body.formulaLibraryOpen {
  overflow: hidden !important;
}

.formulaLibraryOverlay,
.formulaPracticeOverlay {
  font-family:
    "Be Vietnam Pro",
    "Inter",
    -apple-system,
    BlinkMacSystemFont,
    "Segoe UI",
    sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.formulaLibraryOverlay button,
.formulaPracticeOverlay button,
.formulaLibraryOverlay input,
.formulaPracticeOverlay input,
.formulaLibraryOverlay textarea,
.formulaPracticeOverlay textarea {
  font: inherit;
}

.pillFormulaBtn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  color: #3b246d;
  border-color: rgba(109, 40, 217, 0.23);
  background: linear-gradient(
    180deg,
    rgba(250, 245, 255, 0.98),
    rgba(237, 233, 254, 0.94)
  );
}

.pillFormulaBtn:hover,
.pillFormulaBtn[aria-expanded="true"] {
  color: #ffffff;
  border-color: rgba(109, 40, 217, 0.55);
  background: linear-gradient(135deg, #7c3aed, #4f46e5);
  box-shadow: 0 12px 26px rgba(79, 70, 229, 0.24);
}

.pillFormulaIcon {
  font-size: 16px;
  line-height: 1;
  font-weight: 1000;
}

.formulaLibraryOverlay {
  position: fixed;
  inset: 0;
  z-index: 2147483500;
  padding: 18px;
  display: grid;
  place-items: center;
  background: rgba(15, 23, 42, 0.64);
  backdrop-filter: blur(13px);
  opacity: 0;
  transition: opacity 0.18s ease;
}

.formulaLibraryOverlay[hidden] {
  display: none;
}

.formulaLibraryOverlay.isOpen {
  opacity: 1;
}

.formulaLibraryDialog {
  width: min(1320px, calc(100vw - 36px));
  height: min(850px, calc(100dvh - 36px));
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.58);
  border-radius: 30px;
  background: #f8faff;
  box-shadow: 0 34px 90px rgba(15, 23, 42, 0.34);
  transform: translateY(10px) scale(0.985);
  transition: transform 0.2s ease;
}

.formulaLibraryOverlay.isOpen .formulaLibraryDialog {
  transform: translateY(0) scale(1);
}

.formulaLibraryHeader {
  min-height: 88px;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid rgba(79, 70, 229, 0.13);
  background:
    radial-gradient(circle at 82% 0%, rgba(196, 181, 253, 0.48), transparent 28%),
    linear-gradient(135deg, #ffffff, #eef2ff);
}

.formulaLibraryHeading {
  min-width: 0;
  display: flex;
  align-items: center;
  gap: 16px;
}

.formulaLibraryMark {
  width: 54px;
  height: 54px;
  flex: 0 0 54px;
  display: grid;
  place-items: center;
  border-radius: 20px;
  color: #ffffff;
  background: linear-gradient(145deg, #7c3aed, #2563eb);
  box-shadow: 0 14px 28px rgba(79, 70, 229, 0.25);
  font-size: 26px;
  font-weight: 1000;
}

.formulaLibraryHeading h2 {
  margin: 0;
  color: #111b36;
  font-size: clamp(24px, 3vw, 34px);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.035em;
}

.formulaLibraryClose {
  width: 48px;
  height: 48px;
  flex: 0 0 48px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 16px;
  color: #172033;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 10px 22px rgba(15, 23, 42, 0.09);
  cursor: pointer;
  font-size: 27px;
  font-weight: 700;
}

.formulaLibraryClose:hover {
  color: #ffffff;
  background: #ef4444;
}

.formulaLibraryClose:focus-visible,
.formulaCategoryButton:focus-visible {
  outline: 3px solid rgba(79, 70, 229, 0.28);
  outline-offset: 2px;
}

.formulaLibraryBody {
  min-height: 0;
  flex: 1 1 auto;
  display: grid;
  grid-template-columns: 270px minmax(0, 1fr);
}

.formulaCategoryNav {
  min-height: 0;
  padding: 18px 14px;
  display: flex;
  flex-direction: column;
  gap: 9px;
  overflow-y: auto;
  border-right: 1px solid rgba(79, 70, 229, 0.1);
  background: #f1f5ff;
}

.formulaCategoryButton {
  width: 100%;
  min-height: 60px;
  padding: 9px 10px;
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr) auto;
  align-items: center;
  gap: 10px;
  border: 1px solid transparent;
  border-radius: 17px;
  color: #3e4c69;
  background: transparent;
  cursor: pointer;
  text-align: left;
  transition:
    transform 0.14s ease,
    border-color 0.14s ease,
    background 0.14s ease;
}

