[Functionality] Website Accessibility Improvements

## Problem
The current HTML and CSS code has several accessibility issues that can make it difficult for users with disabilities to navigate and use the website. Specifically, the code is missing ARIA attributes that define ways to make web content and web applications more accessible to people with disabilities.

Below is an audit showing some of the accessibility issues:

## Description
Add ARIA attributes: We can add ARIA attributes to HTML elements to provide a way for screen readers and other assistive technologies to interpret the content and interactive elements on the site.

## Alternatives
1. Use a CSS framework: We can use a CSS framework like Bootstrap or Tailwind CSS that has built-in accessibility features.
2. Use a accessibility tools: We can use a accessibility tools like Accessibility Checker or WAVE to identify and fix accessibility issues.

## Additional context
Improving accessibility is an ongoing process that requires regular testing and maintenance. We should regularly test the website for accessibility issues and make updates as needed.

## Implementation
- [x] I would be interested in implementing this feature.

Start by reviewing the website's HTML and CSS against the accessibility audit shown in the issue, then identify the specific elements needing ARIA attributes. There are no files or tests named in the issue. Done means the reported accessibility issues are addressed and the site is checked with an accessibility tool or screen reader.

Written by the indexing model from the issue text.