@media (max-width: 991px) {
  html {
    font-size: 55%;
  }
  .heading {
    font-size: 5rem;
    margin-bottom: 3rem;
  }
}
@media (max-width: 768px) {
  .header .flex #menu-btn {
    display: inline-block;
  }
  .header .flex {
    position: relative;
  }
  .header .flex .navbar {
    position: absolute;
    top: 100%;
    left: 2rem;
    right: 2rem;
    background-color: rgba(0, 0, 0, 0.3);
    -webkit-backdrop-filter: blur(0.4rem);
            backdrop-filter: blur(0.4rem);
    border-radius: 0.5rem;
    transform: scale(0);
    transform-origin: top right;
    box-shadow: 0 0 8px rgba(0, 0, 0, 0.8);
    padding: 1.5rem;
  }
  .header .flex .navbar.active {
    transform: scale(1);
    transition: 0.2s linear;
  }
  .header .flex .navbar a {
    display: block;
    padding: 1.5rem 0.5rem;
    margin: 0.5rem 1.5rem;
    color: #fff;
    border-radius: 0.5rem;
  }
  .header .flex .navbar a:hover {
    background: #FFFFB3;
    -webkit-backdrop-filter: blur(0.3);
            backdrop-filter: blur(0.3);
    color: #000;
  }
  .heading {
    font-size: 3rem;
  }
}
@media (max-width: 450px) {
  html {
    font-size: 50%;
  }
  .heading {
    font-size: 2.5rem;
  }
}