body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
}

.burger-menu {
    cursor: pointer;
    width: 30px;
    height: 30px;
    position: relative;
    margin: 20px;
}

.burger {
    width: 100%;
    height: 4px;
    background: black;
    position: absolute;
    transition: all 0.3s ease;
}

.burger::before,
.burger::after {
    content: '';
    width: 100%;
    height: 4px;
    background: black;
    position: absolute;
    transition: all 0.3s ease;
}

.burger::before {
    top: -10px;
}

.burger::after {
    bottom: -10px;
}

.nav {
    display: none;
    background: #f8f8f8;
    padding: 10px;
    position: absolute;
    top: 60px;
    /* Отступ от верхней части экрана */
    left: 20px;
    /* Отступ от левого края */
    border: 1px solid #ccc;
    border-radius: 5px;
}

.nav.active {
    display: block;
}

.nav ul {
    list-style: none;
    padding: 0;
}

.nav li {
    margin: 10px 0;
}

.nav a {
    text-decoration: none;
    color: black;
}