diff --git a/tools/chatgui/src/code_language.cpp b/tools/chatgui/src/code_language.cpp
index 914d6ff09..ef516d2e1 100644
--- a/tools/chatgui/src/code_language.cpp
+++ b/tools/chatgui/src/code_language.cpp
@@ -14,7 +14,9 @@ struct Rule {
 
 // Каждый признак учитывается один раз: повторение общего слова не повышает уверенность.
 const Rule rules[] = {
-    {C, 3, QRegularExpression(R"(^\s*#\s*include\s*[<][\w/]+\.h[>])", QRegularExpression::MultilineOption)},
+    {C, 3, QRegularExpression(R"(^\s*#\s*include[ \t]+)", QRegularExpression::MultilineOption)},
+    {C, 2, QRegularExpression(R"(^\s*#\s*(?:define|ifdef|ifndef)\s+\w+)", QRegularExpression::MultilineOption)},
+    {C, 2, QRegularExpression(R"(\bunsigned\s+(?:(?:long|int|char)\s+)?\w+\s*[;=])")},
     {C, 4, QRegularExpression(R"(\b(?:void|int|char|double|float|size_t)\s+\**\s*\w+\s*\([^;{}]*\)\s*\{)")},
     {C, 2, QRegularExpression(R"(\b(?:typedef\s+(?:struct|enum)|malloc\s*\(|calloc\s*\(|sizeof\s*\())")},
     {C, 2, QRegularExpression(R"(\b(?:const\s+)?(?:char|void|int)\s*\*+\s*\w+)")},
@@ -23,30 +25,32 @@ const Rule rules[] = {
                                QRegularExpression::MultilineOption)},
     {Cpp, 6, QRegularExpression(R"(\btemplate\s*<|\bnamespace\s+[\w:]+\s*\{)")},
     {Cpp, 4, QRegularExpression(R"(\b(?:class|struct)\s+\w+(?:\s*:\s*[^\n{]+)?\s*\{)")},
-    {Cpp, 3, QRegularExpression(R"(\b(?:public|private|protected)\s*:|\b\w+::~?\w+\s*\()")} ,
+    {Cpp, 3, QRegularExpression(R"(\b(?:public|private|protected)\s*:|\b\w+::~?\w+\s*\()")},
     {Java, 3, QRegularExpression(R"(^\s*(?:package|import)\s+(?:static\s+)?[\w.*]+\s*;)", QRegularExpression::MultilineOption)},
     {Java, 4, QRegularExpression(R"(\b(?:public|protected|private)\s+(?:(?:static|final|abstract)\s+)*(?:class|interface|enum)\s+\w+)")},
-    {Java, 5, QRegularExpression(R"(\b(?:public|protected|private)\s+(?:(?:static|final|synchronized)\s+)*(?:void|boolean|String|int|long)\s+\w+\s*\()")} ,
+    {Java, 5, QRegularExpression(R"(\b(?:public|protected|private)\s+(?:(?:static|final|synchronized)\s+)*)"
+                                R"((?:void|boolean|String|int|long)\s+\w+\s*\()")},
     {Java, 4, QRegularExpression(R"(\b(?:implements|extends)\s+[A-Z]\w*|\bSystem\.(?:out|err)\.)")},
-    {Kotlin, 6, QRegularExpression(R"(\bfun\s+(?:<[^>\n]+>\s*)?[\w.]+\s*\()")} ,
+    {Kotlin, 6, QRegularExpression(R"(\bfun\s+(?:<[^>\n]+>\s*)?[\w.]+\s*\()")},
     {Kotlin, 3, QRegularExpression(R"(^\s*(?:(?:private|public|internal|override|const)\s+)*(?:val|var)\s+\w+\s*[:=])",
                                   QRegularExpression::MultilineOption)},
     {Kotlin, 5, QRegularExpression(R"(\b(?:data\s+class|sealed\s+class|companion\s+object)\b|\bwhen\s*\([^\n]*\)\s*\{)")},
-    {Rust, 7, QRegularExpression(R"(\bfn\s+\w+\s*(?:<[^>\n]+>)?\s*\()")} ,
