diff --git a/cssselect/xpath.py b/cssselect/xpath.py
index 8ef5d7c..ab6694d 100644
--- a/cssselect/xpath.py
+++ b/cssselect/xpath.py
@@ -872,10 +872,10 @@ class HTMLTranslator(GenericTranslator):
 
     Has a more useful implementation of some pseudo-classes based on
     HTML-specific element names and attribute names, as described in
-    the `HTML5 specification`_. It assumes no-quirks mode.
+    the `HTML specification`_. It assumes no-quirks mode.
     The API is the same as :class:`GenericTranslator`.
 
-    .. _HTML5 specification: http://www.w3.org/TR/html5/links.html#selectors
+    .. _HTML specification: https://html.spec.whatwg.org/multipage/semantics-other.html#pseudo-classes
 
     :param xhtml:
         If false (the default), element names and attribute names
@@ -925,62 +925,67 @@ def xpath_link_pseudo(self, xpath: XPathExpr) -> XPathExpr:
     # Links are never visited, the implementation for :visited is the same
     # as in GenericTranslator
 
+    # An element is a descendant of a disabled fieldset ancestor unless it is
+    # a descendant of that fieldset's own first legend element child. lxml's
+    # XPath evaluator has no generate-id() or current(), so the exemption is
+    # tested by checking whether any ancestor legend is also the first legend
+    # child of a disabled ancestor fieldset; with several nested disabled
+    # fieldsets this can exempt an element that a fully spec-accurate
+    # algorithm would still treat as disabled.
+    _disabled_by_fieldset = (
+        "ancestor::fieldset[@disabled] and not("
+        "count(ancestor::legend | ancestor::fieldset[@disabled]/legend[1]) < "
+        "count(ancestor::legend) + count(ancestor::fieldset[@disabled]/legend[1])"
+        ")"
+    )
+
     def xpath_disabled_pseudo(self, xpath: XPathExpr) -> XPathExpr:
-        # http://www.w3.org/TR/html5/section-index.html#attributes-1
+        # https://html.spec.whatwg.org/multipage/semantics-other.html#concept-element-disabled
         return xpath.add_condition(
-            """
+            f"""
         (
             @disabled and
             (
-                (name(.) = 'input' and @type != 'hidden') or
+                name(.) = 'input' or
                 name(.) = 'button' or
                 name(.) = 'select' or
                 name(.) = 'textarea' or
-                name(.) = 'command' or
                 name(.) = 'fieldset' or
                 name(.) = 'optgroup' or
                 name(.) = 'option'
             )
         ) or (
             (
-                (name(.) = 'input' and @type != 'hidden') or
+                name(.) = 'input' or
                 name(.) = 'button' or
                 name(.) = 'select' or
                 name(.) = 'textarea'
             )
-            and ancestor::fieldset[@disabled]
+            and {self._disabled_by_fieldset}
+        ) or (
+            name(.) = 'option' and ancestor::optgroup[@disabled]
         )
         """
         )
-        # FIXME: in the second half, add "and is not a descendant of that
-        # fieldset element's first legend element child, if any."
 