.formulaCategoryButton:hover {
  border-color: rgba(79, 70, 229, 0.13);
  background: rgba(255, 255, 255, 0.78);
  transform: translateX(2px);
}

.formulaCategoryButton.isActive {
  color: #312e81;
  border-color: rgba(79, 70, 229, 0.17);
  background: #ffffff;
  box-shadow: 0 10px 24px rgba(79, 70, 229, 0.1);
}

.formulaCategoryIcon {
  width: 40px;
  height: 40px;
  display: grid;
  place-items: center;
  border-radius: 13px;
  color: #5b21b6;
  background: #ede9fe;
  font-size: 18px;
  font-weight: 1000;
}

.formulaCategoryButton.isActive .formulaCategoryIcon {
  color: #ffffff;
  background: linear-gradient(145deg, #7c3aed, #4f46e5);
}

.formulaCategoryName {
  min-width: 0;
  overflow: hidden;
  font-size: 14px;
  font-weight: 800;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.formulaCategoryCount {
  min-width: 27px;
  height: 25px;
  padding: 0 7px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  color: #64748b;
  background: #e8edf8;
  font-size: 10px;
  font-weight: 800;
}

.formulaLibraryContent {
  min-width: 0;
  min-height: 0;
  padding: 22px;
  overflow-y: auto;
  background:
    radial-gradient(circle at 100% 0%, rgba(224, 231, 255, 0.74), transparent 30%),
    #fbfcff;
}

.formulaCategoryIntro {
  padding: 14px 16px;
  display: flex;
  align-items: center;
  gap: 15px;
  border: 1px solid rgba(79, 70, 229, 0.11);
  border-radius: 21px;
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 12px 28px rgba(30, 41, 59, 0.06);
}

.formulaCategoryIntroIcon {
  width: 46px;
  height: 46px;
  flex: 0 0 46px;
  display: grid;
  place-items: center;
  border-radius: 17px;
  color: #ffffff;
  background: linear-gradient(145deg, #7c3aed, #2563eb);
  font-size: 20px;
  font-weight: 1000;
}

.formulaCategoryIntro h3 {
  margin: 0;
  color: #312e81;
  font-size: clamp(20px, 1.8vw, 22px);
  font-weight: 800;
  line-height: 1.3;
  letter-spacing: -0.015em;
}

.formulaCategoryNotice {
  max-width: 850px;
  margin: 10px 0 0;
  color: #475569;
  font-size: 14px;
  line-height: 1.6;
  font-weight: 600;
}

.formulaFlatGrid {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.formulaGroupedList {
  margin-top: 20px;
  display: grid;
  gap: 22px;
}

.formulaSectionGroup {
  padding: 18px;
  border: 1px solid rgba(79, 70, 229, 0.16);
  border-radius: 21px;
  background:
    linear-gradient(135deg, rgba(238, 242, 255, 0.94), rgba(255, 255, 255, 0.96));
  box-shadow: 0 12px 28px rgba(30, 41, 59, 0.06);
}

.formulaSectionGroup.is-trigonometric {
  border-color: rgba(217, 119, 6, 0.22);
  background:
    linear-gradient(135deg, rgba(255, 247, 237, 0.96), rgba(255, 255, 255, 0.96));
}

.formulaSectionGroup.is-geometric {
  border-color: rgba(5, 150, 105, 0.22);
  background:
    linear-gradient(135deg, rgba(236, 253, 245, 0.96), rgba(255, 255, 255, 0.96));
}

.formulaSectionGroup.is-infinite-geometric {
  border-color: rgba(217, 119, 6, 0.24);
  background:
    linear-gradient(135deg, rgba(255, 251, 235, 0.98), rgba(255, 255, 255, 0.96));
}

.formulaSectionGroupTitle {
  margin: 0 0 16px;
  padding: 0 2px 12px;
  border-bottom: 2px solid rgba(79, 70, 229, 0.15);
  color: #3730a3;
  font-size: clamp(19px, 1.7vw, 21px);
  line-height: 1.4;
  font-weight: 800;
  letter-spacing: -0.01em;
}

.formulaSectionGroup.is-trigonometric .formulaSectionGroupTitle {
  border-bottom-color: rgba(217, 119, 6, 0.18);
  color: #b45309;
}

