*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}

html{
    font-size: 62.5%;
}

body{
    font-size: 1.6rem;
    font-family: Arial, Helvetica, sans-serif;
    background-color: #2e3e4d;
}

.nav-bar{
    background-color: #1f4959;
    margin: 5rem 8rem;
}

.menu{
    list-style: none;
    display: flex;
    flex-wrap: wrap;
}

.menu li{
    position: relative;
}

.menu > li > a{
    display: block;
    font-size: 3.5rem;
    padding: 3rem 5rem;
    color: #fff;
    text-decoration: none;
}

.menu > li > a:hover{
    background-color: rgb(212, 74, 74);
    border-radius: 0.5rem;
}

/* .sub-menu{
    list-style: none;
    position: absolute;
    top: 100%;
    left: 0;
    min-width: 180px;
    background: #23a2cf;
    display: none;
} */
.sub-menu a{
    display: block;
    font-size: 3rem;
    padding: 1.5rem 1.5rem;
    text-decoration: none;
    color: #fff;
    border-bottom: 0.5rem rgb(223, 213, 213) solid;
}

.sub-menu,
.sub-menu-1,
.sub-menu-2 {
  list-style: none;
  position: absolute;
  top: 100%;  /* xổ xuống dưới */
  left: 0;
  min-width: 20rem;
  background:#23a2cf;
  display: none;
}

.sub-menu li,
.sub-menu-1 li,
.sub-menu-2 li {
  position: relative;
}

.sub-menu a:hover,
.sub-menu-1 a:hover,
.sub-menu-2 a:hover {
  background: #ab4343;
}

.menu li:hover > .sub-menu {
  display: block;
}

.sub-menu li:hover > .sub-menu-1 {
  display: block;
}

.sub-menu-1 li:hover > .sub-menu-2 {
  display: block;
}

/* --- Submenu cấp 2 xổ ngang --- */
.sub-menu-1 {
  top: 0;
  left: 100%;
}

.sub-menu-2 {
  top: 0;
  left: 100%;
}