-    {Rust, 5, QRegularExpression(R"(^\s*(?:pub(?:\([^)]*\))?\s+)?(?:use\s+[\w:]+|impl(?:\s*<[^>\n]+>)?\s+\w+))",
+    {Rust, 7, QRegularExpression(R"(\bfn\s+\w+\s*(?:<[^>\n]+>)?\s*\()")},
+    {Rust, 7, QRegularExpression(R"(^\s*(?:pub(?:\([^)]*\))?\s+)?(?:use\s+[\w:]+\s*(?:;|::|\{)|impl(?:\s*<[^>\n]+>)?\s+\w+))",
                                 QRegularExpression::MultilineOption)},
-    {Rust, 3, QRegularExpression(R"(\blet\s+mut\s+|\b(?:println|vec|assert_eq|format)!\s*[(\[]|#\[derive\s*\()")} ,
+    {Rust, 3, QRegularExpression(R"(\blet\s+mut\s+|\b(?:println|vec|assert_eq|format)!\s*[(\[]|#\[derive\s*\()")},
     {Php, 4, QRegularExpression(R"(\$[a-zA-Z_]\w*\s*(?:->|\[|=))")},
     {Php, 4, QRegularExpression(R"(\bfunction\s+\w+\s*\([^\n)]*\$|\b(?:public|private|protected)\s+(?:static\s+)?function\b)")},
     {Php, 3, QRegularExpression(R"(\b(?:echo|require_once|include_once)\b|\barray\s*\(|\$this\b)")},
     {JavaScript, 4, QRegularExpression(R"(\b(?:const|let|var)\s+[a-zA-Z_$][\w$]*\s*=)")},
-    {JavaScript, 3, QRegularExpression(R"(=>|\bfunction\s*[\w$]*\s*\()")} ,
+    {JavaScript, 3, QRegularExpression(R"(=>|\bfunction\s*[\w$]*\s*\()")},
     {JavaScript, 4, QRegularExpression(R"(\b(?:module\.exports|exports\.\w+|console\.\w+|document\.\w+)\b)")},
     {JavaScript, 4, QRegularExpression(R"(^\s*(?:export\s+(?:default|function|const|class)\b|import\s+[^;\n]+\s+from\b))",
                                       QRegularExpression::MultilineOption)},
     {Css, 3, QRegularExpression(R"((?:^|[}\n])\s*[.#]?[\w*-][\w\s.#:>+~,*\[\]="'-]*\s*\{)")},
     {Css, 4, QRegularExpression(R"((?:^|[;{\n])\s*(?:color|background(?:-color)?|font(?:-size|-family|-weight)?|display|position)\s*:[^;{}\n]+;)")},
-    {Css, 4, QRegularExpression(R"((?:^|[;{\n])\s*(?:margin(?:-\w+)?|padding(?:-\w+)?|border(?:-\w+)?|width|height|opacity|align-items)\s*:[^;{}\n]+;)")},
+    {Css, 4, QRegularExpression(R"((?:^|[;{\n])\s*(?:margin(?:-\w+)?|padding(?:-\w+)?|border(?:-\w+)?|width|height|opacity|align-items))"
+                               R"(\s*:[^;{}\n]+;)")},
 };
 }
 
@@ -73,7 +77,9 @@ QString detectCodeLanguage(QStringView source) {
     // Фрагменты HTML без doctype: нужен парный известный тег; JSX с объявлениями JS не выбираем как HTML.
     static const QRegularExpression tags(R"(<(div|span|p|a|ul|li|table|section|form|button|h[1-6])\b[^<>]*>[\s\S]*?</\1\s*>)",
                                         QRegularExpression::CaseInsensitiveOption);
-    if (scores[JavaScript] == 0 && tags.match(code).hasMatch()) scores[Html] = 7;
+    if (scores[JavaScript] == 0 && tags.match(code).hasMatch()) { scores[Html] = 7; scores[Css] = 0; }
+    // std:: и Type::method встречаются также в Rust; use/fn/impl отличают его от C++.