.formulaSectionGroup.is-geometric .formulaSectionGroupTitle {
  border-bottom-color: rgba(5, 150, 105, 0.18);
  color: #047857;
}

.formulaSectionGroup.is-infinite-geometric .formulaSectionGroupTitle {
  border-bottom-color: rgba(217, 119, 6, 0.2);
  color: #b45309;
}

.formulaSectionGrid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.formulaSectionGroupContent {
  min-width: 0;
}

.formulaSectionGroupContent.hasDiagrams {
  display: grid;
  gap: 18px;
}

.formulaSectionTheory {
  min-width: 0;
  padding: 14px 16px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  gap: 13px;
  border: 1px solid rgba(79, 70, 229, 0.13);
  border-radius: 16px;
  background: linear-gradient(135deg, #f5f7ff, #ffffff);
}

.formulaSectionTheoryBadge {
  min-height: 30px;
  padding: 0 11px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  color: #4338ca;
  background: #e0e7ff;
  font-size: 12px;
  line-height: 1;
  font-weight: 800;
}

.formulaSectionTheoryList {
  margin: 0;
  padding-left: 19px;
  display: grid;
  gap: 7px;
  color: #3f4b66;
  font-size: 14px;
  line-height: 1.65;
  font-weight: 600;
}

.formulaDiagramPanel,
.formulaDiagramGrid,
.formulaDiagramCard,
.formulaDiagramStage {
  min-width: 0;
}

.formulaDiagramGrid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
  gap: 14px;
}

.formulaDiagramCard {
  margin: 0;
  padding: 13px;
  display: flex;
  flex-direction: column;
  border: 1px solid rgba(79, 70, 229, 0.13);
  border-radius: 17px;
  background: linear-gradient(155deg, #ffffff, #f7f9ff);
  box-shadow: 0 8px 20px rgba(30, 41, 59, 0.055);
}

.formulaDiagramStage {
  width: 100%;
  position: relative;
  aspect-ratio: 16 / 10;
  border-radius: 13px;
  background:
    linear-gradient(rgba(99, 102, 241, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(99, 102, 241, 0.045) 1px, transparent 1px),
    #fbfcff;
  background-size: 20px 20px;
}

.formulaDiagramCanvas {
  width: 100%;
  height: 100%;
  position: absolute;
  inset: 0;
  display: block;
}

.formulaDiagramFigcaption {
  margin-top: 11px;
  display: grid;
  gap: 4px;
  text-align: center;
}

.formulaDiagramFigcaption strong {
  color: #27336f;
  font-size: 14px;
  line-height: 1.4;
  font-weight: 800;
}

.formulaDiagramFigcaption span {
  color: #526079;
  font-size: 12.5px;
  line-height: 1.55;
  font-weight: 600;
}

.formulaSectionGroup.is-angle-values .formulaEntry,
.formulaSectionGroup.is-angle-conversion .formulaEntry {
  grid-column: 1 / -1;
}

.formulaEntry {
  min-width: 0;
  width: 100%;
  height: auto;
  min-height: 118px;
  padding: 20px 22px;
  overflow: visible;
  border: 1px solid rgba(79, 70, 229, 0.12);
  border-radius: 18px;
  background: #ffffff;
  box-shadow: 0 8px 22px rgba(30, 41, 59, 0.055);
}

.formulaEntryWide {
  grid-column: 1 / -1;
}

@media (min-width: 621px) {
  .formulaLibraryContent[data-formula-category="interest"]
    .formulaFlatGrid
    > .formulaEntry:last-child:nth-child(odd) {
    grid-column: 1 / -1;
  }
}

.formulaEntryTitle {
  width: 100%;
  margin: 0 0 12px;
  color: #27336f;
  font-size: 15px;
  font-weight: 800;
  line-height: 1.5;
  text-align: left;
}

.formulaLibraryContent[data-formula-category="interest"] .formulaEntryTitle {
  font-size: 16px;
  line-height: 1.5;
}

.formulaEntryMain {
  min-width: 0;
  width: 100%;
  height: auto;
  margin-top: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr) 64px;
  align-items: center;
  gap: 18px;
  overflow: visible;
}

.formulaEntryContent {
  min-width: 0;
  width: 100%;
  height: auto;
  display: flex;
  flex-direction: column;
  justify-content: center;
  overflow: visible;
}

