/* =========================================
           1. COMMON / BASE STYLES
           (Variables, Typography, Resets, Components)
           ========================================= */
        :root {
            /* HSL Color System */
            --h-brand: 227;
            --s-brand: 58%;
            --l-brand: 65%;
            
            --h-bg: 220;
            --s-bg: 10%;

            /* Backgrounds */
            --bg-050: hsl(var(--h-bg), var(--s-bg), 7%);
            --bg-100: hsl(var(--h-bg), var(--s-bg), 10%);
            --bg-200: hsl(var(--h-bg), var(--s-bg), 14%);
            --bg-300: hsl(var(--h-bg), var(--s-bg), 18%);
            
            /* Text */
            --text-100: hsl(var(--h-bg), var(--s-bg), 98%);
            --text-200: hsl(var(--h-bg), var(--s-bg), 70%);
            --text-300: hsl(var(--h-bg), var(--s-bg), 50%);

            /* Accents */
            --color-brand: hsl(var(--h-brand), var(--s-brand), var(--l-brand));
            --color-brand-light: hsl(var(--h-brand), var(--s-brand), 75%);
            --color-danger: hsl(0, 70%, 60%);

            /* Typography */
            --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
            --text-base: 0.9375rem;
            --text-sm: 0.8125rem;
            --text-heading: 1.125rem;
            --text-title: 1.5rem;

            /* Spacing */
            --space-1: 0.25rem;
            --space-2: 0.5rem;
            --space-3: 0.75rem;
            --space-4: 1rem;
            --space-5: 1.5rem;
        }

        * { 
            box-sizing: border-box;margin: 0;padding: 0; 
        }

        html {
            scrollbar-width: none;-ms-overflow-style: none;
        }

        body {
            background: var(--bg-100);
            color: var(--text-100);
            font-family: var(--font-sans);
            line-height: 1.5;
            -webkit-font-smoothing: antialiased;
            font-size: var(--text-base);
            overflow-x: hidden;
            width: 100%;
            -ms-overflow-style: none;  /* IE and Edge */
            scrollbar-width: none;  /* Firefox */
        }
        
        ::-webkit-scrollbar {
            display: none;
        }

        /* Typography */
        h1, h2, h3 {
            color: var(--text-100);font-weight: 700;line-height: 1.2;
        }
        h1 { font-size: var(--text-title); }
        h2, h3 { font-size: var(--text-heading); }

        /* Global Font Inheritance */
        button, input, textarea, select, optgroup {font-family: inherit;}

        label {
            display: block; 
            font-size: var(--text-sm);
            color: var(--text-200); 
            margin-bottom: var(--space-1);
            text-transform: uppercase;
            letter-spacing: 0.05em;
            font-weight: 600;
        }

        /* Inputs & Controls */
        input, textarea, select {
            width: 100%; 
            max-width: 100%;
            padding: 0.75rem 1rem;
            background: var(--bg-100); 
            border: 1px solid var(--bg-300); 
            color: var(--text-100); 
            border-radius: 6px; 
            font-size: var(--text-base);
            font-family: inherit;
            transition: background 0.2s, box-shadow 0.2s, border-color 0.2s;
        }
        input, select {
            height: 48px;
        }
        input:focus, textarea:focus, select:focus { 
            background: var(--bg-100);border-color: var(--color-brand);
            outline: none;box-shadow: 0 0 0 1px var(--color-brand); 
        }

        select {
            appearance: none;
            -webkit-appearance: none;
            -moz-appearance: none;
            background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23ffffff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right 1.2rem center;
            background-size: 1rem;
            padding-right: 2.5rem;
            color-scheme: dark; /* Signals browser to use dark system UI */
        }
        
        select option {
            background-color: var(--bg-100);color: var(--text-100);
        }

        /* Custom Select Implementation */
        .custom-select-wrapper {
            position: relative;user-select: none;width: 100%;
        }
        .custom-select {
            position: relative;display: flex;flex-direction: column;
        }
        .custom-select-trigger {
            position: relative;display: flex;align-items: center;
            justify-content: space-between;padding: 0 1.2rem 0 1rem;
            font-size: var(--text-base);font-weight: 400;color: var(--text-100);
            background: var(--bg-100);border: 1px solid var(--bg-300);border-radius: 6px;
            cursor: pointer;transition: all 0.2s;
            height: 48px;
        }
        .custom-select-trigger:after {
            content: '';width: 1rem;height: 1rem;
            background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23ffffff' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
            background-repeat: no-repeat;background-position: center;background-size: contain;transition: transform 0.2s;
        }
        .custom-select.open .custom-select-trigger {
            border-color: var(--color-brand);box-shadow: 0 0 0 1px var(--color-brand);
        }
        .custom-select.open .custom-select-trigger:after {transform: rotate(180deg);}
        .custom-options {
            position: absolute;
            display: block;
            top: 100%;
            left: 0;
            right: 0;
            border: 1px solid var(--bg-300);
            border-radius: 6px;
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
            background: var(--bg-100);
            transition: all 0.2s;
            opacity: 0;
            visibility: hidden;
            pointer-events: none;
            transform: translateY(-10px);
            z-index: 1000;
            margin-top: 6px;
            overflow: hidden;
        }
        .custom-select.open .custom-options {
            opacity: 1;visibility: visible;pointer-events: all;transform: translateY(0);
        }
        .custom-option {
            position: relative;
            display: flex;
            align-items: center;
            padding: 0.75rem 1rem;
            font-size: var(--text-base);
            font-weight: 400;
            color: var(--text-100);
            cursor: pointer;
            transition: all 0.1s;
        }
        .custom-option:hover, .custom-option.selected {
            background-color: var(--color-brand);
            color: #ffffff;
        }

