Philip's macOS theme for Spotify, applied through spicetify-cli.

user.css

/* hiding the "your library" section header */
#view-navigation-bar > div > div.LeftSidebar__scroll-section > div:nth-child(1) > div > h2{
  display: none;
}

/* hiding the "playlists" section header */
#view-navigation-bar > div > div.LeftSidebar__scroll-section > div.LeftSidebar__section.LeftSidebar__section--rootlist > div > div > div > h2{
  display: none;
}

/* hiding n-th option(s) in the first (top) section of sidebar  */
#view-navigation-bar > div > div.LeftSidebar__section > div > ul > li:nth-child(3) {
  display: none;
}

/* hiding n-th option(s) in the second (middle) section of sidebar  */
#view-navigation-bar > div > div.LeftSidebar__scroll-section > div:nth-child(1) > div > ul > li:nth-child(1){
  display: none;
}

#view-navigation-bar > div > div.LeftSidebar__scroll-section > div:nth-child(1) > div > ul > li:nth-child(2){
  display: none;
}

#view-navigation-bar > div > div.LeftSidebar__scroll-section > div:nth-child(1) > div > ul > li:nth-child(4){
  display: none;
}

#view-navigation-bar > div > div.LeftSidebar__scroll-section > div:nth-child(1) > div > ul > li:nth-child(5){
  display: none;
}

#view-navigation-bar > div > div.LeftSidebar__scroll-section > div:nth-child(1) > div > ul > li:nth-child(6){
  display: none;
}

/* hiding "new playlist" button */
#new-playlist-button-mount-point{
  display: none;
}

/* color and other changes to make design match macOS system */
#view-player-footer {
  background: #24252A;
}

.view-player .text-container .text-item-container .text-item .scroll-text-container:after {
  background: linear-gradient(90deg,transparent,#24252A);
  right: 0;
}

#remote-playback-bar {
  background-color: #37383E;
}

#remote-playback-bar > div {
  border-bottom-color: #37383E;
}

#view-navigation-bar > div > div.LeftSidebar__scroll-section {
  background-color: #181818;
}

#view-navigation-bar {
  background-color: #181818;
}

#menu-wrapper {
  background-color: #181818;
}

#menu-wrapper {
  border-right: 1px solid #282828;
}

#view-player-footer {
  border-top: 1px solid #505155;
}

/* for friend activity */

#root > div > div.cards-wrapper > div > div > div {
  background-color: #181818;
}

#root > div > div.buddy-list-title > div {
  background-color: #181818;
}

/* border for friend activity */

#resize-buddy-list {
  border-left: 1px solid #282828;
}

/* hiding header gradient background */

#header-placeholder > div > div.app-header__content > header > div.glue-page-header__background > div.glue-page-header__background-color {
  display: none;
}

#header > div.playlist-header-wrapper > header > div.glue-page-header__background > div.glue-page-header__background-color {
  display: none;
}

/* optional option to change fonts across app to macOS system fonts */
/* 
* {
  font-family: -apple-system,system-ui,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;

  --glue-font-weight-normal: 400;
  --glue-font-weight-black: 700;
} */