/* ============================================================================
   视差滚动 Parallax —— 内容层专用
   ----------------------------------------------------------------------------
   ⚠️ 本文件刻意不触碰以下固定背景层，背景视频保持原样：
        .bg-layer / #bg-video / #video-canvas / .video-overlay
        .ambient-glow / .grain
      视差全部作用在「随页面滚动的正文内容」上，靠层与层之间的速度差制造纵深。

   设计约束（踩过坑，别改）：
      1. 视差位移统一走 transform: translate3d(...)，由 js/parallax.js 写入。
         → 所以被视差的元素**自己不能有别的 transform**（否则会被覆盖）。
         需要「自转 / 浮动」的元素一律往里再套一层承载动画。
      2. 段落标题的视差挂在 .section-header 的**子节点**上，不能挂 .section-header 本身
         —— main.js 的 initReveal() 会给它加 .reveal（transform: translateY(40px) +
         transition: all 0.9s），挂上去会被覆盖、还会被 transition 拖成"糊"。
      3. 位移量一律带 max 上限，避免长页面里偏移过大把版面顶乱。
   ============================================================================ */

/* ---------------------------------------------------------------------------
   1. 段落标题的内部分层视差
      .section-eyebrow / .section-title / .section-desc 三者速度不同 → 标题自带纵深
   --------------------------------------------------------------------------- */
.section-eyebrow,
.section-title,
.section-desc {
  backface-visibility: hidden;
}

/* ---------------------------------------------------------------------------
   2. 「前沿 AI 引力场」整段
   --------------------------------------------------------------------------- */
.plx-field {
  position: relative;
  min-height: 116vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 130px 5%;
  overflow: hidden;
  /* 指针跟随光晕的坐标（js 写入） */
  --mx: 50%;
  --my: 44%;
}

/* 只负责裁切与定位的装饰层外壳：inset 故意做成负值，位移时不会露出边缘 */
.plx-layer {
  position: absolute;
  inset: -16% -8%;
  pointer-events: none;
  z-index: 0;
  will-change: transform;
  backface-visibility: hidden;
}

/* --- 2.1 星点场：两层不同疏密，视差速度不同 → 星空纵深 --- */
.plx-stars::before,
.plx-stars::after {
  content: '';
  position: absolute;
  inset: 0;
}

.plx-stars::before {
  background-image: radial-gradient(circle, rgba(255, 255, 255, 0.34) 1px, transparent 1.5px);
  background-size: 92px 92px;
  opacity: 0.55;
  -webkit-mask-image: radial-gradient(ellipse 78% 70% at 50% 50%, #000 20%, transparent 82%);
  mask-image: radial-gradient(ellipse 78% 70% at 50% 50%, #000 20%, transparent 82%);
}

.plx-stars::after {
  background-image: radial-gradient(circle, rgba(124, 214, 255, 0.30) 1px, transparent 1.7px);
  background-size: 168px 168px;
  background-position: 46px 62px;
  opacity: 0.5;
  -webkit-mask-image: radial-gradient(ellipse 70% 62% at 50% 46%, #000 18%, transparent 84%);
  mask-image: radial-gradient(ellipse 70% 62% at 50% 46%, #000 18%, transparent 84%);
}

/* --- 2.2 星云光团：大半径径向渐变（不用 filter:blur，省 GPU） --- */
.plx-nebula {
  position: absolute;
  border-radius: 50%;
  will-change: transform;
}

.plx-nebula-a {
  width: 62vw;
  height: 62vw;
  max-width: 980px;
  max-height: 980px;
  left: 4%;
  top: 6%;
  background: radial-gradient(circle at 50% 50%,
      rgba(0, 212, 255, 0.20) 0%,
      rgba(0, 150, 255, 0.10) 34%,
      rgba(0, 90, 200, 0.04) 56%,
      transparent 72%);
}

.plx-nebula-b {
  width: 56vw;
  height: 56vw;
  max-width: 900px;
  max-height: 900px;
  right: 2%;
  bottom: 2%;
  background: radial-gradient(circle at 50% 50%,
      rgba(124, 58, 237, 0.22) 0%,
      rgba(90, 40, 190, 0.11) 36%,
      rgba(60, 20, 140, 0.04) 58%,
      transparent 74%);
}

