img max-width: 100% breaks Google Maps

Most of us set a global max-width for responsive images, like so:

img {
    max-width: 100%;
}

However, this breaks the images in Google Maps, such as the Info Window shadow and StreetView icon.

Either don't set all images globally, or reset Maps images using a custom container:

#map img {
    max-width: none;
}