.formulaPlayButton {
  width: 42px;
  height: 42px;
  flex: 0 0 42px;
  position: relative;
  align-self: center;
  justify-self: center;
  display: grid;
  place-items: center;
  border: 1px solid rgba(79, 70, 229, 0.16);
  border-radius: 14px;
  color: #ffffff;
  background: linear-gradient(145deg, #7c3aed, #2563eb);
  box-shadow: 0 6px 14px rgba(79, 70, 229, 0.16);
  cursor: pointer;
  transition:
    transform 0.15s ease,
    box-shadow 0.15s ease,
    filter 0.15s ease;
}

.formulaPlayButton span {
  margin-left: 2px;
  font-size: 14px;
  line-height: 1;
}

.formulaPlayButton:hover {
  transform: scale(1.015);
  filter: brightness(1.04);
  box-shadow: 0 8px 17px rgba(79, 70, 229, 0.19);
}

.formulaPlayButton::after {
  content: attr(data-tooltip);
  min-width: max-content;
  max-width: 220px;
  padding: 7px 9px;
  position: absolute;
  right: 0;
  bottom: calc(100% + 8px);
  z-index: 30;
  border: 1px solid rgba(15, 23, 42, 0.1);
  border-radius: 9px;
  color: #ffffff;
  background: #1e293b;
  box-shadow: 0 8px 20px rgba(15, 23, 42, 0.2);
  font-size: 12px;
  line-height: 1.4;
  font-weight: 700;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transform: translateY(4px);
  transition:
    opacity 0.14s ease,
    transform 0.14s ease;
}

.formulaPlayButton:hover::after,
.formulaPlayButton:focus-visible::after {
  opacity: 1;
  transform: translateY(0);
}

.formulaPlayButton.isCompleted {
  border-color: rgba(234, 88, 12, 0.28);
  background: linear-gradient(145deg, #fb923c, #ea580c);
  box-shadow: 0 6px 14px rgba(234, 88, 12, 0.2);
}

.formulaPlayButton.isCompleted:hover {
  box-shadow: 0 8px 18px rgba(234, 88, 12, 0.3);
}

.formulaPlayButton:focus-visible,
.formulaPracticeClose:focus-visible,
.formulaPracticeCheck:focus-visible,
.formulaPracticeSolutionToggle:focus-visible,
.formulaPracticeNext:focus-visible,
.formulaPracticeReset:focus-visible,
.formulaPracticeBack:focus-visible {
  outline: 3px solid rgba(79, 70, 229, 0.3);
  outline-offset: 2px;
}

.formulaEntryMath {
  min-width: 0;
  width: 100%;
  max-width: 100%;
  height: auto;
  min-height: 0;
  flex: 0 0 auto;
  margin: 0;
  padding: 8px 0;
  display: block;
  overflow: visible;
  color: #172554;
  font-size: clamp(22px, 1.65vw, 26px);
  font-weight: 700;
  line-height: 1.6;
  text-align: center;
}

.formulaEntryMath mjx-container {
  width: 100%;
  max-width: 100%;
  display: block !important;
  margin: 0 !important;
  overflow: visible;
  text-align: center !important;
}

.formulaEntryMath mjx-container > svg {
  max-width: 100%;
  height: auto;
  overflow: visible;
  vertical-align: middle;
}

.formulaEntryNote {
  margin-top: 14px;
  color: #475569;
  font-size: 14px;
  line-height: 1.65;
  font-weight: 600;
  text-align: left;
  overflow-wrap: anywhere;
}

.lessonFormulaButton {
  min-height: 40px;
  padding: 0 15px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  border: 1px solid rgba(109, 40, 217, 0.2);
  border-radius: 999px;
  color: #4c1d95;
  background: linear-gradient(180deg, #faf5ff, #ede9fe);
  box-shadow: 0 9px 20px rgba(79, 70, 229, 0.1);
  cursor: pointer;
  font-size: 13px;
  font-weight: 1000;
}

.lessonFormulaButton:hover {
  color: #ffffff;
  background: linear-gradient(135deg, #7c3aed, #4f46e5);
}

/* ===== Popup luyện tập cho từng công thức ===== */
.formulaPracticeOverlay {
  position: fixed;
  inset: 0;
  z-index: 2147483560;
  padding: 18px;
  display: grid;
  place-items: center;
  background: rgba(7, 15, 35, 0.7);
  backdrop-filter: blur(15px);
  opacity: 0;
  transition: opacity 0.18s ease;
}

