WordPress/wp-admin/css/widgets.css

/* General Widgets Styles */

.widget {
	margin: 0 auto 10px;
	position: relative;
	box-sizing: border-box;
}

.widget-top {
	font-size: 13px;
	font-weight: 600;
	background: #f7f7f7;
}

.widget-top .widget-action {
	border: 0;
	margin: 0;
	padding: 10px;
	background: none;
	cursor: pointer;
	outline: none;
}

.widget-title h3,
.widget-title h4 {
	margin: 0;
	padding: 15px;
	font-size: 1em;
	line-height: 1;
	overflow: hidden;
	white-space: nowrap;
	text-overflow: ellipsis;
	-webkit-user-select: none;
	-moz-user-select: none;
	-ms-user-select: none;
	user-select: none;
}

.widgets-holder-wrap .widget-inside {
	border-top: none;
	padding: 1px 15px 15px 15px;
	line-height: 16px;
}

.in-widget-title,
#widgets-right a.widget-control-edit,
#available-widgets .widget-description {
	color: #666;
}

.deleting .widget-title,
.deleting .widget-top .widget-action .toggle-indicator:before {
	color: #a0a5aa;
}

/* Media Widgets */
.wp-core-ui .media-widget-control.selected .placeholder,
.wp-core-ui .media-widget-control.selected .not-selected,
.wp-core-ui .media-widget-control .selected {
	display: none;
}

.media-widget-control.selected .selected {
	display: inline-block;
}

.media-widget-buttons {
	text-align: left;
	margin-top: 0;
}

.media-widget-control .media-widget-buttons .button {
	width: auto;
	height: auto;
	margin-top: 12px;
	white-space: normal;
}

.media-widget-buttons .button:first-child {
	margin-right: 8px;
}

.media-widget-control .placeholder {
	border: 1px dashed #b4b9be;
	box-sizing: border-box;
	cursor: default;
	line-height: 20px;
	padding: 9px 0;
	position: relative;
	text-align: center;
	width: 100%;
}

.media-widget-control .media-widget-preview {
	text-align: center;
}
.media-widget-control .media-widget-preview .notice {
	text-align: initial;
}
.media-frame .media-widget-embed-notice p code,
.media-widget-control .notice p code {
	padding: 0 3px 0 0;
}
.media-frame .media-widget-embed-notice {
	margin-top: 16px;
}
.media-widget-control .media-widget-preview img {
	max-width: 100%;
}
.media-widget-control .media-widget-preview .wp-video-shortcode {
	background: #000;
}

.media-frame.media-widget .media-toolbar-secondary {
	min-width: 300px;
}

.media-frame.media-widget .image-details .embed-media-settings .setting.align,
.media-frame.media-widget .attachment-display-settings .setting.align,
.media-frame.media-widget .embed-media-settings .setting.align,
.media-frame.media-widget .embed-link-settings .setting.link-text,
.media-frame.media-widget .replace-attachment,
.media-frame.media-widget .checkbox-setting.autoplay {
	display: none;
}

.media-widget-video-preview {
	width: 100%;
}

.media-widget-video-link {
	display: inline-block;
	min-height: 132px;
	width: 100%;
	background: black;
}

.media-widget-video-link .dashicons {
	font: normal 60px/1 'dashicons';
	position: relative;
	width: 100%;
	top: -90px;
	color: white;
	text-decoration: none;
}

.media-widget-video-link.no-poster .dashicons {
	top: 30px;
}

.media-frame #embed-url-field.invalid {
	border: 1px solid #f00;
}

/* Widget Dragging Helpers */
.widget.ui-draggable-dragging {
	min-width: 100%;
}

.widget.ui-sortable-helper {
	opacity: 0.8;
}

.widget-placeholder {
	border: 1px dashed #b4b9be;
	margin: 0 auto 10px;
	height: 45px;
	width: 100%;
	box-sizing: border-box;
}

