In This Life, The Greatest Star In The Universe - Chapter 43:

[Not Pursuing a Career, Just Falling in Love]

Lin Jianzhi was a crybaby with overactive tear ducts. She would cry when nervous, cry when happy, and cry even more when sad.

One day, the senior she had secretly loved for years stood in front of her and handed her a pack of tissues.

Zhu Lishen: “Can you stop crying?”

Lin Jianzhi wanted to explain herself but couldn’t stop sobbing uncontrollably.

Zhu Lishen was going crazy: “What exactly do you want? Do you want me?”

Lin Jianzhi was stunned for a moment before bursting into loud wails.

Zhu Lishen: “!!!”

A scientific genius named Thomas Harrier was transmigrated to an imperial prince body after a car accident that took his life. He found out that he is in a world similar to our own with a timeline akin to early twentieth century. The body that he is occupying was the imperial prince of a failing empire who suddenly rose to power after a successful assassination attempt of his father. Unaware that the attack is just the beginning of what is to come. He faces many challenges throughout. Will Thomas Harrier be able to live his second life in peace while running an empire and getting it back to its former glory? Or will he succumb into a conspiracy lurking within the country's borders?

Expect some:

Cold war era techs.

Super battleship with advanced electronics, propulsion, and fire control systems?
Helicopters?
Missiles?
Modern medicines and equipment?
AC-130?
A nuke?
Challenger or Abrams or Leopard?
F-4 Phantom or MIG-21?
Colored TV's.

Everything!!!

PS. Cover not mine, I just found it on google.

He died at twenty-two—bitter, brilliant, and broken. But death wasn’t the end.Now, Noel wakes up inside a tragic fantasy novel he read long ago... as a nameless extra doomed to die before chapter five. But there’s a catch—this “extra” isn’t ordinary.Armed with future knowledge, a sharp tongue, and a magic talent that defies common sense, Noel won’t just survive.He’ll rewrite the story.Because in this world?The real genius never had a name—until now.

In her previous life, she had misjudged people, mistaking enemies for kin. It wasn't until her body sank to the ocean floor that she had a sudden realization.Reborn seven years earlier, she grasped the Water-Repelling Pearl in hand, navigating unimpeded through lakes and oceans, ready to gather endless treasures. She vowed to carve out her own realm in the marine and collectibles industries.Before the conspiracies could even begin, she strategized every move. She would settle all past grievances—what was being a wealthy heiress? She would be the wealthiest of them all!