How to hide the "left menu" of Bitrix on mobile devices?

Question

1C-Bitrix

Hello!
Please tell me how to hide the "left menu" on mobile devices, I looked in the settings of the menu itself, I found nothing.
Menu styles:

/**Top menu**/
#horizontal-multilevel-menu,#horizontal-multilevel-menu ul
{
  margin:0; padding:0;
  background:#005892;
  min-height:27px;
  width:100%;
  list-style:none;
  font-size:12px;
  float:left
  /*font-size:90%*/
}

#horizontal-multilevel-menu
{

}

/*Links*/
#horizontal-multilevel-menu a
{
  display:block;
  padding:5px 10px;
  /*padding:0.3em 0.8em;*/
  text-decoration:none;
  text-align:center;
}

#horizontal-multilevel-menu li
{
  float:left;
}

/*Root items*/
#horizontal-multilevel-menu li a.root-item
{
  color:#fff;
  font-weight:bold;
  padding:7px 12px;
}

/*Root menu selected*/
#horizontal-multilevel-menu li a.root-item-selected
{
  background:#ad172c;
  color:#fff;
  font-weight:bold;
  padding:7px 12px;
}

/*Root items: hover*/
#horizontal-multilevel-menu li:hover a.root-item, #horizontal-multilevel-menu li.jshover a.root-item
{
  background:#2f595a;
  color:#fff;
}

/*Item-parents*/
#horizontal-multilevel-menu a.parent
{
  background: url(images/arrow.gif) center right no-repeat;
}

/*Denied items*/
#horizontal-multilevel-menu a.denied
{
  background: url(images/lock.gif) center right no-repeat;
}

/*Child-items: hover*/
#horizontal-multilevel-menu li:hover, #horizontal-multilevel-menu li.jshover
{
  background:#D6D6D6;
  color:#fff;
}

/*Child-items selected*/
#horizontal-multilevel-menu li.item-selected
{
  background:#D6D6D6;
  color:#fff;
}

/*Sub-menu box*/
#horizontal-multilevel-menu li ul
{
  position:absolute;
  /*top:-999em;*/
  top:auto;
  display:none;
  z-index:500;

  height:auto;
  /*width:12em;*/
  width:135px;
  background:#F5F5F5;
  border:1px solid #C1C1C1;
}

/*Sub-menu item box*/
#horizontal-multilevel-menu li li
{
  width:100%;
  border-bottom:1px solid #DEDEDE;
}

/*Item link*/
#horizontal-multilevel-menu li ul a
{
  text-align:left;
}

/*Items text color & size */
#horizontal-multilevel-menu li a,
#horizontal-multilevel-menu li:hover li a,
#horizontal-multilevel-menu li.jshover li a,
#horizontal-multilevel-menu li:hover li:hover li a,
#horizontal-multilevel-menu li.jshover li.jshover li a,
#horizontal-multilevel-menu li:hover li:hover li:hover li a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover li a,
#horizontal-multilevel-menu li:hover li:hover li:hover li:hover li a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover li.jshover li a,
#horizontal-multilevel-menu li:hover li:hover li:hover li:hover li:hover li a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover li.jshover li.jshover li a
{
  color:#4F4F4F;
  font-weight:bold;
}

/*Items text color & size: hover*/
#horizontal-multilevel-menu li:hover li:hover a,
#horizontal-multilevel-menu li.jshover li.jshover a,
#horizontal-multilevel-menu li:hover li:hover li:hover a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover a,
#horizontal-multilevel-menu li:hover li:hover li:hover li:hover a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover li.jshover a
#horizontal-multilevel-menu li:hover li:hover li:hover li:hover li:hover a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover li.jshover li.jshover a
#horizontal-multilevel-menu li:hover li:hover li:hover li:hover li:hover li:hover a,
#horizontal-multilevel-menu li.jshover li.jshover li.jshover li.jshover li.jshover li.jshover a
{
  color:#4F4F4F;
}

#horizontal-multilevel-menu li ul ul
{
  margin:-27px 0 0 132px;
  /*margin:-1.93em 0 0 11.6em;*/
}

#horizontal-multilevel-menu li:hover ul ul,
#horizontal-multilevel-menu li.jshover ul ul,
#horizontal-multilevel-menu li:hover ul ul ul,
#horizontal-multilevel-menu li.jshover ul ul ul,
#horizontal-multilevel-menu li:hover ul ul ul ul,
#horizontal-multilevel-menu li.jshover ul ul ul ul,
#horizontal-multilevel-menu li:hover ul ul ul ul ul,
#horizontal-multilevel-menu li.jshover ul ul ul ul ul
{
  /*top:-999em;*/
  display:none;
}

#horizontal-multilevel-menu li:hover ul,
#horizontal-multilevel-menu li.jshover ul,
#horizontal-multilevel-menu li li:hover ul,
#horizontal-multilevel-menu li li.jshover ul,
#horizontal-multilevel-menu li li li:hover ul,
#horizontal-multilevel-menu li li li.jshover ul,
#horizontal-multilevel-menu li li li li:hover ul,
#horizontal-multilevel-menu li li li li.jshover ul,
#horizontal-multilevel-menu li li li li li:hover ul,
#horizontal-multilevel-menu li li li li li.jshover ul
{
  /*z-index:1000;
  top:auto;*/
  display:block;
}

div.menu-clear-left
{
  clear:left;
}

Answer 1

You can write in the styles for the menu

.left-menu {
     display: none;
}

@media (min-width: 768px) {
     .left-menu {
        display: block;
     }
}

Your menu class may differ. You can see it in devtools.