// remove default button style\n  border: $border-width solid transparent; // remove default button style\n  @include border-radius($navbar-toggler-border-radius);\n\n  @include hover-focus() {\n    text-decoration: none;\n  }\n}\n\n// Keep as a separate element so folks can easily override it with another icon\n// or image file as needed.\n.navbar-toggler-icon {\n  display: inline-block;\n  width: 1.5em;\n  height: 1.5em;\n  vertical-align: middle;\n  content: \"\";\n  background: 50% / 100% 100%...