* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #112029;
}

.image-block {
    flex: 0 1 500px;
    height: 400px;
    position: relative;
}

.image-block img {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    border: 10px solid #1b3442;
}

.image-after {
    position: absolute;
    height: 100%;
    left: 0;
    overflow: hidden;
}

.image-after img {
    height: 100%;
}

input[type="range"] {
    position: absolute;
    z-index: 10;
    width: 100%;
    height: 100%;
    background: transparent;
    appearance: none;
}

input[type="range"]::-moz-range-thumb {
   border: none; 
   -moz-appearance: none;
   width: 7px;
   height: 430px;
   background: #68baf5;
   border-radius: 5px;
   box-shadow: 0 0 10px #68baf5, 0 0 20px #68baf5, 0 0 50px #68baf5;
   cursor: e-resize;
} 

input[type="range"]::-webkit-slider-thumb  {
   border: none; 
   -webkit-appearance: none;
   width: 7px;
   height: 430px;
   background: #68baf5;
   border-radius: 5px;
   box-shadow: 0 0 10px #68baf5, 0 0 20px #68baf5, 0 0 50px #68baf5;
   cursor: e-resize;
}