:root {
    --sidebar-bg: #1A1C1E;
    --sidebar-hover: #2A2D30;
    --text-color: #fff;
}

body {
    background-color: #0A0C0E;
    color: var(--text-color);
}

/* .wrapper {
    display: flex;
    min-height: 100vh;
} */

.sidebar {
    background: var(--sidebar-bg);
    width: 300px;
    transition: all 0.3s ease;
    position: fixed;
    height: 100vh;
    overflow-y: scroll;
}

.sidebar.collapsed {
    width: 60px;
    overflow-y: hidden;
}

.sidebar::-webkit-scrollbar {
    display: none; 
  }

.sidebar .logo {
    padding: 20px;
    font-size: 24px;
    font-weight: bold;
    color: var(--text-color);
}

.sidebar.collapsed .logo-text,
.sidebar.collapsed .menu-text,
.sidebar.collapsed .submenu {
    display: none;
}

.menu-item {
    padding: 12px 20px;
    color: var(--text-color);
    display: flex;
    align-items: center;
    cursor: pointer;
    transition: 0.3s;
}

.menu-item:hover {
    background: var(--sidebar-hover);
}

.menu-item i {
    margin-right: 15px;
    font-size: 20px;
}

.submenu {
    padding-left: 20px;
    background: rgba(255,255,255,0.05);
}

.submenu-item {
    padding: 8px 0;
    color: #aaa;
    cursor: pointer;
}

.submenu-item:hover {
    color: var(--text-color);
}

.content {
    margin-left: 260px;
    flex: 1;
    padding: 20px;
    transition: all 0.3s ease;
}

.content.expanded {
    margin-left: 60px;
}

.video-container {
    width: 70%;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 100vh
}

.current-lecture {
    margin-top: 20px;
    padding: 15px;
    background: var(--sidebar-bg);
    border-radius: 8px;
}

.lecture-number {
    color: #666;
    margin-right: 8px;
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .sidebar.active {
        transform: translateX(0);
        z-index: 1;
    }
    .content {
        margin-left: 0;
    }
    .video-container {
        margin-top: 40px;
    }
    .toggle-btn {
        display: block !important;
    }
}

.toggle-btn {
    display: none;
    position: fixed;
    top: 10px;
    right: 10px;
    z-index: 100;
}