/* EIKEN-012: grade-specific learning player shared by six roadmap pages. */
.er-lab {
  --er-accent: #1769d2;
  --er-accent-strong: #0b4fa3;
  --er-accent-soft: #edf5ff;
  --er-ink: #14243a;
  --er-muted: #55657a;
  --er-line: #d8e2ee;
  --er-surface: #fff;
  --er-canvas: #f6f9fc;
  --er-success: #0b7a55;
  --er-success-soft: #eaf8f2;
  --er-error: #b4233a;
  --er-error-soft: #fff0f2;
  margin: 1.25rem 0 2.5rem;
  color: var(--er-ink);
  font-size: 1rem;
}

.g5-page .er-lab {
  --er-accent: #1769d2;
  --er-accent-strong: #0b4fa3;
  --er-accent-soft: #edf5ff;
}

.g4-page .er-lab {
  --er-accent: #087d73;
  --er-accent-strong: #065f58;
  --er-accent-soft: #eaf8f6;
}

.grade3-page .er-lab {
  --er-accent: #7c4cc9;
  --er-accent-strong: #5f35a8;
  --er-accent-soft: #f4effc;
}

.pre2-page .er-lab {
  --er-accent: #b35b0b;
  --er-accent-strong: #884306;
  --er-accent-soft: #fff4e8;
}

.grade2-page .er-lab {
  --er-accent: #b33b63;
  --er-accent-strong: #8f264b;
  --er-accent-soft: #fff0f5;
}

.pre1-page .er-lab {
  --er-accent: #3548a8;
  --er-accent-strong: #243486;
  --er-accent-soft: #eef0ff;
}

.er-lab *,
.er-lab *::before,
.er-lab *::after {
  box-sizing: border-box;
}

.er-lab h2,
.er-lab h3,
.er-lab p {
  margin-top: 0;
}

.er-lab a {
  color: var(--er-accent-strong);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.2em;
}

.er-lab-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(17rem, 0.55fr);
  gap: clamp(1.25rem, 3vw, 2.5rem);
  overflow: hidden;
  padding: clamp(1.5rem, 4vw, 3rem);
  border: 1px solid color-mix(in srgb, var(--er-accent) 24%, #dbe5ef);
  border-radius: 1.5rem;
  background:
    radial-gradient(circle at 92% 2%, color-mix(in srgb, var(--er-accent) 17%, transparent) 0, transparent 35%),
    linear-gradient(135deg, #fff 0%, var(--er-accent-soft) 100%);
  box-shadow: 0 1.25rem 3.5rem rgba(26, 47, 78, 0.09);
}

.er-lab-hero::before {
  position: absolute;
  inset: 0 auto 0 0;
  width: 0.35rem;
  background: linear-gradient(180deg, var(--er-accent), var(--er-accent-strong));
  content: "";
}

.er-lab-hero__copy {
  position: relative;
  z-index: 1;
  align-self: center;
}

.er-lab-eyebrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1.25rem;
}

.er-lab-eyebrow span {
  display: inline-flex;
  align-items: center;
  min-height: 1.9rem;
  padding: 0.25rem 0.72rem;
  border: 1px solid color-mix(in srgb, var(--er-accent) 22%, #d4dfeb);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--er-accent-strong);
  font-size: 0.76rem;
  font-weight: 750;
  letter-spacing: 0.02em;
}

.er-lab-overline,
.er-lab-kicker {
  margin-bottom: 0.55rem;
  color: var(--er-accent-strong);
  font-size: 0.74rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.er-lab-hero h2 {
  max-width: 18em;
  margin-bottom: 0.8rem;
  font-size: clamp(1.55rem, 3vw, 2.35rem);
  font-weight: 780;
  line-height: 1.3;
  letter-spacing: -0.025em;
}

.er-lab-lead {
  max-width: 48rem;
  margin-bottom: 0;
  color: var(--er-muted);
  font-size: clamp(0.98rem, 1.5vw, 1.08rem);
  line-height: 1.85;
}

