BookStack/resources/sass/_editor.scss

#editor.bs-editor {
  padding-top: 0;
}

//.bs-editor .menubar {
//  border-bottom: 1px solid #DDD;
//  padding: 2px;
//}
//
//.bs-editor .menuicon {
//  cursor: pointer;
//  padding: 4px;
//  min-width: 2rem;
//  border-radius: 3px;
//  border: 1px solid transparent;
//  &:hover {
//    background-color: #EEE;
//    border: 1px solid #DDD;
//  }
//}

// The below originated from https://github.com/ProseMirror/prosemirror-menu
// and is therefore subject to the MIT license found here:
// https://github.com/ProseMirror/prosemirror-menu/blob/master/LICENSE

.ProseMirror {
  position: relative;
}

.ProseMirror {
  word-wrap: break-word;
  white-space: pre-wrap;
  white-space: break-spaces;
  -webkit-font-variant-ligatures: none;
  font-variant-ligatures: none;
  font-feature-settings: "liga" 0; /* the above doesn't seem to work in Edge */
}

.ProseMirror pre {
  white-space: pre-wrap;
}

.ProseMirror li {
  position: relative;
}

.ProseMirror-hideselection *::selection { background: transparent; }
.ProseMirror-hideselection *::-moz-selection { background: transparent; }
.ProseMirror-hideselection { caret-color: transparent; }

.ProseMirror-selectednode {
  outline: 2px solid #8cf;
}

/* Make sure li selections wrap around markers */

li.ProseMirror-selectednode {
  outline: none;
}

li.ProseMirror-selectednode:after {
  content: "";
  position: absolute;
  left: -32px;
  right: -2px; top: -2px; bottom: -2px;
  border: 2px solid #8cf;
  pointer-events: none;
}

/* Protect against generic img rules */

img.ProseMirror-separator {
  display: inline !important;
  border: none !important;
  margin: 0 !important;
}

.ProseMirror-textblock-dropdown {
  min-width: 3em;
}

.ProseMirror-menu {
  margin: 0 -4px;
  line-height: 1;
}

.ProseMirror-tooltip .ProseMirror-menu {
  width: -webkit-fit-content;
  width: fit-content;
  white-space: pre;
}

.ProseMirror-menuitem {
  margin-right: 3px;
  display: inline-block;
}

.ProseMirror-menuseparator {
  border-right: 1px solid #ddd;
  margin-right: 3px;
}

.ProseMirror-menu-dropdown, .ProseMirror-menu-dropdown-menu {
  font-size: 90%;
  white-space: nowrap;
}

.ProseMirror-menu-dropdown {
  vertical-align: 1px;
  cursor: pointer;
  position: relative;
  padding-right: 15px;
}

.ProseMirror-menu-dropdown-wrap {
  padding: 1px 0 1px 4px;
  display: inline-block;
  position: relative;
}

.ProseMirror-menu-dropdown:after {
  content: "";
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 4px solid currentColor;
  opacity: .6;
  position: absolute;
  right: 4px;
  top: calc(50% - 2px);
}

.ProseMirror-menu-dropdown-menu, .ProseMirror-menu-submenu {
  position: absolute;
  background: white;
  color: #666;
  border: 1px solid #aaa;
  padding: 2px;
}

.ProseMirror-menu-dropdown-menu {
  z-index: 15;
  min-width: 6em;
}

.ProseMirror-menu-dropdown-item {
  cursor: pointer;
  padding: 2px 8px 2px 4px;
}

.ProseMirror-menu-dropdown-item:hover {
  background: #f2f2f2;
}

.ProseMirror-menu-submenu-wrap {
  position: relative;
  margin-right: 4px;
}

.ProseMirror-menu-submenu-label {
  padding-inline-end: 12px;
  padding-inline-start: 4px;
}

.ProseMirror-menu-submenu-label:after {
  content: "";
  border-top: 4px solid transparent;
  border-bottom: 4px solid transparent;
  border-left: 4px solid currentColor;
  opacity: .6;
  position: absolute;
  right: 4px;
  top: calc(50% - 4px);
}

.ProseMirror-menu-submenu {
  display: none;
  min-width: 10em;
  left: 100%;
  top: -3px;
}

.ProseMirror-menu-active {
  background: #eee;
  border-radius: 4px;
}

.ProseMirror-menu-disabled {
  opacity: .3;
}

.ProseMirror-menu-submenu-wrap:hover > .ProseMirror-menu-submenu, .ProseMirror-menu-submenu-wrap-active > .ProseMirror-menu-submenu {
  display: block;
}

.ProseMirror-menubar {
  border-top-left-radius: inherit;
  border-top-right-radius: inherit;
  position: relative;
  min-height: 1em;
  color: #666;
  padding: 1px 6px;
  top: 0; left: 0; right: 0;
  border-bottom: 1px solid silver;
  background: white;
  z-index: 10;
  -moz-box-sizing: border-box;
  box-sizing: border-box;
  overflow: visible;
}

.ProseMirror-icon {
  display: inline-block;
  line-height: .8;
  vertical-align: -2px; /* Compensate for padding */
  padding: 2px 8px;
  cursor: pointer;
}

.ProseMirror-menu-disabled.ProseMirror-icon {
  cursor: default;
}

.ProseMirror-icon svg {
  fill: currentColor;
  height: 1em;
}

.ProseMirror-icon span {
  vertical-align: text-top;
}

.ProseMirror-gapcursor {
  display: none;
  pointer-events: none;
  position: absolute;
}

.ProseMirror-gapcursor:after {
  content: "";
  display: block;
  position: absolute;
  top: -2px;
  width: 20px;
  border-top: 1px solid black;
  animation: ProseMirror-cursor-blink 1.1s steps(2, start) infinite;
}

