[Firefox 133] Megabar CSS broken.

[mibby]

Describe the bug

RE: #348

  #urlbar[breakout][breakout-extend] {
    top: calc((var(--urlbar-toolbar-height, var(--urlbar-container-height)) - var(--urlbar-height)) / 2) !important;
    left: 0 !important;
    width: 100% !important;
  }

Possible Fix 1: https://old.reddit.com/r/FirefoxCSS/comments/1h2740c/ff133_search_bar_ontop_of_everything/

Find #urlbar[breakout][breakout-extend] and remove lines "top", "left", replace "width" with width: var(--urlbar-width) !important;

  #urlbar[breakout][breakout-extend] {
    width: var(--urlbar-width) !important;
  }

Possible Fix 2: Taking the suggestion from the comment here WesleyBranton/Remove-Firefox-Megabar#14 (comment) does seem to resolve the issue as well.

    #urlbar[breakout][breakout-extend] {
        margin: 4px;
    }

Edit 12/01: There's also the official fix made to the repo now as well.
https://github.com/WesleyBranton/Remove-Firefox-Megabar/blob/main/remove_megabar.css

Expected behavior

No megabar on top of everything.

Screenshots

Without CSS replaced.

With CSS Fix 1.

With CSS Fix 2.

OS

Windows 11

OS - Others

No response

Firefox Version

133.0

Distribution

• Original Lepton
• Lepton's photon style
• Lepton's proton style

Theme

• Light
• Dark
• Alpenglow (System: Light)
• Alpenglow (System: Dark)
• System Default
• Others: (e.g. Photon Colors, Google Chrome Dark, Fairytale Of Nature)

Theme - More Info

No response

user.js setup

user.js setup

//
/* You may copy+paste this file and use it as it is.
 *
 * If you make changes to your about:config while the program is running, the
 * changes will be overwritten by the user.js when the application restarts.
 *
 * To make lasting changes to preferences, you will have to edit the user.js.
 */

/****************************************************************************
 * Betterfox                                                                *
 * "Ad meliora"                                                             *
 * version: 132                                                             *
 * url: https://github.com/yokoffing/Betterfox                              *
****************************************************************************/

/****************************************************************************
 * SECTION: FASTFOX                                                         *
****************************************************************************/
/** GENERAL ***/
user_pref("content.notify.interval", 100000);

/** GFX ***/
user_pref("gfx.canvas.accelerated.cache-items", 4096);
user_pref("gfx.canvas.accelerated.cache-size", 512);
user_pref("gfx.content.skia-font-cache-size", 20);

/** DISK CACHE ***/
user_pref("browser.cache.disk.enable", true);

/** MEDIA CACHE ***/
user_pref("media.memory_cache_max_size", 65536);
user_pref("media.cache_readahead_limit", 7200);
user_pref("media.cache_resume_threshold", 3600);

/** IMAGE CACHE ***/
user_pref("image.mem.decode_bytes_at_a_time", 32768);

/** NETWORK ***/
user_pref("network.http.max-connections", 1800);
user_pref("network.http.max-persistent-connections-per-server", 10);
user_pref("network.http.max-urgent-start-excessive-connections-per-host", 5);
user_pref("network.http.pacing.requests.enabled", false);
user_pref("network.dnsCacheExpiration", 3600);
user_pref("network.ssl_tokens_cache_capacity", 10240);

/** SPECULATIVE LOADING ***/
user_pref("network.dns.disablePrefetch", true);
user_pref("network.dns.disablePrefetchFromHTTPS", true);
user_pref("network.prefetch-next", false);
user_pref("network.predictor.enabled", false);
user_pref("network.predictor.enable-prefetch", false);

/** EXPERIMENTAL ***/
user_pref("layout.css.grid-template-masonry-value.enabled", true);
user_pref("dom.enable_web_task_scheduling", true);

/****************************************************************************
 * SECTION: SECUREFOX                                                       *
****************************************************************************/
/** TRACKING PROTECTION ***/
user_pref("browser.contentblocking.category", "strict");
user_pref("urlclassifier.trackingSkipURLs", "*.reddit.com, *.twitter.com, *.twimg.com, *.tiktok.com");
user_pref("urlclassifier.features.socialtracking.skipURLs", "*.instagram.com, *.twitter.com, *.twimg.com");
user_pref("browser.download.start_downloads_in_tmp_dir", true);
user_pref("browser.helperApps.deleteTempFileOnExit", true);
user_pref("browser.uitour.enabled", false);
user_pref("privacy.globalprivacycontrol.enabled", true);

