/* ============================================
 * WebBook PC Viewer — 見開き表示スタイルシート
 * ============================================ */

/* --- リセット・ベース --- */
* { margin: 0; padding: 0; box-sizing: border-box; }

:root {
  --bg-dark: #1a1a1a;
  --accent: #4a7c59;
  --accent-light: #6ba37a;
  --text-light: #e8e4dc;
  --text-muted: #8a8580;
}

html {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
  background: var(--bg-dark);
  color: var(--text-light);
  height: 100vh;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}

/* --- ビューアコンテナ --- */
.viewer {
  position: relative;
  width: 100vw;
  height: 100vh;
}

/* --- ヘッダー --- */
.viewer__header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  background: linear-gradient(180deg, rgba(26,26,26,0.95) 0%, rgba(26,26,26,0.7) 70%, transparent 100%);
  pointer-events: none;
}

.viewer__header > * { pointer-events: auto; }

.viewer__title {
  font-size: 14px;
  font-weight: 300;
  letter-spacing: 2px;
  color: var(--text-muted);
}

.viewer__title span {
  color: var(--accent-light);
  font-weight: 500;
}

.viewer__page-info {
  font-size: 13px;
  color: var(--text-muted);
  font-weight: 300;
  letter-spacing: 1px;
}

/* --- フルスクリーンボタン --- */
.viewer__fullscreen-btn {
  position: fixed;
  top: 12px; right: 16px;
  z-index: 101;
  width: 36px; height: 36px;
  border-radius: 8px;
  border: 1px solid rgba(255,255,255,0.1);
  background: rgba(26,26,26,0.5);
  backdrop-filter: blur(10px);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
}

.viewer__fullscreen-btn:hover {
  background: rgba(74, 124, 89, 0.3);
  border-color: var(--accent-light);
}

.viewer__fullscreen-btn svg {
  width: 16px; height: 16px;
  fill: none; stroke: var(--text-light);
  stroke-width: 2; stroke-linecap: round; stroke-linejoin: round;
}

/* --- メインエリア --- */
.viewer__main {
  position: absolute;
  top: 40px;
  bottom: 70px;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 0 12px;
}

/* ズーム時: overflow hidden + ドラッグで移動 */
.viewer__main--zoomed {
  overflow: hidden;
  cursor: grab;
}

.viewer__main--dragging,
.viewer__main--dragging * {
  cursor: grabbing !important;
}

/* --- ナビゲーションボタン（左右） --- */
.viewer__nav {
  z-index: 90;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.15);
  background: rgba(26,26,26,0.6);
  backdrop-filter: blur(10px);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  opacity: 0.5;
  flex-shrink: 0;
}

.viewer__nav:hover {
  opacity: 1 !important;
  background: rgba(74, 124, 89, 0.4);
  border-color: var(--accent-light);
  transform: scale(1.1);
}

.viewer__nav svg {
  width: 22px; height: 22px;
  fill: none; stroke: var(--text-light);
  stroke-width: 2; stroke-linecap: round; stroke-linejoin: round;
}

.viewer__nav:disabled {
  opacity: 0.15 !important;
  pointer-events: none;
}

.viewer:hover .viewer__nav:not(:disabled) {
  opacity: 0.7;
}

/* --- 見開きコンテナ --- */
.spread {
  display: flex;
  flex-direction: row;
  align-items: center;
  justify-content: center;
  perspective: 2000px;
}

/* --- ページ（左右） --- */
.spread__page {
  position: relative;
  line-height: 0;
  transition: box-shadow 0.3s ease;
}

/* --- ページめくりアニメーション（3Dフリップ） --- */

/* 進む: 左ページが背表紙(右端)を軸に右へめくれる */
.spread__page--flip-out-fwd {
  transform-origin: right center;
  animation: flipOutForward 0.25s ease-in forwards;
  z-index: 10;
}

/* 進む: 新しい右ページが背表紙(左端)を軸にめくれて現れる */
.spread__page--flip-in-fwd {
  transform-origin: left center;
  animation: flipInForward 0.25s ease-out forwards;
  z-index: 10;
}

/* 戻る: 右ページが背表紙(左端)を軸に左へめくれる */
.spread__page--flip-out-back {
  transform-origin: left center;
  animation: flipOutBack 0.25s ease-in forwards;
  z-index: 10;
}

/* 戻る: 新しい左ページが背表紙(右端)を軸にめくれて現れる */
.spread__page--flip-in-back {
  transform-origin: right center;
  animation: flipInBack 0.25s ease-out forwards;
  z-index: 10;
}

/* めくられる側でないページのフェード */
.spread__page--fade-out {
  animation: pageFadeOut 0.2s ease-in forwards;
}
.spread__page--fade-in {
  animation: pageFadeIn 0.2s ease-out forwards;
}