.formulaPracticeOverlay[hidden] {
  display: none;
}

.formulaPracticeOverlay.isOpen {
  opacity: 1;
}

.formulaPracticeDialog {
  width: min(1040px, calc(100vw - 36px));
  height: min(820px, calc(100dvh - 36px));
  min-height: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, 0.58);
  border-radius: 28px;
  background: #f8faff;
  box-shadow: 0 36px 90px rgba(2, 6, 23, 0.42);
  transform: translateY(10px) scale(0.985);
  transition: transform 0.2s ease;
}

.formulaPracticeOverlay.isOpen .formulaPracticeDialog {
  transform: translateY(0) scale(1);
}

.formulaPracticeHeader {
  min-height: 72px;
  padding: 12px 18px;
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 18px;
  border-bottom: 1px solid rgba(79, 70, 229, 0.13);
  background:
    radial-gradient(circle at 78% 0%, rgba(196, 181, 253, 0.52), transparent 30%),
    linear-gradient(135deg, #ffffff, #eef2ff);
}

.formulaPracticeClose {
  width: 46px;
  height: 46px;
  flex: 0 0 46px;
  display: grid;
  place-items: center;
  border: 1px solid rgba(15, 23, 42, 0.08);
  border-radius: 15px;
  color: #172033;
  background: #ffffff;
  box-shadow: 0 9px 20px rgba(15, 23, 42, 0.09);
  cursor: pointer;
  font-size: 26px;
}

.formulaPracticeClose:hover {
  color: #ffffff;
  background: #ef4444;
}

.formulaPracticeBody {
  min-height: 0;
  flex: 1 1 auto;
  padding: 18px 20px 22px;
  overflow-y: auto;
  background:
    radial-gradient(circle at 100% 0%, rgba(224, 231, 255, 0.75), transparent 30%),
    #f8faff;
}

.formulaPracticeQuestions {
  margin-top: 0;
  display: grid;
  gap: 12px;
}

.formulaPracticeQuestion {
  padding: 17px;
  border: 1px solid rgba(51, 65, 85, 0.11);
  border-radius: 19px;
  background: #ffffff;
  box-shadow: 0 9px 22px rgba(30, 41, 59, 0.05);
}

.formulaPracticeQuestionLabel {
  width: max-content;
  padding: 5px 9px;
  border-radius: 999px;
  color: #5b21b6;
  background: #ede9fe;
  font-size: 9px;
  font-weight: 1000;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.formulaPracticeQuestion h4 {
  margin: 11px 0 8px;
  color: #1e293b;
  font-size: 15px;
  line-height: 1.5;
}

.formulaPracticePromptMath {
  margin: 0 0 13px;
  padding: 11px 12px;
  overflow-x: auto;
  border: 1px solid rgba(79, 70, 229, 0.11);
  border-radius: 13px;
  color: #1e293b;
  background: linear-gradient(135deg, #f8fafc, #f5f3ff);
}

.formulaPracticePromptMath mjx-container {
  margin: 0 !important;
}

.formulaPracticeChoices {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 9px;
  border: 0;
}

.formulaPracticeChoices legend {
  margin-bottom: 7px;
  color: #64748b;
  font-size: 10px;
  font-weight: 900;
}

.formulaPracticeChoice {
  min-height: 54px;
  padding: 9px 12px;
  position: relative;
  display: flex;
  align-items: center;
  gap: 11px;
  overflow: hidden;
  border: 1px solid rgba(100, 116, 139, 0.2);
  border-radius: 14px;
  color: #1e293b;
  background: #f8fafc;
  cursor: pointer;
  transition:
    border-color 0.16s ease,
    background 0.16s ease,
    transform 0.16s ease;
}

.formulaPracticeChoice:hover {
  border-color: rgba(79, 70, 229, 0.42);
  background: #f5f3ff;
  transform: translateY(-1px);
}

.formulaPracticeChoice:focus-within {
  border-color: #6366f1;
  outline: 3px solid rgba(99, 102, 241, 0.13);
}

.formulaPracticeChoice input {
  width: 1px;
  height: 1px;
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.formulaPracticeChoiceLetter {
  width: 32px;
  height: 32px;
  flex: 0 0 32px;
  display: grid;
  place-items: center;
  border-radius: 10px;
  color: #4f46e5;
  background: #e0e7ff;
  font-size: 12px;
  font-weight: 1000;
}

.formulaPracticeChoiceMath {
  min-width: 0;
  flex: 1 1 auto;
  overflow-x: auto;
  font-size: 14px;
}

.formulaPracticeChoiceMath mjx-container {
  margin: 0 !important;
}

.formulaPracticeChoice.isSelected {
  border-color: #6366f1;
  background: #eef2ff;
}

