attr.diff

diff --git a/lib/Mojo/DOM/CSS.pm b/lib/Mojo/DOM/CSS.pm
index f5f94cc..3a1e857 100644
--- a/lib/Mojo/DOM/CSS.pm
+++ b/lib/Mojo/DOM/CSS.pm
@@ -41,14 +41,13 @@ sub _ancestor {
 }
 
 sub _attr {
-  my ($key, $regex, $current) = @_;
+  my ($name_re, $value_re, $current) = @_;
 
   # Ignore namespace prefix
   my $attrs = $current->[2];
-  for my $name (keys %$attrs) {
-    next unless $name =~ /(?:^|:)\Q$key\E$/;
-    return 1 unless defined $attrs->{$name} && defined $regex;
-    return 1 if $attrs->{$name} =~ $regex;
+  for my $name (grep { $_ =~ $name_re } keys %$attrs) {
+    return 1 unless defined $attrs->{$name} && defined $value_re;
+    return 1 if $attrs->{$name} =~ $value_re;
   }
 
   return undef;
@@ -96,7 +95,7 @@ sub _compile {
 
     # Tag
     push @$part, my $selector = [];
-    push @$selector, ['tag', qr/(?:^|:)\Q@{[_unescape($1)]}\E$/]
+    push @$selector, ['tag', _prefix($1)]
       if $element =~ s/^((?:\\\.|\\\#|[^.#])+)// && $1 ne '*';
 
     # Class or ID
@@ -106,11 +105,11 @@ sub _compile {
     }
 
     # Pseudo classes (":not" contains more selectors)
-    push @$selector, ['pc', "$1", $1 eq 'not' ? _compile($2) : _equation($2)]
+    push @$selector, ['pc', lc $1, $1 eq 'not' ? _compile($2) : _equation($2)]
       while $pc =~ /$PSEUDO_CLASS_RE/go;
 
     # Attributes
-    push @$selector, ['attr', _unescape($1), _regex($2 // '', $3 // $4)]
+    push @$selector, ['attr', _prefix($1), _regex($2 // '', $3 // $4)]
       while $attrs =~ /$ATTR_RE/go;
 
     # Combinator
@@ -199,6 +198,8 @@ sub _pc {
   return undef;
 }
 
+sub _prefix {qr/(?:^|:)\Q@{[_unescape(shift)]}\E$/}
+
 sub _regex {
   my ($op, $value) = @_;
   return undef unless defined $value;
@@ -249,9 +250,7 @@ sub _selector {
     elsif ($type eq 'attr') { return undef unless _attr(@$s[1, 2], $current) }
 
     # Pseudo class
-    elsif ($type eq 'pc') {
-      return undef unless _pc(lc $s->[1], $s->[2], $current);
-    }
+    elsif ($type eq 'pc') { return undef unless _pc(@$s[1, 2], $current) }
   }
 
   return 1;