.er-lab-status {
  position: relative;
  z-index: 1;
  align-self: stretch;
  padding: 1.25rem;
  border: 1px solid rgba(255, 255, 255, 0.85);
  border-radius: 1.1rem;
  background: rgba(255, 255, 255, 0.88);
  box-shadow: 0 0.8rem 2rem rgba(26, 47, 78, 0.08);
  backdrop-filter: blur(10px);
}

.er-lab-status__top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.8rem;
}

.er-lab-status__top span {
  color: var(--er-muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.er-lab-status__top strong {
  color: var(--er-accent-strong);
  font-size: 1.55rem;
  line-height: 1;
}

.er-lab-progress {
  overflow: hidden;
  width: 100%;
  height: 0.55rem;
  border-radius: 999px;
  background: #e5ebf2;
}

.er-lab-progress > span {
  display: block;
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--er-accent), var(--er-accent-strong));
  transition: width 220ms ease;
}

.er-lab-status > p {
  min-height: 2.8em;
  margin: 0.75rem 0 1rem;
  color: var(--er-muted);
  font-size: 0.82rem;
  line-height: 1.65;
}

.er-lab-history {
  display: flex;
  align-items: flex-start;
  gap: 0.55rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--er-line);
  color: var(--er-muted);
  font-size: 0.8rem;
  line-height: 1.55;
}

.er-lab-history i {
  margin-top: 0.1rem;
  color: var(--er-accent);
  font-size: 1rem;
}

.er-lab-boundary {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9rem;
  margin: 1rem 0 0;
  padding: 1rem 1.15rem;
  border: 1px solid var(--er-line);
  border-radius: 1rem;
  background: var(--er-surface);
}

.er-lab-boundary > i {
  display: grid;
  place-items: center;
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 0.65rem;
  background: var(--er-accent-soft);
  color: var(--er-accent-strong);
}

.er-lab-boundary strong {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.92rem;
}

.er-lab-boundary p {
  margin-bottom: 0.25rem;
  color: var(--er-muted);
  font-size: 0.82rem;
  line-height: 1.65;
}

.er-lab-boundary a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin-top: 0.2rem;
  font-size: 0.82rem;
  font-weight: 700;
}

.er-lab-section-head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(16rem, 0.65fr);
  align-items: end;
  gap: 1.5rem;
  margin: clamp(2.25rem, 5vw, 3.5rem) 0 1.2rem;
}

.er-lab-section-head h2 {
  margin-bottom: 0;
  font-size: clamp(1.3rem, 2vw, 1.72rem);
  font-weight: 760;
  line-height: 1.4;
  letter-spacing: -0.015em;
}

.er-lab-section-head > p {
  margin-bottom: 0;
  color: var(--er-muted);
  font-size: 0.88rem;
  line-height: 1.7;
}

.er-lab-steps {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0.85rem;
}

.er-lab-step {
  position: relative;
  display: flex;
  min-width: 0;
  min-height: 15rem;
  padding: 1.1rem;
  border: 1px solid var(--er-line);
  border-radius: 1.15rem;
  background: var(--er-surface);
  box-shadow: 0 0.45rem 1.4rem rgba(26, 47, 78, 0.045);
  transition: border-color 160ms ease, transform 160ms ease, box-shadow 160ms ease;
}

.er-lab-step:hover {
  border-color: color-mix(in srgb, var(--er-accent) 45%, var(--er-line));
  box-shadow: 0 0.8rem 1.8rem rgba(26, 47, 78, 0.08);
  transform: translateY(-2px);
}

.er-lab-step.is-complete {
  border-color: color-mix(in srgb, var(--er-success) 40%, var(--er-line));
  background: linear-gradient(160deg, #fff 55%, var(--er-success-soft));
}

