Screenshots:

After installing Enhancer for YouTube extension, go to its settings and paste this code in the 'Custom Theme' box after checking it:

  


#background.ytd-masthead {

background: transparent !important;
}

html.efyt-hide-related body ytd-app ytd-popup-container.style-scope.ytd-app tp-yt-paper-dialog.style-scope.ytd-popup-container {
background-color: var(--second-background) !important;
}

yt-animated-icon path,
#yt-logo-updated_yt5 path {
color: var(--main-text);
fill: var(--main-text);
}







:root { --dimmer-text: #484054; --hover-background: #232225; --main-background: #12111255; --main-color: #3e3847; --main-text: #725e4b; --second-background: #19191a; --shadow: 0 1px .5px rgba(23, 22, 23, .2);
}

.ytChipShapeActive {
  background-color: var(--hover-background);
  color: var(--main-text) !important;
}

.ytChipShapeActive:hover {
  background-color: transparent;

box-shadow:
  color: var(--main-text) !important;
}


.ytChipShapeInactive {
  background-color: var(--main-background);
  color: var(--main-color);
}

.ytChipShapeInactive:hover {
  background-color: var(--hover-background);
}

[class="ytSearchboxComponentSearchButton ytSearchboxComponentSearchButtonDark"] {
background-color: var(--second-background) !important;
}

#video-summary > * {
background-color: var(--hover-background) !important;
}

#video-summary #content {
background-color: transparent !important;
}

#description {
background-color: var(--second-background) !important;
}

.yt-live-chat-viewer-engagement-message-renderer, .yt-live-chat-text-message-renderer {
background-color: var(--second-background) !important;
}

// uncomment below if using transparent zen and zen internet
/* [class="style-scope ytd-two-column-browse-results-renderer"] {
background-color: var(--main-background) !important;
} */
/* ytd-two-column-browse-results-renderer #secondary.ytd-two-column-browse-results-renderer {
  background-color: var(--main-background) !important;
} */



.ytd-browse-feed-actions-renderer button:hover * {
color: var(--dimmer-text) !important;
}

yt-button-shape:hover * {
  background-color: transparent !important;
}

.ytAttributedStringLinkInheritColor {
color: var(--main-text) !important;
}

[style*="color: rgb(255, 255, 255)"], .ytContentMetadataViewModelDelimiter,  {
color: var(--main-text) !important;
}

:root {
--tffc2fd3a644f6275: var(--main-text) !important;
--t4a6da19e16bf221a: var(--main-text) !important;
}

*[role="text"]::selection{
    color: var(--main-text) !important;
    background-color: transparent !important;
}


* {
font-family: 'Bricolage Grotesque' !important; 
font-weight: 400;
} 

#title yt-formatted-string {
font-size: 20px !important;
}

#yt-logo-updated-svg_yt3 path {
color: var(--main-text) !important;
}

#yt-logo-updated_yt3 g:first-child > path:nth-child(2) {
fill: var(--main-text) !important;
}

#voice-search-button {
display: none;
}
#search::placeholder{
color: var(--main-color) !important;
}
button:hover > * > * > * path{
transition: 0.5s fill ease;
}
/*

button:hover > * > * > * path{
fill: var(--main-color);
} */

#yt-logo-updated_yt1 path,
#toolbar path {
fill: var(--main-text);
}

#description.ytd-watch-metadata{
background: var(--second-background);
}
#input-container{
background-color: rgb(25, 25, 26) !important;
}

*[role="text"]{
color: var(--dimmer-text);
}

button > div> span[role="text"]{
color: var(--main-text);
}

.ytp-chrome-bottom * {
color: var(--main-text) !important;
fill: var(--main-text) !important;
}

.ytp-button .ytp-autonav-toggle-button-container {
display: none !important;
} 

.translate-button { 
color: var(--dimmer-text) !important;
}

#published-time-text > * { 
color: var(--dimmer-text) !important;
}

#content-text > * { 
color: var(--main-text);
}

#content-text > *::selection { 
background-color: var(--hover-background) !important;
}

span[class="yt-core-attributed-string--highlight-text-decorator"]{
background-color: var(--hover-background) !important;
}


[class="yt-spec-button-shape-next yt-spec-button-shape-next--text yt-spec-button-shape-next--mono yt-spec-button-shape-next--size-s"]:hover,
[class="yt-spec-button-shape-next yt-spec-button-shape-next--text yt-spec-button-shape-next--mono yt-spec-button-shape-next--size-s yt-spec-button-shape-next--icon-button yt-spec-button-shape-next--override-small-size-icon"]:hover {
background-color: var(--hover-background) !important;
}