/** OCSP & CERTS / HPKP ***/
user_pref("security.OCSP.enabled", 0);
user_pref("security.remote_settings.crlite_filters.enabled", true);
user_pref("security.pki.crlite_mode", 2);

/** SSL / TLS ***/
user_pref("security.ssl.treat_unsafe_negotiation_as_broken", true);
user_pref("browser.xul.error_pages.expert_bad_cert", true);
user_pref("security.tls.enable_0rtt_data", false);

/** DISK AVOIDANCE ***/
user_pref("browser.privatebrowsing.forceMediaMemoryCache", true);
user_pref("browser.sessionstore.interval", 60000);

/** SHUTDOWN & SANITIZING ***/
user_pref("privacy.history.custom", true);

/** SEARCH / URL BAR ***/
//user_pref("browser.urlbar.trimHttps", true);
//user_pref("browser.urlbar.untrimOnUserInteraction.featureGate", true);
user_pref("browser.search.separatePrivateDefault.ui.enabled", true);
user_pref("browser.urlbar.update2.engineAliasRefresh", true);
user_pref("browser.search.suggest.enabled", false);
user_pref("browser.urlbar.quicksuggest.enabled", false);
user_pref("browser.urlbar.groupLabels.enabled", false);
user_pref("browser.formfill.enable", false);
user_pref("security.insecure_connection_text.enabled", true);
user_pref("security.insecure_connection_text.pbmode.enabled", true);
user_pref("network.IDN_show_punycode", true);

/** HTTPS-FIRST POLICY ***/
user_pref("dom.security.https_first", true);

/** PASSWORDS ***/
user_pref("signon.formlessCapture.enabled", false);
user_pref("signon.privateBrowsingCapture.enabled", false);
user_pref("network.auth.subresource-http-auth-allow", 1);
user_pref("editor.truncate_user_pastes", false);

/** MIXED CONTENT + CROSS-SITE ***/
user_pref("security.mixed_content.block_display_content", true);
user_pref("pdfjs.enableScripting", false);

/** EXTENSIONS ***/
user_pref("extensions.enabledScopes", 5);

/** HEADERS / REFERERS ***/
user_pref("network.http.referer.XOriginTrimmingPolicy", 2);

/** CONTAINERS ***/
user_pref("privacy.userContext.ui.enabled", true);

/** SAFE BROWSING ***/
user_pref("browser.safebrowsing.downloads.remote.enabled", false);

/** MOZILLA ***/
user_pref("permissions.default.desktop-notification", 2);
user_pref("permissions.default.geo", 2);
user_pref("permissions.manager.defaultsUrl", "");

/** TELEMETRY ***/
user_pref("datareporting.policy.dataSubmissionEnabled", false);
user_pref("datareporting.healthreport.uploadEnabled", false);
user_pref("toolkit.telemetry.unified", false);
user_pref("toolkit.telemetry.enabled", false);
user_pref("toolkit.telemetry.server", "data:,");
user_pref("toolkit.telemetry.archive.enabled", false);
user_pref("toolkit.telemetry.newProfilePing.enabled", false);
user_pref("toolkit.telemetry.shutdownPingSender.enabled", false);
user_pref("toolkit.telemetry.updatePing.enabled", false);
user_pref("toolkit.telemetry.bhrPing.enabled", false);
user_pref("toolkit.telemetry.firstShutdownPing.enabled", false);
user_pref("toolkit.telemetry.coverage.opt-out", true);
user_pref("toolkit.coverage.opt-out", true);
user_pref("toolkit.coverage.endpoint.base", "");
user_pref("browser.newtabpage.activity-stream.feeds.telemetry", false);
user_pref("browser.newtabpage.activity-stream.telemetry", false);

/** EXPERIMENTS ***/
user_pref("app.shield.optoutstudies.enabled", false);
user_pref("app.normandy.enabled", false);
user_pref("app.normandy.api_url", "");

/** CRASH REPORTS ***/
user_pref("breakpad.reportURL", "");
user_pref("browser.tabs.crashReporting.sendReport", false);

/** DETECTION ***/
user_pref("captivedetect.canonicalURL", "");
user_pref("network.captive-portal-service.enabled", false);
user_pref("network.connectivity-service.enabled", false);

