/* Math Workbench shell layer — loaded AFTER the inline <style> so it wins at equal
 * specificity. Owns: compact one-row top bar, first-viewport empty state, phone/tablet
 * layout (bottom tool bar), recents + tool search, first-run tour, lesson starter,
 * Access additions. Board/object styling stays in index.html. */

/* ------------------------------------------------------------------ top bar */
.topbar {
  gap: 10px;
  padding: 6px 12px;
}
.brand,
.brand .titles {
  flex: none;
  min-width: auto;
}
.brand h1 {
  font-size: 1.02rem;
}
.brand .logo {
  width: 36px;
  height: 36px;
}
.top-actions {
  flex-wrap: nowrap;
  gap: 6px;
  min-width: 0;
}
/* Every top-bar button is icon-only by default; the four primaries earn a label
 * only when the screen is wide enough to show them without wrapping. */
.topbar .tbtn {
  width: 40px;
  height: 40px;
  padding: 0;
  justify-content: center;
}
.topbar .tbtn .txt {
  display: none;
}
@media (min-width: 1300px) {
  .topbar #reasoningStudioBtn,
  .topbar #guideBtn,
  .topbar #liveBtn,
  .topbar #multBtn {
    width: auto;
    padding: 0 12px;
  }
  .topbar #reasoningStudioBtn .txt,
  .topbar #guideBtn .txt,
  .topbar #liveBtn .txt,
  .topbar #multBtn .txt {
    display: inline;
  }
}
@media (max-width: 1100px) {
  .brand .eyebrow {
    display: none;
  }
}
.mwb-more-tools > summary {
  min-height: 40px;
  padding: 0 12px;
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
}
/* Inside the More menu every item keeps its label. */
.mwb-more-menu .tbtn {
  width: auto;
  height: auto;
  min-height: 42px;
  padding: 0 12px;
  justify-content: flex-start;
}
.mwb-more-menu .tbtn .txt {
  display: inline;
}
.mwb-more-menu {
  max-height: min(70vh, 520px);
  overflow-y: auto;
}

/* --------------------------------------------------- first-viewport empty state */
/* In-flow + sticky: it sits at the top of the visible board whatever the scroll
 * position or sheet height, instead of centring in the three-screen-tall sheet. */
.empty-hint {
  position: sticky;
  top: 12%;
  left: auto;
  transform: none;
  margin: 0 auto;
  width: min(440px, 100%);
  max-width: none;
  padding: 24px 20px 0;
  box-sizing: border-box;
}
.empty-hint .big {
  font-size: 2.2rem;
  margin-bottom: 2px;
}
.empty-hint h2 {
  color: #6b7c93;
}

/* ------------------------------------------------------------ phone / tablet */
@media (max-width: 720px) {
  .topbar {
    padding: 5px 8px;
    gap: 6px;
  }
  .brand .titles {
    display: none;
  }
  .top-actions {
    gap: 3px;
    flex: 1;
    justify-content: flex-end;
  }
  .topbar .tbtn {
    width: 38px;
    height: 38px;
  }
  .save-pill {
    padding: 4px 7px;
    font-size: 0.64rem;
  }
  .mwb-more-tools > summary {
    padding: 0 9px;
    min-height: 38px;
  }
  /* Bottom tool bar: the board gets the full width. */
  .stage {
    flex-direction: column;
  }
  .workspace {
    order: 1;
    flex: 1 1 0;
    min-height: 0;
  }
  .rail {
    order: 2;
    width: 100%;
    flex: none;
    flex-direction: row;
    align-items: center;
    overflow-x: auto;
    overflow-y: hidden;
    border-right: 0;
    border-top: 1px solid var(--line);
    padding: 6px 8px;
    gap: 6px;
  }
  .rail .tool {
    flex: none;
    width: 52px;
    height: 52px;
    max-height: none;
    aspect-ratio: auto;
  }
  .rail .op-quick {
    flex: none;
    display: flex;
    gap: 4px;
    margin: 0;
  }
  .rail .opq,
  .rail .opq.wide {
    width: 36px;
    height: 36px;
    max-height: none;
    aspect-ratio: auto;
    grid-column: auto;
  }
  .rail-sep {
    flex: none;
    width: 1px;
    height: 34px;
    margin: 0 3px;
  }
  .flyout {
    left: 8px;
    right: 8px;
    top: auto;
    bottom: 72px;
    width: auto;
    max-height: 60%;
  }
  .guide-drawer {
    left: 8px;
    width: calc(100% - 16px);
  }
  .empty-hint {
    top: 8%;
    padding: 10px 62px 0 14px; /* clear of the page tabs on the right edge */
    width: 100%;
  }
  .empty-hint h2 {
    font-size: 1.1rem;
  }
}
@media (max-width: 374px) {
  .top-actions {
    flex-wrap: wrap;
  }
}
@media (min-width: 721px) and (max-width: 1100px) {
  :root {
    --rail-w: 70px;
  }
}

