{
  "schemaVersion": 2,
  "sourceKind": "structured-spec",
  "confidence": "high",
  "slug": "backtotop",
  "name": "返回顶部 BackToTop",
  "semanticTypeCandidates": [
    "backtotop",
    "scroll-top"
  ],
  "variantDimensions": [
    {
      "name": "progress",
      "values": [
        "ring",
        "none"
      ]
    },
    {
      "name": "position",
      "values": [
        "bottom-right",
        "custom"
      ]
    }
  ],
  "representativeVariants": [
    {
      "progress": "ring",
      "position": "bottom-right",
      "label": "带进度环"
    },
    {
      "progress": "none",
      "position": "bottom-right",
      "label": "无进度环"
    },
    {
      "progress": "ring",
      "position": "custom",
      "label": "自定义位置"
    }
  ],
  "anatomy": {
    "trigger": "页面滚动超过 400px 时出现",
    "button": "右下角悬浮按钮",
    "ring": "可带进度环显示滚动进度",
    "action": "点击平滑滚动回顶部"
  },
  "structurePatterns": {
    "appearAt": "400px",
    "position": "右下角悬浮"
  },
  "usageHints": [
    "页面滚动超过 400px 时出现",
    "右下角悬浮按钮",
    "点击平滑滚动回顶部",
    "可带进度环显示滚动进度",
    "支持自定义位置、样式"
  ],
  "doNotInvent": [
    "进度环的渐变配色"
  ],
  "unknowns": [
    "按钮尺寸与距边距",
    "进度环的线宽"
  ]
}