> .custom-file:nth-last-child(n + 3) .custom-file-label,\n    > .custom-file:nth-last-child(n + 3) .custom-file-label::after {\n      @include border-right-radius(0);\n    }\n  }\n}\n\n\n// Prepend and append\n//\n// While it requires one extra layer of HTML for each, dedicated prepend and\n// append elements allow us to 1) be less clever, 2) simplify our selectors, and\n// 3) support HTML5 form validation.\n\n.input-group-prepend,\n.input-group-append {\n  display: flex;\n\n  // Ensure buttons...