Ghost/ghost/admin/app/styles/addons/gh-koenig/koenig-toolbar.css

/* Contextual toolbar
/* ---------------------------------------------------------- */

.gh-toolbar {
    position: absolute;
    display: flex;
    align-items: center;
    text-align: center;
    color: color(var(--lightgrey) l(-10%));
    background: linear-gradient(
        color(var(--darkgrey) l(-3%)),
        color(var(--darkgrey) l(-8%))
    );
    border-radius: 5px;
    box-shadow: 0 0 0 1px color(var(--darkgrey) l(-10%)), 0 8px 16px rgba(26,39,49,0.16), rgba(255,255,255,0.09) 0 1px 0 0 inset;
}

.gh-toolbar:after {
    display: block;
    content: "";
    position: absolute;
    bottom: -8px;
    left: 50%;
    margin-left: -10px;
    width: 0;
    height: 0;
    border-left: transparent 10px solid;
    border-right: transparent 10px solid;
    border-top: color(var(--darkgrey) l(-10%)) 8px solid;
}

.gh-toolbar-btn {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 40px;
    width: 32px;
    font-size: 1.6rem;
    line-height: 40px;
    transition: text-shadow 0.3s ease;
}

.gh-toolbar-btn:first-child {
    width: 43px;
    padding-left: 8px;
}
.gh-toolbar-btn:last-child {
    width: 43px;
    padding-right: 8px;
}

.gh-toolbar-btn svg {
    height: 1.4rem;
}

.gh-toolbar-btn svg g {
    stroke-width: 2px;
    stroke: color(var(--lightgrey) l(-10%));
}

.gh-toolbar-btn:hover {
    color: #fff;
    cursor: pointer;
    text-shadow: #000 0 1px 6px;
}

.gh-toolbar-btn:hover svg g {
    stroke: #fff;
}

.gh-toolbar-btn-bold {
    font-weight: 700;
}

.gh-toolbar-btn-italic {
    width: 31px;
    font-size: 1.7rem;
    text-indent: -1px;
    font-style: italic;
    font-family: Georgia, Times, serif;
    font-weight: 500;
}

.gh-toolbar-btn-strike {
    text-decoration: line-through;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
}

.gh-toolbar-btn-h1 {
    font-variant: small-caps;
    font-weight: 700;
    -webkit-font-smoothing: antialiased;
}

.gh-toolbar-btn-h2 {
    font-weight: 700;
    font-size: 0.9em;
    font-variant: small-caps;
    line-height: 42px;
    -webkit-font-smoothing: antialiased;
}

.gh-toolbar-btn-quote {
    font-size: 4rem;
    line-height: 62px;
    font-family: Georgia, Times, serif;
    -webkit-font-smoothing: antialiased;
}

.gh-toolbar-divider {
    height: 40px;
    width: 1px;
    margin: 0 9px 0 8px;
    background: color(var(--darkgrey) l(-10%));
    box-shadow: rgba(255,255,255,0.04) 1px 0 0 0;
}