.er-lab-step__check {
  flex: 0 0 auto;
  cursor: pointer;
}

.er-lab-step__check input {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

.er-lab-step__number {
  display: grid;
  place-items: center;
  width: 2.35rem;
  height: 2.35rem;
  margin-right: 0.8rem;
  border: 1px solid color-mix(in srgb, var(--er-accent) 35%, var(--er-line));
  border-radius: 0.8rem;
  background: var(--er-accent-soft);
  color: var(--er-accent-strong);
  font-size: 0.74rem;
  font-weight: 800;
  transition: background 160ms ease, color 160ms ease;
}

.er-lab-step__check input:checked + .er-lab-step__number {
  background: var(--er-success);
  color: #fff;
}

.er-lab-step__check input:focus-visible + .er-lab-step__number {
  outline: 3px solid color-mix(in srgb, var(--er-accent) 35%, transparent);
  outline-offset: 3px;
}

.er-lab-step__body {
  display: flex;
  min-width: 0;
  flex: 1;
  flex-direction: column;
}

.er-lab-step h3 {
  margin-bottom: 0.55rem;
  font-size: 1rem;
  font-weight: 750;
  line-height: 1.5;
}

.er-lab-step p {
  margin-bottom: 1rem;
  color: var(--er-muted);
  font-size: 0.83rem;
  line-height: 1.7;
}

.er-lab-link {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.45rem;
  margin-top: auto;
  padding-top: 0.75rem;
  border-top: 1px solid var(--er-line);
  font-size: 0.82rem;
  font-weight: 750;
  text-decoration: none !important;
}

.er-lab-practice {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1rem;
  align-items: start;
}

.er-lab-question {
  min-width: 0;
  padding: clamp(1.1rem, 2vw, 1.4rem);
  border: 1px solid var(--er-line);
  border-radius: 1.15rem;
  background: var(--er-surface);
  box-shadow: 0 0.45rem 1.4rem rgba(26, 47, 78, 0.045);
}

.er-lab-question.is-correct {
  border-color: color-mix(in srgb, var(--er-success) 48%, var(--er-line));
}

.er-lab-question.is-incorrect {
  border-color: color-mix(in srgb, var(--er-error) 42%, var(--er-line));
}

.er-lab-question__meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.85rem;
  color: var(--er-muted);
  font-size: 0.69rem;
  letter-spacing: 0.08em;
}

.er-lab-question__meta strong {
  padding: 0.22rem 0.55rem;
  border-radius: 999px;
  background: var(--er-accent-soft);
  color: var(--er-accent-strong);
  font-size: 0.72rem;
  letter-spacing: 0;
}

.er-lab-question h3 {
  margin-bottom: 0.55rem;
  font-size: 1.05rem;
  font-weight: 750;
  line-height: 1.65;
}

.er-lab-question__instruction {
  margin-bottom: 1rem;
  color: var(--er-muted);
  font-size: 0.82rem;
  line-height: 1.6;
}

.er-lab-options {
  display: grid;
  gap: 0.55rem;
}

.er-lab-option {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: center;
  gap: 0.7rem;
  width: 100%;
  min-height: 3rem;
  padding: 0.6rem 0.75rem;
  border: 1px solid var(--er-line);
  border-radius: 0.8rem;
  background: #fff;
  color: var(--er-ink);
  text-align: left;
  transition: background 140ms ease, border-color 140ms ease, transform 140ms ease;
}

.er-lab-option:hover:not(:disabled) {
  border-color: var(--er-accent);
  background: var(--er-accent-soft);
  transform: translateX(2px);
}

.er-lab-option:focus-visible,
.er-lab-model-toggle:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--er-accent) 34%, transparent);
  outline-offset: 2px;
}

.er-lab-option:disabled {
  cursor: default;
  opacity: 1;
}

.er-lab-option__mark {
  display: grid;
  place-items: center;
  width: 1.65rem;
  height: 1.65rem;
  border-radius: 0.5rem;
  background: var(--er-canvas);
  color: var(--er-muted);
  font-size: 0.7rem;
  font-weight: 800;
}

.er-lab-option.is-selected {
  border-color: var(--er-accent);
  background: var(--er-accent-soft);
}

.er-lab-option.is-correct {
  border-color: var(--er-success);
  background: var(--er-success-soft);
}

