<style>
polygon{
animation: strokeDefaultPoly 3s linear infinite alternate;
}
@keyframes strokeDefaultPoly {
0% {
stroke-dasharray: 0 50;
}
100% {
stroke-dasharray: 500;
}
}
</style>
<svg width="64" height="73">
<defs>
<linearGradient id="linear" x1="0%" y1="0%" x2="0%" y2="100%">
<stop offset="0%" stop-color="#ddd"/>
<stop offset="50%" stop-color="rgba(8,68,158,0)"/>
<stop offset="80%" stop-color="rgba(6,81,191,1)"/>
<stop offset="100%" stop-color="rgba(0,108,255,0.35)"/>
</linearGradient>
<linearGradient id="linear1" x1="0%" y1="0%" x2="0%" y2="100%">
<stop offset="0%" stop-color="#03ffea"/>
<stop offset="100%" stop-color="#00CEFF"/>
</linearGradient>
</defs>
<polygon fill="url(#linear)" points="30,1 60,17 60,52 30,69 1,52 1,17" stroke="url(#linear1)" stroke-width="2" />
</svg>
image.png
放射性渐变：
<svg height="80" style="position: absolute; left: 6px; top: 7px;">
<defs>
<radialGradient id="greyer1" cx="50%" cy="50%" r="50%" fx="50%" fy="50%">
<stop offset="0%" style="stop-color:#000000; stop-opacity:0"/>
<stop offset="100%" style="stop-color:#2B89A7; stop-opacity:1"/>
</radialGradient>
</defs>
<polygon fill="url(#greyer1)" points="30,1 60,17 60,52 30,69 1,52 1,17" stroke="#00BFF0" stroke-width="2" style="transform: scale(0.9);"/>
</svg>
实现了效果：
image.png
