:root{
     --primary-color:linear-gradient(135deg, #e981ed, #affe7b);;
     --secondary-color:#2a6de1;
     --wax-width:1100px;
}
*{
     margin: 0;
     padding: 0;
     box-sizing: border-box;
}
body{
     font: normal 2rem/1.5 "Arial", sans-serif;
     background: var(--primary-color);
     
        /* background: linear-gradient(135deg, #7055ea, #affe7b); */
     color: #fff;
     /* overflow-x: hidden; */
     padding-bottom: 50px;

}
#main-header {
     background: var(--secondary-color);
     padding: 4rem 0;
}
.container {
     max-width: var(--wax-width);
     margin: 0 auto;
     text-align: center;
}




h1{
     font-size: 4rem;
}

#timeline ul{
background: var(--primary-color);
padding: 50px 0;
}

#timeline ul li {
list-style: none;
position: relative;
width: 6px;
margin: 0 auto;
padding-top: 50px;
background: #fff;
}

/* box uud */
#timeline ul li div {
     position: relative;
     bottom: 0;
     width: 800px;
     padding: 1rem;
     background: var(--secondary-color);
     transition: all 0.5s ease-in-out;
     border-radius: 10px;
     visibility: hidden;
     opacity: 0;
}
/* baruun tal  odd sonsgoi*/
#timeline ul li:nth-child(odd) div{
     left: 40px;
     transform: translate(200px, 0);
}

/* zuun tal */
#timeline ul li:nth-child(even) div{
     left: -834px;
     transform: translate(-200px, 0);
}

/* Dugui tseg  */
#timeline ul li::after{
     content: "";
     position: absolute;
     left: 50%;
     bottom: 0;
     width: 25px;
     height: 25px;
     background: inherit;
     transform: translate(-50%);
     border-radius: 50%;
     transition:background 0.5s ease-in-out;
}

/* sum */
#timeline div :before{
content: "";
position: absolute;
bottom: 5px;
width: 0;
height: 0;
border-style: solid;
/* left: -15px; */
}
/* baruun taliin sum  */
#timeline ul li:nth-child(odd) div :before{
     left: -15px;
     border-width: 8px 16px 8px 0;
     border-color: transparent var(--secondary-color) transparent transparent;
}

/* zuun taliin sum  */
#timeline ul li:nth-child(even) div :before{
     right: -15px;
     border-width: 8px 0px 8px 16px;
     border-color: transparent  transparent transparent var(--secondary-color) ;
}
/* box uudiig haruulah */
#timeline ul li.show div {
     transform: none;
     visibility: visible;
     opacity: 1;
}

#timeline ul li.show:after {
     background: var(--secondary-color);
}

@media(max-width: 900px){
     #timeline ul li div {
          width: 250px;
     }
     #timeline ul li:nth-child(even) div {
          left: -284px;
     }
}


@media(max-width: 600px){
     #timeline ul li  {
          margin-left: 20px;
     }

     #timeline ul li div {
          width: calc(100vw - 90px);
     }

     #timeline ul li:nth-child(even) div {
          left: 40px;
     }

     #timeline ul li:nth-child(even) div :before{
          left: -15px;
          border-width: 8px 16px 8px 0;
          border-color: transparent var(--secondary-color) transparent transparent;
     }
}