/* 页面整体样式 */
        body {
            font-family: "微软雅黑", Arial, sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f8f9fa;
        }

        /* 顶部容器样式 */
        .header {
            display: flex;
            align-items: center;
            justify-content: space-between;
            padding: 20px 40px;
            background-color: #007BFF;
            color: white;
            text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
        }

        .header p {
            font-size: 24px;
            margin: 0;
        }

        .nav-links {
            display: flex;
            gap: 20px;
        }

        .nav-links a {
            text-decoration: none;
            font-size: 18px;
            color: white;
            padding: 5px 10px;
            border-radius: 4px;
            transition: all 0.3s ease;
        }

        .nav-links a:hover {
            background-color: #0056b3;
        }

        .header input[type="text"] {
            width: 300px;
            height: 40px;
            font-size: 16px;
            padding: 5px 10px;
            border: 2px solid #ccc;
            border-radius: 4px;
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
            transition: border-color 0.3s ease, box-shadow 0.3s ease;
        }

        .header input[type="text"]:focus {
            border-color: #007BFF;
            box-shadow: 0 0 8px rgba(0, 123, 255, 0.5);
            outline: none;
        }

        .user-buttons {
            display: flex;
            gap: 10px;
        }

        .user-buttons button {
            background-color: white;
            color: #007BFF;
            border: 2px solid #007BFF;
            border-radius: 4px;
            padding: 8px 15px;
            font-size: 16px;
            cursor: pointer;
            transition: all 0.3s ease;
        }

        .user-buttons button:hover {
            background-color: #0056b3;
            color: white;
        }

        /* 经常出售的物品样式 */
        .common-items {
            padding: 20px 40px;
        }

        .common-items h2 {
            font-size: 28px;
            color: #343a40;
            margin-bottom: 20px;
        }

        .common-items a {
            display: inline-block;
            margin: 10px;
            padding: 10px 20px;
            font-size: 18px;
            color: white;
            background-color: #007BFF;
            border-radius: 4px;
            text-decoration: none;
            transition: all 0.3s ease;
        }

        .common-items a:hover {
            background-color: #0056b3;
        }

        /* 弹窗遮罩层样式 */
        .modal-overlay {
            display: none;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background-color: rgba(0, 0, 0, 0.5);
            z-index: 1000;
        }

        /* 弹窗内容样式 */
        .modal {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background-color: white;
            padding: 20px;
            width: 400px;
            border-radius: 8px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
            z-index: 1001;
            text-align: center;
        }

        .modal h2 {
            font-size: 24px;
            margin-bottom: 10px;
            color: #007BFF;
        }

        .modal form {
            display: flex;
            flex-direction: column;
            gap: 10px;
        }

        .modal input, .modal textarea {
            width: 100%;
            padding: 10px;
            font-size: 16px;
            border: 1px solid #ccc;
            border-radius: 4px;
        }

        .modal button {
            background-color: #007BFF;
            color: white;
            border: none;
            padding: 10px 20px;
            font-size: 16px;
            border-radius: 4px;
            cursor: pointer;
            transition: background-color 0.3s ease;
        }

        .modal button:hover {
            background-color: #0056b3;
        }