.drill-page {
  --drill: #38cfd0;
  --drill-blue: #3b9dff;
  --drill-soft: #a7ebea;
  min-width: 320px;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 72% 7%, rgba(34, 134, 177, 0.11), transparent 30%),
    var(--page);
}

.drill-page .workspace,
.drill-page main {
  background: transparent;
}

.drill-page .navigation-item.is-current {
  background: linear-gradient(90deg, rgba(11, 105, 117, 0.72), rgba(12, 66, 94, 0.5));
  color: var(--drill-soft);
}

.drill-page .navigation-item.is-current .navigation-icon {
  filter: drop-shadow(0 0 5px rgba(56, 207, 208, 0.5));
}

.drill-top-bar {
  min-height: 108px;
  border-bottom-color: rgba(49, 104, 146, 0.3);
}

.drill-top-bar .top-bar-main {
  align-content: center;
}

.drill-top-copy {
  margin: 2px 0 0;
  color: #8298a8;
  font-size: 11px;
}

.drill-main {
  width: 100%;
  max-width: 1260px;
  margin: 0;
  padding: 38px 42px 86px;
}

.drill-eyebrow,
.question-label,
.question-family {
  margin: 0;
  color: var(--drill);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.095em;
  line-height: 1.35;
  text-transform: uppercase;
}

.drill-intro {
  display: grid;
  gap: 28px;
}

.drill-hero-copy {
  position: relative;
  max-width: 800px;
  padding: 10px 0 6px;
}

.drill-hero-copy::after {
  position: absolute;
  top: -12px;
  left: -34px;
  width: 180px;
  height: 180px;
  border: 1px solid rgba(56, 207, 208, 0.065);
  border-radius: 50%;
  box-shadow: 54px 48px 0 -53px rgba(59, 157, 255, 0.15);
  content: "";
  pointer-events: none;
}

.drill-hero-copy h1,
.session-header h1,
.drill-state h1 {
  margin: 7px 0 12px;
  color: var(--text);
  font-family: var(--display-font);
  font-size: clamp(43px, 5.5vw, 70px);
  font-weight: 400;
  letter-spacing: -0.052em;
  line-height: 1;
}

.drill-hero-copy > p:last-child {
  max-width: 740px;
  margin: 0;
  color: #b6c6cd;
  font-size: 15px;
  line-height: 1.65;
}

.mixed-option-card {
  position: relative;
  display: grid;
  min-height: 228px;
  overflow: hidden;
  grid-template-columns: 82px minmax(0, 1fr) auto;
  align-items: center;
  gap: 24px;
  padding: 32px;
  border: 1px solid rgba(62, 139, 170, 0.5);
  border-radius: 17px;
  background:
    linear-gradient(115deg, rgba(5, 35, 53, 0.95), rgba(4, 21, 38, 0.92) 68%),
    var(--surface);
  box-shadow:
    inset 4px 0 0 rgba(56, 207, 208, 0.75),
    0 22px 54px rgba(0, 0, 0, 0.14);
}

.mixed-option-card::after {
  position: absolute;
  right: -70px;
  bottom: -110px;
  width: 360px;
  height: 360px;
  border: 1px solid rgba(56, 207, 208, 0.07);
  border-radius: 50%;
  content: "";
  pointer-events: none;
}

.mixed-option-mark {
  position: relative;
  display: grid;
  width: 74px;
  height: 74px;
  place-items: center;
  border: 1px solid rgba(56, 207, 208, 0.55);
  border-radius: 50%;
  background: rgba(13, 89, 102, 0.24);
  box-shadow: 0 0 30px rgba(56, 207, 208, 0.08);
}

.mixed-option-mark::before,
.mixed-option-mark::after,
.mixed-option-mark span {
  position: absolute;
  border: 2px solid var(--drill);
  border-radius: 50%;
  content: "";
}

.mixed-option-mark::before {
  width: 33px;
  height: 33px;
}

.mixed-option-mark::after {
  width: 14px;
  height: 14px;
}

.mixed-option-mark span {
  width: 4px;
  height: 4px;
  background: var(--drill);
}

.mixed-option-copy {
  position: relative;
  z-index: 1;
  min-width: 0;
}

.mixed-option-copy h2,
.drill-explainer h2,
.empty-studied-state h2 {
  margin: 5px 0 8px;
  color: var(--text);
  font-family: var(--display-font);
  font-size: clamp(27px, 3vw, 36px);
  font-weight: 400;
  letter-spacing: -0.035em;
}

.mixed-option-copy > p:not(.drill-eyebrow) {
  max-width: 630px;
  margin: 0;
  color: #96aab6;
  font-size: 12px;
  line-height: 1.55;
}

