:root{
  /* Primary */
  --light-red: hsl(356, 100%, 66%);                         /*CTA text*/
  --very-light-red: hsl(355, 100%, 74%);                    /*CTA hover background*/
  --very-dark-blue: hsl(208, 49%, 24%);                     /*headings*/

  /* Neutral */
  --white: hsl(0, 0%, 100%);                                 /*text*/
  --grayish-blue: hsl(240, 2%, 79%);                         /*footer text*/
  --very-dark-grayish-blue: hsl(207, 13%, 34%);              /*body copy*/
  --very-dark-black-blue: hsl(240, 10%, 16%);                /*footer background*/

  /* Gradient */
  /* Background gradient - Intro/CTA mobile nav: */
  --very-light-red: hsl(13, 100%, 72%);
  --light-red: hsl(353, 100%, 62%);

  /* Background gradient - body: */
  --very-dark-gray-blue: hsl(237, 17%, 21%);
  --very-dark-desaturated-blue: hsl(237, 23%, 32%);

  /* font */
  --overpass: 'Overpass', sans-serif;
  --ubuntu: 'Ubuntu', sans-serif;
}



/**********devices with width of 540px or less**************/
@media only screen and (max-width: 540px) {
  header{
    padding: 0 20px 80px;
    background-repeat: no-repeat;
    background-position: top 160px left -100px !important;
    background-size: cover !important;
  }
}


/**********devices with width of 1000px or less**************/
@media only screen and (max-width: 1000px) {
  nav{
    padding: 60px 0 0 10px;
  }
  .menu-btn{
    display: flex;
  }
  nav hr{
    display: block;
    width: 85%;
  }
  .menu{
    padding: 30px 0;
    flex-direction: column;
    justify-content: center;
    position: absolute;
    top: -3000px;
    left: 0;
    right: 0;
    margin: auto;
    background: #fff; 
    text-align: center;
    border-radius: 5px;
    transition: .25s;
  }
  .menu ul{
    width: 100%;
  }
  .menu ul li{
    display: block;
  }
  .menu ul li::before{
    display: none;
  }
  .menu ul li a{
    color: #000 ;
  }
  .menu i{
    color: var(--light-red);
  }
  
  .menu ul .sub-menu{
    position: static;
    margin: 20px auto;
    visibility: visible;
    opacity: 1;
    text-align: center;
    background: rgb(245, 245, 245);
    width: 90%;
    display: none;
    padding: 20px 0;
    box-shadow: none;
    border-radius: 5px;
  }
  .menu .sub-menu li{
    margin: 15px;
  }
  .menu .sub-menu a{
    color: var(--very-dark-grayish-blue);
  }
  
  
  .btn-container button{
    display: block;
  }
  .login-btn{
    margin: 20px 0 10px 8px;
    color: #000;
  }
  .sign-up-btn{
    background: linear-gradient(to right, var(--very-light-red), var(--light-red));
    color: #fff;
  }
  .mobile-menu{
    top: 160px;
  }
  .mobile-menu-item > a{
    color:var(--very-dark-grayish-blue) !important;
  }
  .menu ul .mobile-menu-item .sub-menu{
    display: block !important;
  }
}


/**********devices with width of 1500px or less**************/
@media only screen and  (max-width: 1500px){
  header{
    background-position: top -1300px right -1400px;
  }
}



/**********devices with width of 410px or more**************/
@media only screen and (min-width: 410px) {
  .art-infrast-container{
    margin-top: 320px;
  }
  .art-infrast-container img{
    top: -220px;
  }
}


/**********devices with width of 500px or more**************/
@media only screen and (min-width: 500px){
  .art-infrast-container{
    margin-top: 440px;
    padding: 200px 20px 110px 20px;
  }  
  .art-infrast-container img{
    top: -320px;
  }

  .features-2 div p{
    padding: 0 50px;
  }
}


/**********devices with width of 600px or more**************/
@media only screen and (min-width: 600px) {
  header{
    padding: 20px 20px 80px;
  }
  nav{
    padding: 40px 0 0 20px;
  }

  .art-infrast-container{
    margin-top: 300px;
  }
  .art-infrast-container img{
    width: 70%;
    top: -240px;
  }
}


/**********devices with width of 700px or more**************/
@media only screen and (min-width: 700px) {
  .editor p, .robust p{
    padding: 0 140px;
  }
  .mobile-img{
    width: 65%;
  }

  .art-infrast-container{
    margin-top: 320px;
  }
  .art-infrast-container img{
    width: 60%;
    top: -240px;
  }

  .features-2 div p{
    padding: 0 120px;
  }
}


/**********devices with width of 800px or more**************/
@media only screen and (min-width: 800px){
  .art-infrast-container{
    margin-top: 380px;
  }
  .art-infrast-container img{
    width: 60%;
    top: -300px;
  }
}


/**********devices with width of 1000px or more**************/
@media only screen and (min-width: 1000px) {
  body{
    overflow-x: hidden;
  }

