AuthorizedVault.sol

// SPDX-License-Identifier: MIT

pragma solidity ^0.8.0;
import "@openzeppelin/contracts/utils/math/SafeMath.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";

contract AuthorizedVault is ReentrancyGuard {
    using SafeMath for uint256;
    uint256 public fee;
    mapping(address => uint256) public balance;

    function deposit() external payable {
        uint256 depositFee = msg.value / 100;
        balance[msg.sender] += msg.value - depositFee;
        fee += depositFee;
    }

    function withdraw(uint256 amount) external {
        require(balance[msg.sender] >= amount, "Account balance is not enough");
        balance[msg.sender] -= amount;

        (bool success, ) = msg.sender.call{value: amount}("");
        require(success, "Transfer failed.");
    }

    function withdrawFee() external {
        (bool success, ) = msg.sender.call{value: fee}("");
        require(success, "Transfer failed.");
        fee = 0;
    }
}