     def xpath_enabled_pseudo(self, xpath: XPathExpr) -> XPathExpr:
-        # http://www.w3.org/TR/html5/section-index.html#attributes-1
+        # https://html.spec.whatwg.org/multipage/semantics-other.html#concept-element-disabled
         return xpath.add_condition(
-            """
+            f"""
         (
-            @href and (
-                name(.) = 'a' or
-                name(.) = 'link' or
-                name(.) = 'area'
-            )
-        ) or (
             (
-                name(.) = 'command' or
                 name(.) = 'fieldset' or
                 name(.) = 'optgroup'
             )
             and not(@disabled)
         ) or (
             (
-                (name(.) = 'input' and @type != 'hidden') or
+                name(.) = 'input' or
                 name(.) = 'button' or
                 name(.) = 'select' or
-                name(.) = 'textarea' or
-                name(.) = 'keygen'
+                name(.) = 'textarea'
             )
-            and not (@disabled or ancestor::fieldset[@disabled])
+            and not(@disabled) and not({self._disabled_by_fieldset})
         ) or (
             name(.) = 'option' and not(
                 @disabled or ancestor::optgroup[@disabled]
@@ -988,9 +993,3 @@ def xpath_enabled_pseudo(self, xpath: XPathExpr) -> XPathExpr:
         )
         """
         )
-        # FIXME: ... or "li elements that are children of menu elements,
-        # and that have a child element that defines a command, if the first
-        # such element's Disabled State facet is false (not disabled)".
-        # FIXME: after ancestor::fieldset[@disabled], add "and is not a
-        # descendant of that fieldset element's first legend element child,
-        # if any."
diff --git a/tests/test_cssselect.py b/tests/test_cssselect.py
index 8e1b2a7..ad38586 100644
--- a/tests/test_cssselect.py
+++ b/tests/test_cssselect.py
@@ -1393,7 +1393,11 @@ def pcss(main: str, *selectors: str, **kwargs: bool) -> list[str]:
 
         assert pcss("span:only-child") == ["foobar-span"]
         assert pcss("li div:only-child") == ["li-div"]
-        assert pcss("div *:only-child") == ["li-div", "foobar-span"]
+        assert pcss("div *:only-child") == [
+            "li-div",
+            "checkbox-legend-enabled",
+            "foobar-span",
+        ]
         # The root element has no siblings, so it matches :only-child
         # (just like :first-child and :last-child)
         assert pcss("html:only-child") == ["html"]
@@ -1444,7 +1448,8 @@ def pcss(main: str, *selectors: str, **kwargs: bool) -> list[str]:
             "first-li",
             "li-div",
             "p-b",
-            "checkbox-fieldset-disabled",
+            "legend",
+            "checkbox-legend-enabled",
             "area-href",
         ]
         assert pcss("a[href]") == ["tag-anchor", "nofollow-anchor"]
@@ -1536,19 +1541,19 @@ def pcss(main: str, *selectors: str, **kwargs: bool) -> list[str]:
         ]
         assert pcss(":visited", html_only=True) == []
         assert pcss(":enabled", html_only=True) == [
-            "link-href",
-            "tag-anchor",
-            "nofollow-anchor",
             "checkbox-unchecked",
             "text-checked",
+            "hidden-unchecked",
             "checkbox-checked",
-            "area-href",
+            "checkbox-legend-enabled",
         ]
         assert pcss(":disabled", html_only=True) == [
             "checkbox-disabled",
+            "hidden-disabled",
             "checkbox-disabled-checked",
             "fieldset",
             "checkbox-fieldset-disabled",
+            "hidden-fieldset-disabled",
         ]
         assert pcss(":checked", html_only=True) == [
             "checkbox-checked",
@@ -1727,14 +1732,15 @@ def count(selector: str) -> int:
    <input type="checkbox" id="checkbox-unchecked" />
    <input type="checkbox" id="checkbox-disabled" disabled="" />
    <input type="text" id="text-checked" checked="checked" />
-   <input type="hidden" />
-   <input type="hidden" disabled="disabled" />
+   <input type="hidden" id="hidden-unchecked" />
+   <input type="hidden" id="hidden-disabled" disabled="disabled" />
    <input type="checkbox" id="checkbox-checked" checked="checked" />
    <input type="checkbox" id="checkbox-disabled-checked"
           disabled="disabled" checked="checked" />
    <fieldset id="fieldset" disabled="disabled">
+     <legend id="legend"><input type="checkbox" id="checkbox-legend-enabled" /></legend>
      <input type="checkbox" id="checkbox-fieldset-disabled" />
-     <input type="hidden" />
+     <input type="hidden" id="hidden-fieldset-disabled" />
    </fieldset>
  </p>
  <ol id="second-ol">