:root {
            --bg: #f1f5f9;
            --surface: #ffffff;
            --surface-2: #f8fafc;
            --border: #e2e8f0;
            --text: #0f172a;
            --text-muted: #64748b;
            --primary: #0d9488;
            --primary-dark: #0f766e;
            --primary-light: #ccfbf1;
            --accent: #f59e0b;
            --hero-from: #0f172a;
            --hero-mid: #134e4a;
            --hero-to: #0d9488;
            --shadow: 0 1px 3px rgba(15,23,42,0.06), 0 4px 16px rgba(15,23,42,0.04);
            --shadow-lg: 0 8px 30px rgba(15,23,42,0.12);
            --radius: 14px;
        }
        * { box-sizing: border-box; }
        body {
            background: var(--bg);
            min-height: 100vh;
            font-family: "Microsoft YaHei", "PingFang SC", -apple-system, BlinkMacSystemFont, sans-serif;
            color: var(--text);
            margin: 0;
        }

        /* ── Hero ─ */
        .hero {
            background: linear-gradient(145deg, var(--hero-from) 0%, var(--hero-mid) 55%, var(--hero-to) 100%);
            padding: 48px 0 56px;
            position: relative;
            overflow: hidden;
        }
        .hero::before {
            content: '';
            position: absolute;
            inset: 0;
            background: radial-gradient(circle at 80% 20%, rgba(255,255,255,0.08) 0%, transparent 50%);
            pointer-events: none;
        }
        .hero-inner { position: relative; z-index: 1; text-align: center; }
        .hero h1 {
            font-size: 28px;
            font-weight: 700;
            color: #fff;
            margin: 0 0 8px;
        }
        .hero-desc {
            color: rgba(255,255,255,0.72);
            font-size: 14px;
            margin: 0 0 24px;
        }
        .hero-tags {
            display: flex;
            gap: 10px;
            justify-content: center;
            flex-wrap: wrap;
        }
        .hero-tag {
            background: rgba(255,255,255,0.1);
            border: 1px solid rgba(255,255,255,0.18);
            border-radius: 20px;
            padding: 6px 16px;
            font-size: 12px;
            color: rgba(255,255,255,0.85);
        }

        /* ── Layout ── */
        .main-wrap {
            max-width: 1140px;
            margin: -28px auto 0;
            padding: 0 15px 40px;
            position: relative;
            z-index: 2;
        }
        .tool-card {
            background: var(--surface);
            border-radius: var(--radius);
            box-shadow: var(--shadow);
            border: 1px solid var(--border);
            margin-bottom: 20px;
            overflow: visible;
        }
        .tool-card-head {
            padding: 16px 20px;
            border-bottom: 1px solid var(--border);
            display: flex;
            align-items: center;
            gap: 10px;
        }
        .tool-card-icon {
            width: 34px;
            height: 34px;
            border-radius: 8px;
            background: var(--primary-light);
            color: var(--primary);
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 15px;
            flex-shrink: 0;
        }
        .tool-card-icon.orange { background: #fef3c7; color: #d97706; }
        .tool-card-icon.blue { background: #dbeafe; color: #2563eb; }
        .tool-card-title {
            font-size: 15px;
            font-weight: 700;
            color: var(--text);
            margin: 0;
        }
        .tool-card-body { padding: 20px; }

        /* ─ Upload ── */
        .upload-zone {
            border: 2px dashed var(--border);
            border-radius: 12px;
            padding: 48px 20px;
            text-align: center;
            cursor: pointer;
            transition: all 0.25s;
            background: var(--surface-2);
        }
        .upload-zone:hover,
        .upload-zone.dragover {
            border-color: var(--primary);
            background: var(--primary-light);
        }
        .upload-zone .upload-icon {
            font-size: 48px;
            color: #94a3b8;
            margin-bottom: 14px;
        }
        .upload-zone .upload-title {
            font-size: 16px;
            font-weight: 600;
            color: var(--text);
            margin-bottom: 8px;
        }
        .upload-zone .upload-tip {
            font-size: 13px;
            color: var(--text-muted);
            line-height: 1.7;
        }
        .file-preview {
            margin-top: 18px;
            text-align: center;
            padding: 20px;
            background: var(--surface-2);
            border-radius: 10px;
            border: 1px solid var(--border);
            display: none;
        }
        .file-preview img {
            max-width: 160px;
            max-height: 160px;
            border-radius: 8px;
            box-shadow: var(--shadow);
        }
        .file-info {
            margin-top: 12px;
            font-size: 13px;
            color: var(--text-muted);
        }