/****************************************************************************
 * SECTION: PESKYFOX                                                        *
****************************************************************************/
/** MOZILLA UI ***/
user_pref("browser.privatebrowsing.vpnpromourl", "");
user_pref("extensions.getAddons.showPane", false);
user_pref("extensions.htmlaboutaddons.recommendations.enabled", false);
user_pref("browser.discovery.enabled", false);
user_pref("browser.shell.checkDefaultBrowser", false);
user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.addons", false);
user_pref("browser.newtabpage.activity-stream.asrouter.userprefs.cfr.features", false);
user_pref("browser.preferences.moreFromMozilla", false);
user_pref("browser.aboutConfig.showWarning", false);
user_pref("browser.aboutwelcome.enabled", false);
//user_pref("browser.profiles.enabled", true);

/** THEME ADJUSTMENTS ***/
user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true);
user_pref("browser.compactmode.show", true);
user_pref("browser.privateWindowSeparation.enabled", false); // WINDOWS

/** COOKIE BANNER HANDLING ***/
user_pref("cookiebanners.service.mode", 1);
user_pref("cookiebanners.service.mode.privateBrowsing", 1);

/** FULLSCREEN NOTICE ***/
user_pref("full-screen-api.transition-duration.enter", "0 0");
user_pref("full-screen-api.transition-duration.leave", "0 0");
user_pref("full-screen-api.warning.timeout", 0);

/** URL BAR ***/
user_pref("browser.urlbar.suggest.calculator", true);
user_pref("browser.urlbar.unitConversion.enabled", true);
user_pref("browser.urlbar.trending.featureGate", false);

/** NEW TAB PAGE ***/
//user_pref("browser.newtabpage.activity-stream.feeds.topsites", false);
user_pref("browser.newtabpage.activity-stream.showWeather", false);
user_pref("browser.newtabpage.activity-stream.feeds.section.topstories", false);

/** POCKET ***/
user_pref("extensions.pocket.enabled", false);

/** DOWNLOADS ***/
user_pref("browser.download.manager.addToRecentDocs", false);

/** PDF ***/
user_pref("browser.download.open_pdf_attachments_inline", true);

/** TAB BEHAVIOR ***/
user_pref("browser.bookmarks.openInTabClosesMenu", false);
user_pref("browser.menu.showViewImageInfo", true);
user_pref("findbar.highlightAll", true);
user_pref("layout.word_select.eat_space_to_next_word", false);

/****************************************************************************
 * START: MY OVERRIDES                                                      *
****************************************************************************/
// visit https://github.com/yokoffing/Betterfox/wiki/Common-Overrides
// visit https://github.com/yokoffing/Betterfox/wiki/Optional-Hardening
// Enter your personal overrides below this line:

/****************************************************************************
 * SECTION: SMOOTHFOX                                                       *
****************************************************************************/
// visit https://github.com/yokoffing/Betterfox/blob/main/Smoothfox.js
// Enter your scrolling overrides below this line:

/****************************************************************************************
 * OPTION: SHARPEN SCROLLING                                                           *
****************************************************************************************/
// credit: https://github.com/black7375/Firefox-UI-Fix
// only sharpen scrolling
user_pref("apz.overscroll.enabled", true); // DEFAULT NON-LINUX
//user_pref("general.smoothScroll", true); // DEFAULT
user_pref("mousewheel.min_line_scroll_amount", 10); // 10-40; adjust this number to your liking; default=5
user_pref("general.smoothScroll.mouseWheel.durationMinMS", 80); // default=50
user_pref("general.smoothScroll.currentVelocityWeighting", "0.15"); // default=.25
user_pref("general.smoothScroll.stopDecelerationWeighting", "0.6"); // default=.4
// Firefox Nightly only:
// [1] https://bugzilla.mozilla.org/show_bug.cgi?id=1846935
user_pref("general.smoothScroll.msdPhysics.enabled", false); // [FF122+ Nightly]

/****************************************************************************
 * END: BETTERFOX                                                           *
****************************************************************************/


// ** Theme Default Options ****************************************************
// userchrome.css usercontent.css activate
// user_pref("toolkit.legacyUserProfileCustomizations.stylesheets", true);

// Fill SVG Color
user_pref("svg.context-properties.content.enabled", true);