@keyframes ProseMirror-cursor-blink {
  to {
    visibility: hidden;
  }
}

.ProseMirror-focused .ProseMirror-gapcursor {
  display: block;
}
/* Add space around the hr to make clicking it easier */

.ProseMirror-example-setup-style hr {
  border-top: 3px solid #FFF;
  border-bottom: 3px solid #FFF;
  box-sizing: content-box;
}

.ProseMirror ul, .ProseMirror ol {
  padding-left: 30px;
}

.ProseMirror blockquote {
  padding-left: 1em;
  border-left: 3px solid #eee;
  margin-left: 0; margin-right: 0;
}

.ProseMirror-example-setup-style img {
  cursor: default;
}

.ProseMirror-prompt {
  background: white;
  padding: 5px 10px 5px 15px;
  border: 1px solid silver;
  position: fixed;
  border-radius: 3px;
  z-index: 11;
  box-shadow: -.5px 2px 5px rgba(0, 0, 0, .2);
}

.ProseMirror-prompt h5 {
  margin: 0;
  font-weight: normal;
  font-size: 100%;
  color: #444;
}

.ProseMirror-prompt input[type="text"],
.ProseMirror-prompt textarea {
  background: #eee;
  border: none;
  outline: none;
}

.ProseMirror-prompt input[type="text"] {
  padding: 0 4px;
}

.ProseMirror-prompt-close {
  position: absolute;
  left: 2px; top: 1px;
  color: #666;
  border: none; background: transparent; padding: 0;
}

.ProseMirror-prompt-close:after {
  content: "✕";
  font-size: 12px;
}

.ProseMirror-invalid {
  background: #ffc;
  border: 1px solid #cc7;
  border-radius: 4px;
  padding: 5px 10px;
  position: absolute;
  min-width: 10em;
}

.ProseMirror-prompt-buttons {
  margin-top: 5px;
  display: none;
}
#editor, .editor {
  background: white;
  color: black;
  background-clip: padding-box;
  border-radius: 4px;
  border: 2px solid rgba(0, 0, 0, 0.2);
  padding: 5px 0;
  margin-bottom: 23px;
}

.ProseMirror p:first-child,
.ProseMirror h1:first-child,
.ProseMirror h2:first-child,
.ProseMirror h3:first-child,
.ProseMirror h4:first-child,
.ProseMirror h5:first-child,
.ProseMirror h6:first-child {
  margin-top: 10px;
}

.ProseMirror {
  padding: 4px 8px 4px 14px;
  line-height: 1.2;
  outline: none;
}

.ProseMirror p { margin-bottom: 1em }

.ProseMirror-menu-color-grid-container {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
}

.ProseMirror-menu-color-grid-item {
  width: 20px;
  height: 20px;
  border: 2px solid #FFF;
  display: block;
}

.ProseMirror-menu-dialog-wrap {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.1);
  z-index: 50;
  display: grid;
}

.ProseMirror-menu-dialog-title {
  padding: $-xs $-s;
  border-bottom: 1px solid #DDD;
  font-weight: bold;
  position: relative;
  margin-bottom: $-xs;
}

.ProseMirror-menu-dialog-footer {
  padding: $-xs $-s;
  border-top: 1px solid #DDD;
  display: flex;
  justify-content: end;
  margin-top: $-xs;
}

.ProseMirror-menu-dialog-title-close {
  color: #FFF;
  position: absolute;
  top: $-xs + 2px;
  right: $-s;
  border-radius: 9px;
  height: 18px;
  width: 18px;
  text-align: center;
  line-height: 0;
  vertical-align: top;
  display: flex;
  justify-content: center;
  align-items: center;
}

.ProseMirror-menu-dialog {
  background-color: #FFF;
  border: 1px solid #DDD;
  border-radius: 3px;
  box-shadow: $bs-large;
  width: fit-content;
  min-width: 300px;
  min-height: 100px;
  margin: auto;
}

.ProseMirror-menu-dialog-button {
  border: 1px solid #DDD;
  padding: $-xs $-s;
  color: #666;
  min-width: 80px;
  cursor: pointer;
  &:hover {
    background-color: #EEE;
  }
}

.ProseMirror-menu-dialog-button + .ProseMirror-menu-dialog-button {
  margin-left: $-xs;
}

.ProseMirror-menu-dialog-form-row {
  display: grid;
  grid-template-columns: 1fr 2fr;
  align-items: center;
  padding: $-xs 0;
  label {
    padding: 0 $-s;
    font-size: .9rem;
  }
  input {
    margin: 0 $-s;
  }
}

.ProseMirror-menu-dialog-textarea-wrap {
  padding: $-xs $-s;
  label {
    padding: 0 $-s;
    font-size: .9rem;
  }
  textarea {
    width: 100%;
    font-size: 0.8rem;
  }
}

.ProseMirror-imagewrap {
  display: inline-block;
  line-height: 0;
  font-size: 0;
  position: relative;
}
.ProseMirror-imagewrap.ProseMirror-selectednode {
  outline: 0;
}

.ProseMirror img[data-show-handles] {
  outline: 4px solid #000;
}
.ProseMirror-dragdummy {
  position: absolute;
  z-index: 2;
  left: 0;
  top: 0;
  max-width: none !important;
  max-height: none !important;
}
.ProseMirror-grabhandle {
  width: 12px;
  height: 12px;
  border: 2px solid #000;
  z-index: 4;
  position: absolute;
  background-color: #FFF;
}
.ProseMirror-grabhandle-left-top {
  cursor: nw-resize;
}
.ProseMirror-grabhandle-right-top {
  cursor: ne-resize;
}
.ProseMirror-grabhandle-right-bottom {
  cursor: se-resize;
}
.ProseMirror-grabhandle-left-bottom {
  cursor: sw-resize;
}