CSS-0.5px 边框
<div class="border">hello world</div>
.border { width: 150px; height: 40px; border-radius: 4px; text-align: center; line-height: 40px; color: deepskyblue; position: relative; } .border::after { content: ''; display: block; width: 200%; height: 200%; border: 1px solid deepskyblue; transform: scale(0.5); position: absolute; left: 0; top: 0; transform-origin: 0 0; }
效果: