Firefox PWA(Add tab to taskbar) style improve

userChrome.css

[tabs-hidden] {
    /*  用来标签名字定位 */
    position: relative;
    /*  将标签栏中的当前标签重新定位，并排除其他样式影响  */
    #TabsToolbar {
        visibility: visible !important;
        max-height: 0 !important;
        overflow: hidden !important;

        &,
        * {
            position: static !important;
            display: block !important;
        }

        .tab-text[selected] {
            position: absolute !important;
            display: flex !important;
            align-items: center;
            height: 100%;
            top: 0;
            left: 32px;
            pointer-events: none;
        }
    }

    /* 隐藏空格，地址栏，和导航按钮*/
    .titlebar-spacer,
    .urlbar-container,
    #downloads-button,
    #taskbar-tabs-audio,
    #back-button,
    #forward-button,
    #stop-reload-button {
        display: none !important;
    }
    /* 导航栏其余按钮（比如扩展）放最右边 */
    #nav-bar-customization-target {
        justify-content: flex-end;
    }
}

[tabs-hidden] {
    border: none !important;
    & + #browser .browserContainer {
        outline: none !important;
    }
}