#widgets-right .widget-placeholder {
	margin-top: 0;
}

#widgets-right .closed .widget-placeholder {
	height: 0;
	border: 0;
	margin-top: -10px;
}

/* Widget Sidebars */
.sidebar-name {
	position: relative;
	box-sizing: border-box;
}

.sidebar-name-arrow {
	position: absolute;
	top: 0;
	right: 0;
	bottom: 0;
}

.js .sidebar-name {
	cursor: pointer;
}

.sidebar-name h2,
.sidebar-name h3 {
	margin: 0;
	padding: 8px 10px;
	overflow: hidden;
	white-space: nowrap;
}

.widgets-holder-wrap .description {
	padding: 0 0 15px;
	margin: 0;
	font-style: normal;
	color: #72777c;
}

.widget-holder .description,
.inactive-sidebar .description {
	color: #555d66;
}

#widgets-right .widgets-holder-wrap .description {
	padding-left: 7px;
	padding-right: 7px;
}

/* Widgets 2-col Layout */
div.widget-liquid-left {
	margin: 0;
	width: 38%;
	float: left;
}

div.widget-liquid-right {
	float: right;
	width: 58%;
}

/* Widgets Left - Available Widgets */

div#widgets-left {
	padding-top: 12px;
}

div#widgets-left .closed .sidebar-name,
div#widgets-left .inactive-sidebar.closed .sidebar-name {
	margin-bottom: 10px;
}

div#widgets-left .sidebar-name h2,
div#widgets-left .sidebar-name h3 {
	padding: 10px 0;
	margin: 0 10px 0 0;
}

#widgets-left .sidebar-name .sidebar-name-arrow:before {
	padding: 9px;
}

#widgets-left .widgets-holder-wrap,
div#widgets-left .widget-holder {
	background: transparent;
	border: none;
}

#widgets-left .widgets-holder-wrap {
	border: none;
	box-shadow: none;
}

#available-widgets .widget-action {
	display: none;
}

#available-widgets .widget {
	margin: 0;
}

#available-widgets .widget:nth-child(odd) {
	clear: both;
}

#available-widgets .widget .widget-description {
	display: block;
	padding: 10px 15px;
	font-size: 12px;
}

#available-widgets #widget-list {
	position: relative;
}

/* Inactive Sidebars */
#widgets-left .inactive-sidebar {
	clear: both;
	width: 100%;
	background: transparent;
	padding: 0;
	margin: 0 0 20px 0;
	border: none;
	box-shadow: none;
}

#widgets-left .inactive-sidebar.first {
	margin-top: 40px;
}

/* Not sure what this is for... */
div#widgets-left .inactive-sidebar .widget.expanded {
	left: auto;
}

.widget-title-action {
	float: right;
	position: relative;
}

div#widgets-left .inactive-sidebar .widgets-sortables {
	min-height: 42px;
	padding: 0;
	background: transparent;
	margin: 0;
	position: relative;
}

/* Widgets Right */

div#widgets-right .sidebars-column-1,
div#widgets-right .sidebars-column-2 {
	max-width: 450px;
}

div#widgets-right .widgets-holder-wrap {
	margin: 10px 0 0 0;
}

div#widgets-right .sidebar-description {
	min-height: 20px;
	margin-top: -5px;
}

div#widgets-right .sidebar-name h2,
div#widgets-right .sidebar-name h3 {
	padding: 15px 7px;
}

div#widgets-right .sidebar-name .sidebar-name-arrow:before {
	top: 2px;
}

div#widgets-right .widget-top {
	padding: 0;
}

div#widgets-right .widgets-sortables {
	padding: 0 8px;
	margin-bottom: 9px;
	position: relative;
	min-height: 123px;
}

div#widgets-right .closed .widgets-sortables {
	min-height: 0;
	margin-bottom: 0;
}

.sidebar-name .spinner,
.remove-inactive-widgets .spinner {
	float: none;
	position: relative;
	top: -2px;
	margin: -5px 5px;
}