        /* ── Progress ── */
        .progress-wrap { display: none; margin-top: 18px; }
        .progress {
            height: 24px;
            border-radius: 12px;
            margin-bottom: 0;
            background: var(--surface-2);
        }
        .progress-bar {
            line-height: 24px;
            font-size: 12px;
            font-weight: 600;
            border-radius: 12px;
            background: linear-gradient(90deg, var(--primary), var(--primary-dark));
        }
        .progress-text {
            text-align: center;
            margin-top: 8px;
            font-size: 13px;
            color: var(--text-muted);
        }

        /* ── Sizes ── */
        .alert-tip {
            background: #fffbeb;
            border: 1px solid #fde68a;
            border-radius: 8px;
            padding: 12px 14px;
            font-size: 13px;
            color: #92400e;
            margin-bottom: 16px;
            line-height: 1.6;
        }
        .select-all-box {
            text-align: center;
            padding: 10px;
            background: var(--surface-2);
            border-radius: 8px;
            margin-bottom: 14px;
        }
        .select-all-box label {
            margin: 0;
            cursor: pointer;
            font-size: 14px;
            font-weight: 500;
            color: var(--text-muted);
        }
        .size-options { text-align: center; }
        .size-label {
            display: inline-block;
            margin: 5px;
            cursor: pointer;
        }
        .size-label input { display: none; }
        .size-badge {
            display: inline-block;
            padding: 9px 16px;
            border: 2px solid var(--border);
            border-radius: 8px;
            background: #fff;
            color: var(--text);
            font-weight: 500;
            font-size: 13px;
            min-width: 88px;
            transition: all 0.2s;
        }
        .size-label:hover .size-badge {
            border-color: var(--primary);
            background: var(--primary-light);
        }
        .size-label input:checked + .size-badge {
            border-color: var(--primary);
            background: var(--primary);
            color: #fff;
            box-shadow: 0 3px 10px rgba(13,148,136,0.3);
        }

        /* ── Buttons ── */
        .btn-action {
            background: var(--primary);
            border: none;
            border-radius: 8px;
            color: #fff;
            font-size: 15px;
            font-weight: 600;
            padding: 12px 30px;
            transition: all 0.2s;
            box-shadow: 0 4px 12px rgba(13,148,136,0.3);
        }
        .btn-action:hover, .btn-action:focus {
            background: var(--primary-dark);
            color: #fff;
            transform: translateY(-1px);
        }
        .btn-action:disabled {
            opacity: 0.65;
            transform: none;
            cursor: not-allowed;
        }

        /* ─ Info List ── */
        .info-list {
            list-style: none;
            padding: 0;
            margin: 0;
        }
        .info-list li {
            padding: 9px 0;
            font-size: 13px;
            color: var(--text-muted);
            border-bottom: 1px dashed var(--border);
            line-height: 1.6;
        }
        .info-list li:last-child { border-bottom: none; }
        .info-list li .fa { color: var(--primary); margin-right: 8px; }

        /* ── Code Block ── */
        .code-block {
            background: #1e293b;
            border-radius: 8px;
            padding: 14px 16px;
            font-family: "Consolas", "Monaco", monospace;
            font-size: 13px;
            color: #e2e8f0;
            word-break: break-all;
            margin-top: 10px;
            line-height: 1.7;
            overflow-x: auto;
        }
        .code-block .tag { color: #f472b6; }
        .code-block .attr { color: #a78bfa; }
        .code-block .val { color: #34d399; }
        .code-block .comment { color: #64748b; font-style: italic; }

