BloggerにRandom Postボタンを設置

My Blogger Buzz: How to Add Random Post Button in Blogger? http://www.mybloggerbuzz.com/2014/05/random-post-button-blogger.html
こちらのコード

<style>
#mbb-random a {
background-color:#3bb3e0;
padding:10px;
position:relative;
font-family: 'Open Sans', sans-serif;
font-size:12px;
text-decoration:none;
color:#fff;
border: solid 1px #186f8f;
background-image: linear-gradient(bottom, rgb(44,160,202) 0%, rgb(62,184,229) 100%);
background-image: -o-linear-gradient(bottom, rgb(44,160,202) 0%, rgb(62,184,229) 100%);
background-image: -moz-linear-gradient(bottom, rgb(44,160,202) 0%, rgb(62,184,229) 100%);
background-image: -webkit-linear-gradient(bottom, rgb(44,160,202) 0%, rgb(62,184,229) 100%);
background-image: -ms-linear-gradient(bottom, rgb(44,160,202) 0%, rgb(62,184,229) 100%);
background-image: -webkit-gradient(
linear,
left bottom,
left top,
color-stop(0, rgb(44,160,202)),
color-stop(1, rgb(62,184,229))
);
-webkit-box-shadow: inset 0px 1px 0px #7fd2f1, 0px 1px 0px #fff;
-moz-box-shadow: inset 0px 1px 0px #7fd2f1, 0px 1px 0px #fff;
box-shadow: inset 0px 1px 0px #7fd2f1, 0px 1px 0px #fff;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
-o-border-radius: 5px;
border-radius: 5px;
}
#mbb-random a::before {
background-color:#ccd0d5;
content:"";
display:block;
position:absolute;
width:100%;
height:100%;
padding:8px;
left:-8px;
top:-8px;
z-index:-1;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
-o-border-radius: 5px;
border-radius: 5px;
-webkit-box-shadow: inset 0px 1px 1px #909193, 0px 1px 0px #fff;
-moz-box-shadow: inset 0px 1px 1px #909193, 0px 1px 0px #fff;
-o-box-shadow: inset 0px 1px 1px #909193, 0px 1px 0px #fff;
box-shadow: inset 0px 1px 1px #909193, 0px 1px 0px #fff;
}
#mbb-random a:active {
padding-bottom:9px;
padding-left:10px;
padding-right:10px;
padding-top:11px;
top:1px;
background-image: linear-gradient(bottom, rgb(62,184,229) 0%, rgb(44,160,202) 100%);
background-image: -o-linear-gradient(bottom, rgb(62,184,229) 0%, rgb(44,160,202) 100%);
background-image: -moz-linear-gradient(bottom, rgb(62,184,229) 0%, rgb(44,160,202) 100%);
background-image: -webkit-linear-gradient(bottom, rgb(62,184,229) 0%, rgb(44,160,202) 100%);
background-image: -ms-linear-gradient(bottom, rgb(62,184,229) 0%, rgb(44,160,202) 100%);
background-image: -webkit-gradient(
linear,
left bottom,
left top,
color-stop(0, rgb(62,184,229)),
color-stop(1, rgb(44,160,202))
);
}
</style>

<center><div id="mbb-random"></div></center>
<script type="text/javascript">
function showLucky(root){ var feed = root.feed; var entries = feed.entry || []; var entry = feed.entry[0]; for (var j = 0; j < entry.link.length; ++j){if (entry.link[j].rel == 'alternate'){window.location = entry.link[j].href;}}} function fetchLuck(luck){ script = document.createElement('script'); script.src = '/feeds/posts/summary?start-index='+luck+'&max-results=1&alt=json-in-script&callback=showLucky'; script.type = 'text/javascript'; document.getElementsByTagName('head')[0].appendChild(script); } function feelingLucky(root){ var feed = root.feed; var total = parseInt(feed.openSearch$totalResults.$t,10); var luckyNumber = Math.floor(Math.random()*total);luckyNumber++; a = document.createElement('a'); a.href = '#random'; a.rel = luckyNumber; a.onclick = function(){fetchLuck(this.rel);}; a.innerHTML = 'Random Post'; document.getElementById('mbb-random').appendChild(a); } </script><script src="/feeds/posts/summary?max-results=0&alt=json-in-script&callback=feelingLucky">
</script>

を HTML/JavaScript ガジェットとして追加してみました

上と下に余計なものが付いてきましたが、無くなると目立たなくなってしまうのでこれでいいかも

色は好みで変えるしかありませんねぇ
探せば他にもあると思います(他のも見たことがあるので)