@keyframes flipOutForward {
  0%   { transform: rotateY(0deg); opacity: 1; }
  100% { transform: rotateY(45deg); opacity: 0; }
}

@keyframes flipInForward {
  0%   { transform: rotateY(-45deg); opacity: 0; }
  100% { transform: rotateY(0deg); opacity: 1; }
}

@keyframes flipOutBack {
  0%   { transform: rotateY(0deg); opacity: 1; }
  100% { transform: rotateY(-45deg); opacity: 0; }
}

@keyframes flipInBack {
  0%   { transform: rotateY(45deg); opacity: 0; }
  100% { transform: rotateY(0deg); opacity: 1; }
}

@keyframes pageFadeOut {
  0%   { opacity: 1; }
  100% { opacity: 0; }
}

@keyframes pageFadeIn {
  0%   { opacity: 0; }
  100% { opacity: 1; }
}

.spread__page img {
  display: block;
  width: auto;
  height: auto;
  max-height: calc(100vh - 120px);
  max-width: calc(50vw - 60px);
  box-shadow: 0 4px 24px rgba(0,0,0,0.5);
}

.spread__page--single img {
  max-width: none;
}

/* 見開き中央の影 */
.spread__page--left img {
  box-shadow: 4px 0 16px rgba(0,0,0,0.4);
}

.spread__page--right img {
  box-shadow: -4px 0 16px rgba(0,0,0,0.4);
}

/* --- リンクオーバーレイ --- */
.spread__links {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.spread__link {
  position: absolute;
  display: block;
  pointer-events: auto;
  cursor: pointer;
  border: 2px solid rgba(74, 124, 89, 0.5);
  border-radius: 4px;
  background: rgba(74, 124, 89, 0.1);
  transition: all 0.2s ease;
  text-decoration: none;
  box-shadow: inset 0 0 6px rgba(74, 124, 89, 0.15);
}

.spread__link:hover {
  background: rgba(74, 124, 89, 0.25);
  border-color: rgba(74, 124, 89, 0.8);
  box-shadow: 0 0 12px rgba(74, 124, 89, 0.4), inset 0 0 8px rgba(74, 124, 89, 0.2);
}

/* --- コントロールバー（下部） --- */
.controls {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px 24px;
  background: linear-gradient(0deg, rgba(26,26,26,0.95) 0%, rgba(26,26,26,0.7) 70%, transparent 100%);
  gap: 16px;
  pointer-events: none;
}

.controls > * { pointer-events: auto; }

/* --- ズーム表示ラベル --- */
.controls__zoom-label {
  font-size: 11px;
  color: var(--text-muted);
  min-width: 36px;
  text-align: center;
  letter-spacing: 0.5px;
}

/* --- サムネイルバー --- */
.thumb-strip {
  display: flex;
  flex-direction: row-reverse;
  gap: 8px;
  align-items: center;
  overflow-x: auto;
  max-width: 75vw;
  scrollbar-width: none;
}

.thumb-strip::-webkit-scrollbar { display: none; }

.thumb {
  width: 44px;
  height: 58px;
  border-radius: 4px;
  overflow: hidden;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all 0.3s ease;
  opacity: 0.5;
  flex-shrink: 0;
}

.thumb:hover {
  opacity: 0.8;
  transform: translateY(-4px);
}

.thumb--active {
  border-color: var(--accent-light);
  opacity: 1;
  transform: translateY(-4px);
  box-shadow: 0 4px 12px rgba(74, 124, 89, 0.3);
}

.thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* --- ズームボタン --- */
.controls__zoom-btn {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.15);
  background: rgba(26,26,26,0.6);
  backdrop-filter: blur(10px);
  color: var(--text-light);
  font-size: 18px;
  font-weight: 300;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.3s ease;
  flex-shrink: 0;
}

.controls__zoom-btn:hover {
  background: rgba(74, 124, 89, 0.4);
  border-color: var(--accent-light);
  transform: scale(1.1);
}

.controls__zoom-btn:disabled {
  opacity: 0.3;
  pointer-events: none;
}

/* --- ローディング --- */
.loading {
  position: fixed;
  top: 0; left: 0; width: 100%; height: 100%;
  background: var(--bg-dark);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 500;
  transition: opacity 0.5s ease;
}

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

.loading__spinner {
  width: 40px; height: 40px;
  border: 3px solid rgba(255,255,255,0.1);
  border-top-color: var(--accent-light);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading__text {
  margin-top: 16px;
  font-size: 13px;
  color: var(--text-muted);
  letter-spacing: 2px;
}

@keyframes spin { to { transform: rotate(360deg); } }