:root {
            --primary: #4f46e5;
            --primary-hover: #4338ca;
            --primary-light: #eef2ff;
            --text-main: #111827;
            --text-secondary: #4b5563;
            --text-muted: #9ca3af;
            --bg-body: #f3f4f6;
            --bg-card: #ffffff;
            --border-color: #e5e7eb;
            --success: #10b981;
            --error: #ef4444;
            --warning-bg: #fefce8;
            --warning-text: #854d0e;
            --warning-border: #fef08a;
        }

  .pdf_box {
            margin: 0;
            padding: 40px 20px;
            display: flex;
            flex-direction: column;
            align-items: center;
            min-height: 90vh;
        }

       html,body{ font-size:inherit;}
        .mnav {   font-size: 13px;}

        /* 通用工具类 */
        .hidden { display: none !important; }
        .text-center { text-align: center; }
        .flex { display: flex; }
        .flex-col { flex-direction: column; }
        .items-center { align-items: center; }
        .justify-center { justify-content: center; }
        .justify-between { justify-content: space-between; }
        .gap-2 { gap: 0.5rem; }
        .gap-3 { gap: 0.75rem; }
        .gap-4 { gap: 1rem; }
        .w-full { width: 100%; }
        .mt-1 { margin-top: 0.25rem; }
        .mt-2 { margin-top: 0.5rem; }
        .mt-4 { margin-top: 1rem; }
        .mt-8 { margin-top: 2rem; }
        .mb-2 { margin-bottom: 0.5rem; }
        .mb-4 { margin-bottom: 1rem; }
        .mb-6 { margin-bottom: 1.5rem; }
        
        /* 头部样式 */
        .header-pdf {
            text-align: center;
            margin-bottom: 2rem;
        }
        .header-icon {
            color: var(--primary);
            font-size: 3rem;
            margin-bottom: 0.75rem;
        }
        .header-title {
            font-size: 1.875rem;
            font-weight: 700;
            margin: 0;
            color: var(--text-main);
        }
        .header-desc {
            color: var(--text-muted);
            margin-top: 0.5rem;
        }

        /* 主卡片样式 */
        .main-card {
            background-color: var(--bg-card);
            border-radius: 1rem;
            box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
            width: 100%;
            max-width: 42rem;
            overflow: hidden;
        }

        /* 上传区域 */
        .upload-container {
            padding: 2rem;
        }
        .drop-zone {
            border: 2px dashed var(--border-color);
            border-radius: 0.75rem;
            padding: 2.5rem;
            text-align: center;
            cursor: pointer;
            transition: all 0.2s ease;
            background-color: #fafafa;
        }
        .drop-zone:hover, .drop-zone.drag-active {
            border-color: var(--primary);
            background-color: var(--primary-light);
        }
        .upload-icon-circle {
            background-color: var(--primary-light);
            border-radius: 9999px;
            width: 64px;
            height: 64px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
        }
        .upload-icon {
            color: var(--primary);
            font-size: 2rem;
        }
        .upload-text-main {
            font-size: 1.125rem;
            font-weight: 500;
            color: var(--text-secondary);
        }
        .upload-text-sub {
            font-size: 0.875rem;
            color: var(--text-muted);
            margin-top: 0.25rem;
        }

        /* 设置区域 */
        .settings-container {
            border-top: 1px solid #f3f4f6;
        }
        .file-info-bar {
            background-color: var(--primary-light);
            padding: 1rem 1.5rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }
        .file-name {
            font-weight: 500;
            color: var(--text-main);
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            max-width: 200px;
        }
        @media (min-width: 640px) {
            .file-name { max-width: 300px; }
        }
        .page-count {
            font-size: 0.75rem;
            color: var(--text-secondary);
        }
        .btn-remove {
            background: none;
            border: none;
            cursor: pointer;
            color: #9ca3af;
            transition: color 0.2s;
            padding: 4px;
            font-size: 1.25rem;
        }
        .btn-remove:hover {
            color: var(--error);
        }

        .settings-content {
            padding: 1.5rem;
        }
        .section-title {
            font-size: 1.125rem;
            font-weight: 600;
            color: var(--text-main);
            margin-bottom: 1rem;
            margin-top: 0;
        }

