.tabbrowser-tab {
  --tab-label-mask-size: 2em !important;
}

.tabbrowser-tab:hover > .tab-stack > .tab-background:not([selected=true], [multiselected]) {
  background-color: color-mix(in srgb, currentColor 8%, transparent) !important;
}

.tabbrowser-tab[visuallyselected="true"]:hover, #tabbrowser-tabs:not([closebuttons="activetab"]) > #tabbrowser-arrowscrollbox > .tabbrowser-tab:not([visuallyselected="true"]):hover {
    --tab-label-mask-size: 1em;
}

.tab-label-container[textoverflow][labeldirection=ltr]:not([pinned]),
.tab-label-container[textoverflow]:not([labeldirection], [pinned]):-moz-locale-dir(ltr) {
  mask-image: linear-gradient(to left, transparent, black 2em) !important;
}

.tab-label-container[textoverflow][labeldirection=rtl]:not([pinned]),
.tab-label-container[textoverflow]:not([labeldirection], [pinned]):-moz-locale-dir(rtl) {
  mask-image: linear-gradient(to right, transparent, black 2em) !important;
}

.tab-close-button {
    margin-inline-end: calc(var(--inline-tab-padding) / -2);
    width: 24px;
    height: 24px;
    padding: 7px;
}

.tabbrowser-tab:not(:hover) > .tab-stack > .tab-content > .tab-close-button {
    padding-inline-start: 0;
    width: 17px;
}

// Этот скрипт работает в главном окне браузера если включено в настройках

var ucf_custom_script_win = {
    initialized: false,
    get unloadlisteners() {
        delete this.unloadlisteners;
        window.addEventListener("unload", this, { once: true });
        return this.unloadlisteners = [];
    },
    load() {
        if (this.initialized)
            return;
        this.initialized = true;
        // this.specialwidgets.init(); // <-- Special Widgets
        // this.autohidesidebar.init(); // <-- Auto Hide Sidebar
        this.menubarvisibilitychance.setbuttonboxwidth();
        /* ************************************************ */

