滚动页面时导航栏图片无法缩小的问题求助

我现在碰到个头疼的小问题：我想实现两个页面效果——一是滚动页面时，导航栏里的图片能跟着缩小；二是让.hidden-box类的元素滚动到可视区域时实现浮动显示。目前第二个效果是正常工作的，但导航栏的图片不管怎么滚动都完全没反应，就是不缩小，有没有大佬能帮我看看哪里出问题了😭

以下是我写的相关代码：

JavaScript 代码 #

"use strict";

document.addEventListener("DOMContentLoaded", () => {
  const observer = new IntersectionObserver((entries) => {
    entries.forEach((entry) => {
      if (entry.isIntersecting) {
        entry.target.classList.add("show");
      }
    });
  });

  document.querySelectorAll(".hidden-box").forEach((el) => observer.observe(el));

  let navbar = document.querySelector(".navbar");

  window.addEventListener("scroll", function() {
    if (window.scrollY > 50) {
      navbar.classList.add("shrink");
    } else {
      navbar.classList.remove("shrink");
    }
  });
});

CSS 代码 #

.navbar {
  background: white;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  border-bottom: 5px solid;
  border-image: linear-gradient(to right, var(--primary-red), var(--primary-blue)) 1;
  padding: 5px 0;
  transition: all 0.3s ease-in-out;
}

.navbar-brand img {
  width: 300px !important;
  height: auto;
  transition: width 0.3s ease-in-out !important;
}

.navbar.shrink .navbar-brand img {
  width: 200px !important;
}

HTML 代码 #

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.7.1/jquery.min.js"></script>
<script src="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.3/dist/css/bootstrap.min.css" />


<nav class="navbar navbar-expand-lg fixed-top" id="navbar">
  <div class="container">
    <a class="navbar-brand" href="#">
<img src="https://placehold.co/550x305?text=logo550x305.png" class="logo" id="logo" alt="Logo">
</a>
    <button class="navbar-toggler" type="button" data-bs-toggle="collapse" data-bs-target="#navbarNav">
<span class="navbar-toggler-icon"></span>
</button>
    <div class="collapse navbar-collapse" id="navbarNav">
      <ul class="navbar-nav ms-auto">
        <li class="nav-item"><a class="nav-link" href="#">item1</a></li>
        <li class="nav-item"><a class="nav-link" href="#">item2</a></li>
        <li class="nav-item"><a class="nav-link" href="#">item3</a></li>
        <li class="nav-item"><a class="nav-link" href="#">item4</a></li>
        <li class="nav-item"><a class="nav-link" href="">item5</a></li>
      </ul>
    </div>
  </div>
</nav>

备注：内容来源于stack exchange，提问作者Paul Dellert