.formulaPracticeChoice.isSelected .formulaPracticeChoiceLetter {
  color: #ffffff;
  background: #6366f1;
}

.formulaPracticeChoice.isWrong {
  border-color: #ef4444;
  background: #fff1f2;
}

.formulaPracticeChoice.isWrong .formulaPracticeChoiceLetter {
  color: #ffffff;
  background: #ef4444;
}

.formulaPracticeChoice.isCorrect {
  border-color: #16a34a;
  background: #f0fdf4;
}

.formulaPracticeChoice.isCorrect .formulaPracticeChoiceLetter {
  color: #ffffff;
  background: #16a34a;
}

.formulaPracticeChoice:has(input:disabled) {
  cursor: default;
  opacity: 0.68;
  transform: none;
}

.formulaPracticeChoice.isCorrect:has(input:disabled) {
  opacity: 1;
}

.formulaPracticeFeedback {
  min-height: 24px;
  padding-top: 7px;
  font-size: 11px;
  font-weight: 900;
}

.formulaPracticeFeedback.isWrong {
  color: #dc2626;
}

.formulaPracticeFeedback.isCorrect {
  color: #15803d;
}

.formulaPracticeCheck,
.formulaPracticeNext {
  min-height: 42px;
  padding: 0 15px;
  border: 0;
  border-radius: 12px;
  color: #ffffff;
  cursor: pointer;
  font-size: 12px;
  font-weight: 950;
}

.formulaPracticeCheck {
  background: linear-gradient(135deg, #7c3aed, #4f46e5);
  box-shadow: 0 9px 20px rgba(79, 70, 229, 0.2);
}

.formulaPracticeCheck:disabled {
  color: #94a3b8;
  background: #e2e8f0;
  box-shadow: none;
  cursor: not-allowed;
}

.formulaPracticeCheck[hidden] {
  display: none;
}

.formulaPracticeSolutionTools {
  margin-top: 10px;
  display: flex;
}

.formulaPracticeSolutionTools[hidden] {
  display: none;
}

.formulaPracticeSolutionToggle {
  min-height: 40px;
  padding: 0 14px;
  border: 1px solid rgba(14, 116, 144, 0.2);
  border-radius: 12px;
  color: #0e7490;
  background: #ecfeff;
  cursor: pointer;
  font-size: 11px;
  font-weight: 950;
}

.formulaPracticeSolutionToggle[aria-expanded="true"] {
  color: #ffffff;
  background: #0891b2;
}

.formulaPracticeDetailedSolution {
  margin-top: 10px;
  overflow: hidden;
  border: 1px solid rgba(14, 116, 144, 0.18);
  border-radius: 16px;
  color: #164e63;
  background: #f8feff;
}

.formulaPracticeDetailedSolution[hidden] {
  display: none;
}

.formulaPracticeSolutionStep {
  padding: 14px;
}

.formulaPracticeSolutionStep + .formulaPracticeSolutionStep {
  border-top: 1px solid rgba(14, 116, 144, 0.12);
}

.formulaPracticeSolutionStep > span,
.formulaPracticeSolutionConclusion > span {
  display: block;
  margin-bottom: 4px;
  color: #0891b2;
  font-size: 9px;
  font-weight: 1000;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.formulaPracticeSolutionStep > strong {
  display: block;
  color: #164e63;
  font-size: 12px;
}

.formulaPracticeSolutionStep p {
  margin: 8px 0 0;
  color: #475569;
  font-size: 11px;
  font-weight: 720;
  line-height: 1.55;
}

.formulaPracticeSolutionMath {
  margin-top: 8px;
  padding: 10px 11px;
  overflow-x: auto;
  border-radius: 11px;
  background: #ffffff;
}

.formulaPracticeSolutionMath mjx-container {
  margin: 0 !important;
}

.formulaPracticeSolutionConclusion {
  padding: 13px 14px;
  border-top: 1px solid rgba(22, 163, 74, 0.16);
  color: #14532d;
  background: #f0fdf4;
}

.formulaPracticeSolutionConclusion > span {
  color: #16a34a;
}

.formulaPracticeSolutionConclusion > strong {
  margin-right: 10px;
}

.formulaPracticeSolutionConclusion > div {
  margin-top: 7px;
  overflow-x: auto;
}

.formulaPracticeNextWrap {
  display: flex;
  justify-content: flex-end;
  margin-top: 10px;
}