/* 极光扫光：靠 background-position 动画，不占 transform，可与视差叠加 */
.plx-aurora {
  position: absolute;
  inset: 8% -20%;
  background: linear-gradient(104deg,
      transparent 0%,
      rgba(0, 212, 255, 0.07) 28%,
      rgba(124, 58, 237, 0.09) 50%,
      rgba(0, 212, 255, 0.05) 72%,
      transparent 100%);
  background-size: 260% 100%;
  animation: plxAurora 28s ease-in-out infinite;
  will-change: transform;
}

@keyframes plxAurora {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

/* --- 2.3 透视地面网格：透视变换放在内层，外壳留给视差 --- */
.plx-floor {
  position: absolute;
  left: -18%;
  right: -18%;
  bottom: -4%;
  height: 68%;
  will-change: transform;
}

.plx-floor-inner {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(to right, rgba(0, 212, 255, 0.16) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(0, 212, 255, 0.13) 1px, transparent 1px);
  background-size: 68px 68px;
  transform: perspective(640px) rotateX(74deg);
  transform-origin: 50% 100%;
  -webkit-mask-image: linear-gradient(to top, #000 0%, rgba(0, 0, 0, 0.5) 42%, transparent 80%);
  mask-image: linear-gradient(to top, #000 0%, rgba(0, 0, 0, 0.5) 42%, transparent 80%);
}

/* --- 2.4 同心圆环 + 自转轨道 --- */
.plx-ring {
  position: absolute;
  left: 50%;
  top: 50%;
  border-radius: 50%;
  will-change: transform;
}

.plx-ring-a {
  width: 46vmin;
  height: 46vmin;
  margin: -23vmin 0 0 -23vmin;
  border: 1px solid rgba(0, 212, 255, 0.20);
}

.plx-ring-b {
  width: 72vmin;
  height: 72vmin;
  margin: -36vmin 0 0 -36vmin;
  border: 1px dashed rgba(124, 58, 237, 0.22);
}

.plx-ring-c {
  width: 102vmin;
  height: 102vmin;
  margin: -51vmin 0 0 -51vmin;
  border: 1px solid rgba(255, 255, 255, 0.05);
}

/* 自转轨道：外壳负责视差，内层负责自转（避免 transform 互相覆盖） */
.plx-orbit {
  position: absolute;
  left: 50%;
  top: 50%;
  width: 88vmin;
  height: 88vmin;
  margin: -44vmin 0 0 -44vmin;
  will-change: transform;
}

.plx-orbit-ring {
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid transparent;
  border-top-color: rgba(0, 212, 255, 0.55);
  border-right-color: rgba(0, 212, 255, 0.14);
  animation: plxSpin 26s linear infinite;
}

.plx-orbit-ring-2 {
  inset: 10%;
  border-top-color: rgba(124, 58, 237, 0.5);
  border-right-color: transparent;
  border-left-color: rgba(124, 58, 237, 0.16);
  animation-duration: 38s;
  animation-direction: reverse;
}

@keyframes plxSpin {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}

/* 轨道上的运行亮点 */
.plx-orbit-dot {
  position: absolute;
  top: -4px;
  left: 50%;
  width: 8px;
  height: 8px;
  margin-left: -4px;
  border-radius: 50%;
  background: #7cf5ff;
  box-shadow: 0 0 16px 4px rgba(0, 212, 255, 0.65);
}

/* --- 2.5 指针跟随光晕 --- */
.plx-pointer-glow {
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background: radial-gradient(420px circle at var(--mx) var(--my),
      rgba(0, 212, 255, 0.10),
      rgba(124, 58, 237, 0.05) 46%,
      transparent 70%);
  transition: background-position 0.2s ease-out;
  will-change: transform;
}

/* --- 2.6 横向光带 --- */
.plx-beam {
  position: absolute;
  left: -12%;
  right: -12%;
  top: 40%;
  height: 1px;
  z-index: 1;
  pointer-events: none;
  background: linear-gradient(90deg, transparent, rgba(0, 212, 255, 0.42), rgba(124, 58, 237, 0.30), transparent);
  will-change: transform;
}

