* {
  box-sizing: border-box;
}

.menu-btn {
  position: relative;
  width: 30px;
  height: 24px;
  cursor: pointer;
  border: none;
  background: transparent;
  z-index: 1001;
  display: flex;
  align-items: center;
  justify-content: center;
  outline: none;
}

.menu-btn__burger,
.menu-btn__burger::before,
.menu-btn__burger::after {
  content: '';
  display: block;
  width: 30px;
  height: 3px;
  background-color: #333;
  border-radius: 3px;
  transition: all 0.3s ease;
  position: relative;
}

.menu-btn__burger::before {
  position: absolute;
  top: -10px;
}

.menu-btn__burger::after {
  position: absolute;
  top: 10px;
}

.menu-btn.active .menu-btn__burger {
  background-color: transparent;
}

.menu-btn.active .menu-btn__burger::before {
  transform: rotate(45deg);
  top: 0;
}

.menu-btn.active .menu-btn__burger::after {
  transform: rotate(-45deg);
  top: 0;
}

.menu {
  position: fixed;
  top: 0; right: 0;
  height: 100vh;
  width: 80vw;
  max-width: 320px;
  background-color: #fff;
  box-shadow: -2px 0 8px rgba(0,0,0,0.2);
  transform: translateX(100%);
  transition: transform 0.3s ease;
  z-index: 1000;
  padding: 60px 20px 20px;
  overflow-y: auto;
  font-family: Arial, sans-serif;
}

.menu.active {
  transform: translateX(0);
}

.menu__list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.menu__item {
  display: block;
  padding: 15px 0;
  font-size: 18px;
  color: #222;
  text-decoration: none;
  border-bottom: 1px solid #eee;
  transition: color 0.3s ease;
  cursor: pointer;
}

.menu__item:hover {
  color: #007bff;
}

.menu__list li {
  opacity: 0;
  transform: translateX(20px);
  animation-fill-mode: forwards;
}

.menu.active .menu__list li {
  animation-name: slideIn;
  animation-duration: 0.4s;
  animation-timing-function: ease;
  animation-delay: calc(0.1s * var(--i));
}

@keyframes slideIn {
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.overlay {
  position: fixed;
  top: 0; left: 0;
  width: 100vw; height: 100vh;
  background: rgba(0,0,0,0.4);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease;
  z-index: 999;
}

.overlay.active {
  opacity: 1;
  visibility: visible;
}

.submenu {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
  list-style: none;
  padding: 10px 0 10px 15px;
  margin: 0;
  background-color: #f9f9f9;
  border-radius: 4px;
}

.has-submenu.active > .submenu {
  max-height: 500px;
}

.has-submenu > .menu__item::after {
  content: "▾";
  font-size: 12px;
  margin-left: 6px;
  color: #666;
  transition: transform 0.3s ease;
  display: inline-block;
  vertical-align: middle;
  transform-origin: center;
}

.has-submenu.active > .menu__item::after,
.has-submenu:hover > .menu__item::after {
  transform: rotate(180deg);
  color: #007bff;
}

.has-submenu {
  position: relative;
  cursor: pointer;
}
li.has-submenu {
  margin-bottom: 16px;
}
.btn-group {
  margin-bottom: 12px;
}
.dropdown-menu {
  position: relative; /* nếu cần */
  padding: 0;
  margin: 0;
  list-style: none;
}

li[data-submenu-id] {
  position: relative;
}

.popover {
  position: absolute;
  top: 0;
  left: 100%;
  display: none;
  z-index: 1000;
  background-color: white;
  border: 1px solid #ddd;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  min-width: 200px;
  padding: 10px;
  border-radius: 4px;
  max-height: 300px;
  overflow-y: auto;
}
.custom-submenu {
  position: absolute;
  top: 0;
  left: 100%;
  display: none;
  z-index: 1000;
  background-color: white;
  border: 1px solid #ddd;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
  min-width: 200px;
  padding: 10px;
  border-radius: 4px;
}