Update dashboard theme to match app.py styling

[Abs-Futy7]

This pull request updates the custom CSS and UI styling for the dashboard page in dashboard_page.py to better match the application's main theme and provide a more consistent, visually appealing user experience. The changes focus on harmonizing colors, typography, and component styles, as well as improving the layout and appearance of various UI elements such as buttons, cards, metrics, tables, and notification boxes.

UI/UX Theme Alignment and Enhancements:

• Updated the custom CSS to align the dashboard page’s theme with app.py, including background colors, typography, and font weights for headings and body text. This includes expanding the use of the 'Raleway' font and refining color schemes for headings, text, and backgrounds.
• Enhanced the appearance and consistency of buttons (sidebar, global, and secondary), including hover and disabled states, with improved color contrast and sizing for better accessibility and visual clarity. [1] [2] [3]

Component-Specific Styling Improvements:

• Refined metric cards, server status cards, chart containers, tables, and dataframes with updated colors, borders, padding, and shadows to create a cleaner and more modern look.
• Improved notification and information boxes (info, success, error, warning) with solid background colors and border accents for better visibility and consistency.

Layout and Section Updates:

• Changed the "System Server Status" section from a collapsed expander to a prominent section header using custom HTML for better visibility and alignment with other dashboard sections.