        input::-webkit-outer-spin-button,
        input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
        input[type=number] { -moz-appearance: textfield; appearance: textfield; }

        /* Flatpickr Theme */
        .flatpickr-calendar { background: var(--bg-200); border: 1px solid var(--bg-300); box-shadow: 0 4px 6px rgba(0,0,0,0.3); font-family: var(--font-sans); }
        .flatpickr-calendar.arrowTop:before, .flatpickr-calendar.arrowTop:after { border-bottom-color: var(--bg-200); }
        .flatpickr-calendar.arrowBottom:before, .flatpickr-calendar.arrowBottom:after { border-top-color: var(--bg-200); }
        .flatpickr-month { background: var(--bg-200); color: var(--text-100); fill: var(--text-100); }
        .flatpickr-current-month .flatpickr-monthDropdown-months, .flatpickr-current-month input.cur-year { color: var(--text-100); font-weight: 600; }
        .flatpickr-current-month .flatpickr-monthDropdown-months:hover, .flatpickr-current-month input.cur-year:hover { background: var(--bg-300); }
        .flatpickr-weekdays { background: var(--bg-200); }
        span.flatpickr-weekday { background: var(--bg-200); color: var(--text-200); font-weight: 600; }
        .flatpickr-day { color: var(--text-100); border-radius: 6px; }
        .flatpickr-day.flatpickr-disabled { color: var(--text-300); }
        .flatpickr-day:hover, .flatpickr-day:focus { background: var(--bg-300); border-color: var(--bg-300); }
        .flatpickr-day.selected, .flatpickr-day.startRange, .flatpickr-day.endRange { background: var(--color-brand); border-color: var(--color-brand); color: white; }
        .flatpickr-day.inRange { background: var(--bg-300); border-color: var(--bg-300); box-shadow: -5px 0 0 var(--bg-300), 5px 0 0 var(--bg-300); }

        /* Component Visuals */
        .logo-box {
            background: var(--bg-200); 
            border-radius: 8px;
            color: var(--text-200); 
            font-size: var(--text-sm); 
            font-weight: 600; 
            cursor: pointer;
            border: 2px dashed var(--bg-300);
            transition: all 0.2s ease;
            display: flex; align-items: center; justify-content: center;
            position: relative; overflow: hidden;
        }
        .logo-box:hover { border-color: var(--color-brand); background: var(--bg-300); color: var(--text-100); }
        .logo-box img { max-width: 100%; max-height: 100%; object-fit: contain; }
        .logo-box input[type="file"] { position: absolute; top: 0; left: 0; width: 100%; height: 100%; opacity: 0; cursor: pointer; }
        .logo-remove {
            position: absolute; top: 2px; right: 2px;
            background: rgba(0,0,0,0.5); color: white;
            border-radius: 50%; width: 20px; height: 20px;
            display: flex; align-items: center; justify-content: center;
            font-size: 14px; cursor: pointer; z-index: 10;
        }
        .logo-remove:hover { background: var(--color-danger); }
        .from-logo-wrap { display: flex; gap: var(--space-3); align-items: center; }
        .from-logo-wrap .logo-box { margin-top: 0; }
        #logoText { position: absolute; inset: 0; display: flex; align-items: center; justify-content: center; pointer-events: none; text-align: center; }

        .add-line {
            display: inline-flex; align-items: center; justify-content: center;
            color: var(--text-100); background: var(--bg-200);
            font-size: var(--text-sm); font-weight: 600; 
            cursor: pointer; padding: 0.75rem 1.5rem; border-radius: 6px; 
            transition: 0.2s; width: fit-content;
        }
        .add-line:hover { background: var(--bg-300); color: white; }

        .download-btn {
            width: 100%; padding: 1rem; background: var(--color-brand); color: white;
            border: none; border-radius: 8px; font-weight: 600; cursor: pointer; 
            margin-bottom: var(--space-4); font-size: var(--text-base); transition: opacity 0.2s;
        }
        .download-btn:hover { opacity: 0.9; }