        /* ── Result ── */
        .result-section {
            display: none;
            background: var(--surface);
            border-radius: var(--radius);
            box-shadow: var(--shadow-lg);
            border: 1px solid var(--border);
            overflow: hidden;
            margin-top: 20px;
            margin-bottom: 20px;
        }
        .result-header {
            background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
            color: #fff;
            padding: 18px 22px;
            font-size: 16px;
            font-weight: 600;
        }
        .result-body { padding: 24px 22px; }
        .preview-list {
            display: flex;
            flex-wrap: wrap;
            gap: 16px;
            justify-content: center;
            margin-bottom: 24px;
        }
        .preview-item {
            text-align: center;
            padding: 14px;
            border: 1px solid var(--border);
            border-radius: 10px;
            background: var(--surface-2);
            min-width: 110px;
        }
        .preview-icon {
            background: #fff;
            border: 1px solid var(--border);
            border-radius: 8px;
            padding: 10px;
            margin-bottom: 8px;
            display: flex;
            align-items: center;
            justify-content: center;
            min-height: 80px;
        }
        .preview-icon img { image-rendering: pixelated; }
        .preview-size {
            font-size: 12px;
            color: var(--text-muted);
            font-weight: 600;
        }
        .download-buttons { text-align: center; }
        .download-buttons .btn { margin: 5px; border-radius: 8px; }
        .btn-download {
            background: var(--primary);
            border-color: var(--primary);
            color: #fff;
            font-weight: 600;
        }
        .btn-default {
            background: var(--surface-2);
            border-color: var(--border);
            color: var(--text-muted);
            font-weight: 600;
        }
        .btn-default:hover {
            background: var(--border);
            color: var(--text);
        }

        /* ── SEO Content ── */
        .seo-block {
            background: var(--surface);
            border: 1px solid var(--border);
            border-radius: var(--radius);
            padding: 24px 28px;
            line-height: 1.85;
            box-shadow: var(--shadow);
        }
        .seo-block h2 {
            font-size: 18px;
            font-weight: 700;
            color: var(--text);
            margin: 0 0 12px;
        }
        .seo-block h3 {
            font-size: 15px;
            font-weight: 600;
            color: var(--primary-dark);
            margin: 20px 0 8px;
        }
        .seo-block p {
            font-size: 14px;
            color: var(--text-muted);
            margin: 0 0 10px;
        }
        .seo-block ul {
            padding-left: 20px;
            margin: 8px 0;
        }
        .seo-block ul li {
            font-size: 14px;
            color: var(--text-muted);
            margin-bottom: 6px;
        }

        /* ── FAQ ── */
        .faq-item {
            border-bottom: 1px solid var(--border);
            padding: 14px 0;
        }
        .faq-item:last-child { border-bottom: none; }
        .faq-question {
            font-size: 14px;
            font-weight: 600;
            color: var(--text);
            margin-bottom: 6px;
        }
        .faq-question .fa { color: var(--primary); margin-right: 8px; }
        .faq-answer {
            font-size: 13px;
            color: var(--text-muted);
            line-height: 1.7;
            margin: 0;
        }

        /* ─ Footer ── */
        .site-footer {
            text-align: center;
            padding: 24px 20px 32px;
            color: var(--text-muted);
            font-size: 13px;
            max-width: 1140px;
            margin: 0 auto;
        }
        .site-footer a { color: var(--primary); }

        /* ── Loader ── */
        .loader {
            display: inline-block;
            width: 16px;
            height: 16px;
            border: 2px solid rgba(255,255,255,0.3);
            border-radius: 50%;
            border-top-color: #fff;
            animation: spin 0.8s linear infinite;
            margin-right: 8px;
            vertical-align: middle;
        }
        @keyframes spin { to { transform: rotate(360deg); } }

        /* ── Modal ── */
        .modal-header-success { background: #ecfdf5; border-color: #a7f3d0; }
        .modal-header-success .modal-title { color: #065f46; }
        .modal-header-danger { background: #fef2f2; border-color: #fecaca; }
        .modal-header-danger .modal-title { color: #991b1b; }
        .modal-header-warning { background: #fffbeb; border-color: #fde68a; }
        .modal-header-warning .modal-title { color: #92400e; }
        .modal-header-info { background: #eff6ff; border-color: #bfdbfe; }
        .modal-header-info .modal-title { color: #1e40af; }
        .modal-content { border-radius: 12px; overflow: hidden; border: none; box-shadow: var(--shadow-lg); }
        .modal-footer .btn-primary { background: var(--primary); border-color: var(--primary); }
        .modal-footer .btn-primary:hover { background: var(--primary-dark); border-color: var(--primary-dark); }

        /* ── Responsive ─ */
        @media (max-width: 767px) {
            .hero h1 { font-size: 22px; }
            .btn-action { width: 100%; }
            .seo-block { padding: 18px 16px; }
            .preview-item { min-width: 90px; padding: 10px; }
            .preview-icon { min-height: 60px; padding: 8px; }
            .download-buttons .btn { display: block; width: 100%; margin: 8px 0; }
            .site-footer { padding: 20px 15px 24px; }
        }