Angular 4 表单必填字段提示CSS

.ng-valid[required].ng-dirty:not(form),

.ng-valid.required.ng-dirty:not(form) {

    border-left: 5px solid #42A948;

}

.ng-valid[required].ng-pristine:not(form),

.ng-valid.required.ng-pristine:not(form) {

    border-left: 2px solid #EFC26E;

}

.ng-invalid[required].ng-pristine:not(form) {

    border-left: 2px solid #EFC26E;

}

.ng-invalid.ng-dirty:not(form) {

    border-left: 5px solid #a94442;

}