Why buttons in the sidebar of my custom site look strange?

I added some code to sidebar footer. Don't know why but buttons changed their appearance.

image description

Code of module:

<script type="text/javascript">
  SETTINGS_HOST = "//nano.aviasales.ru";
  TP_FORM_SETTINGS = {
    "main": {
        "marker": "0000",
        "width": 200,
        "white_label_host": "",
        "show_logo": true,
        "show_hotels": null,
        "form_type": "avia",
        "currency": "rub",
        "sizes": "square250",
        "search_target": "_blank",
        "origin_iata": "",
        "destination_iata": "",
        "origin_name": null,
        "destination_name": null,
        "border_radius": "2"
    },
    "color_scheme": {
        "icons": "icons_orange",
        "background": "#ffffff",
        "color": "#000000",
        "border_color": "#cccccc",
        "button": "#feb20e",
        "button_text_color": "#ffffff"
    }
};
  (function(){
    var code = ['<div class="aviasales_inlineable">',
      '<div style="visibility: hidden;" data-widgets-forms-inlineable="    {&quot;forms&quot;:&quot;search&quot;,&quot;link&quot;:&quot;/widgets/515f57f9ada1b5465b00003c    .json?locale=ru&quot;}">',
      '<div class="nano_form_tabs_wp ultra_narrow_tabs">',
      '<div class="nano_form_tabs" data-widgets-forms-inlineable-tabs="">',
      '</div></div></div></div>'];
    var loader_url = SETTINGS_HOST + '/assets/nano_ui/widgets/partners/loader_ru.js?no_cache=' +     (+new Date());
      code.push('<' + 'script src="' + loader_url + '">' + '<' +'/script>');
    document.write(code.join(''));
  })();

</script>