transitions w3schools code example

Example 1: html transition

html.color-theme-in-transition,
html.color-theme-in-transition *,
html.color-theme-in-transition *:before,
html.color-theme-in-transition *:after {
	transition: all 750ms !important;  
    transition-delay: 0 !important;
}

Example 2: Using CSS transitions

div {
    transition: <property> <duration> <timing-function> <delay>;
}