body {
            margin: 0;
            padding: 0;
            font-family: Arial, sans-serif;
            background-color: #f5f5f5;
        }
        .header {
            position: fixed;
            top: 0;
            right: 0;
            padding: 10px;
            z-index: 1000;
        }
        .hidden-section {
            display: none;
            margin-top: 20px;
            position: absolute;
            top: 30px;
            right: 10px;
            background: white;
            border: 1px solid #ccc;
            border-radius: 5px;
            padding: 15px;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
            z-index: 1000;
            min-width: 200px;
        }
        .icon {
            cursor: pointer;
            background: #f0f0f0;
            border-radius: 50%;
            width: 13px;
            height: 13px;
            display: flex;
            align-items: center;
            justify-content: center;
            box-shadow: 0 1px 3px rgba(0,0,0,0.2);
            padding: 2px;
            border: 1px solid #ddd;
        }
        .icon:hover {
            background: #e0e0e0;
        }
        .lock-icon {
            width: 12px;
            height: 12px;
            fill: #666;
        }
        .file-list {
            list-style-type: none;
            padding: 0;
        }
        .file-item {
            margin: 5px 0;
        }
        .password-dialog {
            background: white;
            padding: 20px;
            border-radius: 8px;
            margin: 15px 0;
            box-shadow: 0 2px 5px rgba(0,0,0,0.1);
            display: flex;
            justify-content: space-between;
            align-items: center;
        }
        .dialog-content {
            flex-grow: 1;
        }
        .content {
            width: 50%;
            margin: 60px auto 0 auto;
            padding: 20px;
            box-sizing: border-box;
        }
        button {
            background: #4CAF50;
            color: white;
            border: none;
            padding: 10px 40px;
            border-radius: 4px;
            cursor: pointer;
            font-size: 16px;
            transition: background 0.3s;
            white-space: nowrap;
            margin-left: 15px;
        }
        button:hover {
            background: #45a049;
        }
        h1 {
            text-align: center;
            color: #333;
        }
        h3 {
            color: #444;
            margin-top: 0;
            margin-bottom: 0;
        }
        @media (max-width: 768px) {
            .content {
                width: 90%;
            }
            .password-dialog {
                flex-direction: column;
                align-items: flex-start;
            }
            button {
                margin-left: 0;
                margin-top: 10px;
                align-self: flex-end;
            }
        }