html {
  height: auto;
  background: #000;
  scroll-behavior: smooth;
  overflow-x: hidden;
  overflow-y: auto;
}

body {
  height: auto;
  min-height: 100vh;
  min-height: 100dvh;
  margin: 0;
  overflow-x: hidden;
  overflow-y: visible;
  background: #000;
}

.page-scroll,
.page-screen {
  position: relative;
  width: 100%;
}

.page-screen {
  min-height: 100vh;
  min-height: 100dvh;
}

.page-screen-stage {
  z-index: 0;
  background: #000;
}

.page-screen-combination {
  min-height: 0;
  z-index: 200;
  overflow: visible;
  background: #000;
  isolation: isolate;
}

.combination-shell {
  position: relative;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  overflow: visible;
  background:
    radial-gradient(circle at 50% 42%, rgba(65, 122, 255, .11), transparent 42%),
    #000;
}

.combination-frame {
  position: relative;
  z-index: 1;
  display: block;
  width: var(--combination-frame-width, 100%);
  height: var(--combination-frame-height, 100%);
  margin: 0;
  border: 0;
  background: #000;
  transform: scale(var(--combination-frame-scale, 1));
  transform-origin: 0 0;
}

.combination-skeleton {
  position: absolute;
  z-index: 2;
  inset: 0;
  overflow: hidden;
  background:
    linear-gradient(90deg, transparent, rgba(83, 230, 255, .11), transparent) -100vw 0 / 42vw 100% no-repeat,
    repeating-linear-gradient(90deg, rgba(85, 233, 255, .045) 0 1px, transparent 1px calc(16.666vw)),
    linear-gradient(180deg, #02070b, #000);
  animation: combination-skeleton-scan 1.8s ease-in-out infinite;
  pointer-events: none;
}

@keyframes combination-skeleton-scan {
  to { background-position: 150vw 0, 0 0, 0 0; }
}

.scroll-hint {
  position: fixed;
  z-index: 150;
  left: 50%;
  bottom: max(20px, env(safe-area-inset-bottom));
  display: grid;
  justify-items: center;
  gap: 8px;
  color: rgba(212, 243, 255, .72);
  font: 500 11px/1.2 "Microsoft YaHei", sans-serif;
  letter-spacing: .12em;
  opacity: 0;
  visibility: hidden;
  transform: translate(-50%, 12px);
  transition: opacity .28s ease, transform .28s ease, visibility .28s;
  pointer-events: none;
}

.scroll-hint.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translate(-50%, 0);
}

.scroll-hint i {
  display: block;
  width: 13px;
  height: 21px;
  border: 1px solid rgba(95, 230, 255, .58);
  border-radius: 999px;
  box-shadow: 0 0 14px rgba(72, 210, 255, .18);
}

.scroll-hint i::after {
  content: "";
  display: block;
  width: 2px;
  height: 5px;
  margin: 4px auto 0;
  border-radius: 2px;
  background: #fff;
  animation: combination-hint-drop 1.35s ease-in-out infinite;
}

@keyframes combination-hint-drop {
  0%, 100% { opacity: .25; transform: translateY(0); }
  55% { opacity: 1; transform: translateY(7px); }
}

body.has-combination-active .scroll-hint {
  opacity: 0;
  visibility: hidden;
  transform: translate(-50%, 8px);
}

body.has-combination-active .download-center-portal,
body.has-combination-active .brand-profile-popover {
  opacity: 0 !important;
  visibility: hidden !important;
  pointer-events: none !important;
}

body.has-combination-active .experience,
body.has-combination-active .cosmic-background,
body.has-combination-active .original-effects-front {
  visibility: hidden !important;
}

body[data-combination-screen="on"] .site-footer {
  position: relative;
  z-index: 210;
  left: auto;
  bottom: auto;
  width: 100%;
  min-height: 58px;
  padding: 18px 24px;
  transform: none;
  border-top: 1px solid rgba(85, 233, 255, .12);
  background: #000;
}

@media (max-width: 720px) {
  body[data-combination-screen="on"] .site-footer { bottom: auto; padding: 15px 12px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .combination-skeleton,
  .scroll-hint i::after { animation: none; }
  .scroll-hint { transition: opacity .01s linear, visibility .01s linear; transform: translate(-50%, 0); }
}

/* ============================================================
   第二屏总开关
   body[data-combination-screen="off"] 时：首页只保留第一屏，
   第二屏（六大宇宙组合中心）与下滑提示完全不出现。
   恢复方式：把 原版.html 上的 data-combination-screen 改成 "on"。
   ============================================================ */
body[data-combination-screen="off"] {
  min-height: 100vh;
  min-height: 100dvh;
}

body[data-combination-screen="off"] #screen-combination,
body[data-combination-screen="off"] .scroll-hint {
  display: none !important;
}

/* ============================================================
   正常滚动（取消第二屏覆盖第一屏的滑动覆盖效果）
   第一屏原本是 position: fixed 的整屏图层，第二屏滚上来时
   会盖在它上面，看起来像"覆盖式"。这里把第一屏的图层改为
   #screen-stage 内的绝对定位，使它随页面正常向上滚出视口。
   （配合 birth-status-next-five.js 中把图层移入 #screen-stage）
   ============================================================ */
.page-screen-stage {
  position: relative;
  height: 100vh;
  height: 100dvh;
  overflow: hidden;
  isolation: isolate;
}

.page-screen-stage > .cosmic-background,
.page-screen-stage > .experience {
  position: absolute;
  inset: 0;
}

/* 第一屏不再需要在第二屏可见时被强制隐藏：现在它会自然滚走，
   强制隐藏反而会让半屏状态下第一屏突然消失。 */
body.has-combination-active .experience,
body.has-combination-active .cosmic-background,
body.has-combination-active .original-effects-front {
  visibility: visible !important;
}

/* 允许在第一屏上用手势正常上下滚动页面（横向拖拽仍可旋转球体）。 */
.page-screen-stage > .experience,
.page-screen-stage .transplanted-stage-viewport {
  touch-action: pan-y;
}

/* 左侧下载中心侧边栏同样属于第一屏：改为 #screen-stage 内的绝对定位，
   随第一屏一起滚动；也不再在第二屏可见时被强制隐藏。 */
.page-screen-stage > .download-center-portal {
  position: absolute;
}

body.has-combination-active .download-center-portal {
  opacity: 1 !important;
  visibility: visible !important;
  pointer-events: auto !important;
}