* { margin: 0; padding: 0; box-sizing: border-box; }
        body { 
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif; 
            background: #f5f7fa;
            overflow-x: hidden;
        }

        /* Sidebar */
        .sidebar {
            position: fixed;
            left: 0;
            top: 0;
            height: 100vh;
            width: 260px;
            background: #2d3748;
            color: white;
            transition: transform 0.3s ease;
            z-index: 1000;
            overflow-y: auto;
        }

        .sidebar.collapsed {
            transform: translateX(-260px);
        }

        .sidebar-header {
            padding: 20px;
            background: #1a202c;
            display: flex;
            align-items: center;
            gap: 10px;
            min-height: 70px;
        }

        .sidebar-header img {
            max-height: 40px;
            max-width: 120px;
            object-fit: contain;
        }

        .sidebar-header h1 {
            font-size: 20px;
            font-weight: 600;
        }

        .sidebar-menu {
            padding: 20px 0;
        }

        .menu-item {
            display: flex;
            align-items: center;
            gap: 12px;
            padding: 12px 20px;
            color: #cbd5e0;
            text-decoration: none;
            transition: all 0.2s;
        }

        .menu-item:hover {
            background: #4a5568;
            color: white;
        }

        .menu-item.active {
            background: #4299e1;
            color: white;
        }

        .menu-item i {
            width: 20px;
            text-align: center;
        }

        /* Top Bar */
        .topbar {
            position: fixed;
            top: 0;
            left: 260px;
            right: 0;
            height: 60px;
            background: white;
            box-shadow: 0 2px 4px rgba(0,0,0,0.1);
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 0 20px;
            transition: left 0.3s ease, top 0.3s ease;
            z-index: 999;
        }

        body.guest .topbar {
            left: 0;
        }

        /* Adjust topbar when demo banner is present */
        body:has(.demo-mode-banner) .topbar {
            top: 48px;
        }

        body:has(.demo-mode-banner) .sidebar {
            top: 48px;
            height: calc(100vh - 48px);
        }

        body:has(.demo-mode-banner) .main-content {
            margin-top: 108px;
        }

        .topbar.expanded {
            left: 0;
        }

        .topbar-left {
            display: flex;
            align-items: center;
            gap: 15px;
        }

        .menu-toggle {
            background: none;
            border: none;
            font-size: 24px;
            cursor: pointer;
            color: #4a5568;
        }

        .topbar-right {
            display: flex;
            align-items: center;
            gap: 20px;
        }

        .balance-display {
            background: #f7fafc;
            padding: 8px 16px;
            border-radius: 8px;
            font-weight: 600;
            color: #2d3748;
            display: flex;
            align-items: center;
            gap: 10px;
        }

        .balance-amount {
            color: #48bb78;
            font-size: 18px;
        }

        .currency-dropdown {
            position: relative;
            display: inline-block;
        }

        .currency-btn {
            background: #48bb78;
            color: white;
            border: none;
            padding: 4px 10px;
            border-radius: 5px;
            cursor: pointer;
            font-size: 14px;
            font-weight: 600;
            display: flex;
            align-items: center;
            gap: 5px;
        }

        .currency-btn:hover {
            background: #38a169;
        }

        .currency-menu {
            display: none;
            position: absolute;
            top: 100%;
            right: 0;
            background: white;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
            min-width: 120px;
            z-index: 1000;
            max-height: 300px;
            overflow-y: auto;
            margin-top: 5px;
        }

        .currency-menu.show {
            display: block;
        }

        .currency-menu a {
            display: block;
            padding: 10px 15px;
            color: #2d3748;
            text-decoration: none;
            transition: background 0.2s;
            font-size: 14px;
        }

        .currency-menu a:hover {
            background: #f7fafc;
        }

        .currency-menu a.active {
            background: #e6fffa;
            color: #48bb78;
            font-weight: 600;
        }

        .account-dropdown {
            position: relative;
        }

        .account-btn {
            display: flex;
            align-items: center;
            gap: 8px;
            background: none;
            border: none;
            cursor: pointer;
            padding: 8px 12px;
            border-radius: 8px;
            transition: background 0.2s;
        }

        .account-btn:hover {
            background: #f7fafc;
        }

        .account-menu {
            position: absolute;
            top: 100%;
            right: 0;
            margin-top: 8px;
            background: white;
            border-radius: 8px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.15);
            min-width: 200px;
            display: none;
        }

        .account-menu.show {
            display: block;
        }

        .account-menu a {
            display: block;
            padding: 12px 16px;
            color: #2d3748;
            text-decoration: none;
            transition: background 0.2s;
        }

        .account-menu a:hover {
            background: #f7fafc;
        }

        .account-menu a:first-child {
            border-radius: 8px 8px 0 0;
        }

        .account-menu a:last-child {
            border-radius: 0 0 8px 8px;
            color: #e53e3e;
        }

        /* Main Content */
        .main-content {
            margin-left: 260px;
            margin-top: 60px;
            padding: 30px;
            transition: margin-left 0.3s ease;
            min-height: calc(100vh - 60px);
        }

        body.guest .main-content {
            margin-left: 0;
        }

        .main-content.expanded {
            margin-left: 0;
        }

        /* Mobile Responsive */
        @media (max-width: 768px) {
            .sidebar {
                transform: translateX(-260px);
            }

            .sidebar.show {
                transform: translateX(0);
            }

            .topbar {
                left: 0;
            }

            .main-content {
                margin-left: 0;
            }

            .balance-display {
                font-size: 12px;
                padding: 6px 12px;
            }

            .balance-amount {
                font-size: 14px;
            }
        }

        /* Overlay for mobile */
        .sidebar-overlay {
            position: fixed;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: rgba(0,0,0,0.5);
            display: none;
            z-index: 999;
        }

        .sidebar-overlay.show {
            display: block;
        }

        .topbar-nav {
            display: flex;
            gap: 20px;
            margin-left: 20px;
        }
        .topbar-nav a {
            text-decoration: none;
            color: #4a5568;
            font-weight: 500;
            font-size: 14px;
            transition: color 0.2s;
        }
        .topbar-nav a:hover {
            color: #3b82f6;
        }
        .topbar-nav a.active {
            color: #3b82f6;
        }
        .public-auth-btns {
            display: flex;
            gap: 12px;
        }
        .btn-signin {
            text-decoration: none;
            color: #4a5568;
            font-weight: 600;
            font-size: 14px;
            padding: 8px 16px;
        }
        .btn-signup {
            text-decoration: none;
            background: #3b82f6;
            color: white;
            font-weight: 600;
            font-size: 14px;
            padding: 8px 20px;
            border-radius: 8px;
            transition: background 0.2s;
        }
        .btn-signup:hover {
            background: #2563eb;
        }