:root {
            --navy:        #003366;
            --navy-dark:   #002244;
            --navy-light:  #004080;
            --navy-muted:  #e8eef5;
            --navy-border: #c5d5e8;
            --white:       #ffffff;
            --text:        #000000;
            --text-muted:  #4a5568;
            --text-light:  #718096;
            --success:     #1a7f45;
            --success-bg:  #e6f5ec;
            --error:       #c0392b;
            --error-bg:    #fdf0ee;
            --radius:      8px;
            --shadow:      0 2px 8px rgba(0,51,102,0.10);
            --shadow-lg:   0 4px 20px rgba(0,51,102,0.15);
        }

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

        body {
            font-family: "Segoe UI", Arial, sans-serif;
            background: #f0f4f8;
            color: var(--text);
            line-height: 1.6;
            min-height: 100vh;
        }

        /* ── Tool Header ── */
        .tool-header {
            background: var(--navy);
            color: var(--white);
            padding: 18px 0;
            box-shadow: 0 2px 8px rgba(0,51,102,0.2);
        }

        .tool-header .container {
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .tool-title { display: flex; align-items: center; gap: 12px; }

        .tool-icon {
            width: 38px; height: 38px;
            background: rgba(255,255,255,0.15);
            border: 1px solid rgba(255,255,255,0.25);
            border-radius: 8px;
            display: flex; align-items: center; justify-content: center;
            font-size: 18px;
        }

        .tool-title h1 { font-size: 20px; font-weight: 700; color: var(--white); margin: 0; }
        .tool-title p  { font-size: 13px; color: rgba(255,255,255,0.7); margin: 0; }

        .tool-badge {
            background: rgba(255,255,255,0.12);
            border: 1px solid rgba(255,255,255,0.2);
            border-radius: 20px;
            padding: 5px 14px;
            font-size: 12px;
            color: rgba(255,255,255,0.85);
        }

        /* ── Layout ── */
        .container { width: 90%; max-width: 1100px; margin: auto; }
        .tool-body { padding: 32px 0 60px; }

        /* ── Tabs ── */
        .tabs {
            display: flex;
            border-bottom: 2px solid var(--navy-border);
            margin-bottom: 28px;
        }

        .tab-btn {
            padding: 12px 28px;
            border: none;
            background: transparent;
            font-family: "Segoe UI", Arial, sans-serif;
            font-size: 14px; font-weight: 600;
            cursor: pointer;
            color: var(--text-muted);
            border-bottom: 3px solid transparent;
            margin-bottom: -2px;
            transition: all .2s;
            display: flex; align-items: center; gap: 7px;
        }

        .tab-btn.active { color: var(--navy); border-bottom-color: var(--navy); }
        .tab-btn:hover:not(.active) { color: var(--navy); background: var(--navy-muted); }

        /* ── Panels ── */
        .panel { display: none; }
        .panel.active { display: block; animation: fadeUp .25s ease; }

        @keyframes fadeUp {
            from { opacity: 0; transform: translateY(8px); }
            to   { opacity: 1; transform: translateY(0); }
        }

        /* ── Cards ── */
        .card {
            background: var(--white);
            border: 1px solid var(--navy-border);
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            margin-bottom: 20px;
        }

        .card-header {
            padding: 14px 20px;
            border-bottom: 1px solid var(--navy-border);
            background: var(--navy-muted);
            border-radius: var(--radius) var(--radius) 0 0;
            display: flex; align-items: center; gap: 8px;
        }

        .card-header h3 { font-size: 14px; font-weight: 600; color: var(--navy); margin: 0; }
        .card-body { padding: 20px; }

        /* ── Drop Zone ── */
        .drop-zone {
            border: 2px dashed var(--navy-border);
            border-radius: var(--radius);
            background: var(--navy-muted);
            padding: 48px 40px;
            text-align: center;
            cursor: pointer;
            position: relative;
            transition: all .2s ease;
        }

        .drop-zone:hover, .drop-zone.dragging {
            border-color: var(--navy);
            background: #dce8f5;
        }

        .drop-zone input[type=file] {
            position: absolute; inset: 0; opacity: 0;
            cursor: pointer; width: 100%; height: 100%;
        }

        .drop-icon { font-size: 40px; display: block; margin-bottom: 12px; }
        .drop-zone h3 { font-size: 16px; font-weight: 600; color: var(--navy); margin-bottom: 6px; }
        .drop-zone p { color: var(--text-light); font-size: 13px; margin: 0; }

