CSS将顶部菜单项移动到汉堡菜单，以实现较小的屏幕尺寸，而不会复制项目

<div class="navbar">
  <div class="logo">Logo</div>
  <input type="checkbox" id="toggle">
  <label for="toggle" class="toggle-btn">
    <span></span>
    <span></span>
    <span></span>
  </label>
  <ul class="menu">
    <li><a href="#">菜单项1</a></li>
    <li><a href="#">菜单项2</a></li>
    <li><a href="#">菜单项3</a></li>
    <li><a href="#">菜单项4</a></li>
  </ul>
</div>

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px;
}

.logo {
  font-size: 20px;
  font-weight: bold;
}

.toggle-btn {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 20px;
  cursor: pointer;
}

.toggle-btn span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: #000;
}

.menu {
  display: flex;
  list-style: none;
}

.menu li {
  margin-right: 10px;
}

.menu li a {
  text-decoration: none;
  color: #000;
}

/* 媒体查询 */
@media screen and (max-width: 768px) {
  .toggle-btn {
    display: flex;
  }
  
  .menu {
    display: none;
    flex-direction: column;
    align-items: center;
    margin-top: 10px;
  }
  
  .menu li {
    margin: 10px 0;
  }
  
  /* 通过伪类选择器来控制菜单的显示与隐藏 */
  #toggle:checked ~ .menu {
    display: flex;
  }
}