/* --- Reset & Base Styles --- */
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: 'Noto Sans SC', sans-serif;
            background-color: #f3f4f6;
            min-height: 100vh;
            color: #1f2937;
        }
        
          html,body{ font-size:inherit;}
        .website { padding: 90px 10px 30px !important;font-size: 14px;}
        .mnav {   font-size: 13px;}

        /* --- Utilities --- */
        .hidden {
            display: none !important;
        }
        
        /* --- Component Styles --- */
        .main-card {
            background: rgba(255, 255, 255, 0.95);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid rgba(255, 255, 255, 0.3);
            width: 100%;
            max-width: 1180px; /* approx max-w-2xl */
            border-radius: 1.5rem; /* rounded-3xl */
            box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25); /* shadow-2xl */
            overflow: hidden;
            position: relative;
            margin: 0 auto;
        }

        /* Header */
        .header {
            background-color: rgba(255, 255, 255, 0.5);
            border-bottom: 1px solid #f3f4f6;
            padding: 1.5rem;
            display: flex;
            align-items: center;
            justify-content: space-between;
        }

        .header-left {
            display: flex;
            align-items: center;
            gap: 0.75rem; /* space-x-3 */
        }

        .logo-icon {
            width: 2.5rem;
            height: 2.5rem;
            background-color: #2563eb;
            border-radius: 0.75rem;
            display: flex;
            align-items: center;
            justify-content: center;
            color: white;
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
            font-size: 1.25rem;
        }

        .app-title h1 {
            font-size: 1.25rem;
            font-weight: 700;
            color: #1f2937;
            line-height: 1.2;
        }

        .app-title p {
            font-size: 0.75rem;
            color: #6b7280;
        }

        .badge {
            font-size: 0.75rem;
            padding: 0.25rem 0.75rem;
            background-color: #eff6ff;
            color: #2563eb;
            border-radius: 9999px;
            font-weight: 500;
            border: 1px solid #dbeafe;
        }

        /* Content Area */
        .content {
            padding: 2rem;
        }

        /* Drop Zone */
        .drop-zone {
            width: 100%;
            height: 16rem; /* h-64 */
            border-radius: 1rem; /* rounded-2xl */
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            cursor: pointer;
            position: relative;
            transition: all 0.3s ease;
           border: 2px dashed #d1d5db;
        }

        .drop-zone:hover {
            background-color: #f9fafb;
        }

        .drop-zone.active {
            background-color: #eff6ff;
            background-image: url("data:image/svg+xml,%3csvg width='100%25' height='100%25' xmlns='http://www.w3.org/2000/svg'%3e%3crect width='100%25' height='100%25' fill='none' rx='16' ry='16' stroke='%233B82F6FF' stroke-width='3' stroke-dasharray='12%2c 12' stroke-dashoffset='0' stroke-linecap='square'/%3e%3c/svg%3e");
            transform: scale(1.01);
        }

        .drop-icon-circle {
            width: 5rem;
            height: 5rem;
            background-color: #eff6ff;
            color: #3b82f6;
            border-radius: 9999px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-bottom: 1rem;
            transition: transform 0.3s;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            font-size: 2rem;
        }

        .drop-zone:hover .drop-icon-circle {
            transform: scale(1.1);
        }

        .drop-zone input {
            position: absolute;
            inset: 0;
            width: 100%;
            height: 100%;
            opacity: 0;
            cursor: pointer;
            z-index: 10; /* 修复点击问题：确保Input层级最高 */
        }

        .drop-text-main {
            font-size: 1.125rem;
            font-weight: 500;
            color: #374151;
        }

        .drop-text-sub {
            font-size: 0.875rem;
            color: #9ca3af;
            margin-top: 0.5rem;
        }

        /* File Info Card */
        .file-card {
            display: flex;
            align-items: center;
            padding: 1rem;
            background-color: white;
            border-radius: 0.75rem;
            border: 1px solid #f3f4f6;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            margin-bottom: 1.5rem;
        }

        .file-icon {
            width: 3rem;
            height: 3rem;
            background-color: #e0e7ff;
            color: #4f46e5;
            border-radius: 0.5rem;
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 1rem;
            flex-shrink: 0;
            font-size: 1.25rem;
        }

        .file-details {
            flex: 1;
            overflow: hidden;
        }

        .file-name {
            font-weight: 500;
            color: #1f2937;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
        }

        .file-size {
            font-size: 0.75rem;
            color: #6b7280;
        }

        .btn-remove {
            padding: 0.5rem;
            color: #9ca3af;
            border-radius: 9999px;
            background: none;
            border: none;
            cursor: pointer;
            transition: color 0.2s, background-color 0.2s;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 1rem;
        }

        .btn-remove:hover {
            background-color: #fef2f2;
            color: #ef4444;
        }

        /* Controls Panel */
        .controls-grid {
            display: grid;
            grid-template-columns: 1fr;
            gap: 1rem;
            margin-bottom: 1.5rem;
        }

