.btn {
  position: fixed;
  width: 100px;
  height: 100px;
  background: rgba(15, 15, 15, 0.8);
  color: white;
  border: none;
  cursor: pointer;
  overflow: hidden;
  transition: all 0.3s ease-in-out;
  z-index: 10;
  border-radius: 0.5rem;
  display: none;
  animation: pulse-glow 2s ease-in-out infinite;
}

.btn:hover {
  animation-play-state: paused;
}

/* Position helpers */
.top-left {
  top: 10px;
  left: 10px;
}
.top-right {
  top: 10vh;
  right: 5vw;
}
.bottom-left {
  bottom: 5vh;
  left: 5vw;
}
.bottom-right {
  bottom: 5vh;
  right: 5vw;
}
.middle-left {
  top: 40%;
  left: 5vw;
}
.middle-right {
  top: 40%;
  right: 5vw;
}

/* Icon vs. hover‐content */
.btn .icon,
.btn .hover-content {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  width: 90%;
  /* white-space: nowrap; */
}

.btn a {
  color: white;
}

.btn .hover-content {
  display: none;
  font-size: 1.5rem;
}

.btn .display-content {
  display: block;
  text-align: center;
  width: 100%;
  margin-top: auto;
  margin-bottom: auto;
  font-family: monospace;
}

/* Expand on hover */
.btn:hover {
  width: 90vw;
  height: 85vh;
  z-index: 100;
}

/* Re-anchor corners when expanded */
.top-left:hover {
  top: 1vh;
  left: 0.5vw;
}
.top-right:hover {
  top: 10vh;
  right: 5vw;
}
.bottom-left:hover {
  bottom: 5vh;
  left: 5vw;
  animation: none;
}
.bottom-right:hover {
  bottom: 5vh;
  right: 5vw;
}

/* Re-anchor sides when expanded and center vertically */
.middle-left:hover {
  top: 10vh; /* (100vh - 90vh) ÷ 2 = 5vh */
  left: 5vw;
  transform: none;
}
.middle-right:hover {
  top: 10vh;
  right: 5vw;
  transform: none;
}

/* Swap icon/content visibility */
.btn:hover .icon {
  display: none;
}

.btn:hover .display-content {
  display: none;
}

.btn:hover .hover-content {
  display: block;
  z-index: 101;
  cursor: text;
  pointer-events: auto; /* allow interactions like clicking links */
  user-select: text; /* enable text highlighting */
  position: relative;
  top: 0;
  left: 0;
  transform: none;
  width: 100%;
  height: 100%;
  overflow-y: auto;
}

.btn:hover .hover-content * {
  user-select: text;
}

/* ----- Programmatic persistent expand ----- */
.btn.stay-open {
  width: 90vw;
  height: 85vh;
  z-index: 100;
  animation: none !important; /* Force-disable pulsing when maximized, even over inline styles */
}

.btn.stay-open .icon,
.btn.stay-open .display-content {
  display: none;
}

.btn.stay-open .hover-content {
  display: block;
  z-index: 101;
  cursor: text;
  pointer-events: auto;
  user-select: text;
  position: relative;
  top: 0;
  left: 0;
  transform: none;
  width: 100%;
  height: 100%;
  overflow-y: auto;
}

/* Maintain correct anchoring for side buttons */
.top-left.stay-open {
  top: 1vh;
  left: 0.5vw;
}
.top-right.stay-open {
  top: 10vh;
  right: 5vw;
}
.bottom-left.stay-open {
  bottom: 5vh;
  left: 5vw;
}
.bottom-right.stay-open {
  bottom: 5vh;
  right: 5vw;
}
.middle-left.stay-open {
  top: 10vh;
  left: 5vw;
  transform: none;
}
.middle-right.stay-open {
  top: 10vh;
  right: 5vw;
  transform: none;
}

@keyframes pulse-glow {
  0%,
  100% {
    /* transform: scale(1); */
    box-shadow: 0 0 0 0 rgba(255, 255, 255, 0.7);
  }
  50% {
    /* transform: scale(1.02); */
    box-shadow: 0 0 0 10px rgba(52, 152, 219, 0);
  }
}

@keyframes appear {
  0% {
    opacity: 0;
    transform: scale(0);
  }
  100% {
    opacity: 1;
    transform: scale(1);
  }
}

@keyframes disappear {
  0% {
    opacity: 1;
    transform: scale(1);
  }
  100% {
    opacity: 0;
    transform: scale(0);
  }
}

.about {
  height: 100%;
  width: 100%;
  overflow-y: auto;
  justify-content: center;
  align-items: center;
  display: flex;
  flex-direction: column;
}

/* Mobile responsiveness */
@media screen and (max-width: 768px) {
  .btn {
    width: 75px;
    height: 75px;
  }

  .btn .icon {
    font-size: 1.5rem;
  }

  .btn .display-content {
    font-size: 0.7rem;
  }

  /* Adjust positions for mobile */
  .top-right {
    top: 15vh;
    right: 10px;
  }

  .middle-right {
    top: 40%;
    right: 10px;
  }

  .bottom-right {
    bottom: 20px;
    right: 10px;
  }

  .middle-left {
    top: 40%;
    left: 10px;
  }

  .bottom-left {
    bottom: 20px;
    left: 10px;
  }

  .btn:hover {
    width: 95vw;
    height: 80vh;
  }

  .middle-left:hover,
  .middle-right:hover {
    top: 10vh;
  }
}