.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: 250px;
  height: 100%;
  background-color: #13212a;
  color: #fff;
  transform: translateX(0);
  transition: transform 0.3s ease;
  z-index: 1000;
  padding-top: 60px;
  box-shadow: 4px 0 14px rgba(0,0,0,0.5);
  overflow: visible;
}

.sidebar-header {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 60px;
  background: linear-gradient(90deg, rgba(12,103,132,1) 0%, rgba(36,58,152,1) 50%, rgba(255,120,48,1) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid rgba(255,255,255,0.06);
  z-index: 1001;
}

.sidebar-header h2 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 800;
  background: linear-gradient(90deg, #7ef0ff, #ffd27a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: uppercase;
  letter-spacing: 1px;
  text-shadow: 0 4px 18px rgba(18, 200, 230, 0.08), 0 2px 6px rgba(0,0,0,0.6);
}

.sidebar-content { 
  padding: 20px 18px 90px 18px;
}

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

.sidebar ul li.nav-title {
  font-size: 14px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  opacity: 0.95;
  margin: 20px 0 10px 0;
  text-align: center;
  background: linear-gradient(90deg, #7ef0ff, #ffd27a);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-shadow: 0 2px 4px rgba(0,0,0,0.5);
  transition: text-shadow 0.2s ease;
}

.sidebar ul li.nav-title:hover {
  text-shadow: 0 4px 8px rgba(126,240,255,0.5);
}

.sidebar ul li a {
  display: block;
  color: #e6f6f8;
  text-decoration: none;
  font-size: 16px;
  padding: 8px 12px;
  border-radius: 8px;
  transition: all 0.2s ease;
  text-align: center;
  background: rgba(255,255,255,0.05);
  margin: 4px 0;
}

.sidebar ul li a:hover {
  color: #13212a;
  background: linear-gradient(90deg, #7ef0ff, #ffd27a);
  box-shadow: 0 4px 12px rgba(126,240,255,0.25);
  transform: scale(1.05);
}

.toggle-sidebar-btn { 
  position: fixed; 
  top: 15px; 
  left: 15px; 
  background: #1b95d6; 
  border: none; 
  color: #fff; 
  font-size: 20px; 
  padding: 8px 12px; 
  border-radius: 6px; 
  z-index: 1100; 
  display: none; 
}

.lang-switch {
  position: absolute;
  bottom: 60px;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: center;
  gap: 1px;
  padding: 8px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  background: linear-gradient(180deg, rgba(0,0,0,0.15), rgba(0,0,0,0.25));
  z-index: 1002;
} 

.lang-btn {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 10px;
  cursor: pointer;
  padding: 6px;
  transition: transform 0.2s ease, box-shadow 0.2s ease, opacity 0.2s;
  opacity: 0.9;
  box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

.lang-btn:hover {
  transform: scale(1.1);
  opacity: 1;
  box-shadow: 0 0 10px #f1c40f;
}

.lang-btn img {
  display: block;
  width: 24px;
  height: 14px;
  object-fit: cover;
  border-radius: 3px;
  border: 1px solid rgba(0,0,0,0.25);
}

.lang-btn.active { 
  transform: scale(1.12); 
  box-shadow: 0 6px 22px rgba(126,240,255,0.12); 
  filter: drop-shadow(0 0 6px rgba(126,240,255,0.12)); 
}

/* responsive */
@media (max-width: 768px) {
  .sidebar { transform: translateX(-100%); }
  .sidebar.active { transform: translateX(0); }
  .toggle-sidebar-btn { display: block; }
}