amis/packages/amis-ui/scss/components/_portlet.scss

.#{$ns}Portlet {
    border: var(--Portlet-borderWidth) var(--Portlet-borderStyle) var(--Portlet-borderColor);
    border-radius: var(--Portlet-borderRadius);

    padding: var(--gap-base);

    &-tab.unactive-select {
        .is-active {
            a:first-child,
            &:hover > a:first-child,
            > a:first-child:focus {
                border: none !important;
                color: inherit !important;
                cursor: auto !important;
            }
        }
    }

    &-tab.no-divider {
        .#{$ns}Tabs-links {
            border-bottom: none;
        }
    }

    .#{$ns}Tabs-pane {
        padding: unset;
    }

    &-toolbar {
        display: inline-flex;
        float: right;
        justify-content: flex-end;

        .#{$ns}Button {
            margin-left: calc(var(--gap-xs));
        }
    }

    &-header-desc {
        height: 100%;
        overflow: hidden;
        position: relative;
        margin-left: var(--gap-base);
    }
}

.#{$ns}Portlet.no-header {
    .#{$ns}Portlet-tab .#{$ns}Tabs-links {
        display: none;
    }
}