// Restore Compact Mode - 89 Above
// user_pref("browser.compactmode.show", true);

// about:home Search Bar - 89 Above
user_pref("browser.newtabpage.activity-stream.improvesearch.handoffToAwesomebar", false);

// CSS's `:has()` selector #457 - 103 Above
user_pref("layout.css.has-selector.enabled", true);

// Browser Theme Based Scheme - Will be activate 95 Above
// user_pref("layout.css.prefers-color-scheme.content-override", 3);

// ** Theme Related Options ****************************************************
// == Theme Distribution Settings ==============================================
// The rows that are located continuously must be changed `true`/`false` explicitly because there is a collision.
// https://github.com/black7375/Firefox-UI-Fix/wiki/Options#important
user_pref("userChrome.tab.connect_to_window",          true); // Original, Photon
user_pref("userChrome.tab.color_like_toolbar",         true); // Original, Photon

user_pref("userChrome.tab.lepton_like_padding",        true); // Original
user_pref("userChrome.tab.photon_like_padding",       false); // Photon

user_pref("userChrome.tab.dynamic_separator",          true); // Original, Proton
user_pref("userChrome.tab.static_separator",          false); // Photon
user_pref("userChrome.tab.static_separator.selected_accent", false); // Just option
user_pref("userChrome.tab.bar_separator",             false); // Just option

user_pref("userChrome.tab.newtab_button_like_tab",     true); // Original
user_pref("userChrome.tab.newtab_button_smaller",     false); // Photon
user_pref("userChrome.tab.newtab_button_proton",      false); // Proton

user_pref("userChrome.icon.panel_full",                true); // Original, Proton
user_pref("userChrome.icon.panel_photon",             false); // Photon

// Original Only
user_pref("userChrome.tab.box_shadow",                 true);
user_pref("userChrome.tab.bottom_rounded_corner",      true);

// Photon Only
user_pref("userChrome.tab.photon_like_contextline",   false);
user_pref("userChrome.rounding.square_tab",           false);

// Proton Only
// user_pref("userChrome.tab.supernova_like_contextline",   true);

// == Theme Compatibility Settings =============================================
// user_pref("userChrome.compatibility.accent_color",         true); // Firefox v103 Below
// user_pref("userChrome.compatibility.covered_header_image", true);
// user_pref("userChrome.compatibility.panel_cutoff",         true);
// user_pref("userChrome.compatibility.navbar_top_border",    true);
// user_pref("userChrome.compatibility.dynamic_separator",    true); // Need dynamic_separator

// user_pref("userChrome.compatibility.os.linux_non_native_titlebar_button", true);
// user_pref("userChrome.compatibility.os.windows_maximized", true);
// user_pref("userChrome.compatibility.os.win11",             true);

// == Theme Custom Settings ====================================================
// -- User Chrome --------------------------------------------------------------
// user_pref("userChrome.theme.private",                       true);
// user_pref("userChrome.theme.proton_color.dark_blue_accent", true);
// user_pref("userChrome.theme.monospace",                     true);
// user_pref("userChrome.theme.transparent.frame",             true);
// user_pref("userChrome.theme.transparent.menu",              true);
// user_pref("userChrome.theme.transparent.panel",             true);
// user_pref("userChrome.theme.non_native_menu",               true); // only for linux

// user_pref("userChrome.decoration.disable_panel_animate",    true);
// user_pref("userChrome.decoration.disable_sidebar_animate",  true);
// user_pref("userChrome.decoration.panel_button_separator",   true);
// user_pref("userChrome.decoration.panel_arrow",              true);

// user_pref("userChrome.autohide.tab",                        true);
// user_pref("userChrome.autohide.tab.opacity",                true);
// user_pref("userChrome.autohide.tab.blur",                   true);
// user_pref("userChrome.autohide.tabbar",                     true);
// user_pref("userChrome.autohide.navbar",                     true);
// user_pref("userChrome.autohide.bookmarkbar",                true);
// user_pref("userChrome.autohide.sidebar",                    true);
// user_pref("userChrome.autohide.fill_urlbar",                true);
// user_pref("userChrome.autohide.back_button",                true);
// user_pref("userChrome.autohide.forward_button",             true);
// user_pref("userChrome.autohide.page_action",                true);
// user_pref("userChrome.autohide.toolbar_overlap",            true);
// user_pref("userChrome.autohide.toolbar_overlap.allow_layout_shift", true);

