How to remove inline CSS in head?

Sydney automatically generates inline CSS inside the <head> tag, eg:

<style id='sydney-style-inline-css' type='text/css'>
.site-header { position:relative;background-color:rgba(0,0,0,0.9);}
.admin-bar .site-header,.admin-bar .site-header.float-header { top:0;}
.site-header.fixed {position:relative;}
.site-header.float-header {padding:20px 0;}
.site-title { font-size:32px; }
.site-description { font-size:16px; }
#mainnav ul li a { font-size:14px; }
h1 { font-size:52px; }
h2 { font-size:42px; }
h3 { font-size:32px; }
h4 { font-size:25px; }
h5 { font-size:20px; }
h6 { font-size:18px; }
body { font-size:14px; }
.header-image { background-size:cover;}
.header-image { height:300px; }
.site-header.float-header { background-color:rgba(0,0,0,0.9);}
.site-title a, .site-title a:hover { color:#ffffff}
.site-description { color:#ffffff}
#mainnav ul li a, #mainnav ul li::before { color:#ffffff}
#mainnav .sub-menu li a { color:#ffffff}
#mainnav .sub-menu li a { background:#1c1c1c}
.text-slider .maintitle, .text-slider .subtitle { color:#ffffff}
body { color:#767676}
#secondary { background-color:#ffffff}
#secondary, #secondary a, #secondary .widget-title { color:#767676}
.footer-widgets { background-color:#252525}
.site-footer { background-color:#1c1c1c}
.site-footer,.site-footer a { color:#666666}
.overlay { background-color:#000000}

</style>

I don’t want that there; I want my theme to respect the styles I have set in style.css, not override them.

How do I prevent Sydney from generating that code block? (Slapping “!important” all over my CSS file is a stopgap, but I’m looking for a real solution.)

Every style generated there comes from a theme option, so you could basically just use those options. They’re there to make it easier for users who don’t know CSS. To disable them you can go to functions.php, search for styles.php and delete that line.

I understand the utility of providing style options to users who are not CSS-savvy; however, I don’t understand how it makes sense to put those changes directly into the header of each individual page instead of the CSS file. (Even if they’re per-page styles – and I stress that I have not actually made any per-page styles – those can be handled by naming a page and then, again, defining its specific styles in the CSS file along with everything else.)

I’ve built a child theme and don’t want to have to modify functions.php every time I update Sydney. What’s the best solution here? Sydney’s functions.php gets called automatically by the child theme; is there a way to override that?