wagtail/client/scss/components/_button.scss

// Core button style
// Note that these styles include methods to render buttons the same x-browser, described here:
// http: //cbjdigital.com/blog/2010/08/bulletproof_css_input_button_heights
// input[type=submit],
// input[type=reset],
// input[type=button],
.button {
    border-radius: 3px;
    font-family: Open Sans,Arial,sans-serif;
    width: auto;
    height: 2.4em;
    padding: 0 1em;
    font-size: 0.9em;
    font-weight: normal;
    vertical-align: middle;
    display: inline-block;
    background-color: $color-button;
    border: 1px solid $color-button;
    color: $color-white;
    text-decoration: none;
    text-transform: uppercase;
    white-space: nowrap;
    position: relative;
    overflow: hidden;
    box-sizing: border-box;
    -webkit-font-smoothing: auto;
    // stylelint-disable-next-line property-no-vendor-prefix
    -moz-appearance: none;

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


    &.yes {
        background-color: $color-button-yes;
        border: 1px solid $color-button-yes;

        &.button-secondary {
            border: 1px solid $color-button-yes;
            color: $color-button-yes;
            background-color: transparent;
        }

        &:hover {
            color: $color-white;
            border-color: transparent;
            background-color: $color-button-yes-hover;
        }

        &.button-nobg:hover {
            color: $color-button-yes;
            background-color: transparent;
        }
    }

    &.warning {
        background-color: $color-button-warning;
        border: 1px solid $color-button-warning;

        &.button-secondary {
            border: 1px solid $color-button-warning;
            color: $color-button-warning;
            background-color: transparent;
        }

        &:hover {
            color: $color-white;
            border-color: transparent;
            background-color: $color-button-warning-hover;
        }

        &.button-nobg:hover {
            color: $color-button-warning;
            background-color: transparent;
        }
    }


    &.no,
    &.serious {
        background-color: $color-button-no;
        border: 1px solid $color-button-no;

        &.button-secondary {
            border: 1px solid $color-button-no;
            color: $color-button-no;
            background-color: transparent;
        }

        &:hover {
            color: $color-white;
            border-color: transparent;
            background-color: $color-button-no-hover;
        }

        &.button-nobg:hover {
            color: $color-button-no;
            background-color: transparent;
        }
    }

    &.button-nobg {
        border: 0;
        background-color: transparent;
    }

    &.bicolor {
        border: 1px solid transparent;
        padding-left: 3.5em;

        &:before {  // iconfont
            font-size: 1rem;
            position: absolute;
            left: 0;
            top: 0;
            width: 2em;
            line-height: 1.85em;
            height: 100%;
            text-align: center;
            background-color: rgba(0, 0, 0, 0.2);
            display: block;
            border-top-left-radius: inherit;
            border-bottom-left-radius: inherit;
        }

        .icon-wrapper {
            background-color: rgba(0, 0, 0, 0.2);
            display: block;
            position: absolute;
            left: 0;
            top: 0;
            width: 3em;
            line-height: 1.85em;
            height: 100%;
            text-align: center;
            border-top-left-radius: inherit;
            border-bottom-left-radius: inherit;
        }

        &.button--icon {
            &:before {
                display: none;  // TODO: remove once the icon font styles are gone
            }

            .icon {
                @include svg-icon(1rem);
                padding: 0.75em;
            }
        }

        &.button-secondary {
            border: 1px solid rgba(0, 0, 0, 0.2);
        }
    }

    &.button-small.bicolor {
        padding-left: 3.5em;

        .icon-wrapper {
            width: 2em;
        }

        &.button--icon .icon {
            @include svg-icon(0.9rem);
            padding: 0.25em;
        }
    }


    // + input[type=submit],
    // + input[type=reset],
    // + input[type=button],
    + .button {
        // + button {
        margin-left: 1em;
    }

    // A completely unstyled button
    &.unbutton {
        border-radius: 0;
        width: auto;
        height: auto;
        padding: 0;
        font-size: inherit;
        font-weight: normal;
        vertical-align: middle;
        display: inline;
        background-color: transparent;
        border: 0;
        color: inherit;
        text-decoration: none;
        text-transform: uppercase;
        white-space: nowrap;
        position: relative;
        overflow: hidden;
        box-sizing: border-box;
        -webkit-font-smoothing: auto;
        // stylelint-disable-next-line property-no-vendor-prefix
        -moz-appearance: none;
    }

    &:hover {
        background-color: $color-button-hover;
        color: $color-white;
        border-color: transparent;

        &.hover-no {
            background-color: $color-button-no;
        }
    }

    &.button-longrunning {
        span {
            @include transition(all 0.3s ease);
            transform: scale(0.9);
            display: inline-block;
            height: 0.9em;
            position: relative;
            opacity: 0;
            width: 0;
            visibility: hidden;
            text-align: center;
            padding-right: 0;
        }

        em {
            font-style: normal;
        }

        &.button-longrunning-active span {
            transform: scale(1);
            visibility: visible;
            width: 1em;
            opacity: 0.8;
            padding-right: 0.5em;
        }

        .icon-spinner:after {
            text-align: center;
            position: absolute;
            left: 0;
            margin: 0;
            line-height: 1em;
            display: inline-block;
            font-size: 1em;
        }
    }

    &:disabled,
    &[disabled],
    &.disabled {
        background-color: $color-grey-3;
        border-color: $color-grey-3;
        color: $color-grey-2;
        cursor: default;
    }

    &.button-secondary:disabled,
    &.button-secondary[disabled],
    &.button-secondary.disabled {
        background-color: $color-white;
        border-color: $color-grey-3;
        color: $color-grey-3;
    }

    &.button-nostroke {
        border: 0;
    }

    &.button--icon {
        .icon {
            @include svg-icon(1.5em);
        }
    }

