修复中控内嵌顶栏变形：整页导航包进 top-nav-links，embed=1 仍进壳。

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/common/static/instance_page.css

@@ -11,7 +11,10 @@
         .exchange-tag{font-size:.82rem;font-weight:600;color:#b8f5d0;background:#14241e;border:1px solid #2d6a4f;padding:5px 14px;border-radius:999px;letter-spacing:.06em}
         .header-row{display:flex;align-items:center;gap:8px;flex-wrap:wrap;justify-content:center}
         .top-nav{display:grid;grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);align-items:center;gap:10px 12px;margin-bottom:12px}
-        .top-nav-links{grid-column:2;display:flex;gap:8px;flex-wrap:wrap;justify-content:center;min-width:0}
+        .top-nav-links{grid-column:2;display:flex;gap:8px;flex-wrap:wrap;justify-content:center;align-items:center;min-width:0}
+        .top-nav-links > a{flex:0 0 auto;white-space:nowrap}
+        /* 兜底:若链接未包在 .top-nav-links 内,勿被 1fr|auto|1fr 拉成三列变形 */
+        .top-nav > a{justify-self:center;align-self:center;width:max-content;max-width:100%}
         .top-nav-spot-tickers{grid-column:3;justify-self:end;display:flex;flex-direction:column;gap:3px;min-width:0}
         .top-nav a{padding:6px 10px;border:1px solid #304164;border-radius:8px;background:#151a2a;color:#8fc8ff;text-decoration:none}
         .top-nav a.active{background:#2a3f6c;color:#dbe4ff}