// user_pref("userChrome.hidden.tab_icon",                     true);
// user_pref("userChrome.hidden.tab_icon.always",              true);
// user_pref("userChrome.hidden.tabbar",                       true);
// user_pref("userChrome.hidden.navbar",                       true);
// user_pref("userChrome.hidden.private_indicator",            true);
// user_pref("userChrome.hidden.titlebar_container",           true);
// user_pref("userChrome.hidden.sidebar_header",               true);
// user_pref("userChrome.hidden.sidebar_header.vertical_tab_only", true);
// user_pref("userChrome.hidden.urlbar_iconbox",               true);
// user_pref("userChrome.hidden.urlbar_iconbox.label_only",    true);
// user_pref("userChrome.hidden.bookmarkbar_icon",             true);
// user_pref("userChrome.hidden.bookmarkbar_label",            true);
// user_pref("userChrome.hidden.disabled_menu",                true);

// user_pref("userChrome.centered.tab",                        true);
// user_pref("userChrome.centered.tab.label",                  true);
// user_pref("userChrome.centered.urlbar",                     true);
// user_pref("userChrome.centered.bookmarkbar",                true);

// user_pref("userChrome.counter.tab",                         true);
// user_pref("userChrome.counter.bookmark_menu",               true);

// user_pref("userChrome.combined.nav_button",                 true);
// user_pref("userChrome.combined.nav_button.home_button",     true);
// user_pref("userChrome.combined.urlbar.nav_button",          true);
// user_pref("userChrome.combined.urlbar.home_button",         true);
// user_pref("userChrome.combined.urlbar.reload_button",       true);
// user_pref("userChrome.combined.sub_button.none_background", true);
// user_pref("userChrome.combined.sub_button.as_normal",       true);

// user_pref("userChrome.rounding.square_button",              true);
// user_pref("userChrome.rounding.square_dialog",              true);
// user_pref("userChrome.rounding.square_panel",               true);
// user_pref("userChrome.rounding.square_panelitem",           true);
// user_pref("userChrome.rounding.square_menupopup",           true);
// user_pref("userChrome.rounding.square_menuitem",            true);
// user_pref("userChrome.rounding.square_infobox",             true);
// user_pref("userChrome.rounding.square_toolbar",             true);
// user_pref("userChrome.rounding.square_field",               true);
// user_pref("userChrome.rounding.square_urlView_item",        true);
// user_pref("userChrome.rounding.square_checklabel",          true);

// user_pref("userChrome.padding.first_tab",                   true);
// user_pref("userChrome.padding.first_tab.always",            true);
// user_pref("userChrome.padding.drag_space",                  true);
// user_pref("userChrome.padding.drag_space.maximized",        true);

// user_pref("userChrome.padding.toolbar_button.compact",      true);
 user_pref("userChrome.padding.menu_compact",                true);
 user_pref("userChrome.padding.bookmark_menu.compact",       true);
 user_pref("userChrome.padding.urlView_expanding",           true);
 user_pref("userChrome.padding.urlView_result",              true);
 user_pref("userChrome.padding.panel_header",                true);

// user_pref("userChrome.urlbar.iconbox_with_separator",       true);

// user_pref("userChrome.urlView.as_commandbar",               true);
 user_pref("userChrome.urlView.full_width_padding",          true);
 user_pref("userChrome.urlView.always_show_page_actions",    true);
 user_pref("userChrome.urlView.move_icon_to_left",           true);
 user_pref("userChrome.urlView.go_button_when_typing",       true);
 user_pref("userChrome.urlView.focus_item_border",           true);

// user_pref("userChrome.tabbar.as_titlebar",                  true);
// user_pref("userChrome.tabbar.fill_width",                   true);
// user_pref("userChrome.tabbar.multi_row",                    true);
// user_pref("userChrome.tabbar.unscroll",                     true);
// user_pref("userChrome.tabbar.on_bottom",                    true);
// user_pref("userChrome.tabbar.on_bottom.above_bookmark",     true); // Need on_bottom
// user_pref("userChrome.tabbar.on_bottom.menubar_on_top",     true); // Need on_bottom
// user_pref("userChrome.tabbar.on_bottom.hidden_single_tab",  true); // Need on_bottom
// user_pref("userChrome.tabbar.one_liner",                    true);
// user_pref("userChrome.tabbar.one_liner.combine_navbar",     true); // Need one_liner
// user_pref("userChrome.tabbar.one_liner.tabbar_first",       true); // Need one_liner
// user_pref("userChrome.tabbar.one_liner.responsive",         true); // Need one_liner

