Issue #3405576 by kostyashupenko, penyaskito, ankithashetty, shweta__sharma, javi-er: Table drag elements create horizontal scroll on mobile

Issue #3338483 by Gauravvv, Guru2023: Claro: Update -webkit-border-horizontal-spacing with border-spacing

Issue #3223268 by javi-er, dhirendra.mishra, mherchel: Olivero: IE11 primary menu submenus have horizontal scrollbar when submenu item has focus

Issue #3192656 by katannshaw, mherchel, adityasingh, kostyashupenko, ankithashetty, djsagar, BhumikaVarshney, Abhijith S: Text inputs can create horizontal scrolling at narrow viewports in Olivero

Issue #3033734 by dww, pawandubey, MEENA BISHT, Maithri Shetty, Rangaswini, kostyashupenko, priyanka.sahni, pratik_kamble, Vivek Panicker, Indrajith KB, Sivaji, xjm, idebr, bnjmnm, alexpott: Horizontal scrollbar on /admin/modules

Issue #2998748 by MaddieC, lauriii, markconroy, kjay: Horizontal Scrolling when screensize hits 960px

Issue #2749475 by thpoul, Wim Leers, maskedjellybean, Orizontal, bohemier: Duplicate labels for Styles dropdown causes Styles to not render: add validation to prevent this

Issue #2424805 by mdrummond, YesCT, vijaycs85, xjm, marcoscano, ifrik, joelpittet, Jelle_S, attiks, lauriii: Toolbar can no longer switch horizontal and vertical -- expects breakpoints ordered from smallest to largest; responsive images need largest to smallest

Issue #1973456 by echoz: Fixed .element-invisible on element at right causes horizontal scrollbar on desktop or right gap on phone on webkit browsers.

- #100668: Remove gap between textarea and grippie, in Safari.

- Improvement: fixed wrapping in code samples in user module so that admin help doesn't have a huge horizontal scrollbar.  Patch #13 by Al.

Patch by Michael:

admin.css:

* Removed border-bottom for menu list items. The only work around to retain
the border-bottom on lists with nested items is to use divs rather than li
tags as far as I know. I think the list items are still readable this way.
* Made title of site in sidenav more differentiated from menu.
* Made color changes so that all headings are the same hue (navy bluish).
* Modified th text-align: left; for better readability. Modified
border-bottom: 1px solid #ccc; Black addded visual noise.
* Modified tr.dark background-color: #ddd, tr.light background-color: #fff;
* Changed all colors to #xxx three number hex shortcuts.
* Added hr rule to make horizontal rules have height: 1px; color: #ccc;

admin.php:

* Added 1 line to admin.php to include <link rel="stylesheet" ...>. The
stylesheet refers to a misc/print.css stylesheet which may not exist in your
misc/ directory. This fixes the flash of unstyled content that users of Win
IE 5+ are experiencing. You can use this to specify print styles if you
like. See more about this here: http://www.bluerobot.com/web/css/fouc.asp