利用伪元素和scale缩放，例如border：

.btn{
	position: relative;
	
	&::before {
		content: " ";
			position: absolute;
			top: 0;
			left: 0;
			width: 200%;
			height: 200%;
			border: 1px solid #d4a965;
			border-radius: 80rpx;
			transform-origin: 0 0;
			transform: scale(0.5);
		}
}

注：scale缩放时会将间距也缩放