/* =========================================================
   AO · 沉浸式作品浏览器（实验版 V1）
   仅实验副本使用，不影响正式站点。
   依赖 style.css 的 :root 变量（--bg / --accent / --ease / --font）
   ========================================================= */

.imm {
  position: fixed;
  inset: 0;
  z-index: 900;
  display: none;
  background: #050506;
  color: var(--text);
  font-family: var(--font);
  overscroll-behavior: contain;
  touch-action: none;              /* 手势全部由 JS 接管，禁止浏览器滚动/回弹 */
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
  --imm-shift: 0px;                /* 拖拽位移，JS 实时写入 */
  --imm-dur: 460ms;
}

.imm.is-open {
  display: block;
}

/* 进入/退出：整体淡入 + 极轻微缩放，克制不炫技 */
.imm {
  opacity: 0;
  transition: opacity 260ms var(--ease);
}
.imm.is-visible {
  opacity: 1;
}

/* ---------------------------------------------------------
   舞台：三张 slide 纵向堆叠，靠 translateY 切换
   --------------------------------------------------------- */
.imm-track {
  position: absolute;
  inset: 0;
  will-change: transform;
}

.imm-slide {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0;
}

.imm-slide[data-slot="prev"] { transform: translateY(-100%); }
.imm-slide[data-slot="cur"]  { transform: translateY(0); }
.imm-slide[data-slot="next"] { transform: translateY(100%); }

/* 拖拽/动画期间：track 整体位移 */
.imm.is-dragging .imm-track,
.imm.is-animating .imm-track {
  transform: translateY(var(--imm-shift));
}
.imm.is-animating .imm-track {
  /* 起步不过冲、中段匀速、尾部收得干净。
     更激进的曲线（如 .22,.68,.24,1）会让位移在前 40% 就走完 80%，
     手感像「被甩过去」，不像空间移动 */
  transition: transform var(--imm-dur) cubic-bezier(.4, 0, .2, 1);
}

/* ---------------------------------------------------------
   单张作品：封面垫底 + 视频叠加
   视频使用 contain，绝不裁切主体
   --------------------------------------------------------- */
.imm-stage {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* 关键：禁止浏览器原生拖拽图片/视频。
   否则按住拖动会启动原生 drag，浏览器随即派发 pointercancel，
   手势被取消，表现为「拖了但没反应」 */
.imm img,
.imm video {
  -webkit-user-drag: none;
  user-drag: none;
  pointer-events: none;
}

.imm-poster,
.imm-video {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
}

/* 封面铺满可视区。三个槽各有职责：
   - cur 且视频未就绪：作为「清晰封面」兜住画面，避免切换后黑场
   - cur 且视频已就绪：褪成重度虚化的氛围底，让位给视频
   - prev/next：转场时要被看见，保持清晰度
   所以不能一套参数走到底 */
.imm-poster {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: translate(-50%, -50%);
}

/* 当前作品：先清晰，视频可播放后才虚化 */
.imm-slide[data-slot="cur"] .imm-poster {
  filter: brightness(.6) saturate(.96) blur(2px);
  transform: translate(-50%, -50%) scale(1.02);
  transition: filter 520ms var(--ease), transform 520ms var(--ease);
}

.imm.is-loaded .imm-slide[data-slot="cur"] .imm-poster {
  filter: brightness(.26) saturate(.8) blur(22px);
  transform: translate(-50%, -50%) scale(1.18);
}

.imm-slide[data-slot="prev"] .imm-poster,
.imm-slide[data-slot="next"] .imm-poster {
  filter: brightness(.68) saturate(.92) blur(2px);
  transform: translate(-50%, -50%) scale(1.04);
}

.imm-video {
  opacity: 0;
  transition: opacity 320ms var(--ease);
  background: transparent;
}

.imm-video.is-ready {
  opacity: 1;
  box-shadow: 0 20px 70px rgba(0, 0, 0, .5);
}

/* 竖屏 / 横屏都用 max-* 约束，让元素盒子等于内容尺寸，
   这样阴影和圆角都贴合画面本身，而不是撑满整屏 */
.imm-slide[data-orient="portrait"] .imm-video {
  max-width: 100%;
  max-height: 100%;
}

.imm-slide[data-orient="landscape"] .imm-video {
  max-width: 100%;
  max-height: 100%;
}

/* 桌面端：横屏作品别顶到边，留出呼吸感 */
@media (min-width: 900px) {
  .imm-slide[data-orient="landscape"] .imm-video {
    max-width: min(calc(100vw - 180px), 1560px);
    max-height: calc(100vh - 130px);
  }
  .imm-slide[data-orient="portrait"] .imm-video {
    max-height: calc(100vh - 90px);
  }
}

/* 上下边缘渐隐，暗示还有内容 —— 只加在当前作品上，
   相邻槽若也加会形成暗带，让转场显得脏 */
.imm-slide[data-slot="cur"] .imm-stage::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background:
    linear-gradient(to bottom, rgba(5,5,6,.72) 0%, rgba(5,5,6,0) 18%),
    linear-gradient(to top, rgba(5,5,6,.82) 0%, rgba(5,5,6,0) 24%);
}

/* 相邻作品：轻微压暗形成层次，但必须看得清内容 */
.imm-slide[data-slot="prev"] .imm-stage,
.imm-slide[data-slot="next"] .imm-stage {
  filter: brightness(.72) blur(.5px);
}

.imm-slide[data-slot="prev"]::after,
.imm-slide[data-slot="next"]::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(5,5,6,.26);
  pointer-events: none;
}

/* ---------------------------------------------------------
   顶部：关闭 + 序号
   --------------------------------------------------------- */
.imm-top {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: 4;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: max(14px, env(safe-area-inset-top)) clamp(14px, 3vw, 28px) 14px;
  pointer-events: none;
}

.imm-top > * { pointer-events: auto; }

.imm-close {
  width: 42px;
  height: 42px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: rgba(14,14,16,.62);
  border: 1px solid rgba(255,255,255,.14);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  color: var(--text);
  transition: background 200ms, border-color 200ms, transform 200ms;
}

.imm-close:hover { background: rgba(28,28,32,.8); border-color: rgba(255,255,255,.24); }
.imm-close:active { transform: scale(.94); }
.imm-close svg { width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 1.8; }

.imm-counter {
  font-size: 12px;
  letter-spacing: .16em;
  font-variant-numeric: tabular-nums;
  color: rgba(243,241,236,.72);
  padding: 7px 13px;
  border-radius: 999px;
  background: rgba(14,14,16,.55);
  border: 1px solid rgba(255,255,255,.1);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.imm-counter b {
  color: var(--text);
  font-weight: 600;
}

/* ---------------------------------------------------------
   底部：分类 / 标题 / 简介 / 声音
   --------------------------------------------------------- */
.imm-bottom {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 4;
  padding: 0 clamp(18px, 4vw, 40px) max(20px, env(safe-area-inset-bottom));
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  pointer-events: none;
}

.imm-bottom > * { pointer-events: auto; }

.imm-info {
  max-width: min(640px, 72vw);
  transition: opacity 240ms var(--ease);
}

/* 切换瞬间让文字先淡下去，落定后再淡回来，避免硬切 */
.imm.is-switching .imm-info {
  opacity: .12;
}

.imm-cat {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 10.5px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 9px;
}

.imm-cat::before {
  content: "";
  width: 5px;
  height: 5px;
  border-radius: 999px;
  background: var(--accent);
}

.imm-title {
  font-size: clamp(19px, 2.6vw, 30px);
  font-weight: 600;
  letter-spacing: -.015em;
  line-height: 1.2;
  margin: 0 0 7px;
  text-shadow: 0 1px 24px rgba(0,0,0,.5);
}

.imm-meta {
  font-size: 12.5px;
  color: rgba(243,241,236,.56);
  letter-spacing: .01em;
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

.imm-meta span { position: relative; }
.imm-meta span + span::before {
  content: "·";
  margin-right: 10px;
  color: rgba(243,241,236,.32);
}

/* 声音按钮 */
.imm-sound {
  flex: none;
  width: 44px;
  height: 44px;
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: rgba(14,14,16,.62);
  border: 1px solid rgba(255,255,255,.14);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background 200ms, border-color 200ms, transform 200ms;
}

.imm-sound:hover { background: rgba(28,28,32,.8); }
.imm-sound:active { transform: scale(.94); }
.imm-sound svg { width: 18px; height: 18px; fill: none; stroke: currentColor; stroke-width: 1.7; stroke-linecap: round; stroke-linejoin: round; }
.imm-sound .ico-on { display: none; }
.imm-sound.is-unmuted .ico-on { display: block; }
.imm-sound.is-unmuted .ico-off { display: none; }

