/* flipbook-viewer v2.3.0 — Neutral grey theme (#545454), clean & secure */

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

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: #545454;
  color: #e8e8e8;
}

/* ── Loading overlay ── */
#loading-overlay {
  position: fixed;
  inset: 0;
  background: #545454;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  transition: opacity 0.4s ease;
}

#loading-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}

.loading-text {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
  color: #e0e0e0;
}

.progress-bar-container {
  width: 280px;
  height: 6px;
  background: #3a3a3a;
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, #bdbdbd, #f0f0f0);
  border-radius: 3px;
  transition: width 0.3s ease;
}

.loading-percent {
  margin-top: 0.8rem;
  font-size: 0.9rem;
  color: #d0d0d0;
}

/* ── Main layout ── */
#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  width: 100vw;
}

/* ── Book container ── */
#book-container {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  /* 主色 #545454（R84 G84 B84），中心極輕微提亮讓書本浮起 */
  background: radial-gradient(ellipse at center, #5b5b5b 0%, #545454 70%);
}

/* page-flip renders canvases inside this — transform 用於縮放/平移 */
#flipbook {
  /* sized dynamically by JS */
  transform-origin: center center;
  transition: transform 0.15s ease-out;
  will-change: transform;
}

/* 縮放狀態游標：放大時可拖曳平移 */
#book-container.zoomed   { cursor: grab; }
#book-container.grabbing { cursor: grabbing; }
/* 拖曳當下關閉過場，平移才即時跟手 */
#book-container.grabbing #flipbook { transition: none; }

/* ── Controls bar ── */
#controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  padding: 0.75rem 1rem;
  background: #3f3f3f;
  border-top: 1px solid #6a6a6a;
  user-select: none;
  flex-shrink: 0;
}

.ctrl-btn {
  background: #5e5e5e;
  border: 1px solid #707070;
  color: #f0f0f0;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.95rem;
  transition: background 0.2s, border-color 0.2s;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.ctrl-btn:hover {
  background: #6e6e6e;
  border-color: #9a9a9a;
}

.ctrl-btn:active {
  background: #7a7a7a;
}

.ctrl-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

#page-info {
  font-size: 0.9rem;
  color: #d8d8d8;
  min-width: 100px;
  text-align: center;
}

/* 縮放百分比顯示 */
#zoom-info {
  font-size: 0.85rem;
  color: #d8d8d8;
  min-width: 48px;
  text-align: center;
}

/* ── Fullscreen adjustments ── */
:fullscreen #controls,
:-webkit-full-screen #controls {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 10;
  background: rgba(63, 63, 63, 0.92);
}

:fullscreen #book-container,
:-webkit-full-screen #book-container {
  height: 100vh;
  padding-bottom: 60px;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  #controls {
    gap: 0.5rem;
    padding: 0.5rem;
  }

  .ctrl-btn {
    padding: 0.4rem 0.7rem;
    font-size: 0.85rem;
  }

  #page-info {
    font-size: 0.8rem;
    min-width: 70px;
  }

  #zoom-info {
    font-size: 0.78rem;
    min-width: 40px;
  }
}

@media (max-width: 480px) {
  .ctrl-btn .btn-label {
    display: none;
  }
}