#panel {
  opacity: 0;
  transform: translateY(-10px);
  pointer-events: none;
  transition: 0.3s ease;
}
#checkbox:checked ~ #panel {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
#panel {
  position: fixed;
  top: 90px;
  right: 30px;
  /*padding: 20px;*/
  border-radius: 12px;
  z-index: 1000;
}

/* From Uiverse.io by eslam-hany */ 
.button-container {
  display: flex;
  flex-direction: column;          /* ⭐ KLUCZOWA ZMIANA */
  background: var(--card-bg-light);
  width: 50px;                      /* wąski pasek */
  /*height: 200px;*/                    /* wysokość pod ikony */
  padding: 10px 0;
  align-items: center;
  justify-content: space-around;
  gap: 25px;
  border-radius: 12px;
  box-shadow: rgba(0, 0, 0, 0.35) 0px 5px 15px,
    rgba(0, 73, 144, 0.5) 5px 10px 15px;
  transition: all 0.4s ease;
}
.button-container:hover {
  /*height: 260px;*/   /* rozwija się W DÓŁ */
  transition: all 0.5s;
}
body.dark-theme .button-container {
  background: var(--card-bg-dark);
}

.button-container .button {
  outline: 0 !important;
  border: 0 !important;
  width: 40px;
  height: 40px;
  box-sizing: content-box;
  border-radius: 50%;
  background-color: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  transition: all ease-in-out 0.3s, padding 0.4s;
  cursor: pointer;
}

.button-container  .button:hover {
  transform: translateY(-7px) scale(1.15);
  padding: 10px 0;
}

.icon {
  font-size: 30px;
  position: relative;
}

.icon.active {
  filter:
  drop-shadow(0 0 1px var(--accent))
  drop-shadow(0 0 2px var(--accent))
  drop-shadow(0 0 3px var(--accent))
  saturate(2)
  brightness(1.7);
  -webkit-filter:
  drop-shadow(0 0 1px var(--accent))
  drop-shadow(0 0 2px var(--accent))
  drop-shadow(0 0 3px var(--accent))
  saturate(2)
  brightness(1.7);
}