body { font-family:Arial, sans-serif;background:#212121;color:#fff;text-align:center;padding:20px;} .container { max-width:900px;margin:auto;} canvas { background-color:#f1f1f1;height:400px;border:10px ridge hotpink;margin-top:20px;display:block;margin-left:auto;margin-right:auto;} h2 { color:#00cec9;} h4 { color:#fff;} input[type="file"]::file-selector-button { border:3px solid gray;padding:5px;border-radius:0;background-color:#fff;transition:0.5s;cursor:pointer;width:280px;margin-top:10px;} input[type="file"]::file-selector-button:hover { background-color:#00ff00;border:3px solid #00cec9;} .button-group input { margin:10px 5px;} .filter, .filter1, .filter2, .filter3, #reset { padding:10px;border:2px solid #000;cursor:pointer;border-radius:0;width:180px;font-weight:bold;} .filter { background-color:gray;color:white;} .filter1 { background-color:red;color:white;} .filter2 { background-color:goldenrod;color:white;} .filter3 { background-color:blue;color:white;} #reset { background-color:#00cec9;color:#000;} footer { margin-top:40px;font-size:16px;}