@import url('https://fonts.googleapis.com/css?family=Poppins:200,300,400,500,600,700,800,900&display=swap');
*
{
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Poppins', sans-serif;
}


body {
  font-family: 'Arial', sans-serif;
  justify-content: center;
  align-items: center;
  background-color: #161a23;
}


section 
{
  position: relative;
  width: 100%;
  padding: 0 100px;
  display: flex;
  align-items: center;
  background: #21283a;
  overflow-x: hidden;
}
section::before 
{
  content: '';
  position: absolute;
  top: 50%;
  right: 100px;
  transform: translateY(-50%);
  transition: 1s;
}
section.active::before 
{
  background: #21283a;
  box-shadow: 0 0 0 1200px #141821;
}
header 
{
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 30px 100px;
  background-color: #070505;
}
header .logo 
{
  font-size: 1em;
  color: #fff;
  letter-spacing: 1px;
  font-weight: 600;
  text-transform: uppercase;
  text-decoration: none;
  transition: 0.5s;
  transform-origin: left;
}


header .logo span 
{
  color: gold;
  border-bottom: 4px solid #1de5ff;
}


header .toggle 
{
  position: relative;
  width: 30px;
  height: 30px;
  background: url(menu.png);
  background-repeat: no-repeat;
  background-position: center;
  background-size: 30px;
  cursor: pointer;
}
header .toggle.active
{
  background: url(close.png);
  background-repeat: no-repeat;
  background-position: center;
  background-size: 30px;
}


section.active .logo ,
section.active .content,
section.active  .sci
{
  transform: scale(0);
}
.menu 
{
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  flex-direction: column;
  z-index: 2;
  padding-left: 100px;
  opacity: 0;
  visibility: hidden;
  transition: 0.5s;
  background-color: #070505;
}
section.active .menu  
{
  opacity: 1;
  visibility: visible;
  transition-delay: 0.5s;
}
.menu li 
{
  list-style: none;
}
.menu li a 
{
  color: #fff;
  text-decoration: none;
  font-size: 1.5em;
  padding: 5px 10px;
  margin: 5px 0;
  display: inline-block;
  transition: 0.25s;
  background-color: #070505;
}
.menu li:hover a
{
  letter-spacing: 6px;
  background: #fff;
  color: #161a23;
}





    /* now, make it responsive */
    @media (max-width: 991px)
    {
     
      header 
      {
        padding: 20px 40px;
      }
      section::before
      {
        opacity: 0;
      }
      .menu 
      {
        padding-left: 0;
        align-items: center;
      }
    }