panel/app/assets/stylesheets/editor.scss

.editor {
	box-sizing: border-box;
	*, *::before, *::after { box-sizing: inherit; }

	h1, h2, h3, h4, h5, h6, p {
		min-height: 1.4em;
		line-height: 1.4;
		margin: 0;
	}

	mark {
		background: #f206f9;
		padding: 0;
	}

	.selected {
		outline: #f206f9 solid medium;
		outline-offset: 1pt;
	}

	img, video, iframe {
		width: 100%;
		max-width: 600px;
		display: block;
		margin: 0 auto;
	}

	.editor-content {
		div[data-align="left"] { text-align: left; }
		div[data-align="center"] { text-align: center; }
		div[data-align="right"] { text-align: right; }
	}

	*[data-editor-loading] {
		opacity: 0.5;
	}
	*[data-editor-error] {
		filter: grayscale(100%);
	}
}