        .remove-btn {
            color: var(--text-200); cursor: pointer; font-size: var(--text-heading);
            text-align: center; user-select: none;
            transition: transform 0.3s cubic-bezier(0.175, 0.885, 0.32, 1.275), color 0.3s ease;
            display: flex; justify-content: center; align-items: center;
        }
        .remove-btn:hover, .remove-btn:active { color: var(--color-danger); }
        #items:has(.item-row:only-child) .remove-btn { display: none; }
        #items .item-row:last-child { margin-bottom: 0; }

        .toggle-btn {
            background: var(--bg-100); 
            border: 1px solid var(--bg-300); 
            color: var(--text-200);
            font-size: 0.7rem; 
            font-weight: 700; 
            cursor: pointer; 
            padding: 8px 16px; 
            border-radius: 50px; 
            transition: all 0.2s ease;
            letter-spacing: 0.05em;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 1px 2px rgba(0,0,0,0.1);
        }
        .toggle-btn:hover { 
            text-decoration: none; 
            background: var(--bg-300); 
            border-color: var(--color-brand);
            color: var(--text-100);
            transform: translateY(-1px); 
            box-shadow: 0 3px 6px rgba(0,0,0,0.2);
        }

        .remove-gst-btn {
            background: rgba(239, 68, 68, 0.1); /* Subtle red background */
            border-color: rgba(239, 68, 68, 0.3);
            color: var(--color-danger);
            font-size: 0.65rem;
            padding: 4px 12px;
        }
        .remove-gst-btn:hover {
            background: rgba(239, 68, 68, 0.2);
            border-color: var(--color-danger);
            color: var(--color-danger);
            box-shadow: 0 2px 4px rgba(239, 68, 68, 0.15);
        }

        .status-bar {
            position: fixed; top: 0; left: 0; right: 0;
            background: var(--bg-050); z-index: 1000;
        }
        .status-left { font-weight: 700; font-size: var(--text-heading); color: var(--color-brand); letter-spacing: -0.02em; }
        .nav-btn {
            background: none; border: none; color: var(--text-200); cursor: pointer;
            font-size: var(--text-sm); font-weight: 600; transition: color 0.2s;
        }
        .nav-btn:hover { color: var(--text-100); }
        .settings-btn {
            background: none; border: none; color: var(--text-200); cursor: pointer;
            display: flex; align-items: center; justify-content: center;
            transition: color 0.2s;
        }
        .settings-btn:hover { color: var(--text-100); }
        .settings-btn .material-icons { font-size: 24px; }
        .auth-link { text-decoration: none; color: var(--text-100); font-size: var(--text-sm); font-weight: 600; }
        .signup-btn { background: var(--color-brand); color: white; padding: 0.5rem 1rem; border-radius: 6px; font-weight: 600; }
        .menu-toggle { display: none; font-size: var(--text-title); cursor: pointer; color: var(--text-100); background: none; border: none; }

        /* Animation */
        @keyframes fadeInSlide {
            from { opacity: 0; transform: translateY(8px); }
            to { opacity: 1; transform: translateY(0); }
        }

        @keyframes slideDownMenu {
            from { opacity: 0; transform: translateY(-20px); }
            to { opacity: 1; transform: translateY(0); }
        }

        /* Helpers */
        .hidden-row { display: none !important; }
        .gst-col { display: none; } /* Hidden by default */
        body.gst-active .gst-col { display: block; } /* Visible when active (overridden in grid) */
        .mobile-section-title, .mobile-label { display: none; } /* Default hidden (Common) */
        
        .error-placeholder {
            border-color: var(--color-danger) !important;
        }
        .error-placeholder::placeholder {
            color: var(--color-danger) !important;
            opacity: 1;
        }

        /* Wrapper for Qty/Rate to allow side-by-side in mobile but grid in desktop */
        .qty-rate-wrapper, .qty-group, .rate-group { display: contents; }

        /* Quotation Header Styles */
        .quotation-header-content {
            display: flex;
            align-items: center;
            gap: var(--space-3);
            width: 100%;
            padding: 0;
        }

        .quotation-header-content .quotation-label-input {
            flex: 1;
            /* height: 50px; Removed to match other inputs height */
            margin: 0;
            font-size: 1.25rem;
            font-weight: 700;
            padding: 0.55rem 1rem; /* Reduced padding to match standard input height with larger font */
        }

        .quotation-header-content .inv-no-row {
            /* height: 50px; Removed to match other inputs height */
            margin: 0;
            display: flex;
            align-items: center;
            gap: 5px;
            background: var(--bg-100);
            border: 1px solid var(--bg-300);
            border-radius: 6px;
            padding: 0.55rem 8px; /* Adjusted padding */
            transition: border-color 0.2s, box-shadow 0.2s;
        }

        .quotation-header-content .inv-no-row:focus-within {
            border-color: var(--color-brand);
            box-shadow: 0 0 0 1px var(--color-brand);
        }

        .quotation-header-content .inv-no-row input {
            width: 45px;
            text-align: center;
            border: none;
            background: transparent;
            padding: 0;
            height: 100%;
            font-size: 1.25rem;
            font-weight: 700;
        }