/* ------------------------------------------------------------------ utilities */
.wbx-sr-only {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
}
.wbx-muted {
  color: var(--muted, #5b6b82);
  font-size: 0.86rem;
}
.wbx-input {
  width: 100%;
  min-height: 42px;
  padding: 8px 10px;
  box-sizing: border-box;
  border: 2px solid #b8c7d6;
  border-radius: 10px;
  background: #fff;
  color: var(--ink, #14223a);
  font: inherit;
  font-weight: 700;
}
.wbx-input:focus-visible,
.wbx-link:focus-visible,
.wbx-result:focus-visible,
.wbx-chip:focus-visible,
.wbx-tool:focus-visible,
.wbx-recent-btn:focus-visible,
.wbx-skip:focus-visible {
  outline: 3px solid #fbbf24;
  outline-offset: 2px;
}

/* ------------------------------------------------- dialogs (gate, outline, lesson) */
.wbx-gate-bg {
  position: fixed;
  inset: 0;
  z-index: 31000;
  display: grid;
  place-items: center;
  padding: 16px;
  background: rgba(15, 23, 42, 0.55);
}
.wbx-gate {
  width: min(520px, 100%);
  max-height: 88vh;
  overflow: auto;
  padding: 20px 22px;
  border-radius: 18px;
  background: #fff;
  box-shadow: var(--shadow-lg);
}
.wbx-gate h2 {
  margin: 0 0 8px;
  font-size: 1.25rem;
}
.wbx-gate-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 14px;
}
.wbx-gate-row a.tbtn {
  text-decoration: none;
}
.wbx-outline-list {
  display: grid;
  gap: 6px;
  margin: 12px 0;
  padding: 0 0 0 22px;
}
.wbx-outline-list .tbtn {
  width: 100%;
  height: auto;
  min-height: 40px;
  padding: 6px 10px;
  justify-content: flex-start;
  text-align: left;
  white-space: normal;
}
.wbx-skip {
  position: absolute;
  left: 8px;
  top: -60px;
  z-index: 32000;
  padding: 8px 12px;
  border: 2px solid var(--teal);
  border-radius: 10px;
  background: #fff;
  color: var(--ink);
  font-weight: 800;
}
.wbx-skip:focus {
  top: 8px;
}
.wbx-fieldset {
  margin: 12px 0 0;
  padding: 0;
  border: 0;
}
.wbx-fieldset legend {
  margin-bottom: 6px;
  font-weight: 800;
}
.wbx-offer {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  margin: 6px 0;
  padding: 10px;
  border: 1.5px solid var(--line);
  border-radius: 12px;
  cursor: pointer;
  font-size: 0.92rem;
}
.wbx-offer input {
  margin-top: 4px;
  width: 20px;
  height: 20px;
  flex: none;
}
.wbx-banner {
  position: fixed;
  top: 62px;
  left: 50%;
  z-index: 29000;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 8px;
  max-width: calc(100vw - 16px);
  padding: 8px 12px;
  transform: translateX(-50%);
  border: 1.5px solid var(--teal);
  border-radius: 14px;
  background: #fff;
  box-shadow: var(--shadow);
  font-weight: 800;
}

