body {
  background-image: url(../img/bg.jpg);
  background-position: center;
  background-size: cover;
  background-repeat: no-repeat;
  background-attachment: fixed;
  font-family: "Comfortaa", Arial, Helvetica, sans-serif;
}
main {
  background-color: rgba(0, 0, 0, 0.75);
}
footer {
  background-color: #000;
}
#logo {
  width: 75px;
  mix-blend-mode: multiply;
}