:root {
  --vf-backdrop-color: rgba(20, 20, 20, 0.92);
  --vf-button-color: #fff;
  --vf-button-background: rgba(0, 0, 0, 0.45);
  --vf-button-hover-background: rgba(0, 0, 0, 0.75);
  --vf-caption-color: #fff;
  --vf-status-color: #fff;
  --vf-control-size: 48px;
  --vf-z-index: 99999;

  /* ふわっと表示の設定（秒数はここで調整） */
  --vf-fade-duration: 0.6s;      /* 写真がふわっと現れる時間 */
  --vf-fade-scale: 0.96;         /* 現れる直前の大きさ（1にすると拡大なしのフェードのみ） */
  --vf-backdrop-duration: 0.3s;  /* 黒い背景が開く・閉じる時間 */
  --vf-zoom-duration: 0.25s;     /* +ボタンで拡大・縮小する時間 */
}

.vf-backdrop,
.vf-backdrop * {
  box-sizing: border-box;
}

.vf-backdrop {
  position: fixed;
  inset: 0;
  z-index: var(--vf-z-index);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 64px 72px;
  background: var(--vf-backdrop-color);
  opacity: 0;
  transition: opacity var(--vf-backdrop-duration) ease;
  touch-action: pan-y;
}

.vf-backdrop--open {
  opacity: 1;
}

.vf-backdrop--closing {
  opacity: 0;
}

.vf-stage {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  height: 100%;
  overflow: auto;
}

.vf-image {
  display: block;
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
  opacity: 0;
  transform: scale(var(--vf-fade-scale));
  cursor: zoom-in;
  transition:
    opacity var(--vf-fade-duration) ease-out,
    transform var(--vf-fade-duration) ease-out;
}

/* 写真の読み込みが終わったらふわっと表示 */
.vf-image--loaded {
  opacity: 1;
  transform: none;
}

.vf-image--loaded.vf-image--zoomed {
  max-width: none;
  max-height: none;
  transform: scale(2);
  cursor: zoom-out;
  transition-duration: var(--vf-zoom-duration);
}

.vf-image:focus-visible,
.vf-button:focus-visible {
  outline: 2px solid #fff;
  outline-offset: 3px;
}

.vf-toolbar {
  position: absolute;
  top: 12px;
  right: 12px;
  left: 12px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  color: var(--vf-button-color);
}

.vf-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: var(--vf-control-size);
  height: var(--vf-control-size);
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: var(--vf-button-background);
  color: var(--vf-button-color);
  font: inherit;
  font-size: 30px;
  line-height: 1;
  cursor: pointer;
  transition: background-color 150ms ease;
}

.vf-button:hover {
  background: var(--vf-button-hover-background);
}

.vf-counter {
  margin-right: auto;
  padding: 8px 12px;
  font-size: 14px;
}

.vf-previous,
.vf-next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

.vf-previous {
  left: 12px;
}

.vf-next {
  right: 12px;
}

.vf-caption {
  position: absolute;
  right: 72px;
  bottom: 12px;
  left: 72px;
  margin: 0;
  color: var(--vf-caption-color);
  text-align: center;
  overflow-wrap: anywhere;
}

.vf-status {
  position: absolute;
  margin: 0;
  color: var(--vf-status-color);
  text-align: center;
}

.vf-status:empty {
  display: none;
}

@media (max-width: 600px) {
  .vf-backdrop {
    padding: 64px 56px;
  }

  .vf-previous {
    left: 4px;
  }

  .vf-next {
    right: 4px;
  }

  .vf-caption {
    right: 12px;
    bottom: 8px;
    left: 12px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .vf-backdrop,
  .vf-image,
  .vf-button {
    transition-duration: 0.01ms;
  }
}

.vf-button:disabled {
  opacity: 0.3;
  cursor: default;
}

.vf-button:disabled:hover {
  background: var(--vf-button-background);
}