body{background-color:#fff;color:#fff;text-align:center}
.custom-table{width:100%;border-collapse:collapse;background-color:#343a40;color:#fff;margin:10px auto;border-radius:8px;overflow:hidden}
.custom-table td,.custom-table th{padding:6px;text-align:center}
.custom-table th{background-color:rgba(255,255,255,.1);font-weight:700}
.custom-table tr:nth-child(even){background-color:rgba(255,255,255,.05)}
thead{background-color:#ff4d4d;color:#fff}
.form-input{width:50px;padding:5px;text-align:center;background:#495057;border:none;color:#fff;border-radius:4px}
.form-input:focus{outline:0;background:#6c757d}
.calculate-btn{padding:5px 20px;margin-top:10px;background:#ff4d4d;border:none;color:#fff;font-size:16px;border-radius:5px;cursor:pointer;transition:.3s}
.calculate-btn:hover{background:#c60005}
.clear-btn{background-color:#efefef;color:#000;border:none;padding:5px 35px;font-size:16px;cursor:pointer;border-radius:5px;transition:background-color .3s ease,color .3s ease}
.clear-btn:hover{background-color:#ddd}
select{background-color:#495057;color:#fff;border:none;padding:5px;border-radius:4px;appearance:none;cursor:pointer;transition:background-color .3s ease,color .3s ease}
select:hover{background-color:#6c757d}