min-width: 0; // 1\n  padding: 0; // 2\n  margin: 0; // 2\n  border: 0; // 2\n}\n\n// 1. By using `float: left`, the legend will behave like a block element.\n//    This way the border of a fieldset wraps around the legend if present.\n// 2. Fix wrapping bug.\n//    See https://github.com/twbs/bootstrap/issues/29712\n\nlegend {\n  float: left; // 1\n  width: 100%;\n  padding: 0;\n  margin-bottom: $legend-margin-bottom;\n  @include font-size($legend-font-size);\n  font-weight: $legend-font-weight;\n...

https://html.spec.whatwg.org/multipage/#the-fieldset-and-legend-elements\n  min-width: 0;\n  // Reset the default outline behavior of fieldsets so they don't affect page layout.\n  padding: 0;\n  margin: 0;\n  border: 0;\n}\n\n// 1. Correct the text wrapping in Edge and IE.\n// 2. Correct the color inheritance from `fieldset` elements in IE.\nlegend {\n  display: block;\n  width: 100%;\n  max-width: 100%; // 1\n  padding: 0;\n  margin-bottom: .5rem;\n  @include font-size(1.5rem);\n  line-height: inherit;\n...