*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.ui {
  position: fixed;
  inset: 0;
  z-index: 999;
  pointer-events: none;
}

.ui-buttons {
  position: fixed;
  right: 30px;
  top: 20px;
  z-index: 900;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
}

.ui-btn {
  width: 34px;
  height: 34px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background-color: #069494;
  border: 3px double white;
  text-decoration: none;
  color: white;
  font-family: "Monaco", monospace;
  font-size: 1rem;
  cursor: pointer;
  pointer-events: auto;
  position: relative;
  transition: opacity 0.1s ease, background-color 0.1s ease;
  user-select: none;
  appearance: none;
  -webkit-appearance: none;
}

.ui-btn--toggle {
  width: 48px;
  height: 48px;
  font-size: 1.4rem;
  color: black;
  background-color: #eeeeee;
}

.ui-btn:hover {
  opacity: 0.75;
  background-color: #f88379;
}

.ui-btn[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  right: calc(100% + 10px);
  top: 50%;
  transform: translateY(-50%);
  background: rgba(0, 0, 0, 0.85);
  color: #fff;
  padding: 4px 10px;
  border-radius: 4px;
  white-space: nowrap;
  font-family: "Monaco", monospace;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.ui-btn[data-tooltip]:hover::after {
  opacity: 1;
}

.ui-buttons-nav {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-6px);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0s 0.25s;
}

.ui-buttons-nav.open {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  transition: opacity 0.25s ease, transform 0.25s ease, visibility 0s;
}

.ui::before {
  content: "";
  position: absolute;
  inset: 0;
  animation: ui-glow 3s ease-in-out infinite;
  background:
    linear-gradient(to bottom, rgba(255,255,255,0.6), transparent) top    / 100% 30px no-repeat,
    linear-gradient(to top,    rgba(255,255,255,0.6), transparent) bottom / 100% 30px no-repeat,
    linear-gradient(to right,  rgba(255,255,255,0.6), transparent) left   / 30px 100% no-repeat,
    linear-gradient(to left,   rgba(255,255,255,0.6), transparent) right  / 30px 100% no-repeat;
}

@keyframes ui-glow {
  0%, 100% { opacity: 0.3; }
  50%       { opacity: 1;   }
}