/* Dragging a widget over a closed sidebar */
#widgets-right .widgets-holder-wrap.widget-hover {
	border-color: #72777c;
	box-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

/* Accessibility Mode */
.widgets_access #widgets-left .widget .widget-top {
	cursor: auto;
}

.widgets_access #wpwrap .widgets-holder-wrap.closed .sidebar-description,
.widgets_access #wpwrap .widgets-holder-wrap.closed .widget,
.widgets_access #wpwrap .widget-control-edit {
	display: block;
}

.widgets_access #widgets-left .widget .widget-top:hover,
.widgets_access #widgets-right .widget .widget-top:hover {
	border-color: #ddd;
}

#available-widgets .widget-control-edit .edit,
#widgets-left .inactive-sidebar .widget-control-edit .add,
#widgets-right .widget-control-edit .add {
	display: none;
}

.widget-control-edit {
	display: block;
	color: #666;
	background: #EEE;
	padding: 0 15px;
	line-height: 43px;
	border-left: 1px solid #DDD;
}

#widgets-left .widget-control-edit:hover,
#widgets-right .widget-control-edit:hover {
	color: #fff;
	background: #444;
	border-left: 0;
	outline: 1px solid #444;
}

.widgets-holder-wrap .sidebar-name,
.widgets-holder-wrap .sidebar-description {
	-webkit-user-select: none;
	-moz-user-select: none;
	-ms-user-select: none;
	user-select: none;
}

.editwidget {
	margin: 0 auto;
}

.editwidget .widget-inside {
	display: block;
	padding: 0 15px;
}

.editwidget .widget-control-actions {
	margin-top: 20px;
}

.js .widgets-holder-wrap.closed .widget,
.js .widgets-holder-wrap.closed .sidebar-description,
.js .widgets-holder-wrap.closed .remove-inactive-widgets,
.js .widgets-holder-wrap.closed .description,
.js .closed br.clear {
	display: none;
}

.js .widgets-holder-wrap.closed .widget.ui-sortable-helper {
	display: block;
}

/* Hide Widget Settings by Default */
.widget-inside,
.widget-description {
	display: none;
}

.widget-inside {
	background: #fff;
}

/* Dragging widgets over the available widget area show's a "Deactivate" message */
#removing-widget {
	display: none;
	font-weight: 400;
	padding-left: 15px;
	font-size: 12px;
	line-height: 1;
	color: black;
}

.js #removing-widget {
	color: #00a0d2;
}

.widget-control-noform,
#access-off,
.widgets_access .widget-action,
.widgets_access .sidebar-name-arrow,
.widgets_access #access-on,
.widgets_access .widget-holder .description,
.no-js .widget-holder .description {
	display: none;
}

.widgets_access .widget-holder,
.widgets_access #widget-list {
	padding-top: 10px;
}

.widgets_access #access-off {
	display: inline;
}

.widgets_access .sidebar-name,
.widgets_access .widget .widget-top {
	cursor: default;
}


/* Widgets Area Chooser */
.widget-liquid-left #widgets-left.chooser #available-widgets .widget,
.widget-liquid-left #widgets-left.chooser .inactive-sidebar {
	transition: opacity 0.1s linear;
}

.widget-liquid-left #widgets-left.chooser #available-widgets .widget,
.widget-liquid-left #widgets-left.chooser .inactive-sidebar {
	/* -webkit-filter: blur(1px); */
	opacity: 0.2;
	pointer-events: none;
}

.widget-liquid-left #widgets-left.chooser #available-widgets .widget-in-question {
	/* -webkit-filter: none; */
	opacity: 1;
	pointer-events: auto;
}

.widgets-chooser ul,
#widgets-left .widget-in-question .widget-top,
#available-widgets .widget-top:hover,
div#widgets-right .widget-top:hover,
#widgets-left .widget-top:hover {
	border-color: #999;
	box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.widgets-chooser ul.widgets-chooser-sidebars {
	margin: 0;
	list-style-type: none;
	max-height: 300px;
	overflow: auto;
}

