/* Mobile responsive overrides — loaded after theme to win the cascade.
   Rules targeting selectors that themes redefine live here. */

@media (max-width: 900px) {
  .back-to-top-button {
    width: 2rem;
    height: 2rem;
    right: 1.5rem;
    bottom: 1.5rem;
  }

  .toolbar {
    align-items: stretch;
  }

  .toolbar button {
    width: 100%;
  }
}

@media (max-width: 768px) {
  .sync-column {
    padding: 0.75rem;
  }
}

@media (max-width: 600px) {
  .back-to-top-button {
    display: none;
  }

  .page-frame,
  .content-shell {
    width: 100%;
    min-width: 0;
    max-width: 100%;
  }

  .page-header {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .page-nav {
    margin-left: auto;
    margin-right: 0;
  }

  /* mobile UI phase 1: compact header, secondary download CTA, tighter form chrome */
  .page-header {
    align-items: center;
  }

  .theme-picker {
    order: 3;
    flex: 0 1 auto;
    width: auto;
    max-width: 100%;
    min-height: 44px;
    margin-left: 0;
  }

  .theme-picker__select,
  .theme-picker .df-select {
    flex: 0 1 auto;
    min-width: 8.75rem;
    max-width: 9.5rem;
  }

  .theme-picker .df-select__trigger {
    width: 100%;
    min-height: 44px;
  }

  .chatgpt-sticky-download {
    position: static;
    top: auto;
    align-items: flex-start;
    padding: 0.75rem 0.85rem;
    box-shadow: none;
  }

  .chatgpt-sticky-download__button {
    min-height: 44px;
    padding: 0.6rem 0.9rem;
    border: 1px solid var(--accent);
    background: transparent;
    color: var(--accent-strong, var(--accent));
    box-shadow: none;
  }

  .chatgpt-sticky-download__button:hover,
  .chatgpt-sticky-download__button:focus-visible {
    border-color: var(--accent);
    background: rgba(43, 108, 176, 0.08);
    color: var(--accent);
  }

  textarea {
    min-height: 6rem;
    max-height: 10rem;
    overflow: auto;
  }

  .result-panel textarea,
  .field textarea,
  .sync-column textarea {
    min-height: 6rem;
  }

  .run-button,
  .clear-cache-button,
  select,
  .df-select__trigger {
    min-height: 44px;
  }

  .result-panel,
  .chatgpt-step-panel {
    padding: 0.85rem;
  }

  .tool-nav {
    width: 100%;
    max-width: 100%;
  }

  /* mobile UI phase 1 (d3): tool nav collapse */
  .tool-nav {
    display: grid;
    grid-template-columns: minmax(0, 1fr);
    gap: 0.5rem;
    overflow-x: clip;
  }

  .tool-nav__menu-toggle[hidden] {
    display: inline-flex !important;
  }

  .tool-nav__menu-toggle {
    align-items: center;
    justify-content: space-between;
    width: 100%;
    min-height: 44px;
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: transparent;
    color: var(--ink);
    font: inherit;
    font-size: var(--fs-base);
    text-align: left;
    cursor: pointer;
  }

  .tool-nav__menu-toggle::after {
    content: '';
    flex: 0 0 auto;
    width: 0;
    height: 0;
    border-left: 0.3rem solid transparent;
    border-right: 0.3rem solid transparent;
    border-top: 0.4rem solid currentColor;
    opacity: 0.7;
    transition: transform 0.2s ease;
  }

  .tool-nav.is-menu-open .tool-nav__menu-toggle::after {
    transform: rotate(180deg);
  }

  .tool-nav > .tool-nav__group {
    display: none;
    min-width: 0;
    width: 100%;
  }

  .tool-nav.is-menu-open > .tool-nav__group {
    display: block;
  }

  .tool-nav__trigger {
    justify-content: space-between;
    width: 100%;
    min-height: 44px;
    padding-inline: 0.85rem;
  }

  .tool-nav__dropdown {
    max-width: min(100%, 22.5rem);
  }

  .hub-hero,
  .hub-card {
    min-width: 0;
    max-width: 100%;
    overflow-wrap: anywhere;
  }

  /* mobile UI phase 2: home hub */
  .hub-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0.75rem;
  }

  .hub-card {
    min-height: 8.75rem;
  }

  .hub-card[data-kb-entry] {
    cursor: pointer;
  }

  .hub-card[data-kb-entry]:active {
    transform: translateY(1px);
  }

  .hub-hero--primary {
    border-color: var(--accent);
    border-left-color: var(--accent-strong, var(--accent));
    background:
      linear-gradient(180deg, color-mix(in srgb, var(--accent) 10%, var(--panel)) 0%, var(--panel) 100%);
    box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 18%, transparent);
  }

  .hub-hero--primary:hover,
  .hub-hero--primary:focus-visible {
    border-color: var(--accent-strong, var(--accent));
    box-shadow: 0 8px 24px rgba(26, 31, 46, 0.08), 0 0 0 1px color-mix(in srgb, var(--accent-strong, var(--accent)) 28%, transparent);
  }

  .page-footer {
    padding-right: 1rem;
  }

  /* mobile UI phase 2: judge questions */
  .judge-optional-ref {
    margin: 0 0 0.5rem;
  }

  .judge-optional-ref__summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 44px;
    padding: 0.65rem 0.85rem;
    border: 1px solid var(--line);
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    list-style: none;
  }

