fix: «Думал N сек.» holds its arrow inside its highlight, a quiet one

internal/server/web/static/app.css

@@ -945,8 +945,9 @@ main#app > .view:not([hidden]) { animation:view-in .22s ease; } /* no fill: a la
 .ai-text hr { border:0; border-top:1px solid var(--border); margin:8px 0; }
 .ai-think { margin:0 0 6px; }
 .ai-think[hidden] { display:none; }
-.ai-think-h { display:inline-flex; align-items:center; gap:5px; padding:2px 4px 2px 0; background:none; border:0; color:var(--muted); font-size:12.5px; cursor:pointer; }
-.ai-think-h:hover { color:var(--text); }
+.ai-think-h { display:inline-flex; align-items:center; gap:5px; padding:2px 8px 2px 6px; margin-left:-6px; background:none; border:0; border-radius:6px; color:var(--muted); font-size:12.5px; cursor:pointer; }
+.ai-think-h:hover, .ai-think-h:focus-visible { color:var(--text); background:#151a21; }
+.ai-think-h:focus:not(:focus-visible) { background:none; }
 .ai-think-h .chev { display:inline-block; width:10px; text-align:center; font-size:15px; line-height:1; transition:transform .2s ease; }
 .ai-think.open .ai-think-h .chev { transform:rotate(90deg); }
 .ai-think.going .ai-think-h .lbl { background:linear-gradient(90deg, var(--muted) 30%, var(--text) 50%, var(--muted) 70%) 0 0/200% 100%;