grid.svg.htm

<svg height="400" viewBox="0 0 400 400" width="400">
    <defs>
        <pattern id="grid20" width="20" height="20" patternUnits="userSpaceOnUse">
            <path d="M 20 0 L 0 0 0 20" fill="none" stroke="gray" stroke-width="1"></path>
        </pattern>
    </defs>
    <rect fill="white" height="800" width="800" y="0"></rect>
    <rect fill="url(#grid20)" height="800" width="800" y="0"></rect>
    <g transform="translate(0,0) scale(1, 1)">
        <line class="l1 s-black " x1="-200" x2="800" y1="200" y2="200"></line>
        <line class="l1 s-black " stroke="black" x1="200" x2="200" y1="-200" y2="800"></line>
    </g>
    <g transform="translate(200, 200) scale(1,-1)">
        <text class="t36 t-mid bold f-black" x="50" y="50">+ +</text>
        <text class="t36 t-mid bold f-black" x="-50" y="50">- +</text>
        <text class="t36 t-mid bold f-black" x="50" y="-50">+ -</text>
        <text class="t36 t-mid bold f-black" x="-50" y="-50">- -</text>
    </g>
</svg>