    @include media-breakpoint-up(sm) {
        font-size: 0.95em;
        padding: 0 1.4em;
        height: 3em;

        &.bicolor {
            padding-left: 3.7em;

            &:before {
                width: 2em;
                line-height: 2.2em;
                font-size: 1.1rem;
            }
        }

        &.button-small.bicolor {
            // line-height: 2.2em;
            padding-left: 3em;

            &:before {
                width: 1.8em;
                line-height: 1.65em;
            }
        }
    }
}


.button-small {
    padding: 0 0.8em;
    height: 2em;
    font-size: 0.95em;
}

.button-secondary {
    color: $color-button;
    background-color: transparent;
}

// Buttons which are only an icon
.button.icon.text-replace {  // iconfont
    font-size: 0; // unavoidable duplication of setting in icons.scss
    width: 1.8rem;
    height: 1.8rem;

    &:before {
        line-height: 1.7em;
    }

    @include media-breakpoint-up(sm) {
        width: 2.2rem;
        height: 2.2rem;

        &:before {
            line-height: 2.1em;
        }


        &.button-small {
            height: 1.8rem;
            width: 1.8rem;

            // stylelint-disable-next-line max-nesting-depth
            &:before {
                line-height: 1.7em;
            }
        }
    }
}

.button--icon.text-replace {
    font-size: 0;
    text-align: center;

    .icon {
        font-size: initial;
        @include svg-icon(1rem, middle);
        padding: 0.5em;
    }

    &.button-small {
        line-height: 1.7rem;

        .icon {
            padding: 0.25em;
        }
    }

    @include media-breakpoint-up(sm) {
        width: 2.2rem;
        height: 2.2rem;

        &.button-small {
            height: 1.8rem;
            width: 1.8rem;
        }
    }
}

button.button.bicolor .icon-wrapper {
    line-height: 1.65em;  // work around differences in a and button elements
}

.button-neutral {
    color: $color-grey-2;

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

.yes {
    background-color: $color-button-yes;
    border: 1px solid $color-button-yes;

    &.button-secondary {
        border: 1px solid $color-button-yes;
        color: $color-button-yes;
        background-color: transparent;
    }

    &:hover {
        color: $color-white;
        border-color: transparent;
        background-color: $color-button-yes-hover;
    }

    &.button-nobg:hover {
        color: $color-button-yes;
        background-color: transparent;
    }
}

.no,
.serious {
    background-color: $color-button-no;
    border: 1px solid $color-button-no;

    &.button-secondary {
        border: 1px solid $color-button-no;
        color: $color-button-no;
        background-color: transparent;
    }

    &:hover {
        color: $color-white;
        border-color: transparent;
        background-color: $color-button-no-hover;
    }

    &.button-nobg:hover {
        color: $color-button-no;
        background-color: transparent;
    }
}

.button-nobg {
    border: 0;
    background-color: transparent;
}

.bicolor {
    border: 0;
    padding-left: 3.5em;

    &:before {
        font-size: 1rem;
        position: absolute;
        left: 0;
        top: 0;
        width: 2em;
        line-height: 1.85em;
        height: 100%;
        text-align: center;
        background-color: rgba(0, 0, 0, 0.2);
        display: block;
    }
}

.button-small.bicolor {
    padding-left: 3.5em;

    &:before {
        width: 2em;
        font-size: 0.8rem;
        line-height: 1.65em;
    }
}


a.button {
    line-height: 2.4em;
    height: auto;

    &.button-small {
        line-height: 1.85em;
    }

    @include media-breakpoint-up(sm) {
        line-height: 2.9em;
    }
}

// Special styles to counteract Firefox's completely unwarranted assumptions about button styles
input[type=submit],
input[type=reset],
input[type=button],
button {
    padding: 0 1em;

    @include media-breakpoint-up(sm) {
        &.button-small {
            height: 2em;
        }
    }
}

.button-group {
    @include clearfix;

    input[type=submit],
    input[type=reset],
    input[type=button],
    .button,
    button {
        border-radius: 0;
        float: left;
        margin-right: 1px;
        margin-left: 0;

        &:only-child {
            border-radius: 3px;
        }

        &:first-child {
            border-radius: 3px 0 0 3px;
        }

        &:last-child {
            border-radius: 0 3px 3px 0;
            margin-right: 0;
        }
    }

    &.button-group-square {
        &,
        input[type=submit],
        input[type=reset],
        input[type=button],
        .button,
        button {
            border-radius: 0;
        }
    }
}


.multiple {
    padding: 0;
    max-width: 1024px - 50px;
    overflow: hidden;

    > li {
        @include row();
        border-radius: 2px;
        position: relative;
        overflow: hidden;
        background-color: $color-white;
        padding: 1em 10em 1em 1.5em; // 10em padding leaves room for controls
        margin-bottom: 1em;
        border: 1px solid lighten($color-grey-4, 3%); // really trying to avoid creating more greys, but this one is better than grey 4 or 5
    }

    &.moving {
        position: relative;
    }

    li.moving {
        position: absolute;
        width: 100%;
    }

    fieldset {
        padding-top: 0;
        padding-bottom: 0;
    }

    // Object controls
    .controls {
        position: absolute;
        z-index: 1;
        right: 1em;
        top: 1em;
        color: $color-white;

        li {
            float: left;
            margin-right: 1px;

            &:last-child {
                margin-right: 0;
            }
        }

        .disabled {
            display: none;
            visibility: hidden;
        }
    }

}

// wrapper around add button for mutliple objects
.add {
    font-weight: 700;
    cursor: pointer;
    margin-top: 0;
    margin-bottom: 0;
    padding-top: 1em;
    padding-bottom: 2em;
    clear: both;
}