        @media (min-width: 768px) {
            .controls-grid {
                grid-template-columns: 1fr 1fr;
            }
        }

        .form-group label {
            display: block;
            font-size: 0.875rem;
            font-weight: 500;
            color: #374151;
            margin-bottom: 0.5rem;
        }

        .select-wrapper {
            position: relative;
        }

        .form-select {
            display: block;
            width: 100%;
            padding: 0.75rem 1rem;
            padding-right: 2.5rem;
            font-size: 0.875rem; /* sm */
            line-height: 1.25rem;
            background-color: white;
            border: 1px solid #d1d5db;
            border-radius: 0.75rem; /* rounded-xl */
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            appearance: none;
            -webkit-appearance: none;
            cursor: pointer;
        }

        .form-select:focus {
            outline: none;
            border-color: #3b82f6;
            box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.5);
        }

        .select-arrow {
            pointer-events: none;
            position: absolute;
            top: 0;
            bottom: 0;
            right: 0;
            display: flex;
            align-items: center;
            padding-right: 0.5rem;
            color: #374151;
        }

        .btn-primary {
            width: 100%;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 1rem;
            border: 1px solid transparent;
            border-radius: 0.75rem;
            font-size: 1rem;
            font-weight: 500;
            color: white;
            background-color: #2563eb;
            box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
            cursor: pointer;
            transition: all 0.2s;
            gap: 0.5rem;
        }

        .btn-primary:hover {
            background-color: #1d4ed8;
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
        }

        .btn-primary:active {
            transform: scale(0.98);
        }

        /* Progress Panel */
        .progress-panel {
            margin-top: 1.5rem;
        }

        .progress-header {
            display: flex;
            justify-content: space-between;
            align-items: flex-end;
            margin-bottom: 0.5rem;
        }

        .progress-label {
            font-size: 0.875rem;
            font-weight: 500;
            color: #2563eb;
            animation: pulse 2s cubic-bezier(0.4, 0, 0.6, 1) infinite;
        }

        .progress-value {
            font-size: 0.875rem;
            font-weight: 700;
            color: #374151;
        }

        .progress-track {
            width: 100%;
            background-color: #e5e7eb;
            border-radius: 9999px;
            height: 0.75rem;
            overflow: hidden;
        }

        .progress-fill {
            background-color: #2563eb;
            height: 100%;
            border-radius: 9999px;
            transition: width 0.2s linear;
        }

        .progress-note {
            font-size: 0.75rem;
            color: #9ca3af;
            text-align: center;
            margin-top: 0.5rem;
        }

        /* Result Panel */
        .result-panel {
            margin-top: 1.5rem;
            text-align: center;
        }

        .success-icon {
            width: 4rem;
            height: 4rem;
            background-color: #dcfce7;
            color: #22c55e;
            border-radius: 9999px;
            display: flex;
            align-items: center;
            justify-content: center;
            margin: 0 auto 1rem auto;
            font-size: 1.5rem;
        }

        .result-title {
            font-size: 1.125rem;
            font-weight: 700;
            color: #1f2937;
            margin-bottom: 0.25rem;
        }

        .result-desc {
            font-size: 0.875rem;
            color: #6b7280;
            margin-bottom: 1.5rem;
        }

        /* Preview Video */
        .preview-container {
            margin: 1.5rem 0;
            background: #000;
            border-radius: 0.75rem;
            overflow: hidden;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            max-height: 300px;
            display: flex;
            justify-content: center;
        }
        
        .preview-video {
            width: 100%;
            height: auto;
            max-height: 300px;
            display: block;
        }

        .result-actions {
            display: flex;
            gap: 0.75rem;
        }

        .btn-download {
            flex: 1;
            padding: 0.75rem 1rem;
            background-color: #1f2937;
            color: white;
            border-radius: 0.75rem;
            font-weight: 500;
            border: none;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
            transition: background-color 0.2s;
            gap: 0.5rem;
        }

        .btn-download:hover {
            background-color: #111827;
        }

        .btn-reset {
            padding: 0.75rem 1rem;
            background-color: white;
            border: 1px solid #e5e7eb;
            color: #4b5563;
            border-radius: 0.75rem;
            font-weight: 500;
            cursor: pointer;
            transition: background-color 0.2s;
        }

        .btn-reset:hover {
            background-color: #f9fafb;
        }

        /* Footer */
        .footer {
            background-color: #f9fafb;
            padding: 1rem 2rem;
            border-top: 1px solid #f3f4f6;
            text-align: center;
        }

        .footer p {
            font-size: 0.75rem;
            color: #9ca3af;
        }

        /* Animations */
        @keyframes pulse {
            0%, 100% { opacity: 1; }
            50% { opacity: .5; }
        }
        
        @keyframes fadeIn {
            from { opacity: 0; }
            to { opacity: 1; }
        }
        
        .animate-fade-in {
            animation: fadeIn 0.5s ease-out;
        }