jellyfin-web/dashboard-ui/themes/ios.css

html, body {
    font-family: Helvetica Neue;
    /* Setting it here will help prevent white flashes */
    background-color: #1c1c1c;
}

.viewMenuBar, .libraryViewNav {
    background-color: rgba(28,28,28,.97);
}

.ui-page-theme-b {
    background-color: #1c1c1c;
}

.libraryViewNav a {
    font-weight: 400;
    text-transform: none;
    color: #ccc !important;
    padding-top: 16px;
}

.libraryViewNav .ui-btn-active {
    border-bottom-color: transparent;
    color: #539FFD !important;
}

.libraryViewNav {
    border-top: 1px solid #333;
    font-size: 12px;
}

.viewMenuBar {
    border-bottom: 1px solid #333;
}

.barsMenuButton .fa {
    color: #539FFD !important;
}

.btn, .btn-large {
    font-family: Helvetica Neue !important;
}

.pageTitle {
    font-family: Helvetica Neue;
}

.ui-btn {
    font-family: Helvetica Neue;
}

.ui-loader h1 {
    font-family: Helvetica Neue;
}

h1, h1 a {
    font-weight: 400 !important;
}

.btnNotificationsInner {
    font-weight: 400;
}

.channelList {
    font-weight: 400;
}

.channelHeaderCellInner {
    font-weight: 400;
}

.librarySidebarLinks a {
    font-weight: 400 !important;
}

.libraryMenuButtonText {
    font-weight: 500 !important;
    position: relative;
    top: 2px;
}

.libraryPanelHeader span {
    font-weight: 400;
}

.visualCardBox {
    background: none !important;
    -moz-box-shadow: none;
    -ms-box-shadow: none;
    -webkit-box-shadow: none;
    box-shadow: none;
}

    .visualCardBox .outerCardFooter {
        padding: 0;
    }


.viewMenuSearch {
    background: #1c1c1c;
}

.libraryMenuButtonText {
    position: absolute;
    left: 100px;
    right: 100px;
    text-align: center;
    font-size: 16px;
    margin: 0 auto !important;
}

.libraryViewNav .material-icons {
    display: block;
    margin-top: -5px;
    font-size: 15px;
}

.btnActiveCast i {
    color: #539FFD !important;
}
.libraryViewNav a:not(.ui-btn-active):hover {
    color: #539FFD !important;
}