1. Every page on the site can be navigated via the keyboard, without any need for a mouse.
2. The website features accesskeys (:::) that visitors can use to jump to the main sections of the site.
3. All images on the website are tagged with descriptive text.
4. Descriptive text pops up whenever the user hovers the cursor over a link, so that the user can see what links lead to without actually clicking into them.
1. Top block.
2. Main content.
3. Bottom block
1. Alt+U：Top block
2. Alt+C：Main content
3. Alt+Z：Bottom block