  .judge-optional-ref__summary::-webkit-details-marker {
    display: none;
  }

  .judge-optional-ref__summary::after {
    content: '';
    flex: 0 0 auto;
    width: 0.5rem;
    height: 0.5rem;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg);
    transition: transform 0.2s ease;
  }

  .judge-optional-ref[open] > .judge-optional-ref__summary::after {
    transform: rotate(225deg);
  }

  .judge-optional-ref > .field {
    margin-top: 0.65rem;
  }

  /* mobile UI phase 1 (d2): mobile layout picker + distinct workflow stepper */
  .chatgpt-page-toolbar.desktop-only {
    display: flex !important;
    margin-top: 0.75rem;
    margin-bottom: 0.75rem;
  }

  .chatgpt-page-toolbar.desktop-only .chatgpt-layout-picker {
    display: flex;
    flex: 1 1 auto;
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
    width: 100%;
  }

  .chatgpt-page-toolbar.desktop-only .chatgpt-layout-picker__segments {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    width: 100%;
  }

  .chatgpt-page-toolbar.desktop-only .chatgpt-layout-segment {
    min-height: 40px;
    padding: 0.45rem 0.4rem;
    text-align: center;
  }

  /* mobile UI phase 2: compact numbered stepper */
  .chatgpt-step-nav {
    display: flex;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    margin: 0.75rem 0 1rem;
    padding: 0.15rem 0 0.35rem;
    overflow-x: auto;
    overscroll-behavior-x: contain;
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
  }

  .chatgpt-step-tab {
    display: inline-flex;
    flex: 0 0 auto;
    align-items: center;
    justify-content: center;
    width: 2.5rem;
    min-width: 2.5rem;
    height: 2.5rem;
    min-height: 2.5rem;
    padding: 0;
    border: 1px solid var(--line);
    border-radius: 50%;
    background: var(--panel);
    color: var(--muted);
    font-size: var(--fs-sm);
    font-weight: 600;
    line-height: 1;
    text-align: center;
    white-space: nowrap;
  }

  .chatgpt-step-tab__label {
    display: none;
  }

  .chatgpt-step-tab__num {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
  }

  .chatgpt-step-tab.is-active {
    border-color: var(--accent);
    background: var(--accent);
    color: var(--accent-contrast, #fff);
    box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 20%, transparent);
  }

  .chatgpt-step-tab:not(.is-active):not(.is-complete) {
    color: var(--ink);
    opacity: 1;
  }

  .chatgpt-step-tab.is-complete {
    border-color: color-mix(in srgb, var(--accent) 35%, var(--line));
    background: color-mix(in srgb, var(--accent) 12%, var(--panel));
    color: var(--accent-strong);
    opacity: 1;
  }

  /* mobile UI phase 2: ai selector compact */
  .ai-selector {
    padding: 10px;
    margin-bottom: 12px;
  }

  .ai-selector__heading {
    font-size: var(--fs-base);
    margin-bottom: 6px;
  }

  .ai-selector__option-label {
    padding: 8px 10px;
    font-size: var(--fs-sm);
    min-height: 40px;
  }

  /* mobile UI phase 2: deck primer rows */
  .primer-group,
  .primer-group__body,
  .primer-section,
  .primer-section__label,
  .primer-section__copy {
    min-width: 0;
    max-width: 100%;
  }

  .primer-group__summary {
    min-height: 44px;
    padding: 0.65rem 0;
    cursor: pointer;
  }

  .primer-group__badge {
    flex: 0 0 auto;
    max-width: 100%;
  }

  .primer-section {
    padding: 0.8rem 0.85rem;
  }

  .primer-section__label {
    min-height: 44px;
    padding: 0.3rem 0;
    gap: 0.85rem;
    align-items: center;
  }

  .primer-section__label > input[type='checkbox'] {
    width: 1.2rem;
    height: 1.2rem;
    margin: 0;
  }

  .primer-section__copy {
    overflow-wrap: anywhere;
  }

  /* mobile UI phase 2: content kb */
  .kb-filters {
    display: block;
    width: 100%;
  }

  .kb-filters__summary {
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 44px;
    padding: 0.25rem 0;
    color: var(--muted);
    font-size: var(--fs-sm);
    font-weight: 600;
    cursor: pointer;
    list-style: none;
  }

  .kb-filters__summary::-webkit-details-marker {
    display: none;
  }

  .kb-filters__summary::after {
    content: '';
    flex: 0 0 auto;
    width: 0;
    height: 0;
    border-left: 0.3rem solid transparent;
    border-right: 0.3rem solid transparent;
    border-top: 0.4rem solid currentColor;
    opacity: 0.7;
    transition: transform 0.2s ease;
  }

  .kb-filters[open] > .kb-filters__summary::after {
    transform: rotate(180deg);
  }

  .kb-filters > label {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    margin-top: 0.5rem;
  }

  .kb-tag-list {
    max-height: 3.4rem;
    overflow: hidden;
  }

  .hub-card__title > a {
    display: inline-flex;
    align-items: center;
    min-height: 44px;
  }

  /* mobile UI phase 2: polish */
  .help-index__list {
    display: grid;
    gap: 0.5rem;
  }

  .help-index__item {
    margin: 0;
  }

  .help-index__link {
    display: flex;
    align-items: center;
    min-height: 44px;
    padding: 0.7rem 0;
  }

  .feedback-panel {
    margin-top: 0.5rem;
  }
}

@media (max-width: 480px) {
  .page-shell {
    padding: 1rem 0.75rem 2rem;
  }

  .hero h1 {
    font-size: 1.2rem;
  }
}