Hi Corrado Di Blasio,
Thank you for reaching out to us!
To customize the border color of the textbox when it receives focus, please refer to the CSS styles provided below. These styles target the appropriate elements to achieve the desired effect:
.e-float-input:not(.e-input-group) .e-float-line::before, .e-float-input:not(.e-input-group) .e-float-line::after ,
.e-float-input.e-input-group:not(.e-float-icon-left).e-input-focus .e-float-line::before,
.e-float-input.e-control-wrapper.e-input-group:not(.e-float-icon-left) .e-float-line::after {
background: blue;
}
Sample: https://stackblitz.com/edit/angular-isbmyj-zstqnudp?file=src%2Fapp.component.html,src%2Fapp.component.css,package.json,src%2Findex.html
We appreciate your feedback and would like to inform you that we will be updating our documentation accordingly. The correction will be reflected in one of our upcoming releases.
Please feel free to reach out if you have any further questions or need additional assistance.
Regards,
Priyanka K