移动端视网膜（Retina）屏幕下如何解决网页中1px显示问题？

<code class="language-css"><span class="nc">.item</span> <span class="p">{</span>
    <span class="k">position</span><span class="o">:</span> <span class="k">relative</span><span class="p">;</span>
<span class="p">}</span>
<span class="nc">.item</span><span class="nd">:after</span> <span class="p">{</span>
    <span class="k">content</span><span class="o">:</span> <span class="s1">''</span><span class="p">;</span>
    <span class="k">display</span><span class="o">:</span> <span class="k">block</span><span class="p">;</span>
    <span class="k">position</span><span class="o">:</span> <span class="k">absolute</span><span class="p">;</span>
    <span class="k">width</span><span class="o">:</span> <span class="m">100%</span><span class="p">;</span>
    <span class="k">left</span><span class="o">:</span> <span class="m">0</span><span class="p">;</span>
    <span class="k">bottom</span><span class="o">:</span> <span class="m">0</span><span class="p">;</span>
    <span class="k">height</span><span class="o">:</span> <span class="m">1px</span><span class="p">;</span>
    <span class="k">background-color</span><span class="o">:</span> <span class="m">#c8c7cc</span><span class="p">;</span>
    <span class="o">-</span><span class="n">webkit</span><span class="o">-</span><span class="n">transform</span><span class="o">:</span> <span class="n">scaleY</span><span class="p">(</span><span class="m">0</span><span class="o">.</span><span class="m">5</span><span class="p">);</span>
    <span class="n">transform</span><span class="o">:</span> <span class="n">scaleY</span><span class="p">(</span><span class="m">0</span><span class="o">.</span><span class="m">5</span><span class="p">);</span>
<span class="p">}</span>
</code>

• background-image (border-image)
• scale(0.5)
• box-shadow