
  #skillshare:hover+#skillshare-card {
    z-index: 49;
    display: block;
    position: fixed;
    bottom: 12px;
    width: 300px;
    background-color: white;
  }

  #youtube:hover+#youtube-card {
    right: 10px;
    padding: 25px 130px 25px 25px;
  }

  #skillshare:hover+#skillshare-card {
    left: 10px;
    padding: 25px 25px 25px 130px;
  }
}