Tạo khung chứa code (Pre code box) có nút Copy và Download cho Blogger / Blogspot

/* Code Box */
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.pre:not(.str) .prCd{display:none}
.pre.str .prTl{display:none;}
.pre.adv pre{padding-top:60px}
.preM{position:absolute;top:0;right:0;left:0;width:100%;background: rgba(0,0,0,.04);padding:10px 10px 10px 20px;display:flex;justify-content:space-between;align-items:center;flex-wrap:nowrap;z-index:2}
.preT{font-size:12px;font-family: var(--fontC);line-height:1rem;position:relative;overflow:hidden;white-space:nowrap;text-overflow:ellipsis;padding-right:10px;}
.preA{display:flex;gap:8px;white-space:nowrap;}
.preA button{outline:none;border:none;width:30px;height:30px;background:#d9d9d9;padding:0;margin:0;border-radius:50%;transition:border-radius .2s ease;display:inline-flex;align-items:center;justify-content:center;cursor:pointer;}
.preA button:hover{border-radius:40%;}
.preA button >svg{width:18px;height:18px;stroke:none;fill:#2e2e2e;transition: all .5s ease;}
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.pre.cpd .prCp svg .a,.pre:not(.cpd) .prCp svg .b{opacity:0}
.pre.dwn .prDl svg .a, .pre.pnd .prDl svg .a,.pre:not(.pnd) .prDl svg .b,.pre:not(.dwn) .prDl svg .c{opacity:0}
@keyframes jiggle{0%{transform:rotate(0)}20%{transform:rotate(26deg)}40%{transform:rotate(-26deg)}60%{transform:rotate(26deg)}80%{transform:rotate(-26deg)}100%{transform:rotate(0)}}
@-webkit-keyframes jiggle{0%{transform:rotate(0)}20%{transform:rotate(26deg)}40%{transform:rotate(-26deg)}60%{transform:rotate(26deg)}80%{transform:rotate(-26deg)}100%{transform:rotate(0)}}

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  <pre>
        <!--Code-->
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