/* =========================================================
   PRIME GEAR Transition - Core v0.5.4 Stable
   共通エンジン。サイト固有の見た目は子テーマ側で上書きする。
========================================================= */

:root {
  --pg-transition-bg: rgba(12, 13, 15, .94);
  --pg-transition-bg-solid: #0c0d0f;
  --pg-transition-underlay: rgba(12, 13, 15, .17);
  --pg-transition-fg: #f7f7f5;
  --pg-transition-overlay-in: 160ms;
  --pg-transition-overlay-out: 190ms;
  --pg-transition-curtain-duration: 480ms;
  --pg-transition-backdrop-duration: 374ms;
  --pg-transition-backdrop-delay: 58ms;
}

/*
 * 安定版では html / body の overflow・position・scrollbar は変更しない。
 * 幕表示中はJSでtouch / wheel / keyboard入力のみ止める。
 * ネイティブスクロールバーの表示状態には直接干渉しない。
 */

.pg-transition {
  position: fixed;
  inset: 0;
  z-index: 999990;
  width: 100%;
  height: 100%;
  height: 100dvh;
  margin: 0;
  padding: 0;
  overflow: hidden;
  background: transparent;
  color: var(--pg-transition-fg);
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
  /* 遷移中のタッチスクロールだけを幕側で止める。html/bodyやスクロールバーは変更しない。 */
  touch-action: none;
  overscroll-behavior: none;
  contain: layout paint;
}

.pg-transition__backdrop,
.pg-transition__curtain {
  position: absolute;
  inset: 0;
}

/*
 * curtainとは別の薄い残光レイヤー。
 * 幕が上がった瞬間に白いページへ急変するのを防ぎ、
 * 新ページへ自然につなぐ。
 */
.pg-transition__backdrop {
  z-index: 0;
  background: var(--pg-transition-underlay);
  opacity: 1;
  pointer-events: none;
  will-change: opacity;
}

.pg-transition__curtain {
  z-index: 1;
  display: grid;
  place-items: center;
  background: var(--pg-transition-bg);
  transform: translate3d(0, 0, 0);
  -webkit-transform: translate3d(0, 0, 0);
  will-change: transform, opacity;
  backface-visibility: hidden;
}

.pg-transition__visual {
  display: grid;
  place-items: center;
  position: relative;
  opacity: 0;
  transform: translateZ(0);
  -webkit-transform: translateZ(0);
  will-change: transform, opacity;
}


.pg-transition.is-exiting .pg-transition__visual,
.pg-transition.is-initial .pg-transition__visual,
.pg-transition.is-resuming .pg-transition__visual {
  opacity: 1;
}

.pg-transition__visual > svg {
  display: block;
  width: 100%;
  height: 100%;
}


/*
 * 幕終了後はhidden属性で全画面fixedレイヤー自体を描画ツリーから外す。
 * iOS Safari / Chromeのネイティブスクロールインジケーター復帰を妨げないため。
 */
.pg-transition[hidden] {
  display: none !important;
}

.pg-transition.is-hidden {
  visibility: hidden;
  pointer-events: none;
}

.pg-transition.is-hidden .pg-transition__curtain {
  opacity: 0;
  transform: translate3d(0, -102%, 0);
  transition: none;
}

.pg-transition.is-hidden .pg-transition__backdrop {
  opacity: 0;
  transition: none;
}

.pg-transition.is-exiting,
.pg-transition.is-initial,
.pg-transition.is-resuming {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

.pg-transition.is-exiting .pg-transition__curtain,
.pg-transition.is-initial .pg-transition__curtain,
.pg-transition.is-resuming .pg-transition__curtain {
  opacity: 1;
  transform: translate3d(0, 0, 0);
}

.pg-transition.is-exiting .pg-transition__backdrop,
.pg-transition.is-initial .pg-transition__backdrop,
.pg-transition.is-resuming .pg-transition__backdrop {
  opacity: 1;
}

/* 共通フォールバックはフェード。サイト固有CSSで幕などへ変更可能。 */
.pg-transition.is-leaving {
  pointer-events: none;
}

.pg-transition.is-leaving .pg-transition__curtain {
  opacity: 0;
  transition: opacity var(--pg-transition-overlay-out) ease;
}

.pg-transition.is-leaving .pg-transition__backdrop {
  opacity: 0;
  transition: opacity var(--pg-transition-overlay-out) ease;
}

.pg-transition__fallback {
  width: 18px;
  height: 18px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: pg-transition-fallback-spin 0.7s linear infinite;
}

@keyframes pg-transition-fallback-spin {
  to { transform: rotate(360deg); }
}

@media (prefers-reduced-motion: reduce) {
  .pg-transition,
  .pg-transition__curtain,
  .pg-transition__backdrop,
  .pg-transition__visual,
  .pg-transition__visual * {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
  }
}