php-gallery/css/nav.css

/*
  -=-=-= NAV =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
*/
nav {
  margin: 0 0 2rem; padding: 0.5rem;

  width: calc(100vh - 2rem)); height: 2.5rem;

  position: sticky; z-index: 99;
  top: 1rem;

  align-items: center;
  vertical-align: middle;

  background-color: var(--bg); color: var(--fg);
  backdrop-filter: blur(8px);

  border: 0.2rem solid var(--green);
  /*outline: 0.5rem solid var(--bg);*/

  border-radius: var(--rad);
  box-shadow: var(--shadow);
}

nav p {
  margin: 0;
  vertical-align: middle;
}
nav hr {
  margin: 0.5rem 0.2rem; padding: 0;

  opacity: 0;
}

.nav-name p, .nav-name {
  font-family: "Lexend Deca", sans-serif;

  font-size: 22px;

  display: block;
}
.nav-links {
  width: auto;
  justify-content: space-between;
}
@media (max-width: 800px) {
  .nav-name p, .nav-name hr, .nav-name {
    display: none;
  }
  .nav-links {
    width: 100%;
    justify-content: space-around;
  }
}

@media (max-width: 550px) {
  nav {
    margin: 0;

    width: calc(100vw - 2rem));

    position: fixed;
    top: auto; bottom: 0; left: 0; right: 0;

    border: none;
    border-top: 3px solid var(--green);

    backdrop-filter: blur(16px);
  }
  .nav-hide {
    display: none;
  }
  .nav-links a .svg {
    margin: 0;
  }

  footer {
    margin-bottom: 3.5rem !important;
  }
  #back-to-top {
    bottom: 4.5rem !important;
  }
}