wagtail/client/scss/components/_breadcrumb.scss

.breadcrumb {
    @include unlist();
    @include clearfix();
    padding-top: 1.4em;
    font-size: 0.85em;
    line-height: 1.5em;
    margin-left: 2em;
    background: $color-teal;

    .breadcrumb-item {
        display: block;
        float: left;
        position: relative;
        text-decoration: none;
        white-space: nowrap;
        padding: 4px;

        &:hover {
            background: $color-teal-dark;
        }

        &.breadcrumb-dropdown {
            padding: 0;
            font-size: initial;
        }

        .t-default .u-btn-current {
            color: inherit;
            background: rgba(0, 91, 94, 0.6);
            font-size: 1.15em;
            border: 0;
            line-height: 1.6;
        }
    }

    .breadcrumb-link {
        color: $color-white;
        display: block;
        padding: calc(0.5em - 4px) 1em;
        white-space: nowrap;
        line-height: 1.6em;

        &:hover {
            background: $color-teal-dark;
            color: $color-white;

            .arrow_right_icon {
                color: $color-teal;
            }
        }

        .title {
            display: inline-block;
            max-width: 11.8em;
            white-space: nowrap;
            text-overflow: ellipsis;
            overflow: hidden;
            vertical-align: bottom;
        }
    }

    .home_icon {
        @include svg-icon(1em);
        transform: scale(1.5) translate(0, 0.1em);
    }

    .arrow_right_icon {
        @include svg-icon(1em);
        color: $color-teal-dark;
        transform: scale(1.75) translate(0.3em, 0.1em);
    }

    @include media-breakpoint-up(sm) {
        padding-top: 0;
        background: $color-teal-darker;
        margin-left: -($desktop-nice-padding);
        margin-right: -($desktop-nice-padding);

        .home_icon {
            margin-left: 1.25em;
        }

        .arrow_right_icon {
            color: $color-teal;
        }
    }
}