/* ================================================ */
/* HOLOREADER UX ENHANCEMENTS                       */
/* ================================================ */

/* Make the screen a scroll container */
.screen {
  max-height: 85vh;
  overflow-y: auto;
  overflow-x: hidden;
  cursor: grab;
  scroll-behavior: smooth;
}
.screen.grabbing {
  cursor: grabbing;
  scroll-behavior: auto;
  user-select: none;
}

/* Reading progress bar - sits at top of device frame */
.progress-track {
  position: absolute;
  top: 13px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: rgba(26,143,255,0.06);
  border-radius: 1px;
  z-index: 10;
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--blue-bright), var(--cyan));
  border-radius: 1px;
  transition: width 0.15s ease-out;
  box-shadow: 0 0 8px rgba(0,212,255,0.4);
}

/* Custom scrollbar - Blue Frost themed */
.screen::-webkit-scrollbar {
  width: 5px;
}
.screen::-webkit-scrollbar-track {
  background: rgba(26,143,255,0.03);
  border-radius: 3px;
}
.screen::-webkit-scrollbar-thumb {
  background: linear-gradient(180deg, rgba(26,143,255,0.2), rgba(0,212,255,0.3));
  border-radius: 3px;
  border: 1px solid rgba(26,143,255,0.08);
}
.screen::-webkit-scrollbar-thumb:hover {
  background: linear-gradient(180deg, rgba(26,143,255,0.35), rgba(0,212,255,0.45));
}
/* Firefox */
.screen {
  scrollbar-width: thin;
  scrollbar-color: rgba(26,143,255,0.25) rgba(26,143,255,0.03);
}

/* Back to top button */
.back-to-top {
  position: absolute;
  bottom: 24px;
  right: 24px;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: rgba(10,18,36,0.8);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(26,143,255,0.15);
  color: var(--blue-bright);
  font-size: 1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: translateY(10px);
  transition: all 0.3s ease;
  z-index: 10;
  pointer-events: none;
  box-shadow: 0 4px 16px rgba(0,0,0,0.3);
}
.back-to-top.visible {
  opacity: 1;
  transform: translateY(0);
  pointer-events: auto;
}
.back-to-top:hover {
  background: rgba(26,143,255,0.15);
  border-color: var(--blue-bright);
  box-shadow: 0 0 20px rgba(26,143,255,0.2);
}
.back-to-top svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.5;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Keyboard hint (shown briefly on load) */
.kb-hint {
  position: absolute;
  bottom: 24px;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  font-family: var(--mono);
  font-size: 0.5rem;
  color: rgba(77,184,255,0.3);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  opacity: 0;
  transition: all 0.5s ease;
  z-index: 10;
  pointer-events: none;
  white-space: nowrap;
}
.kb-hint.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}