.ytd-comment-engagement-bar
{
color: var(--dimmer-text) !important;
}

.ytd-text-inline-expander *
{
color: var(--main-text) !important;
}

.ytd-text-inline-expander a
{
color: var(--dimmer-text) !important;
}

/*a:hover
{
background-color: var(--hover-background) !important;
outline: 1px solid #CCC;
}*/

.ytSpecButtonShapeNextMono.ytSpecButtonShapeNextFilled
{
background-color: var(--second-background) !important;
}

.ytSpecIconShapeHost > div {
fill: var(--main-text) !important;
}

ytd-watch-metadata * {
color: var(--main-text) !important;
}

.ytContentMetadataViewModelMetadataRow {
color: var(--main-text) !important;
}

yt-formatted-string{
color: var(--main-text) !important;
}

.ytSpecButtonShapeNextButtonTextContent {
color: var(--main-text) !important;
}

#end.ytd-masthead{
min-width: 0 !important;
}

/*#content {
background: var(--main-background);
}*/




.ytSpecButtonShapeNextMono.ytSpecButtonShapeNextTonal:hover {
background: var(--hover-background) !important;
}


.ytSpecButtonShapeNextMono.ytSpecButtonShapeNextTonal {
background: var(--second-background) !important;
}

.ytp-volume-slider-handle::before {
background-color: var(--main-text) !important;
}

.ytp-volume-slider * {
background-color: var(--main-text) !important;
}

[class="style-scope ytd-expander"]{
background-color: transparent !important;
}
ytd-comment-thread-renderer.style-scope:nth-child(1) > div:nth-child(1) > ytd-comment-view-model:nth-child(2) > div:nth-child(3) > div:nth-child(2) > div:nth-child(1) > div:nth-child(2) > span:nth-child(2) > ytd-author-comment-badge-renderer:nth-child(1) {
background-color: var(--second-background);
}


.ytAttributedStringLink {
color: var(--dimmer-text) !important;
}

#tooltip {
background-color: var(--second-background);
}




.ytSpecIconBadgeShapeTypeNotification .ytSpecIconBadgeShapeBadge {
background-color: #232324;
  color: #725e4b;
}

#tooltip {
  color: var(--main-text) !important;
}


.iron-selected.yt-dropdown-menu{
  background-color: var(--main-color) !important;
}

.iron-selected.yt-dropdown-menu * {
color: var(--main-text) !important;
}

.iron-selected.yt-dropdown-menu {
background-color: var(--hover-background) !important;
}


tp-yt-paper-listbox.yt-dropdown-menu tp-yt-paper-item.yt-dropdown-menu:hover {
  background-color: var(--hover-background) !important;
}

*::selection {
background-color: var(--hover-background) !important;
}

.ytSearchboxComponentHostDark {
  color: var(--main-text);
}

.ytSuggestionComponentSuggestion  {
color: var(--main-text) !important;
}

.ytSearchboxComponentHostDark {
  color: var(--main-color) !important;
}

.ytSearchboxComponentSuggestionsContainerDark { 
background-color: var(--second-background) !important;
}

ytd-multi-page-menu-renderer {
background-color: var(--second-background) !important;
}


a.yt-simple-endpoint.yt-formatted-string {
  color: var(--main-color) !important;
}

a:visited {
  color: var(--main-color) !important;
}

.ytBadgeShapeCommerce {
  color: #468041 !important;
background-color: var(--second-background) !important;
border-radius: 16px !important;
padding: 3px 9px 3px 9px !important;
}

.ytSpecIconBadgeShapeTypeNotification .ytSpecIconBadgeShapeBadge {
background-color: var(--hover-background) !important;
  color: var(--main-text) !important;
}

#input-container {
  background-color: transparent !important;
}

[class="ytSpecButtonShapeNextHost ytSpecButtonShapeNextFilled ytSpecButtonShapeNextSizeM ytSpecButtonShapeNextDisabled ytSpecButtonShapeNextEnableBackdropFilterExperiment"]:hover {
  background-color: red important;
}

[class="ytSpecButtonShapeNextHost ytSpecButtonShapeNextFilled ytSpecButtonShapeNextSizeM ytSpecButtonShapeNextDisabled ytSpecButtonShapeNextEnableBackdropFilterExperiment"] {
  background-color: var(--second-background) !important;
}

.ytSpecIconBadgeShapeStyleOverlay .ytSpecIconBadgeShapeBadge
{
border: none !important;
}

tp-yt-paper-toast.yt-notification-action-renderer {
background-color: var(--second-background) !important;
{