:root {
            --nb-primary: #00AFB7;
            --nb-text: #333333;
            --nb-bg: #fdfdfd;
        }

        .faq-section {
            max-width: 800px;
            margin: 40px auto;
            padding: 20px;
            font-family: 'Helvetica Neue', Arial, sans-serif;
            color: var(--nb-text);
        }

        .faq-section h2 {
            text-align: center;
            color: var(--nb-primary);
            margin-bottom: 30px;
            font-size: 28px;
        }

        /* 核心折叠样式 */
        .faq-item {
            margin-bottom: 15px;
            border: 1px solid #eee;
            border-radius: 8px;
            overflow: hidden;
            background: #fff;
            transition: all 0.3s ease;
        }

        .faq-item:hover {
            border-color: var(--nb-primary);
        }

        /* 隐藏原生箭头，自定义样式 */
        details summary {
            padding: 18px 25px;
            font-weight: 600;
            font-size: 17px;
            cursor: pointer;
            list-style: none;
            display: flex;
            justify-content: space-between;
            align-items: center;
            background: #fff;
            color: var(--nb-text);
            transition: background 0.3s;
        }

        details summary::-webkit-details-marker {
            display: none;
        }

        details summary::after {
            content: '+';
            font-size: 22px;
            color: var(--nb-primary);
            font-weight: bold;
        }

        details[open] summary {
            background: var(--nb-primary);
            color: #fff;
        }

        details[open] summary::after {
            content: '−';
            color: #fff;
        }

        .faq-answer {
            padding: 20px 25px;
            line-height: 1.6;
            color: #555;
            background: var(--nb-bg);
            border-top: 1px solid #f0f0f0;
            font-size: 15px;
        }

        /* 动画效果 */
        details[open] .faq-answer {
            animation: slideDown 0.3s ease-out;
        }

        @keyframes slideDown {
            from { opacity: 0; transform: translateY(-10px); }
            to { opacity: 1; transform: translateY(0); }
        }