        .quotation-header-content .inv-no-row input:focus {
            outline: none;
            box-shadow: none;
        }

        /* =========================================
           2. MOBILE MODE (max-width: 768px)
           ========================================= */
        @media (max-width: 768px) {
            .status-bar {
                padding: var(--space-2) var(--space-3);
                min-height: 50px; height: auto;
                flex-wrap: wrap;
                display: flex;
                align-items: center;
            }
            .status-left { order: 1; }
            .status-center, .status-right { display: none; width: 100%; }
            .status-bar.mobile-active .status-center, .status-bar.mobile-active .status-right {
                display: flex; flex-direction: column; gap: var(--space-4);
                margin-top: var(--space-4); padding-bottom: var(--space-4);
                width: 100%; align-items: center;
                animation: slideDownMenu 0.3s ease-out forwards;
            }
            .status-bar.mobile-active .status-center { 
                order: 4; 
                border-top: 1px solid var(--bg-300); 
                border-bottom: 1px solid var(--bg-300);
                padding-top: var(--space-4); 
            }
            .status-bar.mobile-active .status-right { 
                order: 5; 
                margin-top: 0;
                padding-top: var(--space-4);
            }
            .status-right .settings-btn { display: none; }

            .menu-toggle { display: block; order: 3; margin-left: 0; padding: var(--space-2); }
            .settings-btn.mobile-view { display: flex; order: 2; margin-left: auto; padding: var(--space-2); }

            .wrapper {
                flex-direction: column;
                padding: 80px var(--space-4) var(--space-4) var(--space-4);
                gap: 0;
                display: flex;
                width: 100%;
                overflow-x: hidden;
            }

            .title-bar {
                text-align: left; margin-bottom: var(--space-3);
                display: flex; justify-content: space-between; align-items: center;
            }
            
            .inv-no-row {
                display: flex; align-items: center; justify-content: flex-end;
                margin-bottom: 0; flex-shrink: 0; width: auto;
            }
            .inv-no-row input { width: 45px; text-align: center; font-weight: 600; font-size: 1.25rem; /* H2 Hierarchy */ }
            .inv-no-row label { display: inline-flex; margin-bottom: 0; }

            .mobile-meta-group { display: flex; gap: var(--space-3); margin-bottom: var(--space-4); }
            .mobile-meta-group > div { flex: 1; margin-bottom: 0 !important; }

            .address-container { display: grid; grid-template-columns: 1fr; gap: var(--space-4); margin-bottom: var(--space-4); }
            .address-container > div label:not(.switch) { display: none; }
            .auto-height-textarea { min-height: 60px; resize: none !important; overflow: hidden; display: block; }

            .top-meta-fields { width: 100%; gap: var(--space-3); margin-bottom: 0; margin-top: var(--space-4); display: flex; flex-direction: column; }
            .top-meta-fields .field { flex: 1; }

            .item-section { margin-bottom: var(--space-4); display: flex; flex-direction: column; gap: var(--space-3); }
            .item-header { display: none; }

            .item-row {
                display: block; position: relative;
                grid-template-columns: 1fr; gap: var(--space-2);
                padding: var(--space-4); background: var(--bg-200); border-radius: 8px;
                border: 1px solid var(--bg-300); margin-bottom: var(--space-4);
            }
            .item-row textarea, .item-row input { width: 100%; display: block; background: var(--bg-100); height: 38px; min-height: 38px; margin-bottom: var(--space-3); }
            .item-row .mobile-label { display: block; font-size: var(--text-sm); color: var(--text-200); text-transform: uppercase; letter-spacing: 0.05em; font-weight: 600; margin-bottom: var(--space-1); }

            .item-amt {
                display: flex; justify-content: space-between; align-items: center;
                font-size: var(--text-base); font-weight: 700; color: var(--color-brand);
                height: auto; padding-right: 0; margin-bottom: 0; width: 100%; text-align: right;
            }
            .item-amt::before { content: 'Amount: '; color: var(--text-200); font-weight: 600; font-size: var(--text-sm); flex-shrink: 0; }
            .item-amt-value { flex: 1; text-align: right; }

            .remove-btn {
                position: absolute; top: 8px; right: 8px;
                display: inline-flex; width: 24px; height: 24px;
                align-items: center; justify-content: center;
                background: transparent; border-radius: 50%; z-index: 10;
                font-size: 16px; line-height: 1; color: var(--text-200);
                transition: all 0.2s ease;
            }
            .remove-btn:hover {
                background: var(--bg-300); color: var(--color-danger);
            }
            #items:has(.item-row:only-child) .remove-btn { display: none !important; }

