body {
   font-family: 'Segoe UI', Arial, sans-serif;
   background: #fff;
   margin: 0;
   padding: 0;
   color: #111;
}

.sidebar {
   background: #111;
   color: #fff;
   width: 220px;
   height: 100vh;
   position: fixed;
   left: 0;
   top: 0;
   padding: 2rem 1rem 1rem 1rem;
   box-sizing: border-box;
}

.sidebar h2 {
   margin-top: 0;
   font-size: 1.5rem;
   color: #fff;
}

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

.sidebar li {
   margin-bottom: 1rem;
}

.sidebar a,
.sidebar span {
   color: #fff;
   text-decoration: none;
   cursor: pointer;
   font-size: 1.1rem;
   display: block;
   padding: 0.5rem 0.75rem;
   border-radius: 4px;
   transition: background 0.2s;
}

.sidebar a:hover,
.sidebar span:hover {
   background: #222;
}

.submenu ul {
   margin: 0.5rem 0 0 1rem;
   padding: 0;
   display: block;
}

.hidden {
   display: none;
}

.main-content {
   margin-left: 240px;
   padding: 2rem;
   background: #fff;
   min-height: 100vh;
}

.logo-container {
   text-align: center;
   margin-bottom: 2rem;
}

.logo {
   width: 120px;
   height: auto;
   border-radius: 8px;
   background: #fff;
   padding: 0.5rem;
}