/* ---------------------------------------------------------
   播放进度（极细，不干扰画面）
   --------------------------------------------------------- */
.imm-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  z-index: 5;
  background: rgba(255,255,255,.07);
  opacity: 0;
  transition: opacity 300ms;
}

.imm.is-loaded .imm-progress { opacity: 1; }

.imm-progress i {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 160ms linear;
}

/* ---------------------------------------------------------
   首次进入操作提示
   --------------------------------------------------------- */
.imm-hint {
  position: absolute;
  left: 50%;
  bottom: clamp(104px, 17vh, 168px);
  transform: translateX(-50%);
  z-index: 4;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 9px;
  font-size: 11.5px;
  letter-spacing: .1em;
  color: rgba(243,241,236,.72);
  pointer-events: none;
  opacity: 0;
  transition: opacity 400ms var(--ease);
  /* 胶囊底，避免与画面元素互相干扰 */
  padding: 9px 16px;
  border-radius: 999px;
  background: rgba(8,8,10,.5);
  border: 1px solid rgba(255,255,255,.07);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  white-space: nowrap;
}

.imm-hint.is-show { opacity: 1; }

.imm-hint .arrow {
  display: none;
}

@keyframes immArrow {
  0%, 100% { transform: translateY(-5px); opacity: .3; }
  50%      { transform: translateY(4px);  opacity: .85; }
}

/* 桌面端提示换个说法 */
.imm-hint .t-touch { display: block; }
.imm-hint .t-mouse { display: none; }
@media (hover: hover) and (pointer: fine) {
  .imm-hint .t-touch { display: none; }
  .imm-hint .t-mouse { display: block; }
  .imm-hint .arrow { display: none; }
}

/* ---------------------------------------------------------
   边界反馈：到头了，不循环
   --------------------------------------------------------- */
.imm-edge {
  position: absolute;
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  z-index: 4;
  font-size: 11px;
  letter-spacing: .14em;
  color: rgba(243,241,236,.7);
  background: rgba(14,14,16,.7);
  border: 1px solid rgba(255,255,255,.1);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 8px 15px;
  border-radius: 999px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 220ms, transform 220ms var(--ease);
}

.imm-edge.is-top { top: max(70px, calc(env(safe-area-inset-top) + 60px)); }
.imm-edge.is-bottom { bottom: clamp(110px, 18vh, 170px); }

.imm-edge.is-show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* ---------------------------------------------------------
   加载失败 / 重试
   --------------------------------------------------------- */
.imm-error {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: none;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  background: rgba(5,5,6,.86);
  text-align: center;
  padding: 24px;
}

.imm-error.is-show { display: flex; }

.imm-error p {
  font-size: 13px;
  color: rgba(243,241,236,.6);
  letter-spacing: .02em;
}

.imm-retry {
  padding: 9px 20px;
  border-radius: 999px;
  border: 1px solid rgba(255,255,255,.18);
  background: rgba(255,255,255,.06);
  font-size: 12.5px;
  letter-spacing: .04em;
  transition: background 200ms, border-color 200ms;
}

.imm-retry:hover { background: rgba(255,255,255,.11); border-color: rgba(255,255,255,.3); }

/* ---------------------------------------------------------
   移动端微调
   --------------------------------------------------------- */
@media (max-width: 700px) {
  .imm-bottom { flex-direction: column; align-items: flex-start; gap: 14px; }
  .imm-info { max-width: 100%; padding-right: 56px; }
  .imm-sound { position: absolute; right: clamp(18px, 4vw, 40px); bottom: max(20px, env(safe-area-inset-bottom)); }
  .imm-title { font-size: 19px; }
  .imm-meta { font-size: 11.5px; }
  .imm-poster { filter: brightness(.34) saturate(.86); }
}

/* 横屏手机：底部信息压缩，别挡住画面 */
@media (max-height: 500px) and (orientation: landscape) {
  .imm-bottom { padding-bottom: max(10px, env(safe-area-inset-bottom)); }
  .imm-title { font-size: 15px; margin-bottom: 3px; }
  .imm-cat { margin-bottom: 4px; font-size: 9px; }
  .imm-meta { display: none; }
  .imm-hint { display: none; }
}

/* ---------------------------------------------------------
   尊重系统「减少动态效果」
   --------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  .imm,
  .imm-track,
  .imm-video,
  .imm-hint,
  .imm-edge,
  .imm-progress i {
    transition-duration: 1ms !important;
    animation: none !important;
  }
  .imm.is-animating .imm-track { transition-duration: 1ms; }
}