            .summary-box { margin-top: 0; margin-bottom: 0; padding: var(--space-4); background: var(--bg-200); border-radius: 12px; display: flex; flex-direction: column; gap: var(--space-2); }
            .sum-row { display: flex; justify-content: space-between; align-items: center; font-size: var(--text-sm); color: var(--text-200); min-height: 40px; }
            .sum-row label { margin-bottom: 0; }
            .sum-input-group { display: flex; align-items: center; gap: var(--space-3); position: static; }
            .input-prefix-wrapper {
                display: flex; align-items: center;
                background: var(--bg-100); border: 1px solid var(--bg-300);
                border-radius: 6px; padding: 0 12px;
                width: 140px; height: 40px; transition: all 0.2s;
            }
            .input-prefix-wrapper:focus-within { border-color: var(--color-brand); box-shadow: 0 0 0 1px var(--color-brand); }
            .curr-prefix { color: var(--text-200); font-size: var(--text-base); font-weight: 500; margin-right: 8px; user-select: none; line-height: 1; }
            .sum-row input { 
                border: none !important; box-shadow: none !important; background: transparent !important; 
                padding: 0 !important; width: 100% !important; text-align: left !important; height: 100% !important; 
            }
            .inline-remove { 
                position: static; transform: none; width: 24px; height: 24px;
                display: flex; align-items: center; justify-content: center;
                font-size: 20px; color: var(--color-danger); cursor: pointer;
                background: transparent; transition: opacity 0.2s;
            }
            .inline-remove:hover { opacity: 0.8; background: transparent; color: var(--color-danger); }
            .toggle-row { display: flex; gap: var(--space-3); margin-bottom: var(--space-2); justify-content: flex-start; flex-wrap: wrap; }

            .header-top { flex-direction: column; gap: 0; margin-bottom: var(--space-4); display: flex; }
            .logo-box { width: 80px; height: 80px; min-width: 80px; margin-bottom: 0; }
            
            .footer-container { grid-template-columns: 1fr; gap: var(--space-4); margin-bottom: var(--space-4); margin-top: 0 !important; display: grid; }
            .footer-container > div label { display: none; }
            .footer-container textarea { min-height: 80px; resize: none !important; overflow: hidden; }

            .download-btn { margin-bottom: 0; }
            .right-section, .left-section { display: contents; width: 100%; }

            .mobile-section-title {
                display: block; font-size: 0.875rem; /* H3 Hierarchy */ font-weight: 700;
                color: var(--text-200); text-transform: uppercase; letter-spacing: 0.05em;
                margin-bottom: var(--space-2); padding-bottom: var(--space-1); border-bottom: 1px solid var(--bg-300);
            }
            .gst-col { display: none; }
            body.gst-active .gst-col { display: block; flex: 1; } /* Visible and flexed when active */

            .qty-rate-wrapper {
                display: flex;
                gap: var(--space-3);
                width: 100%;
            }
            .qty-group, .rate-group {
                display: block; /* Override contents */
                flex: 1;
            }
        }

        /* =========================================
           3. TABLET MODE (769px - 1024px)
           ========================================= */
        @media (min-width: 769px) and (max-width: 1024px) {
            .settings-btn.mobile-view { display: none; }
            .status-bar {
                height: 60px; padding: 0 var(--space-3);
                display: flex; align-items: center; justify-content: space-between;
            }
            .status-center { display: flex; gap: var(--space-2); }
            .status-right { display: flex; gap: var(--space-2); align-items: center; }

            .wrapper {
                display: flex;
                width: 100%;
                max-width: 100%; /* Full width for tablet */
                margin: 0 auto;
                min-height: 100vh;
                padding: 100px var(--space-3) var(--space-5) var(--space-3);
                gap: var(--space-3);
            }

            .left-section { flex: 1; display: flex; flex-direction: column; gap: var(--space-5); }
            .right-section { width: 280px; display: flex; flex-direction: column; gap: var(--space-4); } /* Slightly narrower sidebar */

            .header-top { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--space-4); }
            .logo-box { width: 80px; height: 80px; min-width: 80px; }
            .top-meta-fields { display: flex; gap: var(--space-3); width: 100%; }
            .top-meta-fields .field { flex: 1; }

            .address-container { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-4); }
            .auto-height-textarea { min-height: 60px; resize: none !important; overflow: hidden; display: block; }

            .item-section { display: flex; flex-direction: column; gap: var(--space-3); }
            
            /* Grid Layouts */
            .item-header, .item-row {
                display: grid;
                grid-template-columns: 1fr 80px 100px 120px 40px;
                gap: var(--space-2); padding: 0 var(--space-2);
                align-items: center;
            }
            .item-header { margin-bottom: 0; color: var(--text-200); font-size: var(--text-sm); text-transform: uppercase; font-weight: 700; border-bottom: none; }
            .item-row { border: none; margin-bottom: var(--space-2); animation: fadeInSlide 0.3s ease-out forwards; align-items: start; }
            
            body.gst-active .item-header, body.gst-active .item-row { 
                grid-template-columns: 1fr 60px 80px 60px 100px 40px; 
            }

            .item-row textarea, .item-row input { height: 38px; min-height: 38px; line-height: 20px; padding: 0.5rem 0.75rem; resize: none !important; overflow: hidden; }
            .item-amt { display: flex; align-items: center; justify-content: flex-end; padding-right: var(--space-2); font-weight: 600; height: 38px; font-size: var(--text-base); color: var(--text-100); width: 100%; text-align: right; }
            .remove-btn { height: 38px; width: 100%; }

