Here are some code snippets to help you change the look of your size chart.
You can put them in your theme.liquid file.
<style> /* change the font and border style of the whole table */ .scr-modal table td { font-family: Arial; border: 1px solid black; } /* make the first row black with white, centered text */ .scr-modal table tr:first-child td { background: black; color: white; text-align: center; } /* give the rows after the first row a white background and center the text */ .scr-modal table tr:nth-child(n+2) td { background: white; text-align: center; } </style>