The entire code is shared in this post:
The part related to tasks is hereunder:
/* Checkboxes instead of brackets in edit mode */
div:not(.CodeMirror-activeline)>.CodeMirror-line span.cm-formatting-task.cm-meta,
div:not(.CodeMirror-activeline)>.CodeMirror-line span.cm-formatting-task.cm-property {
color: transparent;
position: relative;
display: inline !important;
margin-right: -0.1rem;
}
div:not(.CodeMirror-activeline)>.CodeMirror-line span.cm-formatting-task.cm-meta:after,
div:not(.CodeMirror-activeline)>.CodeMirror-line span.cm-formatting-task.cm-property:after {
content: “○”;
position: absolute;
top: 3px;
left: 0px;
color: rgb(219, 95, 12);
font-size: 18px;
}
div:not(.CodeMirror-activeline)>.CodeMirror-line span.cm-formatting-task.cm-property:after {
content: “✓”;
color: rgb(124, 131, 124) !important;
}
span.cm-formatting-task.cm-property ~ span {
text-decoration: line-through;
color: rgb(124, 131, 124) !important;
}