        // Здесь может быть ваш код который сработает по событию "load" не раньше

        /* ************************************************ */
    },
    handleEvent(e) {
        this[e.type](e);
    },
    unload() {
        this.unloadlisteners.forEach(str => {
            try {
                this[str].destructor();
            } catch (e) {}
        });
    },
menubarvisibilitychance: {
        buttons: null,
        buttonsfullscreen: null,
        constructor() {
            var menubar = this.menubar = document.querySelector("#toolbar-menubar");
            if (!menubar) return;
            this.observer = new MutationObserver(() => {
                this.settoolbarvisibility();
            });
            this.observer.observe(menubar, {
                attributeFilter: ["autohide", "inactive"],
                attributes: true,
            });
            this.sizemodechange = new MutationObserver(() => {
                this.setbuttonboxwidth();
            });
            this.sizemodechange.observe(document.documentElement, {
                attributeFilter: ["sizemode"],
                attributes: true,
            });
            ucf_custom_script_win.unloadlisteners.push("menubarvisibilitychance");
            this.settoolbarvisibility();
        },
        settoolbarvisibility() {
            var docElm = document.documentElement;
            if (this.menubar.getAttribute("autohide") == "true" && this.menubar.getAttribute("inactive") == "true") {
                docElm.setAttribute("v_menubar_autohide", true);
                this.setbuttonboxwidth();
            } else
                docElm.setAttribute("v_menubar_autohide", false);
        },
        width(outerRect, innerRect) {
            if (!window.RTL_UI)
                this.width = (outerRect, innerRect) => outerRect.right - innerRect.left;
            else
                this.width = (outerRect, innerRect) => innerRect.right - outerRect.left;
            return this.width(outerRect, innerRect);
        },
        setbuttonboxwidth() {
            var buttons, docElm = document.documentElement;
            if (docElm.getAttribute("sizemode") != "fullscreen")
                buttons = (this.buttons || (this.buttons = this.menubar.querySelector(".titlebar-buttonbox-container")));
            else
                buttons = (this.buttonsfullscreen || (this.buttonsfullscreen = document.querySelector("#window-controls")));
            var innerRect = buttons.getBoundingClientRect();
            if (innerRect.width < 1) {
                docElm.style.setProperty("--v-titlebar-buttonbox-container-width", "0px");
                return;
            }
            var outerRect = docElm.getBoundingClientRect();
            docElm.style.setProperty("--v-titlebar-buttonbox-container-width", `${this.width(outerRect, innerRect)}px`);
        },
        destructor() {
            this.observer.disconnect();
            this.sizemodechange.disconnect();
            this.observer = null;
            this.sizemodechange = null;
        }
    },
    specialwidgets: {
        _timer: null,
        get Customizable() {
            delete this.Customizable;
            if ("createSpecialWidget" in CustomizableUI)
                return this.Customizable = CustomizableUI;
            var scope = null;
            try {
                scope = Cu.import("resource:///modules/CustomizableUI.jsm", {}).CustomizableUIInternal;
            } catch (e) { }
            return this.Customizable = scope;
        },
        init() {
            if (!("CustomizableUI" in window) || !("gCustomizeMode" in window))
                return;
            ucf_custom_script_win.unloadlisteners.push("specialwidgets");
            window.addEventListener("customizationready", this);
        },
        destructor() {
            window.removeEventListener("customizationready", this);
        },
        handleEvent(e) {
            this[e.type](e);
        },
        customizationchange() {
            clearTimeout(this._timer);
            this._timer = setTimeout(() => {
                this.createSpecialWidgets();
            }, 1000);
        },
        customizationready() {
            if (!this.Customizable)
                return;
            this.createSpecialWidgets();
            window.addEventListener("customizationchange", this);
            window.addEventListener("customizationending", this);
        },
        customizationending() {
            window.removeEventListener("customizationchange", this);
            window.removeEventListener("customizationending", this);
        },
        createSpecialWidgets() {
            try {
                let fragment = document.createDocumentFragment();
                if (this.findSpecialWidgets("spring")) {
                    let spring = this.Customizable.createSpecialWidget("spring", document);
                    spring.setAttribute("label", "Растягивающийся интервал");
                    fragment.append(gCustomizeMode.wrapToolbarItem(spring, "palette"));
                }
                if (this.findSpecialWidgets("spacer")) {
                    let spacer = this.Customizable.createSpecialWidget("spacer", document);
                    spacer.setAttribute("label", "Интервал");
                    fragment.append(gCustomizeMode.wrapToolbarItem(spacer, "palette"));
                }
                if (this.findSpecialWidgets("separator")) {
                    let separator = this.Customizable.createSpecialWidget("separator", document);
                    separator.setAttribute("label", "Разделитель");
                    fragment.append(gCustomizeMode.wrapToolbarItem(separator, "palette"));
                }
                gCustomizeMode.visiblePalette.append(fragment);
            } catch (e) {}
        },
        findSpecialWidgets(string) {
            try {
                if (!gCustomizeMode.visiblePalette.querySelector(`toolbar${string}[id^="customizableui-special-${string}"]`))
                    return true;
            } catch (e) {}
            return false;
        }
    },
    autohidesidebar: {
        events: ["dragenter", "drop", "dragexit", "MozLayerTreeReady"],
        init() {
            var sidebar = this.sidebar = document.querySelector("#sidebar-box");
            if (!sidebar) return;
            for (let type of this.events)
                sidebar.addEventListener(type, this);
            ucf_custom_script_win.unloadlisteners.push("autohidesidebar");
            var popup = this.popup = document.querySelector("#sidebarMenu-popup");
            if (!popup) return;
            popup.addEventListener("popupshowing", this);
        },
        destructor() {
            var sidebar = this.sidebar;
            for (let type of this.events)
                sidebar.removeEventListener(type, this);
            if (!this.popup) return;
            this.popup.removeEventListener("popupshowing", this);
        },
        handleEvent(e) {
            this[e.type](e);
        },
        MozLayerTreeReady(e) {
            if (e.originalTarget?.id == "webext-panels-browser" && !this.sidebar.hasAttribute("sidebardrag")) {
                window.addEventListener("mousedown", () => {
                    this.drop();
                }, { once: true });
                this.dragenter();
            }
        },
        popupshowing() {
            this.popup.addEventListener("popuphidden", () => {
                this.drop();
            }, { once: true });
            this.dragenter();
        },
        dragenter() {
            if (!this.sidebar.hasAttribute("sidebardrag"))
                this.sidebar.setAttribute("sidebardrag", "true");
        },
        drop() {
            if (this.sidebar.hasAttribute("sidebardrag"))
                this.sidebar.removeAttribute("sidebardrag");
        },
        dragexit(e) {
            var sidebar = this.sidebar;
            var boxObj = sidebar.getBoundingClientRect(), boxScrn = !sidebar.boxObject ? sidebar : sidebar.boxObject;
            if ((!e.relatedTarget || e.screenY <= (boxScrn.screenY + 5) || e.screenY  >= (boxScrn.screenY + boxObj.height - 5)
                || e.screenX <= (boxScrn.screenX + 5) || e.screenX >= (boxScrn.screenX + boxObj.width - 5))
                && sidebar.hasAttribute("sidebardrag"))
                sidebar.removeAttribute("sidebardrag");
        }
    },
};

if (window.document.readyState != "complete") {
    window.addEventListener("load", function load() {
        ucf_custom_script_win.load();
    }, { once: true });
} else
    ucf_custom_script_win.load();
ucf_custom_script_win.menubarvisibilitychance.constructor();