.main-navigation ul ul {
border-radius: 20px;
}
.main-navigation ul ul li:first-child a {
border-top-left-radius: 20px;
border-top-right-radius: 20px;
}
.main-navigation ul ul li:last-child a {
border-bottom-left-radius: 20px;
border-bottom-right-radius: 20px;
}