.er-lab-option.is-correct .er-lab-option__mark {
  background: var(--er-success);
  color: #fff;
}

.er-lab-option.is-incorrect {
  border-color: var(--er-error);
  background: var(--er-error-soft);
}

.er-lab-option.is-incorrect .er-lab-option__mark {
  background: var(--er-error);
  color: #fff;
}

.er-lab-feedback {
  margin-top: 0.9rem;
  padding: 0.85rem;
  border-radius: 0.8rem;
  background: var(--er-canvas);
}

.er-lab-question.is-correct .er-lab-feedback {
  background: var(--er-success-soft);
}

.er-lab-question.is-incorrect .er-lab-feedback {
  background: var(--er-error-soft);
}

.er-lab-feedback strong {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.86rem;
}

.er-lab-feedback p {
  margin-bottom: 0.45rem;
  color: var(--er-muted);
  font-size: 0.8rem;
  line-height: 1.65;
}

.er-lab-feedback a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.78rem;
  font-weight: 750;
}

.er-lab-audio {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.75rem;
  margin-bottom: 1rem;
  padding: 0.85rem;
  border-radius: 0.9rem;
  background: linear-gradient(135deg, var(--er-accent-soft), #fff);
}

.er-lab-audio__icon {
  display: grid;
  place-items: center;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 50%;
  background: var(--er-accent);
  color: #fff;
}

.er-lab-audio__player {
  min-width: 0;
}

.er-lab-audio__player > span {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--er-accent-strong);
  font-size: 0.73rem;
  font-weight: 750;
}

.er-lab-audio audio {
  display: block;
  width: 100%;
  height: 2.35rem;
}

.er-lab-transcript {
  margin-top: 0.45rem;
  color: var(--er-muted);
  font-size: 0.75rem;
}

.er-lab-transcript summary {
  cursor: pointer;
}

.er-lab-transcript p {
  margin: 0.35rem 0 0;
  color: var(--er-ink);
  font-size: 0.8rem;
}

.er-lab-output {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(16rem, 0.8fr);
  gap: 1rem 1.5rem;
  margin-top: 1rem;
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid color-mix(in srgb, var(--er-accent) 30%, var(--er-line));
  border-radius: 1.2rem;
  background: linear-gradient(140deg, var(--er-accent-soft), #fff 65%);
}

.er-lab-output__intro h3 {
  margin-bottom: 0.45rem;
  font-size: 1.2rem;
  font-weight: 760;
}

.er-lab-output__intro p {
  margin-bottom: 0;
  color: var(--er-muted);
  line-height: 1.75;
}

.er-lab-frame {
  align-self: center;
  padding: 1rem;
  border: 1px solid rgba(255, 255, 255, 0.9);
  border-radius: 0.9rem;
  background: rgba(255, 255, 255, 0.86);
}

.er-lab-frame > span,
.er-lab-model span {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--er-accent-strong);
  font-size: 0.69rem;
  font-weight: 800;
  letter-spacing: 0.08em;
}

.er-lab-frame p {
  margin-bottom: 0;
  font-weight: 700;
  line-height: 1.6;
}

.er-lab-model-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  width: max-content;
  max-width: 100%;
  padding: 0.72rem 0;
  border: 0;
  border-bottom: 1px solid var(--er-accent);
  background: transparent;
  color: var(--er-accent-strong);
  font-weight: 750;
}

.er-lab-model-toggle i {
  transition: transform 160ms ease;
}

.er-lab-model-toggle[aria-expanded="true"] i {
  transform: rotate(180deg);
}

.er-lab-model {
  display: grid;
  grid-column: 1 / -1;
  grid-template-columns: minmax(0, 1fr) minmax(14rem, 0.7fr);
  gap: 1rem;
  padding-top: 1rem;
  border-top: 1px solid color-mix(in srgb, var(--er-accent) 24%, var(--er-line));
}

.er-lab-model[hidden] {
  display: none;
}

.er-lab-model p {
  margin-bottom: 0;
  font-size: 1.02rem;
  font-weight: 700;
  line-height: 1.7;
}

