.mat-stepper-vertical styles change code example
Example: mat-stepper-horizontal-line color change
:host ::ng-deep .last-edited-step-1 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(1)::after,
:host ::ng-deep .last-edited-step-1 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::before,
:host ::ng-deep .last-edited-step-2 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(1)::after,
:host ::ng-deep .last-edited-step-2 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::before,
:host ::ng-deep .last-edited-step-2 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::after,
:host ::ng-deep .last-edited-step-2 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::before,
:host ::ng-deep .last-edited-step-3 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(1)::after,
:host ::ng-deep .last-edited-step-3 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::before,
:host ::ng-deep .last-edited-step-3 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::after,
:host ::ng-deep .last-edited-step-3 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::before,
:host ::ng-deep .last-edited-step-3 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::after,
:host ::ng-deep .last-edited-step-3 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(7)::before,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(1)::after,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::before,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::after,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::before,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::after,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(7)::before,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(7)::after,
:host ::ng-deep .last-edited-step-4 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(9)::before,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(1)::after,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::before,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(3)::after,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::before,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(5)::after,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(7)::before,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(7)::after,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(9)::before,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(11)::after,
:host ::ng-deep .last-edited-step-5 .mat-horizontal-stepper-header-container .mat-step-header:nth-child(13)::before{
border-top-color: #008583!important;
}