/* CSS RESET & BASE STYLES */
        *, *::before, *::after {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease;
        }

        body {
            font-family: 'Poppins', sans-serif;
            background-color: #a0c4ff;
            color: #333;
            min-height: 100vh;
            display: flex;
            justify-content: center;
            align-items: flex-start;
            padding: 2rem;
        }

        .content-body {
            width: 100%;
            max-width: 1200px;
            background-color: #ffffff;
            border-radius: 15px;
            padding: 2rem;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
            animation: fadeIn 0.5s ease-out;
        }

        @keyframes fadeIn {
            from { opacity: 0; transform: scale(0.98); }
            to { opacity: 1; transform: scale(1); }
        }

        /* HEADER */
        .header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 2rem;
            padding-bottom: 1rem;
            border-bottom: 2px solid #eef2ff;
        }

        .header h1 {
            font-size: 2.5rem;
            font-weight: 700;
            color: #1e3a8a;
        }

        .header-actions {
            display: flex;
            align-items: center;
            gap: 1rem;
        }

        .theme-toggle {
            background-color: #f8fafc;
            border: 1px solid #e2e8f0;
            border-radius: 25px;
            padding: 0.5rem 1rem;
            cursor: pointer;
            font-size: 1.2rem;
            transition: all 0.3s ease;
            display: flex;
            align-items: center;
            gap: 0.5rem;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }

        .theme-toggle:hover {
            transform: translateY(-2px);
            box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
        }

        .theme-toggle .moon-icon {
            display: none;
        }

        .back-btn {
            background-color: #4f46e5;
            color: white;
            border: none;
            border-radius: 8px;
            padding: 0.8rem 1.5rem;
            font-family: 'Poppins', sans-serif;
            font-weight: 600;
            cursor: pointer;
            text-decoration: none;
            transition: background-color 0.2s ease;
        }

        .back-btn:hover {
            background-color: #3730a3;
        }

        /* STATS OVERVIEW */
        .stats-overview {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
            gap: 1.5rem;
            margin-bottom: 2rem;
        }

        .stat-card {
            background-color: #f8fafc;
            border: 1px solid #e2e8f0;
            border-radius: 15px;
            padding: 1.5rem;
            text-align: center;
            position: relative;
            overflow: hidden;
        }

        .stat-card::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            height: 4px;
            background: linear-gradient(90deg, #4f46e5, #10b981);
        }

        .stat-icon {
            font-size: 2.5rem;
            margin-bottom: 1rem;
        }

        .stat-number {
            font-size: 2rem;
            font-weight: 700;
            color: #1e3a8a;
            margin-bottom: 0.5rem;
        }

        .stat-label {
            font-size: 0.9rem;
            color: #6b7280;
        }

        /* MAIN CONTENT */
        .main-content {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 2rem;
            margin-bottom: 2rem;
        }

        /* HABIT FORM */
        .habit-form {
            background-color: #f8fafc;
            border: 1px solid #e2e8f0;
            border-radius: 15px;
            padding: 1.5rem;
        }

        .habit-form h3 {
            color: #1e3a8a;
            margin-bottom: 1.5rem;
            font-size: 1.3rem;
        }

        .form-group {
            margin-bottom: 1rem;
        }

        .form-group label {
            display: block;
            margin-bottom: 0.5rem;
            font-weight: 600;
            color: #374151;
        }

        .form-group input,
        .form-group select,
        .form-group textarea {
            width: 100%;
            padding: 0.8rem;
            border: 1px solid #e2e8f0;
            border-radius: 8px;
            font-family: 'Poppins', sans-serif;
            font-size: 0.9rem;
        }

        .submit-btn {
            background-color: #10b981;
            color: white;
            border: none;
            border-radius: 8px;
            padding: 0.8rem 1.5rem;
            font-family: 'Poppins', sans-serif;
            font-weight: 600;
            cursor: pointer;
            width: 100%;
            transition: background-color 0.2s ease;
        }

        .submit-btn:hover {
            background-color: #059669;
        }

        /* HABIT TRACKER */
        .habit-tracker {
            background-color: #f8fafc;
            border: 1px solid #e2e8f0;
            border-radius: 15px;
            padding: 1.5rem;
            max-height: 500px;
            overflow-y: auto;
        }

        .habit-tracker h3 {
            color: #1e3a8a;
            margin-bottom: 1.5rem;
            font-size: 1.3rem;
        }

        .habit-item {
            background-color: white;
            border-radius: 10px;
            padding: 1.5rem;
            margin-bottom: 1rem;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
        }

        .habit-header {
            display: flex;
            justify-content: space-between;
            align-items: center;
            margin-bottom: 1rem;
        }

        .habit-name {
            font-weight: 700;
            color: #1e3a8a;
            font-size: 1.1rem;
        }

        .habit-streak {
            background-color: #fef3c7;
            color: #d97706;
            padding: 0.3rem 0.8rem;
            border-radius: 20px;
            font-size: 0.8rem;
            font-weight: 600;
        }

