从中删除底部边框
   
    <button>
   
   元素:
  
  <button class="⦠group-hover:border-b-0">
  
   为添加不透明的背景颜色
   
    <按钮>
   
   元素。这将隐藏子菜单顶部边框的部分:
  
  <button class="⦠bg-[steelblue]">
  
   确保
   
    <按钮>
   
   元素堆叠在子菜单的顶部:
  
  <button class="⦠relative z-20">
  
   将子菜单元素向上移动一个像素,使顶部边框被上述内容隐藏
   
    <按钮>
   
   元素:
  
  <ul class="⦠-translate-y-px">
  
   删除左上角圆角,使左边缘看起来更无缝:
  
  <ul class="⦠rounded-tl-none">
  
  
  
   
    tailwind.config = {
  theme: {
    extend: {
      colors: {
        cream: 'Moccasin',
        darkgray: 'darkgray',
        darkred: 'darkred',
      },
    },
    screens: {
      '950px': '1px',
    },
  },
};
    body {
  background-color: steelblue;
}
    <script src="https://cdn.tailwindcss.com/3.4.16"></script>
<nav id="menu" class="hidden 950px:flex space-x-6 text-sm">
  <a href="\welcome" class="p-1 hover:text-cream">HOME</a>
  <!-- Shop Dropdown -->
  <div class="relative group">
    <button class="flex items-center p-1 hover:text-cream group-hover:text-cream group-hover:border group-hover:border-b-0 bg-[steelblue] relative z-20">
      SHOP
      <svg xmlns="http://www.w3.org/2000/svg" class="ml-1 w-4 h-4" viewBox="0 0 20 20" fill="white">
        <path fill-rule="evenodd" d="M5.23 7.21a.75.75 0 011.06 0L10 10.92l3.71-3.71a.75.75 0 111.06 1.06l-4 4a.75.75 0 01-1.06 0l-4-4a.75.75 0 010-1.06z" clip-rule="evenodd" />
      </svg>
    </button>
    <ul class="z-10 absolute bg-darkgray border duration-300 group-hover:opacity-100 group-hover:visible invisible left-0 mt-1 opacity-0 py-2 rounded shadow-lg text-white top-[25px] transition w-[215px] -translate-y-px rounded-tl-none">
      <li><a href="\sculptures" class="block px-4 py-2 hover:bg-darkred">CHESS COLLECTION</a></li>
      <li><a href="#" class="block px-4 py-2 hover:bg-darkred">SCULPTURE COLLECTION</a></li>
    </ul>
  </div>
  <!-- Process Dropdown -->
  <div class="relative group">
    <button class="flex items-center p-1 hover:text-cream group-hover:text-cream group-hover:border group-hover:border-b-0 bg-[steelblue] relative z-20">
      PROCESS
      <svg xmlns="http://www.w3.org/2000/svg" class="ml-1 w-4 h-4" viewBox="0 0 20 20" fill="white">
        <path fill-rule="evenodd" d="M5.23 7.21a.75.75 0 011.06 0L10 10.92l3.71-3.71a.75.75 0 111.06 1.06l-4 4a.75.75 0 01-1.06 0l-4-4a.75.75 0 010-1.06z" clip-rule="evenodd" />
      </svg>
    </button>
    <ul class="z-10 absolute bg-darkgray border duration-300 group-hover:opacity-100 group-hover:visible invisible left-0 mt-1 opacity-0 py-2 rounded shadow-lg text-white top-[25px] transition w-[255px] -translate-y-px rounded-tl-none">
      <li><a href="\process" class="block px-4 py-2 hover:bg-darkred">THE PROCESS</a></li>
      <li><a href="\deconstruction" class="block px-4 py-2 hover:bg-darkred">DECONSTRUCTION & SOURCING</a></li>
    </ul>
  </div>
  <a href="#" class="p-1 hover:text-cream">RETAIL</a>
  <a href="#" class="p-1 hover:text-cream">CONTACT US</a>
</nav>