.pool-family-list {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 15px;
}

.pool-family-chip {
  padding: 5px 8px;
  border: 1px solid rgba(65, 133, 160, 0.35);
  border-radius: 999px;
  background: rgba(2, 16, 29, 0.46);
  color: #8faab6;
  font-size: 9px;
}

.pool-family-chip strong {
  color: var(--drill-soft);
  font-weight: 650;
}

.mixed-option-action {
  position: relative;
  z-index: 1;
  display: grid;
  min-width: 190px;
  justify-items: end;
  gap: 2px;
}

.mixed-option-action > strong {
  color: var(--text);
  font-family: var(--display-font);
  font-size: 52px;
  font-weight: 400;
  letter-spacing: -0.04em;
  line-height: 1;
}

.mixed-option-action > span {
  margin-bottom: 15px;
  color: #7e96a4;
  font-size: 10px;
}

.drill-button {
  display: inline-flex;
  min-height: 42px;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 9px 15px;
  border: 1px solid rgba(56, 207, 208, 0.4);
  border-radius: 9px;
  background: rgba(5, 31, 46, 0.62);
  color: var(--text);
  cursor: pointer;
  font: inherit;
  font-size: 11px;
  font-weight: 650;
  text-decoration: none;
  transition: transform 140ms ease, border-color 140ms ease, background 140ms ease;
}

.drill-button.is-primary {
  border-color: rgba(100, 230, 222, 0.48);
  background: linear-gradient(135deg, #0f8a8e, #19789a);
  box-shadow: inset 0 1px 0 rgba(215, 255, 250, 0.14);
}

.drill-button.is-quiet {
  border-color: rgba(76, 115, 139, 0.38);
  background: transparent;
  color: #98aab4;
}

.drill-button:hover:not(:disabled) {
  transform: translateY(-1px);
  border-color: rgba(167, 235, 234, 0.72);
}

.drill-button:disabled {
  cursor: not-allowed;
  opacity: 0.42;
}

.drill-explainer {
  display: grid;
  grid-template-columns: minmax(210px, 0.7fr) minmax(0, 1.5fr);
  align-items: start;
  gap: 38px;
  padding: 25px 28px;
  border: 1px solid rgba(55, 103, 136, 0.34);
  border-radius: 14px;
  background: rgba(4, 17, 31, 0.58);
}

.drill-explainer h2 {
  margin-bottom: 0;
  font-size: 26px;
}

.drill-explainer ol {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.drill-explainer li {
  display: grid;
  grid-template-columns: 27px minmax(0, 1fr);
  gap: 9px;
}

.drill-explainer li > span {
  display: grid;
  width: 25px;
  height: 25px;
  place-items: center;
  border: 1px solid rgba(56, 207, 208, 0.38);
  border-radius: 50%;
  color: var(--drill-soft);
  font-family: var(--math-font);
  font-size: 10px;
}

.drill-explainer li p {
  margin: 0;
  color: #8499a6;
  font-size: 10px;
  line-height: 1.55;
}

.drill-explainer li strong {
  display: block;
  margin-bottom: 2px;
  color: #c9d6d9;
  font-size: 11px;
}

.empty-studied-state {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 25px;
  padding: 25px 28px;
  border: 1px dashed rgba(80, 128, 156, 0.5);
  border-radius: 14px;
  background: rgba(4, 17, 30, 0.44);
}

.empty-studied-state h2 {
  margin-bottom: 4px;
  font-size: 26px;
}

.empty-studied-state p:last-child {
  margin: 0;
  color: #8095a2;
  font-size: 11px;
}

.drill-state {
  display: grid;
  min-height: 430px;
  place-items: center;
  align-content: center;
  text-align: center;
}

.drill-state h1 {
  margin: 13px 0 5px;
  font-size: 38px;
}

.drill-state p {
  margin: 0;
  color: #8197a4;
  font-size: 12px;
}

.drill-state .drill-button {
  margin-top: 20px;
}

.drill-loading-mark {
  width: 34px;
  height: 34px;
  border: 2px solid rgba(56, 207, 208, 0.2);
  border-top-color: var(--drill);
  border-radius: 50%;
  animation: drill-spin 900ms linear infinite;
}

@keyframes drill-spin {
  to { transform: rotate(360deg); }
}

.drill-session {
  display: grid;
  gap: 22px;
}

.session-header {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 28px;
}

.session-header h1 {
  margin-bottom: 0;
  font-size: clamp(36px, 4.4vw, 56px);
}

.session-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(70px, 1fr));
  gap: 8px;
  margin: 0;
}

.session-stats div {
  display: grid;
  min-width: 78px;
  gap: 3px;
  padding: 10px 12px;
  border: 1px solid rgba(55, 103, 136, 0.34);
  border-radius: 9px;
  background: rgba(4, 18, 32, 0.65);
}

