Pertama-tama, tambahkan kode CSS dibawah ini. Lalu letakkan di atas </style> atau ]]></b:skin>.

/* Blogger Sitemap Alphabetically with Letter Heading by igniel.com */
#sitemap5 {font-size:14px; font-weight:400}
#sitemap5 .judul {font-size:150%; background-color:#008c5f; color:#fff; font-weight:600; text-align:center; margin-bottom:20px; padding:15px;}
#sitemap5 a {color:#666; text-decoration:none; transition:all .3s ease;}
#sitemap5 a:hover {color:#000;}
#sitemap5 .isi .abjad {background-color:#2196f3; color:#fff; padding:10px 15px; font-size:110%; font-weight:600; text-transform:uppercase; position:relative;}
#sitemap5 .isi .abjad #top:before {content:''; width:12px; height:calc(100% - 20px); position:absolute; right:0px; top:0px; padding:10px; cursor:pointer; background:rgba(0,0,0,.2) url("data:image/svg+xml,%3Csvg viewBox='0 0 24 24' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M15,20H9V12H4.16L12,4.16L19.84,12H15V20Z' fill='%23fff'/%3E%3C/svg%3E") center / 20px no-repeat;}
#sitemap5 ol, #sitemap5 ol li {list-style-type:none;}
#sitemap5 .nav ol {margin:0px 0px 15px; padding:0px; display:-webkit-box; display:-webkit-flex; display:-moz-box; display:-ms-flexbox; display:flex; flex-wrap:wrap; align-items:center; justify-content:center;}
#sitemap5 .nav ol li {background-color:#444; color:#fff; padding:7px 0px; cursor:pointer; margin:0px 5px 5px 0px; text-align:center; text-transform:uppercase; width:40px;}
#sitemap5 .nav ol li:last-child {margin-right:0px;}
#sitemap5 .isi ol {margin:0px 0px 20px; padding:0px; border:1px solid #ccc; border-top:0px;}
#sitemap5 .isi ol li {color:#666; margin:0px; padding:10px 15px; line-height:1.5em; -webkit-margin-start:0px !important;}
#sitemap5 .isi ol li:nth-of-type(even) {background-color:#e9e9e9;}
#sitemap5 .isi ol li:nth-of-type(odd) {background-color:#fff}
@media screen and (max-width:480px) {
  #sitemap5 {font-size:13px;}
  #sitemap5 .judul {padding:10px;}
  #sitemap5 .isi .abjad {padding:7px 15px;}
}
@media screen and (max-width:360px) {
  #sitemap5 {font-size:12px;}
  #sitemap5 .judul {padding:10px;}
  #sitemap5 .isi .abjad {padding:7px 12px;}
  #sitemap5 .isi ol li {padding:7px 12px;}
}