        /* ── Controls ── */
        .controls-row {
            display: grid;
            grid-template-columns: 1fr 1fr auto;
            gap: 16px; align-items: end;
        }

        .field label {
            display: block;
            font-size: 13px; font-weight: 600;
            color: var(--navy); margin-bottom: 6px;
        }

        select {
            width: 100%;
            background: var(--white);
            border: 1px solid var(--navy-border);
            border-radius: 6px;
            color: var(--text);
            padding: 10px 14px;
            font-family: "Segoe UI", Arial, sans-serif;
            font-size: 14px; cursor: pointer;
            appearance: none;
            background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6' viewBox='0 0 10 6'%3E%3Cpath fill='%23003366' d='M0 0l5 6 5-6z'/%3E%3C/svg%3E");
            background-repeat: no-repeat;
            background-position: right 12px center;
            transition: border-color .2s;
        }

        select:focus { outline: none; border-color: var(--navy); }

        .range-wrap { display: flex; align-items: center; gap: 10px; }

        input[type=range] {
            -webkit-appearance: none; appearance: none;
            flex: 1; height: 4px;
            background: var(--navy-border); border-radius: 2px; outline: none;
        }

        input[type=range]::-webkit-slider-thumb {
            -webkit-appearance: none;
            width: 16px; height: 16px; border-radius: 50%;
            background: var(--navy); cursor: pointer;
            border: 2px solid white;
            box-shadow: 0 1px 4px rgba(0,51,102,0.3);
        }

        .range-val {
            font-size: 13px; font-weight: 600;
            color: var(--navy); min-width: 38px; text-align: right;
        }

        /* ── Buttons ── */
        .btn {
            display: inline-flex; align-items: center; gap: 7px;
            padding: 11px 22px; border: none; border-radius: 6px;
            font-family: "Segoe UI", Arial, sans-serif;
            font-size: 14px; font-weight: 600;
            cursor: pointer; transition: all .2s;
            text-decoration: none; white-space: nowrap;
        }

        .btn-primary {
            background: var(--navy); color: var(--white);
            box-shadow: 0 2px 8px rgba(0,51,102,0.25);
        }
        .btn-primary:hover:not(:disabled) {
            background: var(--navy-light);
            box-shadow: 0 4px 14px rgba(0,51,102,0.35);
            transform: translateY(-1px);
        }
        .btn-primary:disabled {
            background: var(--navy-border); color: var(--text-light);
            cursor: not-allowed; box-shadow: none;
        }

        .btn-success {
            background: var(--success); color: var(--white);
            font-size: 13px; padding: 9px 16px;
        }
        .btn-success:hover { background: #15693a; transform: translateY(-1px); }

        .btn-outline {
            background: var(--white);
            border: 1px solid var(--navy-border);
            color: var(--text-muted);
            font-size: 13px; padding: 9px 16px;
        }
        .btn-outline:hover { border-color: var(--navy); color: var(--navy); }

        /* ── Preview ── */
        .preview-count {
            font-size: 13px; color: var(--text-muted);
            margin-bottom: 14px; padding: 8px 14px;
            background: var(--navy-muted);
            border-radius: 6px; border-left: 3px solid var(--navy);
        }

        .preview-grid {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
            gap: 10px; margin-bottom: 20px;
        }

        .preview-thumb {
            background: var(--navy-muted);
            border: 1px solid var(--navy-border);
            border-radius: 6px; overflow: hidden;
            position: relative; aspect-ratio: 1;
        }

        .preview-thumb img { width: 100%; height: 100%; object-fit: cover; }

        .preview-thumb .remove-btn {
            position: absolute; top: 4px; right: 4px;
            width: 22px; height: 22px;
            background: rgba(0,51,102,0.8);
            border: none; border-radius: 50%;
            color: #fff; font-size: 12px; cursor: pointer;
            display: flex; align-items: center; justify-content: center;
            transition: background .2s;
        }
        .preview-thumb .remove-btn:hover { background: var(--error); }

        /* ── Progress ── */
        .progress-wrap {
            background: var(--navy-muted);
            border: 1px solid var(--navy-border);
            border-radius: var(--radius);
            padding: 16px 20px; margin-bottom: 20px; display: none;
        }
        .progress-wrap.visible { display: block; }
        .progress-label { font-size: 13px; color: var(--navy); font-weight: 500; margin-bottom: 8px; }
        .progress-bar { height: 6px; background: var(--navy-border); border-radius: 3px; overflow: hidden; }
        .progress-fill {
            height: 100%;
            background: linear-gradient(90deg, var(--navy), #0066cc);
            border-radius: 3px; width: 0%; transition: width .4s ease;
        }