.session-stats dt {
  color: #718895;
  font-size: 8px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.session-stats dd {
  margin: 0;
  color: var(--text);
  font-size: 17px;
  font-weight: 650;
}

.question-card {
  overflow: hidden;
  border: 1px solid rgba(61, 126, 158, 0.48);
  border-radius: 17px;
  background: rgba(4, 19, 34, 0.9);
  box-shadow: 0 24px 64px rgba(0, 0, 0, 0.15);
}

.question-loading {
  display: flex;
  min-height: 380px;
  align-items: center;
  justify-content: center;
  gap: 15px;
  color: #93a8b3;
  font-size: 12px;
}

.question-error {
  display: flex;
  min-height: 260px;
  align-items: center;
  justify-content: space-between;
  gap: 28px;
  padding: 30px;
}

.question-error h2 {
  margin: 6px 0 5px;
  color: var(--text);
  font-size: 22px;
}

.question-error p:last-child {
  margin: 0;
  color: #879ca8;
  font-size: 11px;
}

.question-error > div:last-child {
  display: flex;
  gap: 9px;
}

.question-context {
  display: flex;
  min-height: 88px;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 19px 27px;
  border-bottom: 1px solid rgba(54, 104, 135, 0.3);
  background:
    linear-gradient(90deg, rgba(14, 67, 86, 0.42), rgba(4, 20, 35, 0.2)),
    rgba(4, 20, 35, 0.8);
}

.question-context h2 {
  margin: 4px 0 0;
  color: var(--text);
  font-size: 17px;
  font-weight: 650;
}

.difficulty-chip {
  padding: 6px 10px;
  border: 1px solid rgba(104, 222, 172, 0.38);
  border-radius: 999px;
  background: rgba(50, 126, 83, 0.13);
  color: #80dea2;
  font-size: 9px;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.difficulty-chip.is-medium {
  border-color: rgba(242, 176, 76, 0.38);
  background: rgba(141, 91, 25, 0.13);
  color: #f1b85b;
}

.difficulty-chip.is-hard {
  border-color: rgba(242, 105, 105, 0.42);
  background: rgba(141, 50, 50, 0.13);
  color: #f17878;
}

.question-body {
  max-width: 940px;
  margin: 0 auto;
  padding: 42px 38px 36px;
}

.question-prompt {
  margin: 10px 0 23px;
  color: #f0f4f1;
  font-family: var(--math-font);
  font-size: clamp(25px, 3.3vw, 39px);
  font-weight: 500;
  line-height: 1.4;
}

.answer-format {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 11px 13px;
  border-left: 2px solid rgba(56, 207, 208, 0.58);
  background: rgba(7, 35, 49, 0.45);
}

.answer-format span {
  color: #6f8b99;
  font-size: 9px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.answer-format strong {
  color: #b9c9ce;
  font-size: 11px;
  font-weight: 600;
}

.hint-disclosure {
  margin: 18px 0 0;
  border: 1px solid rgba(57, 111, 139, 0.3);
  border-radius: 9px;
  background: rgba(4, 18, 30, 0.42);
}

.hint-disclosure summary,
.worked-steps summary {
  padding: 11px 13px;
  color: var(--drill-soft);
  cursor: pointer;
  font-size: 11px;
  font-weight: 650;
  list-style: none;
}

.hint-disclosure summary::-webkit-details-marker,
.worked-steps summary::-webkit-details-marker {
  display: none;
}

.hint-disclosure summary::before,
.worked-steps summary::before {
  display: inline-block;
  width: 16px;
  content: "+";
}

.hint-disclosure[open] summary::before,
.worked-steps[open] summary::before {
  content: "−";
}

.hint-disclosure ol {
  display: grid;
  gap: 8px;
  margin: 0;
  padding: 3px 35px 17px 44px;
  color: #99acb5;
  font-size: 11px;
  line-height: 1.55;
}

.drill-answer-form {
  display: grid;
  gap: 8px;
  margin-top: 25px;
}

.drill-answer-form label {
  color: #aebdc2;
  font-size: 11px;
  font-weight: 650;
}

.answer-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px;
}

.answer-row input {
  min-width: 0;
  min-height: 48px;
  padding: 10px 13px;
  border: 1px solid rgba(70, 119, 146, 0.55);
  border-radius: 9px;
  outline: none;
  background: rgba(1, 11, 21, 0.72);
  color: var(--text);
  font-family: var(--math-font);
  font-size: 18px;
}

.answer-row input:focus {
  border-color: rgba(56, 207, 208, 0.72);
  box-shadow: 0 0 0 2px rgba(56, 207, 208, 0.08);
}

.answer-feedback {
  min-height: 22px;
  margin: 10px 0 0;
  color: #f0a46f;
  font-size: 11px;
  line-height: 1.5;
}

