/*
 * 首页 3D 产品 Banner（2026-09-30 起正式版，中文首页与无语言前缀的英文首页加载）
 * 3D 内容以 iframe 嵌入 static/home-3d/*.html，与首页样式、脚本完全隔离。
 */

/* 3D Banner 取代原首屏：原首屏对访客不可见、不可聚焦（visibility: hidden），
   只留后台 Banner 标题 h1 给搜索引擎与读屏软件（视觉上裁成 1px）。 */
.vhd-home .vhd-hero {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
  visibility: hidden;
}

.vhd-home .vhd-hero h1 {
  visibility: visible;
}

.vhd-hero3d {
  position: relative;
  display: flex;
  flex-direction: column;
  padding-top: var(--vh3d-header-h, 130px);
  background: #f3f4f6;
}

.vhd-hero3d-stage {
  position: relative;
  height: clamp(560px, 52vw, 760px);
  overflow: hidden;
}

.vhd-hero3d-frame {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  z-index: 1;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.6s ease;
}

.vhd-hero3d-frame.is-active {
  z-index: 2;
  opacity: 1;
  pointer-events: auto;
}

/* 系列切换 */
.vhd-hero3d-switch {
  position: absolute;
  z-index: 3;
  left: 50%;
  bottom: 28px;
  display: flex;
  gap: 6px;
  padding: 6px;
  transform: translateX(-50%);
  border: 1px solid rgba(195, 13, 35, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 8px 24px rgba(27, 30, 35, 0.08);
  backdrop-filter: blur(8px);
}

.vhd-hero3d-switch button {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: #3a3f47;
  font: 500 14px/1 var(--voohu-cn-text-font, "Poppins", "Noto Sans SC", sans-serif);
  white-space: nowrap;
  cursor: pointer;
  transition: background 0.25s, color 0.25s;
}

.vhd-hero3d-switch button i {
  color: #c30d23;
  font: normal 500 11px/1 Consolas, monospace;
  letter-spacing: 0.12em;
}

.vhd-hero3d-switch button:hover {
  color: #c30d23;
}

.vhd-hero3d-switch button.is-active {
  background: #c30d23;
  color: #fff;
}

.vhd-hero3d-switch button.is-active i {
  color: rgba(255, 255, 255, 0.8);
}

.vhd-hero3d-switch button:focus-visible {
  outline: 2px solid #c30d23;
  outline-offset: 2px;
}

@media (max-width: 900px) {
  .vhd-hero3d-stage {
    height: 1000px;
  }

  .vhd-hero3d-switch {
    position: relative;
    left: auto;
    bottom: auto;
    order: -1;
    align-self: center;
    max-width: calc(100% - 32px);
    margin: 14px 16px 0;
    transform: none;
    flex-wrap: wrap;
    justify-content: center;
    border-radius: 22px;
  }

  .vhd-hero3d-switch button {
    padding: 8px 12px;
    font-size: 12.5px;
  }
}

/* 原首屏下方的间距留给旧 Banner，3D Banner 后直接接下一屏 */
.vhd-hero3d ~ .vhd-problems {
  margin-top: 0;
}