        /* ── Results ── */
        .results-list { display: flex; flex-direction: column; gap: 8px; }

        .result-item {
            background: var(--white); border: 1px solid var(--navy-border);
            border-radius: 6px; padding: 14px 18px;
            display: flex; align-items: center; justify-content: space-between;
            gap: 16px; animation: fadeUp .25s ease both;
        }
        .result-item.success { border-left: 3px solid var(--success); }
        .result-item.error   { border-left: 3px solid var(--error); }

        .result-info { flex: 1; min-width: 0; }
        .result-name {
            font-size: 14px; font-weight: 600; color: var(--text);
            white-space: nowrap; overflow: hidden; text-overflow: ellipsis; margin-bottom: 3px;
        }
        .result-meta { font-size: 12px; color: var(--text-muted); display: flex; align-items: center; gap: 10px; }
        .badge-saved { background: var(--success-bg); color: var(--success); padding: 2px 8px; border-radius: 4px; font-size: 11px; font-weight: 700; }
        .badge-error { background: var(--error-bg); color: var(--error); padding: 2px 8px; border-radius: 4px; font-size: 11px; }

        /* ── BG Remove ── */
        .bg-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 20px; }

        .img-card { background: var(--white); border: 1px solid var(--navy-border); border-radius: var(--radius); overflow: hidden; }

        .img-card-header {
            padding: 10px 16px;
            background: var(--navy-muted); border-bottom: 1px solid var(--navy-border);
            font-size: 12px; font-weight: 600; color: var(--navy);
            text-transform: uppercase; letter-spacing: 0.5px;
        }

        .img-card-body {
            padding: 16px; min-height: 200px;
            display: flex; align-items: center; justify-content: center;
        }

        .img-card-body img { max-width: 100%; max-height: 280px; object-fit: contain; border-radius: 4px; }

        .checker-bg {
            background-image:
                linear-gradient(45deg, #d0d8e4 25%, transparent 25%),
                linear-gradient(-45deg, #d0d8e4 25%, transparent 25%),
                linear-gradient(45deg, transparent 75%, #d0d8e4 75%),
                linear-gradient(-45deg, transparent 75%, #d0d8e4 75%);
            background-size: 16px 16px;
            background-position: 0 0, 0 8px, 8px -8px, -8px 0px;
            background-color: #e8eef5;
        }

        .placeholder-msg { color: var(--text-light); font-size: 13px; text-align: center; }

        /* ── Spinner ── */
        .spinner {
            width: 30px; height: 30px;
            border: 3px solid var(--navy-border); border-top-color: var(--navy);
            border-radius: 50%; animation: spin .7s linear infinite;
        }
        @keyframes spin { to { transform: rotate(360deg); } }

        /* ── Info Note ── */
        .info-note {
            background: var(--navy-muted);
            border: 1px solid var(--navy-border);
            border-left: 3px solid var(--navy);
            border-radius: 6px; padding: 10px 14px;
            font-size: 13px; color: var(--text-muted); margin-bottom: 16px;
        }
        .info-note strong { color: var(--navy); }

        /* ── Toast ── */
        .toast-wrap {
            position: fixed; bottom: 24px; right: 24px;
            display: flex; flex-direction: column; gap: 8px; z-index: 9999;
        }
        .toast {
            background: var(--white); border: 1px solid var(--navy-border);
            border-radius: 8px; padding: 12px 18px; font-size: 13px;
            display: flex; align-items: center; gap: 8px;
            box-shadow: var(--shadow-lg); animation: slideIn .25s ease;
            max-width: 300px; color: var(--text);
        }
        .toast.success { border-left: 3px solid var(--success); }
        .toast.error   { border-left: 3px solid var(--error); }

        @keyframes slideIn {
            from { opacity: 0; transform: translateX(16px); }
            to   { opacity: 1; transform: translateX(0); }
        }

        @media (max-width: 700px) {
            .controls-row { grid-template-columns: 1fr 1fr; }
            .controls-row .btn { grid-column: 1/-1; width: 100%; justify-content: center; }
            .bg-grid { grid-template-columns: 1fr; }
            .tool-badge { display: none; }
        }