Logo size fine, but mobile gets eggshape

I did a logo-size modification thanks to advice in a previous thread. That included a line that skipped the tagline. This code was entered in style.css.

#branding img {
	width: 420px;
	height: 140px;
}

#site-title {
    width: 100%;
}

#site-description {
    display: none;
}

Works fine for normal browsers (IE, Chrome etc) but looking in mobile it gets distorted. Here’s how it look in iPhone. First the eggshape (portrait mode, 1st link) then ok in landscape mode (2nd link). iPad is 100% ok.

https://volvop1800club.se/00WP/tempImage/bild1.PNG

https://volvop1800club.se/00WP/tempImage/bild2.PNG

Any possibility to fix this? I am using a child theme.

Site prototype is here: https://volvop1800club.se/00WP/