editor.js/src/styles/popover.css

/** 
 * Popover styles
 */
.ce-popover {
  --border-radius: 6px;
  --width: 200px;
  --max-height: 270px;
  --padding: 6px;
  --offset-from-target: 8px;
  --color-border: #e8e8eb;
  --color-shadow: rgba(13,20,33,0.13);
  --color-background: white;
  --color-text-primary: black;
  --color-text-secondary: #707684;
  --color-border-icon: rgb(201 201 204 / 48%);
  --color-border-icon-disabled: #EFF0F1;
  --color-text-icon-active: #388AE5;
  --color-background-icon-active: rgba(56, 138, 229, 0.1);
  --color-background-item-focus: rgba(34, 186, 255, 0.08);
  --color-shadow-item-focus: rgba(7, 161, 227, 0.08);
  --color-background-item-hover: #eff2f5;
  --color-background-item-confirm: #E24A4A;
  --color-background-item-confirm-hover: #CE4343;

  min-width: var(--width);
  width: var(--width);
  max-height: var(--max-height);
  border-radius: var(--border-radius);
  overflow: hidden;
  box-sizing: border-box;
  box-shadow: 0 3px 15px -3px var(--color-shadow);
  position: absolute;
  left: 0;
  top: calc(100% + var(--offset-from-target));
  background: var(--color-background);
  display: flex;
  flex-direction: column;
  z-index: 4;

  opacity: 0;
  max-height: 0;
  pointer-events: none;
  padding: 0;
  border: none;

  &--opened {
    opacity: 1;
    padding: var(--padding);
    max-height: var(--max-height);
    pointer-events: auto;
    animation: panelShowing 100ms ease;
    border: 1px solid var(--color-border);

    @media (--mobile) {
      animation: panelShowingMobile 250ms ease;
    }
  }

  &__items {
    overflow-y: auto;
    overscroll-behavior: contain;
  }

  &__overlay {
    @media (--mobile) {
      position: fixed;
      top: 0;
      bottom: 0;
      left: 0;
      right: 0;
      background: var(--color-dark);
      z-index: 3;
      opacity: 0.5;
      transition: opacity 0.12s ease-in;
      will-change: opacity;
      visibility: visible;
    }

    &--hidden {
      display: none;
    }
  }

  &--open-top {
    top: calc(-1 * (var(--offset-from-target) + var(--popover-height)));
  }

  @media (--mobile) {
    --offset: 5px;

    position: fixed;
    max-width: none;
    min-width: calc(100% - var(--offset) * 2);
    left: var(--offset);
    right: var(--offset);
    bottom: calc(var(--offset) + env(safe-area-inset-bottom));
    top: auto;
    border-radius: 10px;

    .ce-popover__search {
      display: none;
    }
  }

  &__search, &__custom-content:not(:empty) {
    margin-bottom: 5px;
  }

  &__nothing-found-message {
    color: var(--grayText);
    display: none;
    cursor: default;
    padding: 3px;
    font-size: 14px;
    line-height: 20px;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;

    &--displayed {
      display: block;
    }
  }

  &__custom-content:not(:empty) {
    padding: 4px;

    @media (--not-mobile) {
      padding: 0;
    }
  }

  &__custom-content--hidden {
    display: none;
  }
}


/** 
 * Popover item styles
 */
.ce-popover-item {
  --border-radius: 6px;
  --icon-size: 20px;
  --icon-size-mobile: 28px;

  border-radius: var(--border-radius);
  display: flex;
  align-items: center;
  padding: 3px;
  color: var(--color-text-primary);
  user-select: none;

  @media (--mobile) {
    padding: 4px;
  }

  &:not(:last-of-type) {
    margin-bottom: 1px;
  }

  &__icon {
    border-radius: 5px;
    width: 26px;
    height: 26px;
    box-shadow: 0 0 0 1px var(--color-border-icon);
    background: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 10px;

    svg {
      width: var(--icon-size);
      height: var(--icon-size);
    }

    @media (--mobile){
      width: 36px;
      height: 36px;
      border-radius: 8px;

      svg {
        width: var(--icon-size-mobile);
        height: var(--icon-size-mobile);
      }
    }
  }

  &__title {
    font-size: 14px;
    line-height: 20px;
    font-weight: 500;

    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;

    @media (--mobile) {
      font-size: 16px;
    }
  }

  &__secondary-title {
    color: var(--color-text-secondary);
    font-size: 12px;
    margin-left: auto;
    white-space: nowrap;
    letter-spacing: -0.1em;
    padding-right: 5px;
    margin-bottom: -2px;
    opacity: 0.6;

    @media (--mobile){
      display: none;
    }
  }

  &--active {
    background: var(--color-background-icon-active);
    color: var(--color-text-icon-active);

    .ce-popover-item__icon {
      box-shadow: none;
    }
  }

  &--disabled {
    color: var(--color-text-secondary);
    cursor: default;
    pointer-events: none;

    .ce-popover-item__icon {
      box-shadow: 0 0 0 1px var(--color-border-icon-disabled);
    }
  }

  &--focused {
    &:not(.ce-popover-item--no-focus) {
      box-shadow: inset 0 0 0px 1px var(--color-shadow-item-focus);
      background: var(--color-background-item-focus) !important;
    }
  }

  &--hidden {
    display: none;
  }

  @media (--can-hover) {
    &:hover {
      cursor: pointer;
      
      &:not(.ce-popover-item--no-hover) {
        background-color: var(--color-background-item-hover);
      }

      .ce-popover-item__icon {
        box-shadow: none;
      }
    }
  }

  &--confirmation {
    background: var(--color-background-item-confirm);

    .ce-popover-item__icon {
      color: var(--color-background-item-confirm);
    }

    .ce-popover-item__title {
      color: white;
    }

    /* confirmation hover */
    &:not(.ce-popover-item--no-hover) {
      @media (--can-hover) {
        &:hover {
          background: var(--color-background-item-confirm-hover);
        }
      }
    }

    /* confirmation focus */
    &:not(.ce-popover-item--no-focus) {
      &.ce-popover-item--focused {
        background: var(--color-background-item-confirm-hover) !important;
      }
    }

  }

  &--confirmation, &--active, &--focused {
    .ce-popover-item__icon {
      box-shadow: none;
    }
  }
}


/** 
 * Animations
 */
@keyframes panelShowing {
  from {
    opacity: 0;
    transform: translateY(-8px) scale(0.9);
  }

  70% {
    opacity: 1;
    transform: translateY(2px);
  }

  to {

    transform: translateY(0);
  }
}

@keyframes panelShowingMobile {
  from {
    opacity: 0;
    transform: translateY(14px) scale(0.98);
  }

  70% {
    opacity: 1;
    transform: translateY(-4px);
  }

  to {

    transform: translateY(0);
  }
}


.wobble {
  animation-name: wobble;
  animation-duration: 400ms;
}

/**
 * @author Nick Pettit - https://github.com/nickpettit/glide
 */
@keyframes wobble {
  from {
    transform: translate3d(0, 0, 0);
  }

  15% {
    transform: translate3d(-9%, 0, 0);
  }

  30% {
    transform: translate3d(9%, 0, 0);
  }

  45% {
    transform: translate3d(-4%, 0, 0);
  }

  60% {
    transform: translate3d(4%, 0, 0);
  }

  75% {
    transform: translate3d(-1%, 0, 0);
  }

  to {
    transform: translate3d(0, 0, 0);
  }
}