<div className="flex h-screen bg-slate-50 font-sans overflow-hidden">
    
    {/* Sidebar */}
    <aside 
      className={`bg-white border-r border-slate-200 flex flex-col transition-all duration-300 ease-in-out relative z-10 ${
        isCollapsed ? 'w-20' : 'w-64'
      }`}
    >
      {/* Header */}
      <div className="h-16 flex items-center px-4 border-b border-slate-100 shrink-0">
        <div className="flex items-center gap-3 overflow-hidden whitespace-nowrap">
          <div className="w-10 h-10 rounded-xl bg-blue-600 flex items-center justify-center shrink-0 shadow-sm shadow-blue-200">
            <Hexagon className="w-6 h-6 text-white" />
          </div>
          <span 
            className={`font-bold text-slate-800 text-xl transition-all duration-300 overflow-hidden ${
              isCollapsed ? 'max-w-0 opacity-0' : 'max-w-[200px] opacity-100'
            }`}
          >
            DashUI
          </span>
        </div>
      </div>

      {/* Navigation */}
      <nav className="flex-1 py-6 px-3 space-y-2 overflow-y-auto overflow-x-hidden">
        {navItems.map((item, index) => (
          <a 
            key={index}
            href="#" 
            className={`flex items-center gap-3 px-3 py-3 rounded-xl transition-colors group relative ${
              item.active 
                ? 'text-blue-700 bg-blue-50 hover:bg-blue-100' 
                : 'text-slate-500 hover:bg-slate-100 hover:text-slate-900'
            }`}
          >
            <item.icon className="w-6 h-6 shrink-0" />
            
            <span 
              className={`font-semibold whitespace-nowrap transition-all duration-300 flex-1 text-sm overflow-hidden ${
                isCollapsed ? 'max-w-0 opacity-0' : 'max-w-[200px] opacity-100'
              }`}
            >
              {item.label}
            </span>

            {/* Badge display (only when expanded) */}
            {!isCollapsed && item.badge && (
              <span className="bg-blue-100 text-blue-700 py-0.5 px-2 rounded-full text-xs font-bold whitespace-nowrap">
                {item.badge}
              </span>
            )}

            {/* Tooltip (displayed on hover only when collapsed) */}
            {isCollapsed && (
              <div className="absolute left-14 hidden group-hover:block bg-slate-800 text-white text-xs px-2.5 py-1.5 rounded-md shadow-lg z-20 whitespace-nowrap pointer-events-none opacity-0 transition-opacity duration-200 group-hover:opacity-100">
                {item.label}
              </div>
            )}
          </a>
        ))}
      </nav>

      {/* Footer Profile */}
      <div className="p-4 border-t border-slate-100 shrink-0">
        <a href="#" className="flex items-center gap-3 hover:bg-slate-50 p-2 -m-2 rounded-xl transition-colors">
          <img 
            src="https://i.pravatar.cc/150?u=a042581f4e29026704d" 
            alt="User Avatar" 
            className="w-10 h-10 rounded-full shrink-0 border border-slate-200 object-cover" 
          />
          <div 
            className={`flex-1 min-w-0 transition-all duration-300 overflow-hidden ${
              isCollapsed ? 'max-w-0 opacity-0' : 'max-w-[200px] opacity-100'
            }`}
          >
            <p className="text-sm font-semibold text-slate-900 truncate">Jane Doe</p>
            <p className="text-xs text-slate-500 truncate">Admin</p>
          </div>
        </a>
      </div>
    </aside>

    {/* Toggle Button */}
    <button 
      onClick={() => setIsCollapsed(!isCollapsed)}
      className={`absolute top-6 z-20 cursor-pointer bg-white border border-slate-200 text-slate-500 hover:text-blue-600 hover:bg-blue-50 rounded-full p-1.5 shadow-sm transition-all duration-300 ${
        isCollapsed ? 'left-[4.2rem]' : 'left-[15rem]'
      }`}
      aria-label={isCollapsed ? "Expand sidebar" : "Collapse sidebar"}
    >
      <ChevronLeft className={`w-4 h-4 transition-transform duration-300 ${isCollapsed ? 'rotate-180' : ''}`} />
    </button>

{/* Ana İçerik Alanı (Örnek) */}
    <main className="flex-1 p-8 overflow-y-auto">
      <h1 className="text-2xl font-bold text-slate-900">Kontrol Paneli</h1>
      <p className="text-slate-500 mt-1">Kenar çubuğundan bir öğe seçin.</p>
    </main>

</div>
);
}