.formulaPracticeNextWrap[hidden] {
  display: none;
}

.formulaPracticeNext {
  background: linear-gradient(135deg, #16a34a, #059669);
  box-shadow: 0 9px 20px rgba(5, 150, 105, 0.2);
}

.formulaPracticeComplete {
  min-height: 330px;
  padding: 34px 20px;
  display: grid;
  place-items: center;
  align-content: center;
  text-align: center;
  border: 1px solid rgba(34, 197, 94, 0.2);
  border-radius: 22px;
  background:
    radial-gradient(circle at 50% 0%, rgba(187, 247, 208, 0.72), transparent 45%),
    #ffffff;
  box-shadow: 0 12px 28px rgba(22, 101, 52, 0.08);
}

.formulaPracticeCompleteIcon {
  width: 72px;
  height: 72px;
  margin-bottom: 15px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  color: #ffffff;
  background: linear-gradient(135deg, #22c55e, #059669);
  box-shadow: 0 15px 28px rgba(5, 150, 105, 0.24);
  font-size: 35px;
  font-weight: 1000;
}

.formulaPracticeComplete h4 {
  margin: 7px 0 8px;
  color: #14532d;
  font-size: 23px;
}

.formulaPracticeComplete p {
  max-width: 520px;
  margin: 0;
  color: #64748b;
  font-size: 12px;
  font-weight: 700;
  line-height: 1.55;
}

.formulaPracticeComplete button {
  min-height: 43px;
  margin-top: 18px;
  padding: 0 16px;
  border: 0;
  border-radius: 13px;
  color: #ffffff;
  background: linear-gradient(135deg, #16a34a, #059669);
  cursor: pointer;
  font-size: 12px;
  font-weight: 950;
}

.formulaPracticeFooter {
  min-height: 76px;
  padding: 13px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  border-top: 1px solid rgba(79, 70, 229, 0.11);
  background: #ffffff;
}

.formulaPracticeProgress {
  color: #64748b;
  font-size: 12px;
  font-weight: 750;
}

.formulaPracticeProgress strong {
  color: #6d28d9;
}

.formulaPracticeFooterActions {
  display: flex;
  gap: 9px;
}

.formulaPracticeReset,
.formulaPracticeBack {
  min-height: 42px;
  padding: 0 15px;
  border-radius: 13px;
  cursor: pointer;
  font-size: 12px;
  font-weight: 950;
}

.formulaPracticeReset {
  border: 1px solid rgba(51, 65, 85, 0.12);
  color: #475569;
  background: #f8fafc;
}

.formulaPracticeBack {
  border: 0;
  color: #ffffff;
  background: linear-gradient(135deg, #7c3aed, #4f46e5);
  box-shadow: 0 10px 22px rgba(79, 70, 229, 0.2);
}

@media (max-width: 900px) {
  .formulaLibraryOverlay {
    padding: 10px;
  }

  .formulaLibraryDialog {
    width: calc(100vw - 20px);
    height: calc(100dvh - 20px);
    border-radius: 23px;
  }

  .formulaLibraryHeader {
    min-height: 94px;
    padding: 15px 17px;
  }

  .formulaLibraryMark {
    width: 50px;
    height: 50px;
    flex-basis: 50px;
    border-radius: 16px;
    font-size: 24px;
  }

  .formulaLibraryBody {
    grid-template-columns: 1fr;
    grid-template-rows: auto minmax(0, 1fr);
  }

  .formulaCategoryNav {
    padding: 10px;
    flex-direction: row;
    overflow-x: auto;
    overflow-y: hidden;
    border-right: 0;
    border-bottom: 1px solid rgba(79, 70, 229, 0.1);
  }

  .formulaCategoryButton {
    width: auto;
    min-width: max-content;
    min-height: 48px;
    grid-template-columns: 34px auto auto;
    border-radius: 14px;
  }

  .formulaCategoryIcon {
    width: 34px;
    height: 34px;
    border-radius: 11px;
    font-size: 15px;
  }

  .formulaLibraryContent {
    padding: 14px;
  }

  .formulaPracticeOverlay {
    padding: 10px;
  }

  .formulaPracticeDialog {
    width: calc(100vw - 20px);
    height: calc(100dvh - 20px);
    border-radius: 23px;
  }
}

@media (max-width: 760px) {
  .formulaFlatGrid,
  .formulaSectionGrid {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .formulaEntryWide {
    grid-column: 1 / -1;
  }

