input boxes
            function createPinInputs(length) {
                pinContainer.innerHTML = '';
                pinDigits = [];
                
                for (let i = 0; i < length; i++) {
                    const input = document.createElement('input');
                    input.type = 'password';
                    input.className = 'pin-digit';
                    input.maxLength = 1;
                    input.pattern = '[0-9]';
                    input.inputMode = 'numeric';
          