/* --- 2.7 前沿方向标签：每颗自己的视差速度 --- */
/* 统一装在 .plx-chips 里，这样 nth-child 定位不会被同级装饰元素打乱 */
.plx-chips {
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
}

.plx-chip {
  position: absolute;
  padding: 9px 17px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  white-space: nowrap;
  color: rgba(248, 250, 252, 0.88);
  background: rgba(6, 12, 24, 0.46);
  border: 1px solid rgba(255, 255, 255, 0.10);
  -webkit-backdrop-filter: blur(9px);
  backdrop-filter: blur(9px);
  animation: plxChipPulse 5.5s ease-in-out infinite;
  will-change: transform;
}

/* 呼吸用 box-shadow / 边框色，不用 transform —— 留给视差 */
@keyframes plxChipPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(0, 212, 255, 0); border-color: rgba(255, 255, 255, 0.10); }
  50% { box-shadow: 0 0 22px 0 rgba(0, 212, 255, 0.14); border-color: rgba(0, 212, 255, 0.24); }
}

/* 标签落位（百分比，随容器缩放）
   约束：正文区宽 860px 居中，所以左右两列标签必须落在正文列之外，
   且纵向别挤到中段（统计数字一带）。 */
.plx-chips .plx-chip:nth-child(1) { left: 5%; top: 21%; animation-delay: 0s; }
.plx-chips .plx-chip:nth-child(2) { left: 2%; top: 58%; animation-delay: -1.2s; }
.plx-chips .plx-chip:nth-child(3) { left: 30%; top: 13%; animation-delay: -2.4s; }
.plx-chips .plx-chip:nth-child(4) { right: 6%; top: 25%; animation-delay: -3.6s; }
.plx-chips .plx-chip:nth-child(5) { right: 2%; top: 58%; animation-delay: -4.8s; }
.plx-chips .plx-chip:nth-child(6) { right: 31%; top: 12%; animation-delay: -0.9s; }
.plx-chips .plx-chip:nth-child(7) { left: 10%; bottom: 17%; animation-delay: -2.1s; }
.plx-chips .plx-chip:nth-child(8) { right: 11%; bottom: 15%; animation-delay: -3.3s; }

/* --- 2.8 段落收边 ---
   上边缘刻意从「全透明」开始ramp，避免与上一段（视频直接透出的 hero 底部）
   出现一条生硬的明暗接缝；下边缘压深，与下一段自然衔接。
   中间保持低透明度，背景视频依旧清晰可见。 */
.plx-field::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 4;
  pointer-events: none;
  background: linear-gradient(to bottom,
      transparent 0%,
      rgba(2, 2, 5, 0.26) 14%,
      rgba(2, 2, 5, 0.32) 46%,
      rgba(2, 2, 5, 0.52) 80%,
      rgba(2, 2, 5, 0.94) 100%);
}

/* --- 2.9 中央主体 --- */
.plx-core {
  position: relative;
  z-index: 6;
  max-width: 860px;
  text-align: center;
}

/* 正文后方的一团柔和暗场：保证文字在任何视频画面上都清晰，
   同时不遮挡背景视频（只是压暗一圈，边缘完全化开）。 */
.plx-core::before {
  content: '';
  position: absolute;
  left: 50%;
  top: 50%;
  width: 136%;
  height: 176%;
  transform: translate(-50%, -50%);
  z-index: -1;
  pointer-events: none;
  background: radial-gradient(ellipse at 50% 50%,
      rgba(2, 2, 5, 0.86) 0%,
      rgba(2, 2, 5, 0.72) 34%,
      rgba(2, 2, 5, 0.42) 56%,
      rgba(2, 2, 5, 0.16) 72%,
      transparent 82%);
}

.plx-emblem {
  width: 60px;
  height: 60px;
  margin: 0 auto 26px;
  display: block;
}

.plx-emblem svg {
  width: 100%;
  height: 100%;
  filter: drop-shadow(0 0 18px rgba(0, 212, 255, 0.45));
}

.plx-eyebrow {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.24em;
  text-transform: uppercase;
  color: var(--primary);
  margin-bottom: 20px;
}

