Unnecessary property conflict error(s?).

```scss
// grid.block.scss
:scope {
width: 1128px;
box-sizing: content-box;
padding: 0 30px;
display: block;
margin: auto;
position: relative;
}
```

```scss
// header.block.scss
.content {
display: flex;
display: resolve("grid"); // Feels like this should be resolved by the cascade when using composes, but acceptable for now.
height: 100%;
}

.content[width="fixed"] {
composes: grid;
}

.content[width="full"] {
margin: resolve("grid"); // is exclusive with .content[width="fixed"] so there's not a conflict.
margin: 0 item-spacing(6);
}
```