:root {
            --primary: #333DA5;
            --dark: #1e293b;
            --width: 280px;
        }
        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }
        body {
            font-family: 'Segoe UI', sans-serif;
            background: #f8fafc;
            min-height: 100vh;
        }

        /* Overlay */
        .overlay {
            position: fixed;
            inset: 0;
            background: rgba(0, 0, 0, 0.6);
            opacity: 0;
            visibility: hidden;
            transition: all 0.3s;
            z-index: 999;
        }
        .overlay.active {
            opacity: 1;
            visibility: visible;
        }

        /* Floating Menu Button (Mobile only) */
        #menuBtn {
            position: fixed;
            top: 55px;
            right: 20px;
            width: 56px;
            height: 56px;
            background: var(--primary);
            color: white;
            border: none;
            border-radius: 50%;
            font-size: 24px;
            cursor: pointer;
            z-index: 1001;
            box-shadow: 0 10px 30px rgba(99, 102, 241, 0.4);
            transition: transform 0.3s;
            display: none;
        }
        #menuBtn:hover {
            transform: scale(1.12);
        }

        /* Sidebar - Right & Hidden by default */
        .sidebar {
            position: fixed;
            top: 0;
            right: 0;
            width: var(--width);
            height: 100%;
            background: var(--dark);
            transform: translateX(100%);
            transition: transform 0.4s cubic-bezier(0.68, -0.55, 0.27, 1.55);
            z-index: 1000;
            padding: 20px 0;
            box-shadow: -8px 0 30px rgba(0, 0, 0, 0.4);
            overflow-y: auto;
        }
        .sidebar.active {
            transform: translateX(0);
        }

        /* Logo */
        .logo {
            padding: 0 25px 40px;
            color: white;
            font-size: 28px;
            font-weight: 700;
        }
        .logo i {
            color: var(--primary);
        }

        /* Menu */
        .nav-menu {
            list-style: none;
        }
        .nav-item {
            margin: 8px 20px;
        }
        .nav-link {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 16px 20px;
            color: #cbd5e1;
            text-decoration: none;
            border-radius: 12px;
            cursor: pointer;
            transition: all 0.3s;
        }
        .nav-link:hover {
            background: rgba(255, 255, 255, 0.1);
            color: white;
        }
        .nav-link.active {
            background: var(--primary);
            color: white;
            font-weight: 600;
        }
        .nav-link i:first-child {
            width: 35px;
            font-size: 20px;
            text-align: center;
        }
        .arrow {
            transition: transform 0.3s;
        }
        .arrow.rotate {
            transform: rotate(90deg);
        }

        /* Submenu - Fixed: Now shows ALL items */
        .submenu {
            list-style: none;
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.6s cubic-bezier(0.68, -0.55, 0.27, 1.55), padding 0.6s ease;
            background: rgba(0, 0, 0, 0.3);
            border-radius: 0 0 12px 12px;
            margin: 0 10px 10px;
        }
        .submenu.active {
            max-height: 2000px; /* Very high value – fits all your items easily */
            padding: 12px 0;
            overflow-y: auto;   /* Only scrolls if extremely long */
        }
        .submenu a {
            display: block;
            padding: 12px 20px 12px 70px;
            color: #94a3b8;
            text-decoration: none;
            font-size: 14.5px;
            transition: all 0.3s;
        }
        .submenu a:hover {
            color: white;
            background: rgba(255, 255, 255, 0.1);
            padding-left: 80px;
        }

        /* Mobile */
        @media (max-width: 600px) {
            #menuBtn {
                display: block;
            }
        }