[css-cascade] Update WHATWG links

Author: fantasai

css-cascade-3/Overview.bs

@@ -119,11 +119,11 @@ Importing Style Sheets: the ''@import'' rule</h2>
 Content-Type of CSS Style Sheets</h3>
 
 	The processing of imported style sheets depends on the actual type of the linked resource.
-	If the resource does not have <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type metadata</a>,
-	or the host document is in <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#quirks-mode">quirks mode</a>
-	and has the <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/origin-0.html#same-origin">same origin</a> as the imported style sheet,
+	If the resource does not have <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#content-type">Content-Type metadata</a>,
+	or the host document is in <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#quirks-mode">quirks mode</a>
+	and has the <a href="https://html.spec.whatwg.org/multipage/browsers.html#same-origin">same origin</a> as the imported style sheet,
 	the type of the linked resource is <code>text/css</code>.
-	Otherwise, the type is determined from its <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type metadata</a>.
+	Otherwise, the type is determined from its <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#content-type">Content-Type metadata</a>.
 
 	If the linked resource's type is <code>text/css</code>,
 	it must be interpreted as a CSS style sheet.

css-cascade/Overview.bs

@@ -187,11 +187,11 @@ Processing Stylesheet Imports</h3>
 Content-Type of CSS Style Sheets</h3>
 
 	The processing of imported style sheets depends on the actual type of the linked resource.
-	If the resource does not have <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type metadata</a>,
-	or the host document is in <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/infrastructure.html#quirks-mode">quirks mode</a>
-	and has the <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/origin-0.html#same-origin">same origin</a> as the imported style sheet,
+	If the resource does not have <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#content-type">Content-Type metadata</a>,
+	or the host document is in <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#quirks-mode">quirks mode</a>
+	and has the <a href="https://html.spec.whatwg.org/multipage/browsers.html#same-origin">same origin</a> as the imported style sheet,
 	the type of the linked resource is <code>text/css</code>.
-	Otherwise, the type is determined from its <a href="http://www.whatwg.org/specs/web-apps/current-work/multipage/fetching-resources.html#content-type">Content-Type metadata</a>.
+	Otherwise, the type is determined from its <a href="https://html.spec.whatwg.org/multipage/infrastructure.html#content-type">Content-Type metadata</a>.
 
 	If the linked resource's type is <code>text/css</code>,
 	it must be interpreted as a CSS style sheet.