How can I extend or overwrite component decorators in Angular Material 2? - angular-material2

Question

I am nesting a <mat-nav-list> inside of a <mat-expansion-panel> component. At runtime, Angular Material 2 is creating html, in my specific case:
<div class="mat-expansion-panel-body">...</div>
Which also is getting styles assigned to it. I am unable to overwrite these styles using the component style sheet like I normally would.
Looking through the source, I am seeing this:
/node_modules/#angular/material/esm2015/expansion.js
MatExpansionPanel.decorators = [
{ type: Component, args: [{styles: [".mat-expansion-panel{transition:box-shadow 280ms cubic-bezier(.4,0,.2,1);box-sizing:content-box;display:block;margin:0;transition:margin 225ms cubic-bezier(.4,0,.2,1)}.mat-expansion-panel:not([class*=mat-elevation-z]){box-shadow:0 3px 1px -2px rgba(0,0,0,.2),0 2px 2px 0 rgba(0,0,0,.14),0 1px 5px 0 rgba(0,0,0,.12)}.mat-expansion-panel-content{overflow:hidden}.mat-expansion-panel-body{margin:0 24px 16px;overflow:auto}
...
I'm sure this isn't the exact code that is creating the component, but it does contain the css I would like to override:
...
.mat-expansion-panel-body{margin:0 24px 16px;overflow:auto}
...
How can I modify the decorator to remove the margin?
Here is what my .ts file looks like so far:
#Component({
selector: 'my-selector',
templateUrl: './my-selector.component.html',
styleUrls: ['./my-selector.component.scss']
})
export class MyComponent implements OnInit, OnDestroy {...}
Thank you for any suggestions!

Answer 1

I wish I could take credit for the solution that seems to work, but here is a thread with a similar problem.
I was able to remove the margin like this:
my-template.component.html
<mat-expansion-panel *ngFor="let foo of bar" class="my-sidenav">
<mat-expansion-panel-header>
...
</mat-expansion-panel-header>
<mat-nav-list>
<mat-list-item>...</mat-list-item>
</mat-nav-list>
</mat-expansion-panel>
my-component.component.scss
/deep/ .my-sidenav {
.mat-expansion-panel-body {
margin: 0;
}
}