Hello Rifaldi Adrian,
Do you want that the date picker look exactly as the one on the attached image? If yes there is a lot of work in CSS to do, but is possible.
If you want just to change the CSS from the current day, you can use this code:
.is-today .pika-button {
background-color: transparent;
border: var(--border-size-s) dashed var(--color-red);
border-radius: var(--border-radius-circle);
}
Check this link to see the result:
https://personal-gxzlvs5j.outsystemscloud.com/DatepickerTest/
Hope it helps,
Nuno Rodrigues