SVG inner shadow
by nilloc
HTML
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" width="500" height="600">
<defs>
<filter id="innershadow" x0="-50%" y0="-50%" width="200%" height="200%">
<feGaussianBlur in="SourceAlpha" stdDeviation="2" result="blur"></feGaussianBlur>
<feOffset dy="-2" dx="0"></feOffset>
<feComposite in2="SourceAlpha" operator="arithmetic" k2="-1" k3="1" result="shadowDiff"></feComposite>
<feFlood flood-color="#000000" flood-opacity="0.5"></feFlood>
<feComposite in2="shadowDiff" operator="in"></feComposite>
<feComposite in2="SourceGraphic" operator="over" result="firstfilter"></feComposite>
<!-- <feGaussianBlur in="firstfilter" stdDeviation="3" result="blur2"></feGaussianBlur>
<feOffset dy="-2" dx="0"></feOffset>
<feComposite in2="firstfilter" operator="arithmetic" k2="-1" k3="1" result="shadowDiff"></feComposite> -->
<!-- <feFlood flood-color="#FFFFFF" flood-opacity="0.5"></feFlood>
<feComposite in2="shadowDiff" operator="in"></feComposite>
<feComposite in2="firstfilter" operator="over"></feComposite> -->
</filter>
</defs>
<circle cx="300" cy="200" r="40" filter="url(#innershadow)" fill="orange"></circle>
<!-- <path d="M200 260L280 260L400 290L250 320e" stroke-width="10" stroke="#cccccc" stroke-linecap="round" stroke-linejoin="round" fill="none" filter="url(#innershadow)"></path> -->
<circle cx="300" cy="400" r="40" fill="tan"></circle>
</svg>