Remove the <style> tags around your <link> tag.
The <style> tag is used to define style information for an HTML document as known as CSS.Inside the <style> element you specify how HTML elements should render in a browser by writing CSS.
In a <style> your write pure CSS. You can't link your stylesheet inside a <style> tag.
You should end up with this:
<!DOCTYPE html><html><head><title>Christian Potts' Virtual Resume</title><link rel="stylesheet" type="text/css" href="style.css" /></head><body><h1>Hello World</h1></body></html>