Set Square

<svg
    xmlns="http://www.w3.org/2000/svg"
    width="682.667"
    height="682.667"
    viewBox="0 0 682.667 682.667"
>
    <defs>
        <linearGradient
            id="b"
            x1="0"
            x2="1"
            y1="0"
            y2="0"
            gradientTransform="matrix(512 0 0 512 -108.666 590.667)"
            gradientUnits="userSpaceOnUse"
            spreadMethod="pad"
        >
            <stop offset="0" stop-opacity="1" stop-color="#80d8ff" />
            <stop offset="1" stop-opacity="1" stop-color="#ea80fc" />
        </linearGradient>
        <clipPath id="a" clipPathUnits="userSpaceOnUse">
            <path d="M0 512h512V0H0Z" />
        </clipPath>
    </defs>
    <g clip-path="url(#a)" transform="matrix(1.33333 0 0 -1.33333 0 682.667)">
        <path
            d="M0 0v-226h226Zm-10 157.333L383.333-236v-78.667h-472v472z"
            transform="translate(108.666 334.667)"
            fill="none"
            stroke="url(#b)"
            stroke-width="40"
            stroke-linecap="round"
            stroke-linejoin="round"
            stroke-miterlimit="10"
            stroke-dasharray="none"
            stroke-opacity="1"
        />
    </g>
</svg>