Night Mode

<svg
    xmlns="http://www.w3.org/2000/svg"
    width="512"
    height="512"
    viewBox="0 0 512 512"
>
    <linearGradient
        id="a"
        x1="256"
        x2="256"
        y1="512"
        y2="0"
        gradientUnits="userSpaceOnUse"
    >
        <stop offset="0" stop-color="#a93aff" />
        <stop offset="1" stop-color="#ff81ff" />
    </linearGradient>
    <linearGradient
        id="b"
        x1="249.716"
        x2="249.716"
        y1="452"
        y2="60"
        gradientUnits="userSpaceOnUse"
    >
        <stop offset="0" stop-color="#ffbef9" />
        <stop offset="1" stop-color="#fff1ff" />
    </linearGradient>
    <path
        fill="url(#a)"
        d="M361 0H151c-24.814 0-45 20.186-45 45v422c0 24.814 20.186 45 45 45h210c24.814 0 45-20.186 45-45V45c0-24.814-20.186-45-45-45z"
    />
    <path
        fill="url(#b)"
        d="M211 90h90c8.291 0 15-6.709 15-15s-6.709-15-15-15h-90c-8.291 0-15 6.709-15 15s6.709 15 15 15zm101.616 178.656c-18.911 7.939-41.602-7.09-41.616-27.656.015-20.537 22.705-35.581 41.616-27.656 6.035 2.563 13.154.835 17.373-4.277a14.983 14.983 0 0 0 .923-17.871C314.14 166.029 286.146 151 256 151c-49.629 0-90 40.371-90 90s40.371 90 90 90c30.146 0 58.14-15.029 74.912-40.195a14.983 14.983 0 0 0-.923-17.871c-4.233-5.113-11.323-6.841-17.373-4.278zM271 422h-30c-8.291 0-15 6.709-15 15s6.709 15 15 15h30c8.291 0 15-6.709 15-15s-6.709-15-15-15z"
    />
</svg>