body {
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
            max-width: 800px;
            margin: 0 auto;
            padding: 20px;
            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
            min-height: 100vh;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
        }

        .app-container {
            background: white;
            padding: 40px;
            border-radius: 20px;
            box-shadow: 0 20px 40px rgba(0,0,0,0.1);
            text-align: center;
            max-width: 600px;
            width: 100%;
        }

        h1 {
            color: #333;
            margin-bottom: 10px;
            font-size: 2.2em;
            font-weight: 300;
        }

        .subtitle {
            color: #666;
            margin-bottom: 30px;
            font-size: 1.1em;
        }

        .screenshot-button {
            position: relative;
            display: inline-block;
            cursor: pointer;
            transition: all 0.3s ease;
            border-radius: 15px;
            overflow: hidden;
            box-shadow: 0 10px 25px rgba(0,0,0,0.15);
            margin: 20px 0;
        }

        .screenshot-button:hover {
            transform: translateY(-5px);
            box-shadow: 0 20px 40px rgba(0,0,0,0.2);
        }

        .screenshot-button::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background: linear-gradient(45deg, rgba(102, 126, 234, 0.1), rgba(118, 75, 162, 0.1));
            opacity: 0;
            transition: opacity 0.3s ease;
            z-index: 1;
        }

        .screenshot-button:hover::before {
            opacity: 1;
        }

        .screenshot-placeholder {
            width: 100%;
            max-width: 500px;
            height: 300px;
            background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
            display: flex;
            align-items: center;
            justify-content: center;
            border: 3px dashed #ccc;
            color: #888;
            font-size: 1.1em;
            position: relative;
            z-index: 0;
        }

        .screenshot-image {
            width: 100%;
            max-width: 500px;
            height: auto;
            display: block;
        }

        .play-overlay {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            width: 80px;
            height: 80px;
            background: rgba(255, 255, 255, 0.9);
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            z-index: 2;
            transition: all 0.3s ease;
        }

        .screenshot-button:hover .play-overlay {
            background: rgba(255, 255, 255, 1);
            transform: translate(-50%, -50%) scale(1.1);
        }

        .play-icon {
            width: 0;
            height: 0;
            border-left: 20px solid #667eea;
            border-top: 12px solid transparent;
            border-bottom: 12px solid transparent;
            margin-left: 5px;
        }

        .launch-text {
            margin-top: 15px;
            color: #555;
            font-size: 1em;
        }

        .instructions {
            background: #f8f9ff;
            padding: 20px;
            border-radius: 10px;
            margin-top: 30px;
            color: #555;
            line-height: 1.6;
        }

        .instructions h3 {
            color: #333;
            margin-top: 0;
        }

        .url-input {
            width: 100%;
            max-width: 400px;
            padding: 12px;
            border: 2px solid #e0e0e0;
            border-radius: 8px;
            font-size: 1em;
            margin: 10px 0;
            transition: border-color 0.3s ease;
        }

        .url-input:focus {
            outline: none;
            border-color: #667eea;
        }

        .update-button {
            background: linear-gradient(45deg, #667eea, #764ba2);
            color: white;
            border: none;
            padding: 12px 24px;
            border-radius: 8px;
            cursor: pointer;
            font-size: 1em;
            margin-left: 10px;
            transition: all 0.3s ease;
        }

        .update-button:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 15px rgba(0,0,0,0.2);
        }

        @media (max-width: 600px) {
            .app-container {
                padding: 20px;
            }
            
            h1 {
                font-size: 1.8em;
            }
            
            .screenshot-placeholder {
                height: 250px;
            }
        }