.widgets-chooser {
	display: none;
}

.widgets-chooser ul {
	border: 1px solid #ccc;
}

.widgets-chooser li {
	padding: 10px 15px 10px 35px;
	border-bottom: 1px solid #ccc;
	background: #fff;
	margin: 0;
	cursor: pointer;
	outline: none;
	position: relative;
	transition: background 0.2s ease-in-out;
}

 /* @todo looks like these hover/focus states are overridden by .widgets-chooser-selected */
.widgets-chooser li:hover,
.widgets-chooser li:focus {
	background: rgba(255,255,255,0.7);
}

.widgets-chooser li:focus:before {
	content: "\f147";
	display: block;
	-webkit-font-smoothing: antialiased;
	font: normal 26px/1 dashicons;
	color: #555d66;
	position: absolute;
	top: 7px;
	left: 5px;
}

.widgets-chooser li:last-child {
	border: none;
}

.widgets-chooser li.widgets-chooser-selected {
	background: #00a0d2;
	color: #fff;
}

.widgets-chooser li.widgets-chooser-selected:before,
.widgets-chooser li.widgets-chooser-selected:focus:before {
	content: "\f147";
	display: block;
	-webkit-font-smoothing: antialiased;
	font: normal 26px/1 dashicons;
	color: #fff;
	position: absolute;
	top: 7px;
	left: 5px;
}

.widgets-chooser .widgets-chooser-actions {
	padding: 10px 0 12px 0;
	text-align: center;
}

.widgets-chooser button {
	margin-right: 5px;
}

#available-widgets .widget .widget-top {
	cursor: pointer;
}

#available-widgets .widget.ui-draggable-dragging .widget-top {
	cursor: move;
}

/* =Specific widget styling
-------------------------------------------------------------- */
.text-widget-fields {
	position: relative;
}
.text-widget-fields [hidden] {
	display: none;
}
.text-widget-fields .wp-pointer.wp-pointer-top {
	position: absolute;
	z-index: 3;
	top: 100px;
	right: 10px;
	left: 10px;
}
.text-widget-fields .wp-pointer .wp-pointer-arrow {
	left: auto;
	right: 15px;
}
.text-widget-fields .wp-pointer .wp-pointer-buttons {
	line-height: 1.4em;
}

/* =Media Queries
-------------------------------------------------------------- */

@media screen and (max-width: 480px) {
	div.widget-liquid-left {
		width: 100%;
		float: none;
		border-right: none;
		padding-right: 0;
	}

	#widgets-left .sidebar-name {
		margin-right: 0;
	}

	#widgets-left #available-widgets .widget-top {
		margin-right: 0;
	}

	#widgets-left .inactive-sidebar .widgets-sortables {
		margin-right: 0;
	}

	div.widget-liquid-right {
		width: 100%;
		float: none;
	}

	div.widget {
		margin: 0 auto 10px !important;
		max-width: 480px;
	}
}

@media screen and (max-width: 320px) {
	div.widget {
		max-width: 320px;
	}
}

@media only screen and (min-width: 1250px) {
	#widgets-left #available-widgets .widget {
		width: 49%;
		float: left;
	}

	.widget.ui-draggable-dragging {
		min-width: 49%;
	}

	#widgets-left #available-widgets .widget:nth-child(even) {
		float: right;
	}

	#widgets-right .sidebars-column-1,
	#widgets-right .sidebars-column-2 {
		float: left;
		width: 49%;
	}

	#widgets-right .sidebars-column-1 {
		margin-right: 2%;
	}

	#widgets-right.single-sidebar .sidebars-column-1,
	#widgets-right.single-sidebar .sidebars-column-2 {
		float: none;
		width: 100%;
		margin: 0;
	}
}