Bootstrap connects only to localhost/site/ , if you keep localhost/site/index/index (this is the same page), then it will not work anymore. It turns out that it is looking for a bootstrap at the address localhost/site/index/index/View/css/bootstrap.css and it is at the address localhost/site/View/css/bootstrap.css Maybe I am doing something wrong. Site structure mvc. Method Render
protected function render($templateName) { ob_start(); //динамический контент $render = SITE_DIR . DS . 'View' . DS . $this->name . DS . $templateName . '.php'; if ($render) { include ($render); } //дефолтный шаблон в нем я подключаю bootstrap $content = ob_get_clean(); include SITE_DIR . DS . 'View' . DS . 'Layout' . DS .'default' . '.php'; }