  .formulaSectionGroupTitle {
    font-size: 19px;
  }

  .formulaEntry {
    min-height: 110px;
    padding: 18px;
  }

  .formulaEntryMain {
    grid-template-columns: minmax(0, 1fr) 56px;
    gap: 15px;
  }

  .formulaEntryMath {
    font-size: clamp(20px, 3.2vw, 23px);
  }
}

@media (max-width: 620px) {
  .formulaLibraryOverlay {
    padding: 0;
  }

  .formulaLibraryDialog {
    width: 100vw;
    height: 100dvh;
    border: 0;
    border-radius: 0;
  }

  .formulaLibraryHeader {
    min-height: 82px;
  }

  .formulaLibraryMark {
    width: 42px;
    height: 42px;
    flex-basis: 42px;
    border-radius: 13px;
    font-size: 21px;
  }

  .formulaLibraryHeading {
    gap: 10px;
  }

  .formulaLibraryHeading h2 {
    font-size: 21px;
  }

  .formulaLibraryClose {
    width: 42px;
    height: 42px;
    flex-basis: 42px;
    border-radius: 13px;
  }

  .formulaCategoryName {
    font-size: 12px;
  }

  .formulaCategoryCount {
    display: none;
  }

  .formulaCategoryIntro {
    padding: 14px;
  }

  .formulaCategoryIntroIcon {
    width: 44px;
    height: 44px;
    flex-basis: 44px;
    border-radius: 14px;
    font-size: 19px;
  }

  .formulaCategoryIntro h3 {
    font-size: 20px;
  }

  .formulaFlatGrid,
  .formulaSectionGrid {
    grid-template-columns: 1fr;
  }

  .formulaSectionGroup {
    padding: 12px;
    border-radius: 18px;
  }

  .formulaSectionGroupTitle {
    margin-bottom: 13px;
    padding-bottom: 10px;
    font-size: 18px;
    line-height: 1.45;
  }

  .formulaSectionTheory {
    padding: 13px;
    grid-template-columns: 1fr;
    gap: 9px;
  }

  .formulaSectionTheoryBadge {
    width: max-content;
  }

  .formulaSectionTheoryList {
    padding-left: 18px;
    font-size: 13px;
    line-height: 1.6;
  }

  .formulaDiagramGrid {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .formulaDiagramCard {
    padding: 11px;
  }

  .formulaEntry {
    min-height: 104px;
    padding: 15px 14px;
    border-radius: 16px;
  }

  .formulaEntryMain {
    grid-template-columns: minmax(0, 1fr) 50px;
    gap: 12px;
  }

  .formulaEntryTitle,
  .formulaLibraryContent[data-formula-category="interest"] .formulaEntryTitle {
    margin-bottom: 10px;
    font-size: 14px;
    line-height: 1.5;
  }

  .formulaEntryMath {
    padding: 6px 0;
    font-size: clamp(19px, 5vw, 21px);
    line-height: 1.55;
  }

  .formulaEntryNote {
    margin-top: 11px;
    font-size: 13px;
    line-height: 1.6;
  }

  .formulaPlayButton {
    width: 40px;
    height: 40px;
    flex-basis: 40px;
    border-radius: 13px;
  }

  .formulaPracticeOverlay {
    padding: 0;
  }

  .formulaPracticeDialog {
    width: 100vw;
    height: 100dvh;
    border: 0;
    border-radius: 0;
  }

  .formulaPracticeHeader {
    min-height: 64px;
    padding: 9px 12px;
  }

  .formulaPracticeBody {
    padding: 12px;
  }

  .formulaPracticeQuestion {
    padding: 14px;
  }

  .formulaPracticeCheck,
  .formulaPracticeSolutionToggle,
  .formulaPracticeNext {
    width: 100%;
  }

  .formulaPracticeFooter {
    padding: 10px 12px;
    align-items: stretch;
    flex-direction: column;
  }

  .formulaPracticeFooterActions {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .formulaPracticeReset,
  .formulaPracticeBack {
    padding-inline: 10px;
  }

  .lessonFormulaButton {
    min-height: 38px;
    padding: 0 12px;
    font-size: 12px;
  }
}

@media (min-width: 1024px) and (max-width: 1179px) {
  .topActions .pillFormulaBtn {
    gap: 3px;
    padding-inline: 7px;
  }

  .topActions .pillFormulaIcon {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .formulaLibraryOverlay,
  .formulaLibraryDialog,
  .formulaCategoryButton,
  .formulaPlayButton,
  .formulaPracticeOverlay,
  .formulaPracticeDialog {
    transition: none !important;
  }
}