ade21ee4e0109c70e29860d5393306e48e6a44d3
lrnassar
  Mon Mar 16 16:38:58 2026 -0700
Adding keyboard navigation accessibility to the Genome Browser menu bar and all main CGI pages. Converts non-focusable menu bar span elements to keyboard-accessible buttons using the W3C disclosure navigation pattern, adds aria-expanded state for screen readers, skip navigation link, and main content landmark. Also adds a Keyboard Navigation section to the accessibility page with screenshots. refs #37252

diff --git src/hg/htdocs/accessibility.html src/hg/htdocs/accessibility.html
index b25dd6ffd9a..da8d10d8a43 100755
--- src/hg/htdocs/accessibility.html
+++ src/hg/htdocs/accessibility.html
@@ -1,67 +1,104 @@
 <!DOCTYPE html>
 <!--#set var="TITLE" value="Accessibility options in the UCSC Genome Browser" -->
 <!--#set var="ROOT" value="." -->
 
 <!-- Relative paths to support mirror sites with non-standard GB docs install -->
 <!--#include virtual="$ROOT/inc/gbPageStart.html" -->
 
 <h1>Accessibility options in the UCSC Genome Browser</h1>
 <p>
 This page provides information about accessibility options in the UCSC Genome Browser, including 
 internal configuration settings and third-party tools. While we are not affiliated with the external 
 tools listed, we offer them as helpful suggestions for improving accessibility. If you know of 
 additional resources that may benefit the community, please contact us at 
 genome-www@soe.ucsc.edu so we can consider including them.</p>
 
 <h2>Font and Font Sizes</h2>
 <p>
 <b>Fonts:</b> The Genome Browser supports various fonts that can facilitate reading and 
 interpretation of the tracks display. These include the <a target="_blank"
 href="https://opendyslexic.org/">OpenDyslexic</a> font designed by Abbie Gonzalez 
 to mitigate some of the common reading errors caused by dyslexia, and the 
 <a target="_blank" href="https://fonts.google.com/specimen/Atkinson+Hyperlegible">
 Atkinson Hyperlegible</a> font, designed by the 
 <a href="https://www.brailleinstitute.org/freefont/" target="_blank">Braille Institute</a>.</p>
 <p>
 The font can be configured anytime from the tracks display via the blue bar menu <b>Genome Browser </b>
 &gt <b>Configure</b>, the keyboard shortcuts <b>C + F</b>, or clicking the 
 <button type="button">Configure</button> button below the image.</p>
 
 <div class="text-center">
   <img src="images/howToChangeFont.gif" alt="GIF showing how to change
 Genome Browser fonts" width='50%'></div>
 
 <p>
 <b>Font sizes and tooltip sizes:</b> The font size and tooltip text size can also be changed in 
 the same configuration menu shown above. The tooltip text size is shown when you mouseover any 
 items.</p>
 
 <div class="text-center">
   <img src="images/increasedTooltipSize.png" alt="An example of a tooltip with increased
 text size" width='60%'></div>
 
+<h2>Keyboard Navigation</h2>
+<p>
+The Genome Browser supports keyboard navigation across all main pages, including the Gateway,
+Genome Browser tracks display, BLAT, Table Browser, and In-Silico PCR.</p>
+
+<p>
+<b>Skip to main content:</b> Press <b>Tab</b> once on any page to reveal a
+"Skip to main content" link. Press <b>Enter</b> to bypass the navigation menu and jump
+directly to the page content. This is especially helpful for users navigating with a keyboard
+or switch device.</p>
+
+<div class="text-center">
+  <img src="images/skipNavLink.png" alt="The 'Skip to main content' link appearing at the
+top left of the page when focused via keyboard" width='40%'></div>
+
+<p>
+<b>Menu bar navigation:</b> All items in the top navigation menu bar are accessible by
+keyboard. Press <b>Tab</b> to move through menu items. Dropdown menus (such as Tools,
+Downloads, Help) open automatically when their parent item receives focus. Press
+<b>Enter</b> to follow a link or <b>Escape</b> to close an open dropdown and return
+to the menu bar.</p>
+
+<div class="text-center">
+  <img src="images/keyboardMenuNav.png" alt="The Tools dropdown menu open via keyboard
+focus, showing a white focus ring around the Tools button" width='40%'></div>
+
+<p>
+<b>Screen reader landmarks:</b> Each page is structured with a <em>navigation</em> landmark
+for the menu bar and a <em>main</em> landmark for the page content. Screen reader users can
+use landmark navigation to jump between these regions (e.g., the <b>D</b> key in NVDA or
+the rotor in VoiceOver).</p>
+
+<p>
+<b>Keyboard shortcuts:</b> In addition to standard Tab navigation, the Genome Browser
+tracks display supports keyboard shortcuts for common actions. Press <b>?</b> on the
+tracks page to see available shortcuts.</p>
+
 <h2>Display and Color</h2>
 <p>
 <b>Inverted colors and high contrast display:</b> We recommend using native OS tools for color 
 display options on the Genome Browser. Below is an example of our tracks display using 
 the "Inverted Colors Mode" as outlined by the <a target="_blank"
 href="https://www.a11yproject.com/posts/operating-system-and-browser-accessibility-display-modes/#inverted-colors-mode"
 >Operating System and Browser Accessibility Display Modes</a> page on the <a target="_blank"
 href="https://www.a11yproject.com/">A11Y Project</a> website. High contrast 
 and Filtered colors mode may also be helpful.</p>
 
 <div class="text-center">
   <img src="images/browserInvertedColors.png" alt="An example of the Browser tracks display
 with inverted image colors" width='60%'></div>
 
 <p>
 <b>Visual Snow Syndrome (VSS):</b> Some users have found the <a target="_blank"
 href="https://github.com/belvederef/visual-snow-relief-overlay">Visual Snow Relief Overlay</a> 
 tool useful in reducing symptoms of the visual snow condition. The tool creates a static noise 
 overlay that allows users to interact with the windows and controls underneath the overlay. 
 However, please note the <a target="_blank" 
 href="https://github.com/belvederef/visual-snow-relief-overlay/blob/main/DISCLAIMER.md">
 Medical Disclaimer</a> regarding the use of this tool.</p>
 
 
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