.plx-title {
  font-size: clamp(2.3rem, 6.2vw, 4.3rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.035em;
  margin-bottom: 24px;
  filter: drop-shadow(0 6px 34px rgba(0, 212, 255, 0.22));
}

.plx-title .plx-grad {
  background: linear-gradient(98deg, #ffffff 0%, #9fefff 26%, #00d4ff 52%, #7c3aed 96%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.plx-desc {
  font-size: clamp(1rem, 1.7vw, 1.16rem);
  line-height: 1.85;
  color: var(--text-secondary);
  max-width: 660px;
  margin: 0 auto;
}

.plx-stats {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: clamp(26px, 5vw, 68px);
  margin-top: 52px;
}

.plx-stat {
  min-width: 96px;
}

.plx-stat-value {
  font-size: clamp(1.75rem, 4vw, 2.55rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.02em;
  background: linear-gradient(180deg, #ffffff 0%, #8fe6ff 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.plx-stat-label {
  margin-top: 8px;
  font-size: 0.78rem;
  letter-spacing: 0.14em;
  color: var(--text-tertiary);
  text-transform: uppercase;
}

/* 向下滚动提示 */
.plx-hint {
  position: absolute;
  left: 50%;
  bottom: 34px;
  z-index: 6;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: 0.68rem;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--text-tertiary);
}

.plx-hint-arrow {
  width: 1px;
  height: 30px;
  background: linear-gradient(to bottom, rgba(0, 212, 255, 0.7), transparent);
  animation: plxHint 2.1s ease-in-out infinite;
}

@keyframes plxHint {
  0%, 100% { opacity: 0.25; transform: scaleY(0.7); transform-origin: top; }
  50% { opacity: 1; transform: scaleY(1); transform-origin: top; }
}

/* ---------------------------------------------------------------------------
   3. 平板
   --------------------------------------------------------------------------- */
@media (max-width: 1100px) {
  .plx-field { min-height: 104vh; }

  .plx-chips .plx-chip:nth-child(3),
  .plx-chips .plx-chip:nth-child(6) { display: none; }
}

/* ---------------------------------------------------------------------------
   4. 手机：装饰退到背景里，前沿标签改成流式标签云
      —— 小屏上正文几乎占满宽度，绝对定位的标签一定会压到字，
         所以改为正常流：正文在上、标签云在下，并且禁掉标签的纵向位移。
   --------------------------------------------------------------------------- */
@media (max-width: 760px) {
  .plx-field {
    flex-direction: column;
    justify-content: center;
    gap: 26px;
    min-height: auto;
    padding: 84px 6%;
  }

  .plx-core { order: 1; }
  .plx-chips { order: 2; }

  .plx-chips {
    position: static;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 9px;
    max-width: 100%;
    z-index: 2;
  }

  .plx-chips .plx-chip {
    position: static;
    font-size: 0.72rem;
    padding: 7px 13px;
    animation-delay: 0s;
    /* 流式排布下再做纵向位移会压到正文，直接关掉 */
    transform: none !important;
  }

  /* 手机上只留 6 颗，避免标签云太长 */
  .plx-chips .plx-chip:nth-child(n + 7) { display: none; }

  .plx-ring-c { display: none; }
  .plx-stats { gap: 22px 34px; margin-top: 36px; }
  .plx-stat { min-width: 84px; }
  .plx-stat-label { font-size: 0.7rem; letter-spacing: 0.1em; }
  .plx-hint { display: none; }
}

/* ---------------------------------------------------------------------------
   5. 降低动态效果偏好：视差与装饰动画全部让位
   --------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  .plx-layer,
  .plx-nebula,
  .plx-aurora,
  .plx-floor,
  .plx-ring,
  .plx-orbit,
  .plx-chip,
  .plx-beam,
  .plx-orbit-ring,
  .plx-hint-arrow {
    animation: none !important;
    transform: none !important;
    will-change: auto !important;
  }

  .section-eyebrow,
  .section-title,
  .section-desc {
    transform: none !important;
  }

  .plx-field { min-height: auto; padding: 110px 5%; }
}