summary {
  writing-mode: vertical-lr;
  width: 23px;
  height: 17px;
  background-color: var(--primColor);
  border: 2px solid var(--secoColor);
  border-radius: var(--cornerRad);
  color: var(--secoColor);
  cursor: pointer;
  user-select: none;
  outline: none;
  transition: transform 200ms ease-in-out 0s;
  font-family: Arial;
  font-size: 18px;
}
summary::before,
summary::after { position: static; top: 0; left: 0; }
summary::before { content: ""; }
summary::after { content: "III"; letter-spacing: -1px; }
summary:hover { transform: scale(1.1); }
summary::marker { font-size: 0; }
summary::-webkit-details-marker { display: none; }

details { margin: 0; }
details[open] .menu_bar { animation-name: menuAnim; }
details[open] summary::before { content: "X"; }
details[open] summary::after { content: ""; }
details::before {
  content: "";
  color: var(--secoColor);
  position: absolute;
  opacity: 0.4;
}
details[open]::before { animation: fadeMe 300ms linear forwards; }

.menu_bar {
  font-family: Arial;
  height: 0;
  width: fit-content;
  border-radius: var(--cornerRad);
  background-color: var(--primColor);
  box-shadow: 0 4px 12px 0 rgba(0, 0, 0, 0.2);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
  animation: closeMenu 300ms ease-in-out forwards;
}
.menu_bar a {
  padding: 12px 24px;
  color: var(--secoColor);
  border-bottom: 2px solid rgba(0, 0, 0, 0.1);
  text-decoration: none;
  transition: filter 200ms linear 0s;
}
.menu_bar a:nth-of-type(1) { padding-top: 24px; }
.menu_bar a:nth-last-of-type(1) { border-bottom: none; }
.menu_bar a:hover { filter: brightness(200%); }

@keyframes menuAnim {
  0% { height: 0; }
  100% { height: 312px; }
}
@keyframes fadeMe {
  0% { opacity: 0.4; }
  100% { opacity: 0; }
}