        /* Tabs */
        .tabs {
            display: flex;
            gap: 0.5rem;
            border-bottom: 1px solid var(--border-color);
            margin-bottom: 1.5rem;
        }
        .tab-btn {
            background: none;
            border: none;
            padding: 0.75rem 1rem;
            font-size: 1rem;
            font-weight: 500;
            color: var(--text-muted);
            border-bottom: 2px solid transparent;
            cursor: pointer;
            transition: all 0.2s;
        }
        .tab-btn:hover {
            color: var(--text-secondary);
        }
        .tab-btn.active {
            color: var(--primary);
            border-bottom-color: var(--primary);
        }

        /* 表单元素 */
        .input-label {
            display: block;
            font-size: 0.875rem;
            font-weight: 500;
            color: var(--text-secondary);
            margin-bottom: 0.5rem;
        }
        .input-field {
            display: block;
            width: 100%;
            border-radius: 0.375rem;
            border: 1px solid var(--border-color);
            padding: 0.5rem 0.75rem;
            font-size: 0.875rem;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
        }
        .input-field:focus {
            outline: none;
            border-color: var(--primary);
            box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
        }
        .input-hint {
            font-size: 0.75rem;
            color: var(--text-muted);
            margin-top: 0.5rem;
            line-height: 1.4;
        }

        /* 警告框 */
        .warning-box {
            background-color: var(--warning-bg);
            border: 1px solid var(--warning-border);
            border-radius: 0.5rem;
            padding: 1rem;
            display: flex;
            gap: 0.75rem;
            color: var(--warning-text);
            font-size: 0.875rem;
        }

        /* 按钮 */
        .btn-primary {
            background-color: var(--primary);
            color: white;
            font-weight: 500;
            padding: 0.75rem 1rem;
            border-radius: 0.5rem;
            border: none;
            cursor: pointer;
            transition: background-color 0.2s;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            width: 100%;
            font-size: 1.125rem;
            height: 3rem;
            box-shadow: 0 4px 6px -1px rgba(79, 70, 229, 0.2);
        }
        .btn-primary:hover {
            background-color: var(--primary-hover);
        }
        .btn-primary:disabled {
            opacity: 0.7;
            cursor: not-allowed;
        }

        /* 状态消息 */
        .status-message {
            margin-top: 1rem;
            text-align: center;
            font-size: 0.875rem;
            font-weight: 500;
        }
        .status-processing { color: var(--primary); }
        .status-success { color: var(--success); }
        .status-error { color: var(--error); }

        /* 特性展示区 */
        .features-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 1.5rem;
            max-width: 56rem;
            width: 100%;
            margin-top: 3rem;
        }
        @media (min-width: 768px) {
            .features-grid {
                grid-template-columns: repeat(3, 1fr);
            }
        }
        .feature-card {
            background-color: var(--bg-card);
            padding: 1.5rem;
            border-radius: 0.75rem;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
        }
        .feature-icon-box {
            width: 2.5rem;
            height: 2.5rem;
            border-radius: 0.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
            font-size: 1.5rem;
        }
        .feature-title {
            font-weight: 600;
            color: var(--text-main);
            margin: 0 0 0.5rem 0;
        }
        .feature-desc {
            font-size: 0.875rem;
            color: var(--text-muted);
            margin: 0;
            line-height: 1.5;
        }
        
        /* 颜色辅助类 */
        .text-blue { color: #2563eb; }
        .bg-blue-light { background-color: #dbeafe; }
        .text-green { color: #059669; }
        .bg-green-light { background-color: #d1fae5; }
        .text-purple { color: #7c3aed; }
        .bg-purple-light { background-color: #ede9fe; }

        /* 动画 */
        @keyframes spin {
            from { transform: rotate(0deg); }
            to { transform: rotate(360deg); }
        }
        .animate-spin {
            animation: spin 1s linear infinite;
        }
        .animate-pulse {
            animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
        }
        @keyframes pulse {
            0%, 100% { opacity: 1; }
            50% { opacity: .5; }
        }