YouTube Dark Stylesheet

style.css

/* imo, Roboto is too narrow, this spaces it more nicely */
html, body,
ytd-page-manager > *.ytd-page-manager {
    letter-spacing: 0.2px;
    background-color: rgba(38, 43, 55, 1) !important;
}

/* VIDEO TITLE */
.title.ytd-video-primary-info-renderer {
    color: #dce1eb;
    font-size: 22px !important;
}
#video-title.yt-simple-endpoint.ytd-grid-video-renderer {
    color: #dce1eb;
}
.title.ytd-guide-entry-renderer {
    color: #dce1eb;
}

/* VIDEO DESC */
.content.ytd-video-secondary-info-renderer {
   color: #cbd1dd;
}

.count-text.ytd-comments-header-renderer {
    color: #cbd1dd;
}

#owner-name.ytd-video-owner-renderer {
    font-size: 1.6rem;
    margin-bottom: 4px;
}

/* VIDEO MENU BTN TEXT */
ytd-toggle-button-renderer.force-icon-button a.ytd-toggle-button-renderer {
    font-size: 15px;
}

/* COMMENT TEXT, RELATED VIDS TITLE TEXT */
#content-text.ytd-comment-renderer,
#video-title {
    color: #cbd1dd;
    font-size: 14px !important;
}

/* COMMENT USERNAME, MORE/LESS BTN */
#author-text.yt-simple-endpoint.ytd-comment-renderer,
.more-button.ytd-comment-renderer, .less-button.ytd-comment-renderer {
    color: rgba(140, 202, 255, 0.9);
    font-size: 13px !important;
}

/* COMMENT USERNAME (OP) */
ytd-author-comment-badge-renderer.creator {
   background-color: rgb(72, 122, 235) !important;
}
ytd-author-comment-badge-renderer.creator yt-formatted-string {
    color: white !important;
}
    

/* NAVBAR, CHANNEL HEADER, NOTIFICATIONS BOX */
#masthead,
#channel-header.ytd-c4-tabbed-header-renderer,
#tabs-inner-container.ytd-c4-tabbed-header-renderer,
ytd-multi-page-menu-renderer {
 background-color: rgba(21, 25, 36, 1);
 box-shadow: 0 6px 50px rgba(0, 0, 0, 0.3);
}

/* POPOVERS */
paper-menu {
    background-color: rgba(21, 25, 36, 0.94);
    border-radius: 4px;
}
.dropdown-content.paper-menu-button {
    background-color: transparent;
}

/* THUMBNAILS */
ytd-thumbnail.ytd-compact-video-renderer,
ytd-thumbnail.ytd-video-renderer {
    box-shadow: 0 4px 20px -4px rgba(0, 0, 0, 0.4);
}
ytd-thumbnail.ytd-compact-video-renderer img,
ytd-thumbnail.ytd-video-renderer img {
    border-radius: 2px;
}

/* SEARCH */
ytd-searchbox[mode=legacy] #container.ytd-searchbox {
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid transparent;
    box-shadow: none;
    border-radius: 2px;
}
#search-icon-legacy.ytd-searchbox {
    background-color: transparent;
    border: none;
    border-radius: 3px;
    width: 50px;
}
ytd-searchbox[mode=legacy] #search-icon-legacy.ytd-searchbox:hover > yt-icon {
    color: rgba(255,255,255,0.8) !important;
}
ytd-searchbox[mode=legacy] #search-icon-legacy.ytd-searchbox:hover {
    background-color: transparent;
}

/* SIDEBBAR */
ytd-guide-renderer.ytd-app,
app-drawer.ytd-app:not([persistent]) #header.ytd-app {
     background-color: rgb(34, 37, 48);
}
#endpoint.yt-simple-endpoint.ytd-guide-entry-renderer:hover {
    background-color: rgb(53, 58, 69);
}