+    if (scores[Rust] >= 7) scores[Cpp] = 0;
     // C является подмножеством C++: специфичные конструкции C++ имеют приоритет.
     if (scores[Cpp] >= 6) scores[C] = 0;
     int best = 0, second = 0;
diff --git a/tools/chatgui/tests/test_code_language.cpp b/tools/chatgui/tests/test_code_language.cpp
index 030ab8f91..df8601ad5 100644
--- a/tools/chatgui/tests/test_code_language.cpp
+++ b/tools/chatgui/tests/test_code_language.cpp
@@ -20,12 +20,15 @@ private slots:
         QTest::newRow("java") << "package example;\npublic class Hello { public static void main(String[] args) {} }" << "Java";
         QTest::newRow("kotlin") << "fun main() { println(\"hello\") }" << "Kotlin";
         QTest::newRow("rust") << "fn main() { println!(\"hello\"); }" << "Rust";
+        QTest::newRow("rust-std") << "use std::{borrow::Cow, collections::BTreeSet};" << "Rust";
+        QTest::newRow("c-macros") << "#include \"local.h\"\n#define COUNT 4\nunsigned long value;" << "C";
         QTest::newRow("php") << "<?php\necho 'hello';" << "PHP/PHP";
         QTest::newRow("php-fragment") << "function hello($name) { $message = $name; return $message; }" << "PHP/PHP";
         QTest::newRow("javascript") << "const greet = (name) => console.log(name);" << "JavaScript";
         QTest::newRow("css") << ".hello { color: red; margin: 1px; }" << "CSS";
         QTest::newRow("html") << "<!doctype html>\n<html><script>const f = () => 1;</script></html>" << "HTML";
         QTest::newRow("html-fragment") << "<div class=\"hello\"><span>Hello</span></div>" << "HTML";
+        QTest::newRow("html-css") << "<style>.x { color: red; margin: 1px; }</style><p>Hello</p>" << "HTML";
         QTest::newRow("empty") << "" << "";
         QTest::newRow("ambiguous") << "int x = 42;" << "";
         QTest::newRow("prose") << "Java and Kotlin have class and function declarations; use CSS for color." << "";
@@ -54,7 +57,7 @@ private slots:
             const auto bytes = source.readAll();
             QCOMPARE(QString::fromLatin1(QCryptographicHash::hash(bytes, QCryptographicHash::Sha256).toHex()), entry["sha256"].toString());
             const QString text = QString::fromUtf8(bytes), expected = entry["language"].toString();
-            const auto check = [&](const QString& code, const char* kind, Counts& counts) {
+            const auto check = [&](const QString& code, const QString& expected, const char* kind, Counts& counts) {
                 const QString actual = detectCodeLanguage(code);
                 if (actual == expected) ++counts.correct;
                 else if (actual.isEmpty()) ++counts.unknown;
@@ -62,11 +65,15 @@ private slots:
                 GUI_INFO("corpus: file=%s kind=%s expected=%s actual=%s", qPrintable(path), kind,
                          qPrintable(expected), actual.isEmpty() ? "unknown" : qPrintable(actual));
             };
-            check(text, "full", full);
+            check(text, expected, "full", full);
             const auto lines = text.split('\n');
             // Фиксированные окна, не выбираемые по результату: начало, середина, конец по 20 строк.
-            for (int start : {0, qMax(0, int(lines.size()) / 2 - 10), qMax(0, int(lines.size()) - 20)})
-                check(lines.mid(start, 20).join('\n'), "snippet", snippets);
+            int window = 0;
+            const auto labels = entry["snippets"].toArray();
+            for (int start : {0, qMax(0, int(lines.size()) / 2 - 10), qMax(0, int(lines.size()) - 20)}) {
+                const QString label = labels.isEmpty() ? expected : labels[window].toString();
+                check(lines.mid(start, 20).join('\n'), label, "snippet", snippets); ++window;
+            }
         }
         GUI_INFO("corpus totals: full correct=%d unknown=%d wrong=%d; snippets correct=%d unknown=%d wrong=%d",
                  full.correct, full.unknown, full.wrong, snippets.correct, snippets.unknown, snippets.wrong);