hexo-theme-keep/layout/_partial/tools.ejs

<div class="tools-container">
    <ul class="tools-list">
        <li class="search-btn">
            <i class="fa fa-search"></i>
        </li>
        <li class="mode-toggle-btn">
            <i class="fa fa-moon-o"></i>
        </li>
    </ul>
</div>