style.css

:root{
    --bordercolor:#ccc;
    --textcolor:rgba(0,0,0,0.6);
    --buttonwidth:40px;
    --iconopacity: 0.65;
    --letterspace:0.02rem;
}

body{
    background: #f9f9f9;
    margin: 0;
    padding: 0;
    font-size: 16px;
}
*{
    margin: 0;
    padding: 0;
    font-size: inherit;
    font-family: 'Roboto';
    text-shadow: none;
    letter-spacing: var(--letterspace);
    box-sizing: border-box;

}
.wrapper{
    display: grid;
    grid-template-areas: 
    "header header header header"
    "sidebar videos videos videos";
    grid-template-columns: 240px 1fr 1fr;
    position: relative;
}

/* header */
.top{
    display: grid;
    grid-template-columns: repeat(2,auto) 1fr repeat(4,auto);
    align-items: center;
    grid-gap: 8px;
    background: white;
    padding: 8px 15px;
    grid-area: header;

}
.back_btn, .top > .search_btn{
    display: none;
}

.top button{
    width: var(--buttonwidth);
    height: var(--buttonwidth);
    background: transparent;
    border: none;
    padding: 8px;
    cursor: pointer;
    opacity: var(--iconopacity);
}


.user_avatar img{
    width: 100%;
    height: 100%;
}
.user_avatar{
    opacity: 1 !important;

}
.top .logo {
    opacity: 1;
    width: 100px;
}
.search{
    display: grid;
    grid-template-columns: 30px 1fr [search-start]  minmax(100px,500px) auto 1fr 30px;
    align-items: center;
}
.search input{
    padding-left: 5px;
    height:32px;
    border: 1px solid var(--bordercolor);
    border-right: none;
    grid-column: search-start;
}

.search button{
    background: #f8f8f8;
    border: 1px solid var(--bordercolor);
    height: 32px;
    width: 70px;
    padding:5px
}
@media(max-width:700px){
    .search{
        display: none;
    }

    .top > .search_btn{
        display: block;
        justify-self: right;
    }

    .top.search_active > * {
        display: none;

    }

    .top.search_active .search{
        display: grid;
        grid-column: 2/-1;
        grid-template-columns: [search-start] 1fr auto;
    }

    .top.search_active .back_btn{
        display: inline;
    }
   
}

.sidebar{
    width: 240px;
    background: white;
    color: black;
    top:0;
    width: 240px;
    grid-area: sidebar;
    position: absolute;
    transition: all 0.5s;
}

.sidebar ul{
    border-bottom: 1px solid rgba(0,0,0,0.1);
    padding: 10px 0;
}
.sidebar .title{
    text-transform: uppercase;
    padding-left: 18px;
    padding-top: 10px;
    display: block;
    color: rgba(0,0,0,0.7);
    font-weight: 600;
}
.sidebar ul li{
    display: grid;
    grid-template-columns: 24px 1fr;
    grid-gap: 24px;
    padding: 8px;
    align-items: center;
    padding: 10px 23px;
    cursor: pointer;

}

.sidebar li:hover{
    background: rgba(0,0,0,0.1);
}

.sidebar ul:first-of-type li:first-child{
    background: rgba(0,0,0,0.1);
}

.sidebar ul li svg{
    opacity: var(--iconopacity);
}

.sidebar_small{
    display: none;
    background: white;
    min-height: 100vh;

}

.sidebar_small ul li{
    display: grid;
    grid-template-columns: 28px;
    justify-content: center;
    justify-items: center;
    grid-gap: 0;

    padding: 20px 0;
    font-size: 0.6rem;  
    letter-spacing: 0.03rem;  
}
.sidebar_small ul li:first-child{
    color: #c00;
    fill: #c00;
}

.sidebar_small ul li svg{
    opacity: var(--iconopacity);
}
.sidebar_small ul li:hover{
    background: rgba(0,0,0,0.1);
    cursor: pointer;
}
@media(max-width:1300px){
    .sidebar{
        position: absolute;
        width: 240px;
        left: -240px;
        top:0;
        z-index: 10;
    }

    .sidebar_small{
        display: block;
    }

    .wrapper{
        grid-template-columns: 70px 1fr 1fr;
    }
}
@media(max-width:700px){
    .sidebar_small{
        display: none !important;
    }
    .wrapper{
        grid-template-columns: 1fr;
    }
}


.wrapper.menu_overlay .sidebar{
    left:0;
}

.wrapper.menu_small .sidebar_small{
    display: block;
}

.wrapper.menu_small{
    grid-template-columns: 70px 1fr 1fr ;
}
.wrapper.wrapper.menu_small .sidebar{
    left:-240px;
}


/* Videos Section */
.videos{
    grid-area: videos;
    display: grid;
    grid-template-columns: repeat(auto-fit,minmax(290px,1fr));
    grid-gap: 15px;
    padding: 0 10px;
}

.videos h2{
    grid-column: 1 / -1;
    padding: 35px 20px  0 20px;
    font-size: 1.25rem;
    letter-spacing: 0.06rem;
}

.videos .video{
    display: grid;
    grid-template-columns: 55px 1fr;
    grid-gap: 5px;
    font-size: 1rem;
    align-items: center;
    cursor: pointer;
    margin-bottom: 35px;
}

.videos .video img{
    width: 100%;
}

.videos .video .avatar{
    padding: 4px;
    height: 100%;
}

.videos .video .thumbnail{
    grid-column: 1 / -1;
}

.videos .video .channel,.videos .video .details{
    grid-column: span 1 / -1;
    color: var(--textcolor);
    font-weight: bold;
    font-size: 0.8rem;

}
.videos .video .title{
    font-size: 0.9rem;
    font-weight: bold;
    line-height: 1.2;
}

@media(max-width:700px){
    .videos{
        grid-column: 1 / -1;
    }
}