/* Mục lục bài viết (nav.toc-v2): thu gọn mặc định, mở ra cuộn trong khung, nhiều cột trên màn rộng */
nav.toc-v2{background:#eaf6fc;border-left:5px solid #0a66ac;border-radius:0 8px 8px 0;margin:0 0 24px;padding:0 16px}
nav.toc-v2 summary{cursor:pointer;padding:12px 0;font-weight:700;color:#0b4a85;font-size:17px;list-style:none;display:flex;justify-content:space-between;align-items:center;gap:12px}
nav.toc-v2 summary::-webkit-details-marker{display:none}
nav.toc-v2 summary::after{content:'+';flex:none;width:28px;height:28px;border-radius:50%;background:#0a66ac;color:#fff;text-align:center;line-height:27px;font-size:20px}
nav.toc-v2 details[open] summary::after{content:'–'}
nav.toc-v2 ol{list-style:none!important;margin:0 0 12px;padding:0 4px 0 0;max-height:min(52vh,380px);overflow:auto;display:grid;grid-template-columns:1fr;gap:0 28px}
nav.toc-v2 li{list-style:none!important;margin:0;padding:7px 0;border-bottom:1px dashed #c5dff0}
nav.toc-v2 li a{display:-webkit-box;-webkit-box-orient:vertical;-webkit-line-clamp:2;overflow:hidden;padding:0;font-size:15px;line-height:1.4;color:#0a66ac;text-decoration:none}
nav.toc-v2 li a:hover{color:#0b4a85;text-decoration:underline}
@media (min-width:768px){nav.toc-v2 ol{grid-template-columns:1fr 1fr;max-height:none}nav.toc-v2 li a{-webkit-line-clamp:1}}