/* ------------------------------------------------------- empty-state links */
.wbx-hint-links {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  justify-content: center;
  margin-top: 12px;
  pointer-events: auto;
}
.wbx-link {
  border: 0;
  background: transparent;
  color: var(--teal);
  font-weight: 800;
  font-size: 0.86rem;
  text-decoration: underline;
  cursor: pointer;
  min-height: 36px;
  padding: 0 4px;
}

/* ------------------------------------------------ tool search + recent tools */
.wbx-tool {
  position: relative;
  flex: none;
  width: 100%;
  aspect-ratio: 1 / 1;
  max-height: 60px;
  border-radius: 13px;
  border: 1.5px dashed #b8c6d8;
  background: #fff;
  color: var(--ink);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  cursor: pointer;
}
.wbx-tool .glyph {
  font-size: 1.2rem;
  line-height: 1;
}
.wbx-tool .lbl {
  font-size: 0.6rem;
  font-weight: 800;
  color: var(--muted);
}
.wbx-tool:hover,
.wbx-tool[aria-expanded="true"] {
  border-color: var(--teal);
  background: var(--teal-light);
}
.wbx-recent {
  display: grid;
  gap: 3px;
}
.wbx-recent[hidden] {
  display: none;
}
.wbx-recent-btn {
  min-height: 26px;
  padding: 0 3px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--teal);
  font-size: 0.55rem;
  font-weight: 800;
  line-height: 1.1;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.wbx-pop {
  position: fixed;
  left: calc(var(--rail-w) + 8px);
  top: 120px;
  z-index: 27000;
  width: min(320px, calc(100vw - 16px));
  max-height: min(70vh, 520px);
  overflow: auto;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 16px;
  background: #fff;
  box-shadow: var(--shadow-lg);
}
.wbx-pop-label {
  display: block;
  margin-bottom: 6px;
  font-weight: 800;
}
.wbx-results {
  display: grid;
  gap: 4px;
  margin: 6px 0 0;
  padding: 0;
  list-style: none;
}
.wbx-results-head {
  margin-top: 6px;
  color: var(--muted);
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.wbx-result {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
  min-height: 44px;
  padding: 4px 8px;
  border: 1px solid transparent;
  border-radius: 10px;
  background: transparent;
  color: var(--ink);
  font-weight: 800;
  text-align: left;
}
.wbx-result:hover {
  border-color: var(--teal);
  background: var(--teal-light);
}
.wbx-result-icon {
  display: grid;
  place-items: center;
  width: 44px;
  height: 36px;
  flex: none;
}
.wbx-result-icon svg {
  max-width: 44px;
  max-height: 34px;
}
@media (max-width: 720px) {
  .wbx-tool {
    flex: none;
    width: 52px;
    height: 52px;
    max-height: none;
    aspect-ratio: auto;
  }
  .wbx-recent {
    display: flex;
    flex: none;
    gap: 4px;
  }
  .wbx-recent-btn {
    width: 64px;
    min-height: 40px;
  }
  .wbx-pop {
    left: 8px;
    right: 8px;
    top: auto;
    bottom: 74px;
    width: auto;
  }
}

/* --------------------------------------------------------------------- tour */
.wbx-tour-ring {
  position: fixed;
  z-index: 33000;
  border: 3px solid #fbbf24;
  border-radius: 14px;
  box-shadow: 0 0 0 9999px rgba(15, 23, 42, 0.45);
  pointer-events: none;
}
.wbx-tour {
  position: fixed;
  z-index: 33001;
  padding: 14px 16px;
  border-radius: 16px;
  background: #fff;
  box-shadow: var(--shadow-lg);
}
.wbx-tour p {
  margin: 0 0 8px;
}
.wbx-tour-text {
  font-weight: 800;
  line-height: 1.4;
}
.wbx-tour-row {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: flex-end;
}
.wbx-tour .tbtn {
  width: auto;
  padding: 0 12px;
}