/* 基础样式 - 模仿Bootstrap风格 */
        :root {
            --primary: #0d6efd;
            --secondary: #6c757d;
            --success: #198754;
            --info: #0dcaf0;
            --light: #f8f9fa;
            --dark: #212529;
            --white: #fff;
            --gray: #6c757d;
            --gray-dark: #343a40;
            --font-sans-serif: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            --font-monospace: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", "Courier New", monospace;
        }

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: var(--font-sans-serif);
            line-height: 1.5;
            color: var(--dark);
            background-color: var(--light);
        }

        .container {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 15px;
        }

        /* 导航栏样式 */
        .navbar {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 1rem 0;
            background-color: var(--white);
            box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
            position: relative;
        }

        .navbar-brand {
            font-size: 1.5rem;
            font-weight: 600;
            color: var(--primary);
            text-decoration: none;
            transition: color 0.3s ease;
            margin-left: 10px;
        }

        .navbar-brand:hover {
            color: var(--dark);
        }

        .navbar-nav {
            display: flex;
            list-style: none;
            margin-right: 10px;
        }

        .nav-item {
            margin-left: 1.5rem;
        }

        .nav-link {
            padding: 0.5rem 1rem;
            text-decoration: none;
            color: var(--dark);
            font-weight: 500;
            border-radius: 0.25rem;
            transition: all 0.3s ease;
        }

        .btn {
            display: inline-block;
            font-weight: 400;
            line-height: 1.5;
            text-align: center;
            text-decoration: none;
            vertical-align: middle;
            cursor: pointer;
            user-select: none;
            background-color: transparent;
            border: 1px solid transparent;
            padding: 0.375rem 0.75rem;
            font-size: 1rem;
            border-radius: 0.25rem;
            transition: all 0.15s ease-in-out;
        }

        .btn-outline-primary {
            color: var(--primary);
            border-color: var(--primary);
        }

        .btn-outline-primary:hover {
            color: var(--white);
            background-color: var(--primary);
        }

        .btn-primary {
            color: var(--white);
            background-color: var(--primary);
            border-color: var(--primary);
        }

        .btn-primary:hover {
            background-color: #0b5ed7;
            border-color: #0a58ca;
        }
        /* 新增的用户名按钮样式 */
        .user-info {
            display: flex;
            align-items: center;
            margin-right: 1rem;
        }

        .username-btn {
            display: flex;
            align-items: center;
            padding: 0.5rem 1rem;
            background-color: var(--primary);
            color: white;
            border-radius: 0.25rem;
            text-decoration: none;
            transition: all 0.3s ease;
            border: none;
            cursor: pointer;
        }

        .username-btn:hover {
            background-color: #0b5ed7;
            transform: translateY(-2px);
        }

        .user-avatar {
            width: 24px;
            height: 24px;
            border-radius: 50%;
            background-color: white;
            color: var(--primary);
            display: flex;
            align-items: center;
            justify-content: center;
            margin-right: 0.5rem;
            font-weight: bold;
        }