// user_pref("userChrome.tab.bottom_rounded_corner.all",       true);
// user_pref("userChrome.tab.bottom_rounded_corner.australis", true);
// user_pref("userChrome.tab.bottom_rounded_corner.edge",      true);
// user_pref("userChrome.tab.bottom_rounded_corner.chrome",    true);
// user_pref("userChrome.tab.bottom_rounded_corner.chrome_legacy", true);
// user_pref("userChrome.tab.bottom_rounded_corner.wave",      true);
// user_pref("userChrome.tab.always_show_tab_icon",            true);
// user_pref("userChrome.tab.close_button_at_pinned",          true);
// user_pref("userChrome.tab.close_button_at_pinned.always",   true);
// user_pref("userChrome.tab.close_button_at_pinned.background", true);
// user_pref("userChrome.tab.close_button_at_hover.always",    true); // Need close_button_at_hover
// user_pref("userChrome.tab.close_button_at_hover.with_selected", true);  // Need close_button_at_hover
// user_pref("userChrome.tab.sound_show_label",                true); // Need remove sound_hide_label
// user_pref("userChrome.tab.container.on_top",                true);
// user_pref("userChrome.tab.container.always_long",           true);
// user_pref("userChrome.tab.sound_with_favicons.on_center",   true);
// user_pref("userChrome.tab.selected_bold",                   true);

// user_pref("userChrome.navbar.as_sidebar",                   true);

// user_pref("userChrome.bookmarkbar.multi_row",               true);

// user_pref("userChrome.findbar.floating_on_top",             true);

// user_pref("userChrome.panel.remove_strip",                  true);
// user_pref("userChrome.panel.full_width_separator",          true);
// user_pref("userChrome.panel.full_width_padding",            true);

// user_pref("userChrome.sidebar.overlap",                     true);

// user_pref("userChrome.icon.disabled",                       true);
// user_pref("userChrome.icon.account_image_to_right",         true);
// user_pref("userChrome.icon.account_label_to_right",         true);
// user_pref("userChrome.icon.menu.full",                      true);
// user_pref("userChrome.icon.global_menu.mac",                true);

// -- User Content -------------------------------------------------------------
// user_pref("userContent.player.ui.twoline",                  true);

// user_pref("userContent.newTab.hidden_logo",                 true);
// user_pref("userContent.newTab.background_image",            true); // Need wallpaper image to `userContent.css`. :root { --uc-newTab-wallpaper: url("../icons/background_image.png"); }

// user_pref("userContent.page.proton_color.dark_blue_accent", true);
// user_pref("userContent.page.proton_color.system_accent",    true);
// user_pref("userContent.page.dark_mode.pdf",                 true);
// user_pref("userContent.page.monospace",                     true);

// == Theme Default Settings ===================================================
// -- User Chrome --------------------------------------------------------------
user_pref("userChrome.compatibility.theme",       true);
user_pref("userChrome.compatibility.os",          true);

user_pref("userChrome.theme.built_in_contrast",   true);
user_pref("userChrome.theme.system_default",      true);
user_pref("userChrome.theme.proton_color",        true);
user_pref("userChrome.theme.proton_chrome",       true); // Need proton_color
user_pref("userChrome.theme.fully_color",         true); // Need proton_color
user_pref("userChrome.theme.fully_dark",          true); // Need proton_color

user_pref("userChrome.decoration.cursor",         true);
user_pref("userChrome.decoration.field_border",   true);
user_pref("userChrome.decoration.download_panel", true);
user_pref("userChrome.decoration.animate",        true);

user_pref("userChrome.padding.tabbar_width",      true);
user_pref("userChrome.padding.tabbar_height",     true);
user_pref("userChrome.padding.toolbar_button",    true);
user_pref("userChrome.padding.navbar_width",      true);
user_pref("userChrome.padding.urlbar",            true);
user_pref("userChrome.padding.bookmarkbar",       true);
user_pref("userChrome.padding.infobar",           true);
user_pref("userChrome.padding.menu",              true);
user_pref("userChrome.padding.bookmark_menu",     true);
user_pref("userChrome.padding.global_menubar",    true);
user_pref("userChrome.padding.panel",             true);
user_pref("userChrome.padding.popup_panel",       true);