.answer-feedback.is-correct {
  color: #70df96;
}

.worked-feedback {
  margin-top: 18px;
  padding: 20px;
  border: 1px solid rgba(85, 205, 126, 0.35);
  border-radius: 11px;
  background: linear-gradient(135deg, rgba(24, 86, 54, 0.22), rgba(5, 30, 29, 0.34));
}

.worked-heading {
  display: flex;
  align-items: center;
  gap: 12px;
}

.worked-heading > span {
  display: grid;
  width: 34px;
  height: 34px;
  flex: 0 0 auto;
  place-items: center;
  border: 1px solid rgba(100, 224, 140, 0.5);
  border-radius: 50%;
  color: #6ee095;
}

.worked-heading p {
  margin: 0 0 2px;
  color: #6ee095;
  font-size: 8px;
  font-weight: 700;
  letter-spacing: 0.08em;
}

.worked-heading h3 {
  margin: 0;
  color: var(--text);
  font-size: 16px;
}

.worked-answer {
  margin: 18px 0 8px;
  color: #86e5a4;
  font-family: var(--math-font);
  font-size: 21px;
  font-weight: 600;
}

.worked-feedback > p:not(.worked-answer) {
  margin: 0;
  color: #a6b9b8;
  font-size: 11px;
  line-height: 1.6;
}

.worked-steps {
  margin-top: 14px;
  border-top: 1px solid rgba(95, 179, 123, 0.22);
}

.worked-steps summary {
  padding-inline: 0;
  color: #83d99d;
}

.worked-step {
  padding: 13px 0;
  border-top: 1px solid rgba(86, 151, 109, 0.18);
}

.worked-step h4 {
  margin: 0 0 5px;
  color: #d5e0dc;
  font-size: 12px;
}

.worked-step p {
  margin: 0;
  color: #94aaa6;
  font-size: 11px;
  line-height: 1.6;
}

.question-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 27px;
  border-top: 1px solid rgba(54, 104, 135, 0.3);
  background: rgba(3, 15, 27, 0.7);
}

.drill-text-link {
  margin-right: auto;
  color: #75cbd3;
  font-size: 10px;
  text-decoration: none;
}

.drill-text-link:hover {
  color: var(--drill-soft);
  text-decoration: underline;
}

.drill-button:focus-visible,
.drill-text-link:focus-visible,
.hint-disclosure summary:focus-visible,
.worked-steps summary:focus-visible {
  outline: 2px solid var(--drill-soft);
  outline-offset: 3px;
}

@media (max-width: 1050px) {
  .mixed-option-card {
    grid-template-columns: 70px minmax(0, 1fr);
  }

  .mixed-option-action {
    grid-column: 2;
    grid-template-columns: auto auto minmax(170px, auto);
    align-items: center;
    justify-items: start;
    gap: 8px;
  }

  .mixed-option-action > strong {
    font-size: 30px;
  }

  .mixed-option-action > span {
    margin: 0 10px 0 0;
  }

  .drill-explainer {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .session-header {
    display: grid;
  }
}

@media (max-width: 780px) {
  .drill-main {
    padding: 28px 22px 90px;
  }

  .mixed-option-card {
    grid-template-columns: 1fr;
    padding: 25px;
  }

  .mixed-option-mark {
    width: 60px;
    height: 60px;
  }

  .mixed-option-action {
    grid-column: auto;
  }

  .drill-explainer ol {
    grid-template-columns: 1fr;
  }

  .empty-studied-state {
    display: grid;
  }

  .session-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .question-body {
    padding: 30px 23px;
  }
}

@media (max-width: 520px) {
  .drill-main {
    padding: 24px 13px 92px;
  }

  .drill-hero-copy h1 {
    font-size: 44px;
  }

  .mixed-option-card {
    padding: 22px 19px;
  }

  .mixed-option-action {
    grid-template-columns: auto 1fr;
  }

  .mixed-option-action .drill-button {
    grid-column: 1 / -1;
    width: 100%;
  }

  .question-context {
    align-items: start;
    padding: 17px;
  }

  .question-error {
    display: grid;
    padding: 22px;
  }

  .question-error > div:last-child {
    display: grid;
  }

  .question-body {
    padding: 26px 17px;
  }

  .question-prompt {
    font-size: 25px;
  }

  .answer-format {
    display: grid;
  }

  .answer-row {
    grid-template-columns: 1fr;
  }

  .answer-row .drill-button {
    width: 100%;
  }

  .question-actions {
    display: grid;
    grid-template-columns: 1fr;
    padding: 15px 17px;
  }

  .question-actions .drill-button {
    width: 100%;
  }

  .drill-text-link {
    margin: 0 0 4px;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  .drill-button {
    transition: none;
  }

  .drill-loading-mark {
    animation: none;
  }
}