            .title-bar { text-align: right; margin-bottom: var(--space-4); }
            .inv-no-row { display: flex; justify-content: flex-end; align-items: center; gap: var(--space-2); margin-top: var(--space-2); }
            .inv-no-row input { width: 45px; text-align: center; font-weight: 600; }

            .summary-box { margin-top: var(--space-4); padding: var(--space-3); background: var(--bg-200); border-radius: 12px; display: flex; flex-direction: column; gap: var(--space-2); }
            .sum-row { display: flex; justify-content: space-between; align-items: center; font-size: var(--text-sm); color: var(--text-200); min-height: 40px; }
            .sum-row label { margin-bottom: 0; }
            .sum-row:not(.hidden-row) { animation: fadeInSlide 0.3s ease-out forwards; }
            .sum-input-group { display: flex; align-items: center; gap: var(--space-3); position: static; }
            .input-prefix-wrapper {
                display: flex; align-items: center;
                background: var(--bg-100); border: 1px solid var(--bg-300);
                border-radius: 6px; padding: 0 12px;
                width: 140px; height: 40px; transition: all 0.2s;
            }
            .input-prefix-wrapper:focus-within { border-color: var(--color-brand); box-shadow: 0 0 0 1px var(--color-brand); }
            .curr-prefix { color: var(--text-200); font-size: var(--text-base); font-weight: 500; margin-right: 8px; user-select: none; line-height: 1; }
            .sum-row input { 
                border: none !important; box-shadow: none !important; background: transparent !important; 
                padding: 0 !important; width: 100% !important; text-align: left !important; height: 100% !important; 
            }
            .inline-remove { 
                position: static; transform: none; width: 24px; height: 24px;
                display: flex; align-items: center; justify-content: center;
                font-size: 20px; color: var(--color-danger); cursor: pointer;
                background: transparent; transition: opacity 0.2s;
            }
            .inline-remove:hover { opacity: 0.8; background: transparent; color: var(--color-danger); }
            .toggle-row { display: flex; gap: var(--space-3); margin-bottom: var(--space-2); justify-content: flex-start; flex-wrap: wrap; }

            .footer-container { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-4); margin-top: var(--space-4); }
            .footer-container textarea { min-height: 80px; resize: none !important; overflow: hidden; }
            
            .mobile-meta-group { display: block; margin-top: 10px; }
            .mobile-meta-group > div { margin-bottom: 15px; }
        }

        /* =========================================
           4. DESKTOP MODE (min-width: 1025px)
           ========================================= */
        @media (min-width: 1025px) {
            .settings-btn.mobile-view { display: none; }
            .status-bar {
                height: 60px; padding: 0 var(--space-5);
                display: flex; align-items: center; justify-content: space-between;
            }
            .status-center { display: flex; gap: var(--space-4); }
            .status-right { display: flex; gap: var(--space-3); align-items: center; }

            .wrapper {
                display: flex;
                max-width: 1200px;
                margin: 0 auto;
                min-height: 100vh;
                padding: 100px var(--space-4) var(--space-5) var(--space-4);
                gap: var(--space-5);
            }

            .left-section { flex: 1; display: flex; flex-direction: column; gap: var(--space-5); }
            .right-section { width: 320px; display: flex; flex-direction: column; gap: var(--space-4); }

            .header-top { display: flex; justify-content: space-between; align-items: flex-start; gap: var(--space-4); }
            .logo-box { width: 80px; height: 80px; min-width: 80px; }
            .top-meta-fields { display: flex; gap: var(--space-3); width: 100%; }
            .top-meta-fields .field { flex: 1; }

            .address-container { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-4); }
            .auto-height-textarea { min-height: 60px; resize: none !important; overflow: hidden; display: block; }

            .item-section { display: flex; flex-direction: column; gap: var(--space-3); }

            /* Grid Layouts */
            .item-header, .item-row {
                display: grid;
                grid-template-columns: 1fr 80px 100px 120px 40px;
                gap: var(--space-2); padding: 0 var(--space-2);
                align-items: center;
            }
            .item-header { margin-bottom: 0; color: var(--text-200); font-size: var(--text-sm); text-transform: uppercase; font-weight: 700; border-bottom: none; }
            .item-row { border: none; margin-bottom: var(--space-2); animation: fadeInSlide 0.3s ease-out forwards; align-items: start; }
            
            body.gst-active .item-header, body.gst-active .item-row { 
                grid-template-columns: 1fr 60px 80px 60px 100px 40px; 
            }

            .item-row textarea, .item-row input { height: 38px; min-height: 38px; line-height: 20px; padding: 0.5rem 0.75rem; resize: none !important; overflow: hidden; }
            .item-amt { display: flex; align-items: center; justify-content: flex-end; padding-right: var(--space-2); font-weight: 600; height: 38px; font-size: var(--text-base); color: var(--text-100); width: 100%; text-align: right; }
            .remove-btn { height: 38px; width: 100%; }

