tabby/terminus-core/src/components/tabHeader.component.scss

$tabs-height: 40px;

:host {
    line-height: $tabs-height - 2px;
    cursor: pointer;

    flex: 1000 1 200px;
    width: 200px;

    display: flex;
    flex-direction: row;
    min-width: 0;

    overflow: hidden;

    transition: 0.25s ease-out all;

    border-top: 1px solid transparent;

    .index {
        flex: none;
        font-weight: bold;

        margin-left: 10px;
        width: 20px;
        border-radius: 10px;
        line-height: 38px;
        text-align: center;
        transition: 0.25s all;
    }

    .name {
        flex: auto;
        margin: 0 1px 0 10px;
        overflow: hidden;
        white-space: nowrap;
        text-overflow: ellipsis;
        min-width: 0;
    }

    button {
        display: block;
        flex: none;
        background: transparent;
        opacity: 0;

        $button-size: $tabs-height * 0.6;
        width: $button-size;
        height: $button-size;
        border-radius: $button-size / 2;
        line-height: $button-size * 0.8;
        margin-top: ($tabs-height - $button-size) * 0.4;
        margin-right: 10px;

        text-align: center;
        font-size: 20px;
    }

    &:hover button {
        transition: 0.25s opacity;
        display: block;
        opacity: 1;
    }
}