  .intro h1{
    font-size: 3.4rem;
  }
  .intro-learn-btn,
  .intro-strt-btn{
    font-size: 1.05rem;
  }
  .intro div{
    margin-top: 50px;
  }

  .art-infrast-container{
    padding: 80px 20px;
    display: flex;
    justify-content: flex-end;
    margin-top: 200px;
  }
  .art-infrast-container::before{
    width: 80%;
    background-position: bottom -100px left -170px;
  }
  .art-infrast-container img{
    left: 0;
    top: -25%;
    transform: translate(0);
    width: 50%;
  }
  .art-infrast-container div{
    width: 50%;
    text-align: start;
  }

  .features-2-container{
    margin: 120px 0 0 0;
  }
  .features-2-container img{
    width: 80%;
  }
  .features-2 div p{
    padding: 0 160px;
  }

  footer{
    justify-content: space-between;
    align-items: flex-start;
    flex-direction: row;
    padding: 80px 100px;
  }
  footer ul{
    text-align: start;
  }
  footer p{
    text-align: start;
  }
  .list-1, .list-2, .list-3{
    width: 18%;
    margin: 0;
  }
  .logo-container{
    width: 18%;
  }
}


/**********devices with width of 1100px or more**************/
@media only screen and (min-width: 1100px) {
  header{
    padding: 0 80px 40px;
  }
  
  .future-container{
    position: relative;
  }
  .feature-container{
    flex-direction: row;
    justify-content: flex-start;
    height: 460px;
  }
  .features{
    width: 50%;
    text-align: start;
    padding-left: 80px;
  }
  .editor{
    margin-top: 0;
  }
  .editor h2, .editor p, 
  .robust h2, .robust p{
    padding: 0;
  }
  .feature-container img{
    top: -5%;
    position: absolute;
    right: -17%;
    width: 60%;
  }
  .mobile-img{
    display: none;
  }
  .desktop-img{
    display: inline-block;
  }

  .art-infrast-container{
    margin-top: 140px;
    padding: 80px;
  }
  .art-infrast-container img{
    width: 45%;
    left: 40px;
  }

  .features-2-container{
    justify-content: flex-end;
    flex-direction: row;
    text-align: start;
    margin: 160px 0 0 0;
    position: relative;
  }
  .features-2-container img{
    position: absolute;
    top: 0;
    left: -18.5%;
    width: 60%;
    height: 600px;
  }
  
  .features-2{
    padding-right: 80px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    width: 48%;
    margin: 0;
    height: 600px;
  }
  .feature-free-open-simple{
    margin-bottom: 40px;
  }
  .features-2 div p{
    padding: 0;
  }
}


/**********devices with width of 1250px or more**************/
@media only screen and (min-width: 1250px) {
  header{
    padding: 0 140px 40px;
  }
  nav{
    padding: 80px 0 0 0;
  }
  .feature-container{
    height: 520px;
  }
  .features{
    padding-left: 120px;
  }
  .future-container h1{
    font-size: 2.1rem;
    position: relative;
    top: 40px;
  }
  .editor h2, .robust h2{
    font-size: 1.7rem;
  }
  .editor p, .robust p{
    font-size: 1.1rem;
  }

  .art-infrast-container{
    padding: 80px 140px;
  }

  .art-infrast-container img{
    width: 40%;
    left: 80px;
  }

  .features-2{
    padding-right: 140px;
  }

  footer{
    padding: 80px 140px;
  }
}


/**********devices with width of 1350px or more**************/
@media only screen and (min-width: 1350px) {
  .feature-container{
    height: 580px;
  }
  .features{
    padding-left: 140px;
    width: 45%;
    padding-top: 40px;
  }

  .art-infrast-container{
    padding: 80px 140px;
  }

  .art-infrast-container img{
    top: -32%;
    width: 40%;
    left: 100px;
  }
}


/**********devices with width of 1440px or more**************/
@media only screen and (min-width: 1440px){
  .art-infrast-container{
    margin-top: 200px;
  }
  .art-infrast-container img{
    top: -36%;
  }

  .features-2-container img{
    height: 700px;
  }
  
  .features-2{
    height: 700px;
  }
}


/**********devices with width of 1540px or more**************/
@media only screen and (min-width: 1540px) {
  header{
    padding: 0 200px 40px;
  }
  
  .features{
    padding-top: 60px;
    padding-left: 200px;
  }
  .feature-container img{
    width: 60%;
    height: 130%;
  }

  .art-infrast-container{
    padding: 80px 200px;
    margin-top: 240px;
  }
  .art-infrast-container img{
    width: 35%;
    top: -30%;
    left: 160px;
  }

  .features-2{
    padding-right: 200px;
  }

  .features-2-container{
    justify-content: flex-end;
    flex-direction: row;
    text-align: start;
    margin: 260px 0 0 0;
    position: relative;
  }

  footer{
    padding: 80px 200px;
  }

}


/**********devices with width of 1640px or more**************/
@media only screen and (min-width: 1640px) {
  .art-infrast-container img{
    top: -50%;
  }

  .features-2-container img{
    height: 900px;
  }
  
  .features-2{
    height: 900px;
  }
}