[PinkMilk]

CSS4 solution:

.selectable{
    -webkit-touch-callout: all; /* iOS Safari */
    -webkit-user-select: all; /* Safari */
    -khtml-user-select: all; /* Konqueror HTML */
    -moz-user-select: all; /* Firefox */
    -ms-user-select: all; /* Internet Explorer/Edge */
    user-select: all; /* Chrome and Opera */
}

user-select is a CSS Module Level 4 specification, that is currently a draft and non-standard CSS property, but browsers support it well ? see #search=user-select.

Read more on user-select here on MDN and play with it here in w3scools

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