#dev-panel-toggle {
  position: fixed;
  top: 50%;
  right: 0;
  left: auto;
  transform: translateY(-50%);
  /* Match LINKS toggle layering: hidden behind offcanvas/backdrop when opened. */
  z-index: 1001;
  background: var(--kesson-dev-toggle-bg);
  backdrop-filter: blur(8px);
  border: 1px solid var(--kesson-dev-toggle-border);
  border-right: none;
  border-radius: 4px 0 0 4px;
  color: var(--kesson-dev-toggle-text);
  font-size: var(--kesson-dev-hud-font-size, 0.80rem);
  font-family: monospace;
  padding: 8px 5px;
  cursor: pointer;
  writing-mode: vertical-rl;
  letter-spacing: 0.1em;
  transition: all 0.3s ease;
}

#dev-panel-toggle.is-hidden {
  opacity: 0;
  pointer-events: none;
}

#dev-panel-toggle:hover {
  color: var(--kesson-dev-toggle-text-hover);
  background: var(--kesson-dev-toggle-bg-hover);
}

#dev-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: min(92vw, 420px);
  height: 100vh;
  z-index: 1200;
  color: #d9e5ff;
  background: var(--kesson-dev-panel-bg);
  border-left: 1px solid var(--kesson-dev-panel-border);
  transform: translateX(100%);
  transition: transform 0.25s ease;
  overflow: hidden;
  pointer-events: auto;
}

#dev-panel.is-open {
  transform: translateX(0);
}

#dev-panel .dev-panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  border-bottom: 1px solid var(--kesson-dev-panel-header-border);
}

#dev-panel .dev-panel-title {
  margin: 0;
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  color: var(--kesson-dev-panel-title-color);
}

#dev-panel .dev-panel-body {
  height: calc(100vh - 58px);
  overflow-y: auto;
  padding: 12px;
}

#dev-panel .accordion-button {
  background: var(--kesson-dev-panel-accordion-bg);
  color: var(--kesson-dev-panel-accordion-text);
}

#dev-panel .accordion-button:not(.collapsed) {
  background: var(--kesson-dev-panel-accordion-active-bg);
  color: #fff;
}

#dev-panel .accordion-button:focus {
  box-shadow: 0 0 0 0.2rem rgba(90, 140, 220, 0.45);
}

#dev-panel .accordion-body {
  background: var(--kesson-dev-panel-body-bg);
}

#dev-panel .form-label {
  font-size: 0.72rem;
  margin-bottom: 0.25rem;
  color: var(--kesson-dev-panel-label-color);
}

#dev-panel .form-range {
  margin-bottom: 0.25rem;
}

#dev-panel .dev-row {
  margin-bottom: 0.75rem;
}

#dev-panel .dev-group-help {
  margin: 0 0 0.75rem;
  font-size: 0.80rem;
  line-height: 1.45;
  color: var(--kesson-dev-panel-help-color);
}

#dev-panel .dev-row-help {
  margin-top: 0.2rem;
  font-size: 0.80rem;
  line-height: 1.35;
  color: var(--kesson-dev-panel-help-sub-color);
}

#dev-panel .dev-row-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

#dev-panel .dev-value {
  font-size: 0.72rem;
  color: var(--kesson-dev-panel-value-color);
  min-width: 58px;
  text-align: right;
}

#dev-panel .dev-json-actions {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}

#dev-panel .dev-json-status {
  font-size: 0.72rem;
  color: var(--kesson-dev-panel-status-color);
  margin-top: 6px;
  min-height: 1.2em;
}

#dev-panel .dev-panel-empty {
  padding: 12px;
  border: 1px solid var(--kesson-dev-panel-empty-border);
  border-radius: 8px;
  color: var(--kesson-dev-panel-empty-text);
  background: var(--kesson-dev-panel-empty-bg);
  font-size: 0.72rem;
}

#dev-panel .form-check-input:checked {
  background-color: #5d8fe3;
  border-color: #5d8fe3;
}

#dev-version-badge {
  display: inline-flex;
  align-items: center;
  margin-left: 0.5rem;
  padding: 0.2rem 0.45rem;
  border-radius: 999px;
  border: 1px solid var(--kesson-dev-hud-border);
  background: var(--kesson-dev-hud-bg);
  color: var(--kesson-dev-hud-text);
  font-size: 0.80rem;
  letter-spacing: 0.04em;
  line-height: 1;
  backdrop-filter: blur(7px);
  pointer-events: none;
  white-space: nowrap;
}

@media (max-width: 767.98px) {
  #dev-version-badge {
    display: none;
  }
}

@media (max-width: 640px) {
  #dev-panel-toggle {
    top: 50%;
    right: 0;
    left: auto;
  }

  #dev-panel {
    width: 100vw;
  }
}