user_pref("userChrome.tab.multi_selected",        true);
user_pref("userChrome.tab.unloaded",              true);
user_pref("userChrome.tab.letters_cleary",        true);
user_pref("userChrome.tab.close_button_at_hover", true);
user_pref("userChrome.tab.sound_hide_label",      true);
user_pref("userChrome.tab.sound_with_favicons",   true);
user_pref("userChrome.tab.pip",                   true);
user_pref("userChrome.tab.container",             true);
user_pref("userChrome.tab.crashed",               true);

user_pref("userChrome.fullscreen.overlap",        true);
user_pref("userChrome.fullscreen.show_bookmarkbar", true);

user_pref("userChrome.icon.library",              true);
user_pref("userChrome.icon.panel",                true);
user_pref("userChrome.icon.menu",                 true);
user_pref("userChrome.icon.context_menu",         true);
user_pref("userChrome.icon.global_menu",          true);
user_pref("userChrome.icon.global_menubar",       true);
user_pref("userChrome.icon.1-25px_stroke",        true);

// -- User Content -------------------------------------------------------------
user_pref("userContent.player.ui",             true);
user_pref("userContent.player.icon",           true);
user_pref("userContent.player.noaudio",        true);
user_pref("userContent.player.size",           true);
user_pref("userContent.player.click_to_play",  true);
user_pref("userContent.player.animate",        true);

user_pref("userContent.newTab.full_icon",      true);
user_pref("userContent.newTab.animate",        true);
user_pref("userContent.newTab.pocket_to_last", true);
user_pref("userContent.newTab.searchbar",      true);

user_pref("userContent.page.field_border",     true);
user_pref("userContent.page.illustration",     true);
user_pref("userContent.page.proton_color",     true);
user_pref("userContent.page.dark_mode",        true); // Need proton_color
user_pref("userContent.page.proton",           true); // Need proton_color

// ** Useful Options ***********************************************************
// Tab preview
// https://blog.nightly.mozilla.org/2024/02/06/a-preview-of-tab-previews-these-weeks-in-firefox-issue-153/
user_pref("browser.tabs.hoverPreview.enabled", false);

// Paste suggestion at urlbar
// https://blog.nightly.mozilla.org/2023/12/04/url-gonna-want-to-check-this-out-these-weeks-in-firefox-issue-150/
user_pref("browser.urlbar.clipboard.featureGate", true);

// Integrated calculator at urlbar
// user_pref("browser.urlbar.suggest.calculator", true);

// Integrated unit convertor at urlbar
// user_pref("browser.urlbar.unitConversion.enabled", true);

// Draw in Titlebar
// user_pref("browser.tabs.drawInTitlebar", true);
// user_pref("browser.tabs.inTitlebar",        1); // Nightly, 96 Above

// Searchbar, Removed from settings starting with FF v122
// user_pref("browser.search.widget.inNavBar",    true);

// Firefox view search
// https://blog.nightly.mozilla.org/2023/12/14/better-searching-in-firefox-to-close-out-2023-these-weeks-in-firefox-issue-151/
// user_pref("browser.firefox-view.search.enabled",       true);
// user_pref("browser.firefox-view.virtual-list.enabled", true);

// Firefox screenshot
// https://blog.nightly.mozilla.org/2024/01/22/happy-new-year-these-weeks-in-firefox-issue-152/
// user_pref("screenshots.browser.component.enabled", true);

// ** Scrolling Settings *******************************************************
// == Only Sharpen Scrolling ===================================================
//         Pref                                             Value      Original
/*
user_pref("mousewheel.min_line_scroll_amount",                 10); //        5
user_pref("general.smoothScroll.mouseWheel.durationMinMS",     80); //       50
user_pref("general.smoothScroll.currentVelocityWeighting", "0.15"); //   "0.25"
user_pref("general.smoothScroll.stopDecelerationWeighting", "0.6"); //    "0.4"
*/

