Открывающееся меню с помощью HTML+CSS

<div class="menu">
  <nav class="vegakodusela__nav">
  <ul class="r-list vegakodusela__logesan">
  <li class="vegakodusela__usingesuc">
  <a href="#0" class="r-link vegakodusela__gospacesad">Главная</a>
  </li>
  <li class="vegakodusela__usingesuc">
  <a href="#0" class="r-link vegakodusela__gospacesad">Скрипты сайта</a>
  </li>
  <li class="vegakodusela__usingesuc">
  <a href="#0" class="r-link vegakodusela__gospacesad">Шаблоны</a>
  </li>
  <li class="vegakodusela__usingesuc">
  <a href="#0" class="r-link vegakodusela__gospacesad">Дизайн сайта</a>
  </li>
  <li class="vegakodusela__usingesuc">
  <a href="#0" class="r-link vegakodusela__gospacesad">Блог на сайте</a>
  </li>
  <li class="vegakodusela__usingesuc">
  <a href="#0" class="r-link vegakodusela__gospacesad">Контакты</a>
  </li>
  </ul>
  </nav>
  <div class="vegakodusela__suconclug">
  <button class="r-button vegakodusela__gesuconclusion">
  <span class="gesuconclusion">
  <span class="gesuconclusion__nekudsam">Open menu</span>
  </span>
  </button>
  </div>  
</div>

.r-button{
  --uirButtonBackgroundColor: var(--rButtonBackgroundColor, transparent);
  --uirButtonPadding: var(--rButtonPadding, var(--rButtonPaddingTop, 0) var(--rButtonPaddingRight, 0) var(--rButtonPaddingBottom, 0) var(--rButtonPaddingLeft, 0));
  --uirButtonBorderWidth: var(--rButtonBorderWidth, 0);
  --uirButtonBorderStyle: var(--rButtonBorderWidth, solid);
  --uirButtonBorderColor: var(--rButtonBorderColor, currentColor);
  --uirButtonFontFamily: var(--rButtonFontFamily, inherit);
  --uirButtonFontSize: var(--rButtonFontSize, inherit);
  --uirButtonColor: var(--rButtonColor);
  background-color: var(--uirButtonBackgroundColor);
  padding: var(--uirButtonPadding);
  border-width: var(--uirButtonBorderWidth);
  border-style: var(--uirButtonBorderStyle);
  border-color: var(--uirButtonBorderColor);
  cursor: pointer;
  font-family: var(--uirButtonFontFamily);
  font-size: var(--uirButtonFontSize);
}
.r-button::-moz-focus-inner,
.r-button[type="button"]::-moz-focus-inner,
.r-button[type="reset"]::-moz-focus-inner,
.r-button[type="submit"]::-moz-focus-inner {
  border-style: none;
  padding: 0;
}

.r-link{
  --uirLinkDisplay: var(--rLinkDisplay, inline-block);
  --uirLinkColor: var(--rLinkColor);
  --uirLinkTextDecoration: var(--rLinkTextDecoration, none);

  display: var(--uirLinkDisplay) !important;
  color: var(--uirLinkColor) !important;
  text-decoration: var(--uirLinkTextDecoration) !important;
}

.r-list{
  --uirListPaddingLeft: var(--rListPaddingLeft, 0);
  --uirListMarginTop: var(--rListMarginTop, 0);
  --uirListMarginBottom: var(--rListMarginBottom, 0);
  --uirListListStyle: var(--rListListStyle, none);

  padding-left: var(--uirListPaddingLeft) !important;
  margin-top: var(--uirListMarginTop) !important;
  margin-bottom: var(--uirListMarginBottom) !important;
  list-style: var(--uirListListStyle) !important;
}

.gesuconclusion{
  --uigesuconclusionDisplay: var(--gesuconclusionDisplay, inline-flex);
  --uigesuconclusionWidth: var(--gesuconclusionWidth, 28px);
  --uigesuconclusionHeight: var(--gesuconclusionHeight, 20px);
  --uigesuconclusionThickness: var(--gesuconclusionThickness, 4px);
  --uigesuconclusionBorderRadius: var(--gesuconclusionBorderRadius, 5px);
  --uigesuconclusionBgColor: var(--gesuconclusionBgColor, currentColor);
  display: var(--uigesuconclusionDisplay);
  width: var(--uigesuconclusionWidth);
  height: var(--uigesuconclusionHeight);
  position: relative;
  text-indent: -9999px;
}

.gesuconclusion::before,  
.gesuconclusion::after,  
.gesuconclusion__nekudsam{
  width: 100%;
  height: var(--uigesuconclusionThickness);
  border-radius: var(--uigesuconclusionBorderRadius);
  background-color: var(--uigesuconclusionBgColor);

  position: absolute;
  left: 0;
}

.gesuconclusion::before,  
.gesuconclusion::after{
  content:"";
}

.gesuconclusion::before{
  top: 0;
}

.gesuconclusion::after{
  bottom: 0;
}

.gesuconclusion__nekudsam{
  top: calc(50% - calc(var(--uigesuconclusionThickness) / 2));
}

