.tester-mode-panel {
  position: fixed; top: 86px; right: 16px; z-index: 80;
  display: grid; gap: 6px; width: min(420px, calc(100vw - 32px));
  padding: 10px 12px; box-sizing: border-box;
  border: 1px solid var(--ui-border); border-radius: var(--ui-radius);
  background: var(--ui-surface); color: var(--ui-text); box-shadow: var(--ui-shadow);
  font-family: var(--ui-font); font-size: 12px;
}
.tester-mode-panel[hidden] { display: none; }
.tester-mode-panel.is-enabled { border: 2px solid var(--ui-accent); }
.tester-mode-panel strong { color: var(--ui-accent); }
.tester-mode-panel label { display: flex; align-items: center; gap: 8px; }
.tester-mode-panel select, .tester-mode-panel button {
  min-height: 32px; padding: 5px 8px; font: inherit; color: var(--ui-text);
  border: 1px solid var(--ui-border); border-radius: var(--ui-radius-sm); background: var(--ui-surface-muted);
}
.tester-mode-panel select { flex: 1; min-width: 0; }
.tester-mode-panel :focus-visible { outline: 2px solid var(--ui-focus); outline-offset: 2px; }
@media (max-width: 640px) {
  .tester-mode-panel { top: auto; bottom: 72px; right: 8px; width: calc(100vw - 16px); }
}