HTML

<a href="" class="maru arrow">ボタン</a>

CSS

.arrow { position: relative; display: inline-block; padding: 0 16px 0 0; color: #000; vertical-align: middle; text-decoration: none; }
.arrow::before, .arrow::after { position: absolute; top: 0; bottom: 0; right: 0; margin: auto; content: ""; vertical-align: middle; }
.maru::before { width: 12px; height: 12px; -webkit-border-radius: 50%; border-radius: 50%; background: #fff; }
.maru::after { right: 5px; width: 3px; height: 3.2px;/* .2がないとホバー時にずれる */ border-top: 1px solid #4cbbd0; border-right: 1px solid #4cbbd0; -webkit-transform: rotate(45deg); transform: rotate(45deg); }
.maru:hover::after { border-color: #4cbbd0; }