Some sensible defaults for your img elements ^↗

img {  max-width: 100%;              /* [1] */  height: auto;                 /* [1] */  vertical-align: middle;       /* [2] */  font-style: italic;           /* [3] */  background-repeat: no-repeat; /* [4] */  background-size: cover;       /* [4] */  shape-margin: 0.75rem;        /* [5] */}

Harry notes that adding font-style: italic is to make alt text look different from regular text.