// == Smooth Scrolling ==========================================================
// ** Scrolling Options ********************************************************
// based on natural smooth scrolling v2 by aveyo
// this preset will reset couple extra variables for consistency
//         Pref                                              Value                 Original
/*
user_pref("apz.allow_zooming",                               true);            ///     true
user_pref("apz.force_disable_desktop_zooming_scrollbars",   false);            ///    false
user_pref("apz.paint_skipping.enabled",                      true);            ///     true
user_pref("apz.windows.use_direct_manipulation",             true);            ///     true
user_pref("dom.event.wheel-deltaMode-lines.always-disabled", true);            ///    false
user_pref("general.smoothScroll.currentVelocityWeighting", "0.12");            ///   "0.25" <- 1. If scroll too slow, set to "0.15"
user_pref("general.smoothScroll.durationToIntervalRatio",    1000);            ///      200
user_pref("general.smoothScroll.lines.durationMaxMS",         100);            ///      150
user_pref("general.smoothScroll.lines.durationMinMS",           0);            ///      150
user_pref("general.smoothScroll.mouseWheel.durationMaxMS",    100);            ///      200
user_pref("general.smoothScroll.mouseWheel.durationMinMS",      0);            ///       50
user_pref("general.smoothScroll.mouseWheel.migrationPercent", 100);            ///      100
user_pref("general.smoothScroll.msdPhysics.continuousMotionMaxDeltaMS", 12);   ///      120
user_pref("general.smoothScroll.msdPhysics.enabled",                  true);   ///    false
user_pref("general.smoothScroll.msdPhysics.motionBeginSpringConstant", 200);   ///     1250
user_pref("general.smoothScroll.msdPhysics.regularSpringConstant",     200);   ///     1000
user_pref("general.smoothScroll.msdPhysics.slowdownMinDeltaMS",         10);   ///       12
user_pref("general.smoothScroll.msdPhysics.slowdownMinDeltaRatio",  "1.20");   ///    "1.3"
user_pref("general.smoothScroll.msdPhysics.slowdownSpringConstant",   1000);   ///     2000
user_pref("general.smoothScroll.other.durationMaxMS",         100);            ///      150
user_pref("general.smoothScroll.other.durationMinMS",           0);            ///      150
user_pref("general.smoothScroll.pages.durationMaxMS",         100);            ///      150
user_pref("general.smoothScroll.pages.durationMinMS",           0);            ///      150
user_pref("general.smoothScroll.pixels.durationMaxMS",        100);            ///      150
user_pref("general.smoothScroll.pixels.durationMinMS",          0);            ///      150
user_pref("general.smoothScroll.scrollbars.durationMaxMS",    100);            ///      150
user_pref("general.smoothScroll.scrollbars.durationMinMS",      0);            ///      150
user_pref("general.smoothScroll.stopDecelerationWeighting", "0.6");            ///    "0.4"
user_pref("layers.async-pan-zoom.enabled",                   true);            ///     true
user_pref("layout.css.scroll-behavior.spring-constant",   "250.0");            ///   "250.0"
user_pref("mousewheel.acceleration.factor",                     3);            ///       10
user_pref("mousewheel.acceleration.start",                     -1);            ///       -1
user_pref("mousewheel.default.delta_multiplier_x",            100);            ///      100
user_pref("mousewheel.default.delta_multiplier_y",            100);            ///      100
user_pref("mousewheel.default.delta_multiplier_z",            100);            ///      100
user_pref("mousewheel.min_line_scroll_amount",                  0);            ///        5
user_pref("mousewheel.system_scroll_override.enabled",       true);            ///     true <- 2. If scroll too fast, set to false
user_pref("mousewheel.system_scroll_override_on_root_content.enabled", false); ///     true
user_pref("mousewheel.transaction.timeout",                  1500);            ///     1500
user_pref("toolkit.scrollbox.horizontalScrollDistance",         4);            ///        5
user_pref("toolkit.scrollbox.verticalScrollDistance",           3);            ///        3
*/

Additional context

Alternative implementation that might be better?
https://github.com/Aris-t2/CustomCSSforFx/blob/master/current/css/locationbar/megabar_expanding_breakout_disabled.css

Related fixes for megabar.
https://old.reddit.com/r/FirefoxCSS/comments/1h17vmy/megabar_breaks_css_when_typing_v133/
https://old.reddit.com/r/firefox/comments/1gkgk4o/firefox_developer_edition_address_bar_expanding/lvlyw06/
https://bugzilla.mozilla.org/show_bug.cgi?id=1921811

[mibby]

Maybe slightly related as well, #titlebar does not exist anymore and is used all over the .css.

[mid-kid]

Thanks! Fix 1 did it for me.