\"active\" buttons to the front to overlay\n // the borders properly\n @include hover() {\n z-index: 1;\n }\n &:focus,\n &:active,\n &.active {\n z-index: 1;\n }\n }\n}\n\n// Optional: Group multiple button groups together for a toolbar\n.btn-toolbar {\n display: flex;\n flex-wrap: wrap;\n justify-content: flex-start;\n\n .input-group {\n width: auto;\n }\n}\n\n.btn-group {\n // Prevent double borders when buttons are next to each other\n > .btn:not(:first-child),\n...