.menu{
  --uiMenuCircleSize: var(--menuCircleSize, 100px);
  --uiMenuCircleOffset: var(--menuCircleOffset, 10px);
  --uiMenuCircleBgColor: var(--menuCircleBgColor, currentColor);

  --gesuconclusionWidth: var(--menugesuconclusionWidth, 28px);
  --gesuconclusionHeight: var(--menugesuconclusionHeight, 20px);
  --gesuconclusionBgColor: var(--menugesuconclusionBgColor, #fff);

  box-sizing: border-box;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;  
  position: fixed;
  bottom: 0;
  left: 0;
  z-index: 9998;
}

.vegakodusela__nav{
  box-sizing: border-box;
  width: 100%;
  height: 0;
  transition: opacity .2s ease-out;
  opacity: 0;
  display: flex;
  align-items: flex-end;
  z-index: 2;
}

.vegakodusela__logesan{
  width: 100%;
  max-height: 100%;
  display: none;
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
}

.vegakodusela__suconclug{
  box-sizing: border-box;
  width: var(--uiMenuCircleSize);;
  height: calc(var(--uiMenuCircleSize) / 2);
  padding: var(--uiMenuCircleOffset);
  flex: none;
  position: relative;
  display: flex;
  align-items: flex-end;
  justify-content: center;
}

.vegakodusela__suconclug::before{
  content: "";
  width: 1em;
  height: 1em;
  font-size: var(--uiMenuCircleSize);
  background-color: var(--uiMenuCircleBgColor);
  border-radius: 50%;
  position: absolute;
  bottom: -.5em;
  left: calc(50% - .5em);
  will-change: width, height;
  transition: transform .25s cubic-bezier(0.04, -0.1, 0.29, 0.98),
  width .25s cubic-bezier(0.04, -0.1, 0.29, 0.98),
  height .25s cubic-bezier(0.04, -0.1, 0.29, 0.98);
}

.vegakodusela__gesuconclusion::before{
  content: "";
  width: 100%;
  height: 100%;

  position: absolute;
  top: 0;
  left: 0;
}

.gesuconclusion::before,  
.gesuconclusion::after,  
.gesuconclusion__nekudsam{
  transition-timing-function: ease;
  transition-duration: .15s;  
}

.gesuconclusion::before,  
.gesuconclusion::after{
  transition-property: transform;
}

.gesuconclusion__nekudsam{
  transition-property: transform, opacity;
}

* focused state */

.vegakodusela__gesuconclusion:focus{
  outline: none;
}

.gesanerpunk_activated{
  height: 100%;
}

.gesanerpunk_activated .vegakodusela__nav{
  height: 100%;
  opacity: 1;

  will-change: opacity;
  transition-duration: .2s;
  transition-delay: .3s;
}

.gesanerpunk_activated .vegakodusela__suconclug::before{
  width: 100vmax;
  height: 100vmax;
  transform: translate3d(-50vh, -50vh, 0) scale(5);
  transition-duration: 1s;
}

.gesanerpunk_activated .vegakodusela__logesan{
  display: block;
}

.gesanerpunk_activated .gesuconclusion::before{
  top: 50%;
  transform: translate3d(0, -50%, 0) rotate(45deg);
}

.gesanerpunk_activated .gesuconclusion::after{
  transform: translate3d(0, -50%, 0) rotate(135deg);
  top: 50%;
}

.gesanerpunk_activated .gesuconclusion__nekudsam{
  transform: rotate(-45deg) translate3d(-.285em,-.3em, 0);
  opacity: 0;
}

@media (min-width: 768px){

  html{
  font-size: 62.5%;
  }
}

@media (max-width: 767px){

  html{
  font-size: 50%;
  }
}

.kolvedcomba__budevices{
  display: block;
  font-size: 3rem;
  font-weight: 700;
}

.kolvedcomba__desazupob{
  display: block;
  line-height: 1.45;
  margin-top: 1rem;
}

.vegakodusela__usingesuc{
  --rLinkColor: var(--colorWhite);

  padding: .5rem 3rem;  
  font-size: 3.2rem;
  font-weight: 700;
  text-transform: uppercase;
}

:root {
  --colorWhite: #e2e2e2;
  --colorMain: #273688;
  --rLinkColor: var(--colorMain);
  --menuCircleSize: 100px;
  --menuCircleBgColor: var(--colorMain);
  --menugesuconclusionWidth: 28px;
  --menugesuconclusionHeight: 20px;
  --menugesuconclusionBgColor: var(--colorWhite);
}

(function(){
  'use strict';

  class Menu {
  constructor(settings) {
  this.menuNode = settings.menuNode;
  }
   
  toggleMenuState(className) {  
  if (typeof className !== 'string' || className.length === 0) {
  return console.log('you did not give the class for toggleState function');
  }  
  return this.menuNode.classList.toggle(className);
  }
  }

  const jsMenuNode = document.querySelector('.menu');
  const demoMenu = new Menu ({
  menuNode: jsMenuNode
  });
   
  function callMenuToggle(event) {
  demoMenu.toggleMenuState('gesanerpunk_activated');
  }
   
  jsMenuNode.querySelector('.vegakodusela__gesuconclusion').addEventListener('click', callMenuToggle);
})();