.selector {
  position: relative;
  z-index: 10;
  margin: 2rem auto 4rem;
}

.navigation {
  margin: 0 auto;
  width: 100%;
  max-width: 348px;
}

.mobile-dropdown {
  position: relative;
  display: block;
  width: 100%;
  margin: 0 auto;
  height: 4rem;
}

.dropdown-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.1rem 2rem 1rem;
  background-color: #fff;
  border: 1px solid #707070;
  border-radius: 0.4rem;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 16px;
  height: 40px;
}

.dropdown-header::after {
  content: "";
  display: block;
  width: 18px;
  height: 12px;
  background-image: url(../images/common/arrow-down.svg);
  background-size: contain;
  background-repeat: no-repeat;
  background-position: center;
  transition: transform 0.3s ease;
}

.mobile-dropdown.open .dropdown-header {
  border-radius: 0.4rem 0.4rem 0 0;
  border-bottom: 0px solid transparent;
}

.mobile-dropdown.open .dropdown-header::after {
  transform: scaleY(-1);
}

.dropdown-title {
  font-weight: 700;
  font-size: 1.6rem;
  color: #000;
}

.dropdown-list {
  width: 100%;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  background-color: white;
  border: 1px solid #707070;
  border-top: none;
  border-radius: 0 0 8px 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, opacity 0.3s ease;
  opacity: 0;
  z-index: 1000;
}

.mobile-dropdown.open .dropdown-list {
  max-height: 400px;
  opacity: 1;
}

.dropdown-list li:last-child {
  border-bottom: none;
}

.dropdown-list .nav-item {
  display: block;
  padding: 10px 20px;
  text-decoration: none;
  transition: all 0.3s ease;
  font-size: 16px;
  font-weight: 700;
  color: #c7c7c7;
}

.dropdown-list .nav-item.active {
  color: #000;
}

@media (min-width: 768px) {
  .navigation {
    margin: 0 auto;
    max-width: 660px;
  }

  .dropdown-header {
    background-color: #f7f7f8;
  }

  .dropdown-list .nav-item {
    background-color: #f7f7f8;
    cursor: pointer;
  }

  .dropdown-list .nav-item:hover {
    background-color: #ebe9e9;
  }
}