/* ==========================================================================
   通用图片大图查看器（Lightbox）—— 零依赖，纯原生 CSS
   前台品牌橙红 #c73e1d / 后台蓝 #2563eb（通过 body[data-viewer-theme] 切换）
   ========================================================================== */

:root {
  --iv-accent: #c73e1d;              /* 默认前台品牌色 */
  --iv-overlay: rgba(15, 23, 42, 0.92);
  --iv-panel: rgba(30, 41, 59, 0.72);
  --iv-panel-border: rgba(255, 255, 255, 0.12);
  --iv-btn: rgba(255, 255, 255, 0.10);
  --iv-btn-hover: rgba(255, 255, 255, 0.20);
  --iv-text: #ffffff;
  --iv-text-dim: #cbd5e1;
  --iv-radius: 12px;
  --iv-shadow: 0 12px 40px rgba(0, 0, 0, 0.45);
}

/* 后台蓝色主题 */
body[data-viewer-theme="admin"] {
  --iv-accent: #2563eb;
}

/* 可点击查看的图片：轻微交互提示 */
[data-image-viewer] {
  cursor: zoom-in;
  transition: filter 0.2s ease, transform 0.2s ease;
}
[data-image-viewer]:hover {
  filter: brightness(1.04);
}

/* 遮罩层 */
.iv-overlay {
  position: fixed;
  inset: 0;
  z-index: 99999;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--iv-overlay);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.28s ease, visibility 0.28s ease;
  overflow: hidden;
  user-select: none;
  -webkit-user-select: none;
}
.iv-overlay.iv-open {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

/* 画布区 */
.iv-stage {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* 大图 */
.iv-image {
  max-width: 90vw;
  max-height: 82vh;
  object-fit: contain;
  transform-origin: center center;
  transform: scale(0.92);
  opacity: 0;
  transition: opacity 0.28s ease, transform 0.28s cubic-bezier(0.22, 1, 0.36, 1);
  will-change: transform;
  box-shadow: var(--iv-shadow);
  border-radius: 4px;
  cursor: grab;
}
.iv-overlay.iv-open .iv-image.iv-ready {
  opacity: 1;
}
.iv-image.iv-dragging {
  cursor: grabbing;
  transition: none;
}

/* Loading 指示器 */
.iv-loading {
  position: absolute;
  width: 46px;
  height: 46px;
  border: 3px solid rgba(255, 255, 255, 0.25);
  border-top-color: var(--iv-accent);
  border-radius: 50%;
  animation: iv-spin 0.8s linear infinite;
}
@keyframes iv-spin {
  to { transform: rotate(360deg); }
}

/* 顶部计数 / 标题 */
.iv-counter {
  position: absolute;
  top: 20px;
  left: 50%;
  transform: translateX(-50%);
  color: var(--iv-text-dim);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.5px;
  background: var(--iv-panel);
  border: 1px solid var(--iv-panel-border);
  padding: 6px 16px;
  border-radius: 999px;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}

/* 工具条（底部胶囊面板） */
.iv-toolbar {
  position: absolute;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  background: var(--iv-panel);
  border: 1px solid var(--iv-panel-border);
  border-radius: 999px;
  box-shadow: var(--iv-shadow);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
}

.iv-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: none;
  border-radius: 50%;
  background: var(--iv-btn);
  color: var(--iv-text);
  cursor: pointer;
  transition: background 0.18s ease, transform 0.18s ease, color 0.18s ease;
}
.iv-btn:hover {
  background: var(--iv-accent);
  color: #fff;
  transform: translateY(-2px);
}
.iv-btn:active {
  transform: translateY(0);
}
.iv-btn svg {
  width: 20px;
  height: 20px;
  pointer-events: none;
}

.iv-toolbar-sep {
  width: 1px;
  height: 24px;
  background: var(--iv-panel-border);
  margin: 0 4px;
}

/* 缩放百分比 */
.iv-zoom-label {
  min-width: 52px;
  text-align: center;
  color: var(--iv-text-dim);
  font-size: 13px;
  font-weight: 500;
}

/* 关闭按钮（右上角） */
.iv-close {
  position: absolute;
  top: 18px;
  right: 22px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--iv-panel-border);
  border-radius: 50%;
  background: var(--iv-panel);
  color: var(--iv-text);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.18s ease, transform 0.18s ease, color 0.18s ease;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.iv-close:hover {
  background: var(--iv-accent);
  color: #fff;
  transform: rotate(90deg);
}
.iv-close svg { width: 22px; height: 22px; pointer-events: none; }

/* 左右切换箭头（画廊模式） */
.iv-nav {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 52px;
  height: 52px;
  border: 1px solid var(--iv-panel-border);
  border-radius: 50%;
  background: var(--iv-panel);
  color: var(--iv-text);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background 0.18s ease, transform 0.18s ease, color 0.18s ease, opacity 0.18s ease;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  opacity: 0.75;
}
.iv-nav:hover {
  background: var(--iv-accent);
  color: #fff;
  opacity: 1;
}
.iv-nav svg { width: 26px; height: 26px; pointer-events: none; }
.iv-nav-prev { left: 24px; }
.iv-nav-prev:hover { transform: translateY(-50%) translateX(-3px); }
.iv-nav-next { right: 24px; }
.iv-nav-next:hover { transform: translateY(-50%) translateX(3px); }
.iv-nav[hidden] { display: none; }

/* 移动端适配 */
@media (max-width: 640px) {
  .iv-toolbar { bottom: 16px; gap: 2px; padding: 6px 8px; }
  .iv-btn { width: 36px; height: 36px; }
  .iv-btn svg { width: 18px; height: 18px; }
  .iv-zoom-label { display: none; }
  .iv-nav { width: 44px; height: 44px; }
  .iv-image { max-width: 96vw; max-height: 72vh; }
}