Как зафиксировать элемент Header в React

Если делать position: sticky, мой дочерний элемент с именем класса .blot с стилем position: absolute, постоянно работает

repository: https://github.com/halowddyep/42cups

JS:

import styles from "./Navbar.module.css";
import { NavLink } from "react-router-dom";
import logo from "../../assets/images/logo.jpg";
import blot from "../../assets/images/blot.png";
import bag from "../../assets/images/bag.png";
import { useAppSelector } from "../../hooks/hooks";

const Navbar: React.FC = () => {
  const sum = useAppSelector((state) => state.items.sum);
  const numberOfProducts = useAppSelector(
    (state) => state.items.numberOfProducts
  );


  return (
    <header className={styles.header}>
      <NavLink to="/" className={styles.logoBlock}>
        <img
          src={logo}
          height="80px"
          width="80px"
          className={styles.logo}
          alt="logo"
        ></img>
      </NavLink>
      <div className={styles.navigationBlock}>
        <NavLink to="/assortment" className={styles.navItem}>
          <p>Ассортимент</p>
          <img
            className={styles.blot}
            src={blot}
            height="100%"
            width="100%"
            alt="blot"
          ></img>
        </NavLink>
        <NavLink to="/franchise" className={styles.navItem}>
          <p>Франшиза</p>
          <img
            className={styles.blot}
            src={blot}
            height="100%"
            width="100%"
            alt="blot"
          ></img>
        </NavLink>
        <NavLink to="/company" className={styles.navItem}>
          <p>О компании</p>
          <img
            className={styles.blot}
            src={blot}
            height="100%"
            width="100%"
            alt="blot"
          ></img>
        </NavLink>
        <NavLink to="/contact" className={styles.navItem}>
          <p>Контакты</p>
          <img
            className={styles.blot}
            src={blot}
            height="100%"
            width="100%"
            alt="blot"
          ></img>
        </NavLink>
      </div>
      <NavLink to="/cart" className={styles.cartBlock}>
        <img src={bag} width="30px" height="30px" alt="bag"></img>
        <div className={styles.info}>
          {sum} ₽ <br></br>
          {numberOfProducts} товаров
        </div>
      </NavLink>
    </header>
  );
};

export default Navbar;

CSS:

.header {
  font-family: "Trebuchet-MS", sans-serif;
  display: flex;
  width: 100%;
  height: 100px;
  background-color: #fff;
  color: #000;
  font-weight: 600;
  box-shadow: 0 14px 19px rgb(0 0 0 / 20%);
  /* position: sticky; */
  top: 0;
}

.logoBlock {
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 20%;
  height: 100%;
}

.logoBlock .logo {
  display: flex;
  align-items: center;
  justify-content: center;
}

.navigationBlock {
  display: flex;
  width: 60%;
  height: 100%;
}

.navItem {
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 25%;
  height: 100%;
  color: #000;
  position: relative;
}

.navItem p {
  z-index: 2;
}

.navItem:hover {
  color: #fff;
}

.navItem:hover .blot {
  z-index: 1;
}

.cartBlock {
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 20%;
  height: 100%;
  color: #000;
}

.header a {
  text-decoration: none;
}

.blot {
  position: absolute;
  z-index: -1;
}

.info {
  margin-left: 10px;
  font-weight: 400;
}