/* bài 1 */
h1 {
    color: red;
}

.highlight {
    color: blue;
}

#special {
    text-decoration: underline ;
}

.box > p {
    background-color: yellow;
}

ul > li {
    border: solid 2px black;
}

/* bài 2 */
a:hover {
    color: orange;
}

button:active {
    background-color: green;
}

ul > li:first-child {
    color: blue;
}

ol > li:last-child {
    color: red;
}

li:nth-child(odd) {
    background-color: gray ;
}
/* bài 3 */
h2::before {
    content:"👉" ;
}

li::after {
    content: "✔";
}

p::first-letter {
    font-size: 30px;
    color: red;
}

p::first-line {
    background-color: yellow;
}

p::selection {
    background-color: green;
}