@syncfusion/ej2-inputs/styles/signature/bootstrap4.css

A package of Essential JS 2 input components such as Textbox, Color-picker, Masked-textbox, Numeric-textbox, Slider, Upload, and Form-validator that is used to get input from the users.

.e-signature.e-control {
  border: 1px solid;
}

.e-signature.e-control {
  background-color: #fff;
  border: 1px solid;
  border-color: #dee2e6;
}