JButton S1L1Reset = new JButton("Reset");
    S1L1Reset.setFont(new Font("Work Sans", Font.PLAIN, 14));
    S1L1Reset.setForeground(new Color(90, 90, 90));
    S1L1Reset.setBackground(new Color(220, 208, 192));
    S1L1Reset.setOpaque(true);

class RoundedBorder implements Border {

     private int radius;

     RoundedBorder(int radius) {
        this.radius = radius;
     }

    public Insets getBorderInsets(Component c) {
        return new Insets(this.radius+1, this.radius+1, this.radius+2, this.radius);
    }

    public boolean isBorderOpaque() {
        return true;
    }

    public void paintBorder(Component c, Graphics g, int x, int y, int width, int height) {
        g.drawRoundRect(x, y, width-1, height-1, radius, radius);
    }
}

JButton S1L1Reset = new JButton("Reset");
    S1L1Reset.setFont(new Font("Work Sans", Font.PLAIN, 14));
    S1L1Reset.setForeground(new Color(90, 90, 90));
    S1L1Reset.setBackground(new Color(220, 208, 192));
    S1L1Reset.setOpaque(true);
    S1L1Reset.setBorderPainted(false);
    S1L1Reset.setBorder(new RoundedBorder(20)); //new line of code added