            .title-bar { text-align: right; margin-bottom: var(--space-4); }
            .inv-no-row { display: flex; justify-content: flex-end; align-items: center; gap: var(--space-2); margin-top: var(--space-2); }
            .inv-no-row input { width: 45px; text-align: center; font-weight: 600; }

            .summary-box { margin-top: var(--space-4); padding: var(--space-3); background: var(--bg-200); border-radius: 12px; display: flex; flex-direction: column; gap: var(--space-2); }
            .sum-row { display: flex; justify-content: space-between; align-items: center; font-size: var(--text-sm); color: var(--text-200); min-height: 40px; }
            .sum-row label { margin-bottom: 0; }
            .sum-row:not(.hidden-row) { animation: fadeInSlide 0.3s ease-out forwards; }
            .sum-input-group { display: flex; align-items: center; gap: var(--space-3); position: static; }
            .input-prefix-wrapper {
                display: flex; align-items: center;
                background: var(--bg-100); border: 1px solid var(--bg-300);
                border-radius: 6px; padding: 0 12px;
                width: 140px; height: 40px; transition: all 0.2s;
            }
            .input-prefix-wrapper:focus-within { border-color: var(--color-brand); box-shadow: 0 0 0 1px var(--color-brand); }
            .curr-prefix { color: var(--text-200); font-size: var(--text-base); font-weight: 500; margin-right: 8px; user-select: none; line-height: 1; }
            .sum-row input { 
                border: none !important; box-shadow: none !important; background: transparent !important; 
                padding: 0 !important; width: 100% !important; text-align: left !important; height: 100% !important; 
            }
            .inline-remove { 
                position: static; transform: none; width: 24px; height: 24px;
                display: flex; align-items: center; justify-content: center;
                font-size: 20px; color: var(--color-danger); cursor: pointer;
                background: transparent; transition: opacity 0.2s;
            }
            .inline-remove:hover { opacity: 0.8; background: transparent; color: var(--color-danger); }
            .toggle-row { display: flex; gap: var(--space-3); margin-bottom: var(--space-2); justify-content: flex-start; flex-wrap: wrap; }

            .footer-container { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-4); margin-top: var(--space-4); }
            .footer-container textarea { min-height: 80px; resize: none !important; overflow: hidden; }

            .mobile-meta-group { display: block; margin-top: 10px; }
            .mobile-meta-group > div { margin-bottom: 15px; }
        }
        /* History Modal */
        .modal-overlay {
            position: fixed; top: 0; left: 0; right: 0; bottom: 0;
            background: rgba(0, 0, 0, 0.5); z-index: 2000;
            display: none; justify-content: center; align-items: center;
            opacity: 0; transition: opacity 0.3s ease;
            backdrop-filter: blur(5px);
            -webkit-backdrop-filter: blur(5px);
        }
        .modal-overlay.open { display: flex; opacity: 1; }
        .modal-content {
            background: var(--bg-100); width: 90%; max-width: 600px;
            border-radius: 12px; padding: var(--space-5);
            max-height: 80vh; overflow-y: auto;
            position: relative; box-shadow: 0 10px 25px rgba(0,0,0,0.2);
            transform: translateY(20px); transition: transform 0.3s ease;
        }
        .modal-overlay.open .modal-content { transform: translateY(0); }
        .modal-header {
            display: flex; justify-content: space-between; align-items: center;
            margin-bottom: var(--space-4); border-bottom: 1px solid var(--bg-300);
            padding-bottom: var(--space-3);
        }
        .modal-title { font-size: var(--text-heading); font-weight: 700; color: var(--text-100); }
        .close-modal { background: none; border: none; font-size: 24px; color: var(--text-200); cursor: pointer; }
        .history-list { list-style: none; display: flex; flex-direction: column; gap: var(--space-2); }
        .history-item {
            background: var(--bg-200); padding: var(--space-3); border-radius: 8px;
            display: flex; justify-content: space-between; align-items: center;
        }
        .history-info { display: flex; flex-direction: column; gap: 4px; }
        .history-date { font-size: var(--text-sm); color: var(--text-200); }
        .history-client { font-weight: 600; color: var(--text-100); }
        .history-amount { font-weight: 700; color: var(--color-brand); }
        .history-actions { display: flex; gap: var(--space-2); }
        .btn-sm { padding: 4px 8px; font-size: var(--text-sm); border-radius: 4px; cursor: pointer; border: none; font-family: inherit; }
        .btn-danger { background: rgba(239, 68, 68, 0.1); color: var(--color-danger); }
        .btn-danger:hover { background: rgba(239, 68, 68, 0.2); }
        .empty-history { text-align: center; color: var(--text-200); padding: var(--space-5); }
        /* Item Description Customization */
        .item-description-input {
            overflow: hidden !important;
            text-align: left;
            resize: none;
            padding-top: 9px;
            padding-bottom: 9px;
            line-height: 20px;
        }
        .item-description-input:focus::placeholder {
            color: transparent;
        }
        /* Preview Modal */
    .preview-overlay {
        position: fixed; top: 0; left: 0; right: 0; bottom: 0;
        background: rgba(0, 0, 0, 0.85); z-index: 3000;
        display: none; flex-direction: column; align-items: center; justify-content: center;
        backdrop-filter: blur(5px);
        opacity: 0; transition: opacity 0.3s ease;
    }
    .preview-overlay.open { opacity: 1; }
    