/* MINOR TEXT (off-white) */
#published-time-text.ytd-comment-renderer [is=yt-endpoint], 
ytd-button-renderer #button.ytd-button-renderer, 
yt-icon,
#metadata-line.ytd-grid-video-renderer,
.more-button.ytd-comment-replies-renderer, .less-button.ytd-comment-replies-renderer,
.more-button.ytd-video-secondary-info-renderer, .less-button.ytd-video-secondary-info-renderer,
.date.ytd-video-secondary-info-renderer,
#metadata.ytd-video-meta-block,
.view-count,
#title.ytd-metadata-row-renderer,
#byline.ytd-video-meta-block,
#metadata-line.ytd-video-meta-block,
#label.ytd-pinned-comment-badge-renderer,
paper-tab:not(.iron-selected) > .tab-content.paper-tab,
#footer.ytd-guide-renderer  #guide-links-primary a, #footer.ytd-guide-renderer  #guide-links-secondary a,
#autoplay.ytd-compact-autoplay-renderer,
#title-annotation.ytd-shelf-renderer,
paper-button.yt-next-continuation,
#description-text.ytd-video-renderer,
ytd-toggle-button-renderer.force-icon-button a.ytd-toggle-button-renderer,
#subtitle.ytd-shelf-renderer,
#published-time-text.ytd-comment-renderer {
    color: rgba(180, 190, 200, 0.8) !important;
}

/* LIKE BTN */
ytd-toggle-button-renderer.force-icon-button a.ytd-toggle-button-renderer .style-default-active {
    color: white !important;
}

#top-level-buttons ytd-toggle-button-renderer.style-default-active:first-child yt-icon,
#like-button .style-default-active > yt-icon {
    color: #5fd9b1 !important;
}

#top-level-buttons ytd-toggle-button-renderer.style-default-active:nth-child(2) yt-icon,
#dislike-button .style-default-active > yt-icon {
    color: hsl(3, 100%, 66%) !important;
}

/* COMMENT BTN */
ytd-button-renderer #button.ytd-button-renderer.style-primary {
 color: white !important;   
}

paper-button {
    background-color: transparent;
}

/* VIEWS */
.view-count {
    font-size: 18px;
}

/* RED ICON */
ytd-guide-entry-renderer[active] .guide-icon.ytd-guide-entry-renderer {
    color: rgba(255, 78, 78, 0.83) !important;
}

/* RED 'NEW' ICON */
.badge-style-type-simple.ytd-badge-supported-renderer {
    background-color: rgba(96, 100, 118, 0.83);
    color: rgba(255, 255, 255, 0.78);
}

/* LINKS */
[is=yt-endpoint],
.yt-simple-endpoint,
paper-tab:not(.iron-selected):hover > .tab-content {
   color: rgba(140, 202, 255, 0.9);
}
[is=yt-endpoint]:hover,
.yt-simple-endpoint:hover {
    color: rgba(180, 230, 255, 1);
}

/* SUBSCRIBE BTN */
paper-button.ytd-subscribe-button-renderer {
    background: linear-gradient(90deg,hsl(341, 80%, 49%), hsl(3, 81.8%, 49.6%));
    transition: all 0.2s ease;
}
paper-button.ytd-subscribe-button-renderer:hover {
    filter: brightness(1.25);
}
paper-button[subscribed].ytd-subscribe-button-renderer {
    background: hsl(0, 0%, 93.3%);
}

/* VOTE COUNT (on comments) */
#vote-count.ytd-comment-action-buttons-renderer {
 color: #5fd9b1;   
}

/* LIKE BAR */
#sentiment.ytd-video-primary-info-renderer {
 width: 255px;
 height: 3px;
 margin-top: 6px;
}
#like-bar.ytd-sentiment-bar-renderer {
 height: 3px;   
}

youtube-dark-stylesheet.markdown

YouTube Dark Stylesheet

A Pen by Captain Anonymous on CodePen.

License.