        .habit-description {
            color: #6b7280;
            font-size: 0.9rem;
            margin-bottom: 1rem;
        }

        .habit-actions {
            display: flex;
            gap: 0.5rem;
            justify-content: center;
        }

        .action-btn {
            background-color: #4f46e5;
            color: white;
            border: none;
            border-radius: 6px;
            padding: 0.5rem 1rem;
            font-family: 'Poppins', sans-serif;
            font-size: 0.8rem;
            cursor: pointer;
            transition: background-color 0.2s ease;
        }

        .action-btn:hover {
            background-color: #3730a3;
        }

        .action-btn.complete {
            background-color: #10b981;
        }

        .action-btn.complete:hover {
            background-color: #059669;
        }

        .action-btn.delete {
            background-color: #ef4444;
        }

        .action-btn.delete:hover {
            background-color: #dc2626;
        }

        .action-btn:disabled {
            background-color: #9ca3af;
            cursor: not-allowed;
        }

        /* DARK MODE STYLES */
        [data-theme="dark"] body {
            background-color: #1e293b;
        }

        [data-theme="dark"] .content-body {
            background-color: #334155;
            color: #e2e8f0;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
        }

        [data-theme="dark"] .header {
            border-bottom-color: #475569;
        }

        [data-theme="dark"] .header h1 {
            color: #60a5fa;
        }

        [data-theme="dark"] .theme-toggle {
            background-color: #475569;
            border-color: #64748b;
            color: #e2e8f0;
        }

        [data-theme="dark"] .theme-toggle .sun-icon {
            display: none;
        }

        [data-theme="dark"] .theme-toggle .moon-icon {
            display: inline;
        }

        [data-theme="dark"] .back-btn {
            background-color: #3b82f6;
        }

        [data-theme="dark"] .back-btn:hover {
            background-color: #2563eb;
        }

        [data-theme="dark"] .stat-card {
            background-color: #475569;
            border-color: #64748b;
            color: #e2e8f0;
        }

        [data-theme="dark"] .stat-number {
            color: #60a5fa;
        }

        [data-theme="dark"] .stat-label {
            color: #94a3b8;
        }

        [data-theme="dark"] .habit-form,
        [data-theme="dark"] .habit-tracker {
            background-color: #475569;
            border-color: #64748b;
        }

        [data-theme="dark"] .habit-form h3,
        [data-theme="dark"] .habit-tracker h3 {
            color: #60a5fa;
        }

        [data-theme="dark"] .form-group label {
            color: #cbd5e1;
        }

        [data-theme="dark"] .form-group input,
        [data-theme="dark"] .form-group select,
        [data-theme="dark"] .form-group textarea {
            background-color: #1e293b;
            border-color: #475569;
            color: #e2e8f0;
        }

        [data-theme="dark"] .form-group input::placeholder,
        [data-theme="dark"] .form-group textarea::placeholder {
            color: #94a3b8;
        }

        [data-theme="dark"] .submit-btn {
            background-color: #059669;
        }

        [data-theme="dark"] .submit-btn:hover {
            background-color: #047857;
        }

        [data-theme="dark"] .habit-item {
            background-color: #1e293b;
            color: #e2e8f0;
        }

        [data-theme="dark"] .habit-name {
            color: #60a5fa;
        }

        [data-theme="dark"] .habit-description {
            color: #94a3b8;
        }

        [data-theme="dark"] .habit-streak {
            background-color: #d97706;
            color: #fef3c7;
        }

        [data-theme="dark"] .action-btn {
            background-color: #3b82f6;
        }

        [data-theme="dark"] .action-btn:hover {
            background-color: #2563eb;
        }

        [data-theme="dark"] .action-btn.complete {
            background-color: #059669;
        }

        [data-theme="dark"] .action-btn.complete:hover {
            background-color: #047857;
        }

        [data-theme="dark"] .action-btn.delete {
            background-color: #dc2626;
        }

        [data-theme="dark"] .action-btn.delete:hover {
            background-color: #b91c1c;
        }

        [data-theme="dark"] .action-btn:disabled {
            background-color: #64748b;
        }

        [data-theme="dark"] .empty-state {
            color: #94a3b8;
        }

        [data-theme="dark"] .empty-state h4 {
            color: #cbd5e1;
        }

        /* RESPONSIVE DESIGN */
        @media (max-width: 768px) {
            body {
                padding: 1rem;
            }
            
            .content-body {
                padding: 1.5rem;
            }
            
            .header h1 {
                font-size: 2rem;
            }
            
            .stats-overview {
                grid-template-columns: 1fr 1fr;
            }
            
            .main-content {
                grid-template-columns: 1fr;
            }
        }

        /* EMPTY STATE */
        .empty-state {
            text-align: center;
            padding: 2rem;
            color: #6b7280;
        }

        .empty-state .icon {
            font-size: 3rem;
            margin-bottom: 1rem;
        }

        .empty-state h4 {
            margin-bottom: 0.5rem;
            color: #374151;
        }

        .empty-state p {
            font-size: 0.9rem;
        }