newsupernova/lib/web/mage/adminhtml/wysiwyg/tiny_mce/themes/ui.css

/**
 * Copyright © Magento, Inc. All rights reserved.
 * See COPYING.txt for license details.
 */
.magento-placeholder {
    display: inline-block;
    margin: 0 5px;
    background: #dff7ff;
    outline: 2px solid #c0dffa;
    padding: 2px 4px;
    vertical-align: bottom;
    height: 20px;
    cursor: pointer !important;
    font-weight: normal;
    font-style: normal;
    font-size: 14px;
    color: #000;
    box-sizing: initial;
    word-break: break-all;
}

.magento-placeholder-error {
    display: inline-block;
    margin: 0 5px;
    background: #ffc0cb;
    outline: 2px solid #F7AAAA !important;
    padding: 2px 4px;
    vertical-align: bottom;
    height: 20px;
}

.magento-placeholder-error:before {
    content: '';
    display: inline-block;
    background-image: url(data:image/png;base64,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);
    background-repeat: no-repeat;
    background-position-x: 1px;
    background-position-y: 1px;
    width: 20px;
    height: inherit;
    margin-right: 4px;
    vertical-align: middle;
}

.magento-placeholder-error img {
    display: none;
}

.magento-placeholder-error[data-mce-selected] {
    outline: 2px solid #E12525 !important;
}

.magento-placeholder-error img,
.magento-placeholder img {
    vertical-align: middle;
    max-height: 20px;
    margin-right: 5px;
}