WordPress 500 Error Recovery and make it normal as it was earlier

Cost: 600 inr fixed price and 5 star ratings
Time: 5 to 7 hrs today only
My WordPress site on a shared-hosting plan has suddenly thrown a 500 Internal Server Error and the front-end design is completely broken. I did not install new plugins, switch themes, or run any updates right before this happened, so the cause is still unknown.

I can give you full access to the hosting control panel, database, and error logs. I need you to:

• Identify the root cause of the 500 error using the logs and any other diagnostic tools you prefer.
• Restore the site so every page loads correctly and the layout, styling, and functionality return to exactly how they looked and worked before the crash.
• Verify that the admin dashboard is stable and free of hidden issues once the fix is applied.
• Provide a brief summary of what was wrong and the steps you took, so I can avoid the same problem in the future.

The job is complete once the site is publicly accessible, displays normally on desktop and mobile, and no related errors appear in the server logs.