style.css

* {
    box-sizing: border-box;
}
:root{
    --bkcolor: #fff;
}

.header {
  height: 60px;
  top: 0px;
  width: 100%;
}
.header h1{
    margin:0px;
    padding-top: 6px;
}

.body-area{
    width: 85vw;
    margin: auto;
}

.left-menu {
  width: 200px;
  padding:5px;
  display: none;
}
.menu-list-wrp{
    height: 60vh;
    overflow-y: auto;
    padding-right: 5px;
}
.left-menu .thumb{
    height: 100px;
}
.left-menu img{
    height: 100px;
}
.left-menu ul{
    padding: 0px;
    list-style: none;
}
.left-menu .menu-list{
    /* border:1px solid; */
}
.left-menu li{
    margin-bottom:5px;
}

.left-menu li i{
    padding: 0px;
    width:15px;
}

.left-menu ul li > i{
    -webkit-transition: all linear 0.2s;
    -moz-transition: all linear 0.2s;
    -o-transition: all linear 0.2s;
    transition: all linear 0.2s;
}
.left-menu ul li.opened > i{
    transform: rotate(45deg);
}

.left-menu ul li span:hover{
    border-bottom: 2px solid;
}

.left-menu li span{
    font-size: 1.2em;
    vertical-align: top;
    word-break: break-all;
    padding-left: 2px;
    line-height: 1.6;
}

.indent{
    margin-left: 15px;
    
}

.submenu{

    -webkit-transition: all linear 0.2s;
    -moz-transition: all linear 0.2s;
    -o-transition: all linear 0.2s;
    transition: all linear 0.2s;
    height: 0px;
    position: relative;
    top: 0px;
    margin-left: 10px;
    opacity: 0;
}
.closed{
    height: 0px;
    top: 0px;
    display: none;
}

.open{
    display: inline-block;
    opacity: 1;
    position: relative;
    /* border: 1px solid; */
    height: auto;
    top: 0px;
}

.nav-bar{
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.nav-bar .fa{
    cursor: pointer;
}

.main-body {
    /* border: 1px solid green; */
    width: 85vw;
    height: 80vh;
    margin: auto;
    overflow: hidden;
    position: absolute;
}

.main-body .slide-frame{
    /* border: 1px solid red; */
    display: flex;
    flex-direction: row;
    flex-flow: row;
    justify-content: flex-start;
    overflow: hidden;
    flex-wrap: wrap;
    height: 80vh;

    -webkit-transition: all 0.6s linear;
    -moz-transition: all 0.6s linear;
    -o-transition: all 0.6s linear;
    transition:all 0.6s linear;

    position:absolute;
}

.main-body .slide{
    border: 1px solid blue;
    width: 85vw;
    height: 80vh;
    padding: 10px;
    
}

.main-body .h1{
    border-bottom: 2px solid;
    width: 75vw;
    margin: auto;
    padding: 5px;
    margin-bottom: 20px;
}

.c-pointer{
    cursor: pointer;
}

.file-list{
    
    /* border: 1px solid; */
    justify-content: center;
    flex-flow: wrap;
    margin: auto;
    width: 75vw;
    padding: 0;
    display: -webkit-box;
    display: -ms-flexbox;
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: flex-start;
    align-content: stretch;

    -webkit-box-orient: horizontal;
    -webkit-box-direction: normal;
    -ms-flex-direction: row;
    -ms-flex-wrap: wrap;
    -webkit-box-align: center;
    -ms-flex-align: center;
    -ms-flex-line-pack: stretch;
    -webkit-box-pack: center;
    -ms-flex-pack: center;

    overflow-y: auto;
    height: 73vh;


}
 .file{
    /* border: 1px solid; */
    height: 200px;
    width: 200px;
    margin: 10px;
    background-position: 50% 50%;
    background-size: contain;
    background-repeat: no-repeat;
    align-content: baseline;
    display: flex;
    flex-flow: column;
    justify-content: flex-end;
    border-bottom: 2px solid var(--bkcolor);
    /* background-position-y: 0px; */
 }
 .file:hover{
     cursor:zoom-in;
     border-bottom: 2px solid;
     /* box-shadow: 0px 0px 5px #232020; */
 }
 .file span{
     border:1px solid;
 }
 .modal-body{
    display: flex;
    justify-content: center;
    padding: 2px;
 }

 .modal-body img{
        max-height: 300px;
 }
 .modal-footer{
    text-align: center !important;
 }
 .modal-footer input{
  opacity: 0;
  width: 5px;
  position: fixed;
  left: -100%;
}