Replaced the `applyDeepSeaTheme` function in `main.js` to apply a cohesive DeepSea theme, including extensive CSS variable definitions for UI elements.
In `theme.js`, updated styles to ensure visibility of pool hashrate text, enhanced button hover effects, and added direct DOM manipulation for consistent styling.
These changes improve the overall visual consistency and user experience of the application.
Introduces a responsive theme toggle button with styles for desktop and mobile views in `theme-toggle.css`. Updates `BitcoinProgressBar.js` to support dynamic theme changes and adds a new `updateTheme` method. Enhances `main.js` for theme management based on user preferences in `localStorage`. Modifies `base.html` and other HTML files to include the theme toggle button and necessary scripts. Introduces `theme.js` for managing theme constants and applying the DeepSea theme.