---
id: 5d822fd413a79914d39e98fe
title: Step 54
challengeType: 0
dashedName: step-54
---
# --description--
Add these properties to `.bb2a`:
```css
margin: auto;
width: 5vw;
height: 5vw;
border-top: 1vw solid #000;
border-bottom: 1vw solid #000;
border-left: 1vw solid #999;
border-right: 1vw solid #999;
```
After you add these, you can see how a thick border on an element gives you some angles where two sides meet. You are going to use that bottom border as the top of the building.
# --hints--
You should give `.bb2a` a `margin` of `auto`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.margin, "auto");
```
You should give `.bb2a` a `width` of `auto`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.width, "5vw");
```
You should give `.bb2a` a `height` of `5vw`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.height, "5vw");
```
You should give `.bb2a` a `border-top` of `1vw solid #000`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.borderTop, "1vw solid rgb(0, 0, 0)");
```
You should give `.bb2a` a `border-bottom` of `1vw solid #000`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.borderBottom, "1vw solid rgb(0, 0, 0)");
```
You should give `.bb2a` a `border-left` of `1vw solid #999`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.borderLeft, "1vw solid rgb(153, 153, 153)");
```
You should give `.bb2a` a `border-right` of `1vw solid #999`.
```js
assert.equal(new __helpers.CSSHelp(document).getStyle('.bb2a')?.borderRight, "1vw solid rgb(153, 153, 153)");
```
# --seed--
## --seed-contents--
```html