Rambox-CE/ext/packages/ext-theme-neutral/sass/src/window/MessageBox.scss

.#{$prefix}message-box .#{$prefix}window-body {
    background-color: $messagebox-body-background-color;
    border-width: $messagebox-body-border-width;
    @if $messagebox-body-border-width != 0 {
        border-color: $messagebox-body-border-color;
        border-style: $messagebox-body-border-style;
    }
}

.#{$prefix}message-box-info,
.#{$prefix}message-box-warning,
.#{$prefix}message-box-question,
.#{$prefix}message-box-error {
    background-position: $messagebox-icon-background-position;
    background-repeat: no-repeat;
}

@if $include-rtl {
    .#{$prefix}rtl {
        &.#{$prefix}message-box-info,
        &.#{$prefix}message-box-warning,
        &.#{$prefix}message-box-question,
        &.#{$prefix}message-box-error {
            background-position: rtl-background-position($messagebox-icon-background-position)
        }
    }
}

.#{$prefix}message-box-icon {
    height: $messagebox-icon-size;
    width: $messagebox-icon-size;
    margin-right: $messagebox-icon-spacing;
}

.#{$prefix}message-box-info {
    background-image: theme-background-image('shared/icon-info');
}

.#{$prefix}message-box-warning {
    background-image: theme-background-image('shared/icon-warning');
}

.#{$prefix}message-box-question {
    background-image: theme-background-image('shared/icon-question');
}

.#{$prefix}message-box-error {
    background-image: theme-background-image('shared/icon-error');
}