github-redesign-fixes.user.css

/* ==UserStyle==
@name           Github redesign fixes
@namespace      github.com/openstyles/stylus
@version        2.0.0
@description    Fixes various issues with Github's redesign
@author         LunarTwilight
@updateURL      https://gist.github.com/LunarTwilight/44c05e0a7d6163ec3266e0283aec1e8c/raw/github-redesign-fixes.user.css
@preprocessor   less
@var            color background "Readme header background color" #f1f8ff
@var            color border "Readme header border color" #e6e4e4
@var            text paddingRegular "Amount of padding used on the header on regular pages" 66.5px
@var            text paddingFullWidth "Amount of padding used on the header on full width pages" 32px
@var            checkbox readme "Enable giving the readme header a background" 1
==/UserStyle== */
@-moz-document domain("github.com") {
/* Make header not full width */
.padding(@amount) {
    .AppHeader > div {
        padding-left: @amount;
        padding-right: @amount;
    }
}
body:not(.notifications-v2) {
    &:not(.full-width) {
        .padding(@paddingRegular);
    }
    &.full-width {
        .padding(@paddingFullWidth);
    }
}

/*
    - Readme header background
    - Make the bottom of the readme not have extra padding
*/
#readme {
    > div:first-child when (@readme = 1) {
        background-color: @background !important;
        border-bottom: 1px solid @border !important;
    }
    > div:last-child {
        padding-bottom: 8px !important;
    }
}
}

Thanks for this, it's the best one I've been able to find so far. I forked it and added several changes which improve the alignment a bit and also align the header when you're logged in. Feel free to use them or not, as you like. https://gist.github.com/afontenot/212cfb0e7f8eb90bac683509b6a0c68d

@afontenot Ah thanks, kinda surprised that people other than just me use it heh. I looked at your changes and incorporated the change for resizing the header to match the page content width. The header(s?) are a bit wider than the page content for gists, but I think that if I were to make them smaller I might run into issues with the username + gist title length.