scope.diff

diff --git a/lib/Mojo/DOM/CSS.pm b/lib/Mojo/DOM/CSS.pm
index 88de1dc..a6f2721 100644
--- a/lib/Mojo/DOM/CSS.pm
+++ b/lib/Mojo/DOM/CSS.pm
@@ -27,7 +27,9 @@ sub _ancestor {
   my ($selectors, $current, $tree, $one, $pos) = @_;
 
   while ($current = $current->[3]) {
-    return undef if $current->[0] eq 'root' || $current eq $tree;
+    return undef
+      if ($current->[0] eq 'root' || $current eq $tree)
+      && !_scope($selectors->[$pos]);
     return 1 if _combinator($selectors, $current, $tree, $pos);
     last if $one;
   }
@@ -54,7 +56,7 @@ sub _combinator {
   # Selector
   return undef unless my $c = $selectors->[$pos];
   if (ref $c) {
-    return undef unless _selector($c, $current);
+    return undef unless _selector($c, $current, $tree);
     return 1 unless $c = $selectors->[++$pos];
   }
 
@@ -82,8 +84,11 @@ sub _compile {
     # Separator
     if ($css =~ /\G\s*,\s*/gc) { push @$group, [] }
 
-    # Combinator
-    elsif ($css =~ /\G\s*([ >+~])\s*/gc) { push @$selectors, $1 }
+    # Combinator (and implicit ":scope")
+    elsif ($css =~ /\G\s*([ >+~])\s*/gc) {
+      push @$last, ['pc', 'scope'] unless @$last;
+      push @$selectors, $1;
+    }
 
     # Class or ID
     elsif ($css =~ /\G([.#])((?:$ESCAPE_RE\s|\\.|[^,.#:[ >~+])+)/gco) {
@@ -142,7 +147,10 @@ sub _match {
 sub _name {qr/(?:^|:)\Q@{[_unescape(shift)]}\E$/}
 
 sub _pc {
-  my ($class, $args, $current) = @_;
+  my ($class, $args, $current, $tree) = @_;
+
+  # ":scope"
+  return $current->[0] eq 'root' || $current eq $tree if $class eq 'scope';
 
   # ":empty"
   return !grep { !_empty($_) } @$current[4 .. $#$current] if $class eq 'empty';
@@ -186,6 +194,8 @@ sub _pc {
   return undef;
 }
 
+sub _scope { $_[0] && $_[0][0][0] eq 'pc' && $_[0][0][1] eq 'scope' }
+
 sub _select {
   my ($one, $tree, $group) = @_;
 
@@ -203,7 +213,7 @@ sub _select {
 }
 
 sub _selector {
-  my ($selector, $current) = @_;
+  my ($selector, $current, $tree) = @_;
 
   for my $s (@$selector) {
     my $type = $s->[0];
@@ -215,7 +225,9 @@ sub _selector {
     elsif ($type eq 'attr') { return undef unless _attr(@$s[1, 2], $current) }
 
     # Pseudo-class
-    elsif ($type eq 'pc') { return undef unless _pc(@$s[1, 2], $current) }
+    elsif ($type eq 'pc') {
+      return undef unless _pc(@$s[1, 2], $current, $tree);
+    }
   }
 
   return 1;
diff --git a/t/mojo/dom.t b/t/mojo/dom.t
index da76dee..b23dd17 100644
--- a/t/mojo/dom.t
+++ b/t/mojo/dom.t
@@ -1218,6 +1218,21 @@ is $dom->at('#♥ ~ #☃ ~ *:nth-last-child(1)')->text, 'G', 'right text';
 is $dom->at('#♥ + *:nth-last-child(2)')->text,        'F', 'right text';
 is $dom->at('#♥ ~ *:nth-last-child(2)')->text,        'F', 'right text';
 
+# Scoped selectors
+$dom = Mojo::DOM::->new(<<EOF);
+<div>
+  <p>One</p>
+  <p>Two</p>
+</div>
+<div>
+  <p>Three</p>
+  <p>Four</p>
+</div>
+EOF
+is $dom->at('div')->at(':scope > p')->text, 'One', 'right text';
+is $dom->at('p')->at(':scope + p')->text, 'Two', 'right text';
+is $dom->find('div')->last->at(':scope > p')->text, 'Three', 'right text';
+
 # Adding nodes
 $dom = Mojo::DOM->new(<<EOF);
 <ul>