    .preview-container {
        background: transparent;max-width: 90%;max-height: 80vh;
        overflow: auto;border-radius: 8px;
        box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
        margin-bottom: 20px;display: block;transform: scale(0.95); transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    }
    .preview-overlay.open .preview-container { transform: scale(1); }

    .preview-actions {
        display: flex; gap: 15px;background: var(--bg-200);padding: 15px 25px;border-radius: 50px;box-shadow: 0 4px 6px rgba(0,0,0,0.3);
    }
    
    .preview-actions button {
        padding: 10px 24px;border-radius: 25px;font-weight: 600;font-size: 1rem;cursor: pointer;border: none;transition: transform 0.2s;
    }
    
    .preview-actions .btn-cancel { background: var(--bg-300); color: var(--text-100); }
    .preview-actions .btn-confirm { background: var(--color-brand); color: white; }
    
    .preview-actions button:hover { transform: translateY(-2px); }

    /* Toggle Switch */
    .switch {
      position: relative;
      display: inline-block;
      width: 36px;
      height: 20px;
    }
    
    .switch input { 
      opacity: 0;
      width: 0;
      height: 0;
    }
    
    .slider {
      position: absolute;
      cursor: pointer;
      top: 0;
      left: 0;
      right: 0;
      bottom: 0;
      background-color: var(--bg-300);
      transition: .4s;
      border-radius: 20px;
    }
    
    .slider:before {
      position: absolute;
      content: "";
      height: 16px;
      width: 16px;
      left: 2px;
      bottom: 2px;
      background-color: white;
      transition: .4s;
      border-radius: 50%;
    }
    
    input:checked + .slider {
      background-color: var(--color-brand);
    }
    
    input:checked + .slider:before {
      transform: translateX(16px);
    }
    
    /* Flexible Section Title */
    .flexible-section-title {
        display: flex; 
        justify-content: space-between; 
        align-items: center; 
        margin-bottom: var(--space-1);
        min-height: 28px; /* Ensure equal height with or without toggle */
        
        /* Default Desktop Style (mimic label) */
        font-size: var(--text-sm);
        color: var(--text-200); 
        text-transform: uppercase;
        letter-spacing: 0.05em;
        font-weight: 600;
    }
    
    @media (max-width: 768px) {
        .flexible-section-title {
            /* Mobile Style (mimic mobile-section-title) */
            font-size: 0.875rem;
            font-weight: 700;
            margin-bottom: var(--space-2); 
            padding-bottom: var(--space-1); 
            border-bottom: 1px solid var(--bg-300);
        }
    }
    
    /* Auth Modal Styles */
    .auth-tabs { display: flex; border-bottom: 1px solid var(--bg-300); margin-bottom: 20px; }
    .auth-tab { flex: 1; padding: 12px; text-align: center; cursor: pointer; color: var(--text-200); border-bottom: 2px solid transparent; transition: all 0.2s; }
    .auth-tab:hover { color: var(--text-100); }
    .auth-tab.active { color: var(--color-brand); border-bottom-color: var(--color-brand); font-weight: 600; }
    .auth-form { display: flex; flex-direction: column; gap: 15px; }
    .auth-field label { display: block; margin-bottom: 5px; font-size: var(--text-sm); color: var(--text-200); }
    .auth-input { background: var(--bg-100); border: 1px solid var(--bg-300); color: var(--text-100); padding: 12px; border-radius: 6px; width: 100%; outline: none; transition: border-color 0.2s; }
    .auth-input:focus { border-color: var(--color-brand); }
    .auth-btn { background: var(--color-brand); color: white; padding: 12px; border-radius: 6px; border: none; cursor: pointer; font-weight: 600; width: 100%; margin-top: 10px; }
    .auth-btn:hover { background: var(--color-brand-light); }
    .auth-error { color: var(--color-danger); font-size: var(--text-sm); display: none; margin-top: 10px; text-align: center; background: rgba(239, 68, 68, 0.1); padding: 10px; border-radius: 6px; }
    .user-profile { display: flex; align-items: center; gap: 10px; }
    .user-avatar { width: 32px; height: 32px; background: var(--color-brand); border-radius: 50%; display: flex; align-items: center; justify-content: center; color: white; font-weight: 600; font-size: 14px; }
    .user-menu-btn { background: none; border: none; color: var(--text-200); cursor: pointer; font-size: var(--text-sm); }
    .user-menu-btn:hover { color: var(--text-100); }