.er-lab-model ul {
  display: grid;
  gap: 0.35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.er-lab-model li {
  display: flex;
  align-items: flex-start;
  gap: 0.4rem;
  color: var(--er-muted);
  font-size: 0.8rem;
  line-height: 1.55;
}

.er-lab-model li i {
  color: var(--er-success);
}

.er-lab-result {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: 1.25rem;
  margin-top: 1rem;
  padding: 1.1rem 1.25rem;
  border: 1px solid var(--er-line);
  border-radius: 1rem;
  background: var(--er-surface);
}

.er-lab-result.is-complete {
  border-color: color-mix(in srgb, var(--er-success) 38%, var(--er-line));
  background: linear-gradient(130deg, var(--er-success-soft), #fff 65%);
}

.er-lab-result__score {
  min-width: 5.6rem;
  padding-right: 1.15rem;
  border-right: 1px solid var(--er-line);
  text-align: center;
}

.er-lab-result__score > span {
  display: block;
  color: var(--er-muted);
  font-size: 0.7rem;
}

.er-lab-result__score strong {
  color: var(--er-accent-strong);
  font-size: 1.45rem;
}

.er-lab-result h3 {
  margin-bottom: 0.2rem;
  font-size: 1rem;
  font-weight: 760;
}

.er-lab-result p {
  margin-bottom: 0;
  color: var(--er-muted);
  font-size: 0.82rem;
  line-height: 1.55;
}

.er-lab-result__link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.7rem 0;
  font-size: 0.82rem;
  font-weight: 750;
  text-decoration: none !important;
}

.er-lab-result__actions {
  display: grid;
  justify-items: end;
  gap: 0.25rem;
}

.er-lab-reset {
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--er-muted);
  font-size: 0.7rem;
  text-decoration: underline;
  text-underline-offset: 0.2em;
}

.er-lab-reset:hover {
  color: var(--er-accent-strong);
}

@media (max-width: 991.98px) {
  .er-lab-hero {
    grid-template-columns: minmax(0, 1fr);
  }

  .er-lab-status {
    max-width: none;
  }

  .er-lab-steps,
  .er-lab-practice {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .er-lab-practice .er-lab-question:last-child {
    grid-column: 1 / -1;
  }
}

@media (max-width: 767.98px) {
  .er-lab {
    margin-top: 1rem;
  }

  .er-lab-hero {
    padding: 1.25rem;
    border-radius: 1.15rem;
  }

  .er-lab-section-head,
  .er-lab-output {
    grid-template-columns: minmax(0, 1fr);
  }

  .er-lab-section-head {
    align-items: start;
    gap: 0.5rem;
  }

  .er-lab-model {
    grid-template-columns: minmax(0, 1fr);
  }

  .er-lab-result {
    grid-template-columns: auto minmax(0, 1fr);
  }

  .er-lab-result__actions {
    grid-column: 1 / -1;
    justify-items: end;
    padding-top: 0.4rem;
    border-top: 1px solid var(--er-line);
  }
}

@media (max-width: 575.98px) {
  .er-lab-eyebrow {
    margin-bottom: 1rem;
  }

  .er-lab-eyebrow span {
    font-size: 0.7rem;
  }

  .er-lab-hero h2 {
    font-size: 1.45rem;
  }

  .er-lab-steps,
  .er-lab-practice {
    grid-template-columns: minmax(0, 1fr);
  }

  .er-lab-practice .er-lab-question:last-child {
    grid-column: auto;
  }

  .er-lab-step {
    min-height: 0;
  }

  .er-lab-boundary {
    grid-template-columns: minmax(0, 1fr);
  }

  .er-lab-boundary > i {
    width: 1.9rem;
    height: 1.9rem;
  }

  .er-lab-output {
    padding: 1.1rem;
  }

  .er-lab-result {
    grid-template-columns: minmax(0, 1fr);
  }

  .er-lab-result__score {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    padding: 0 0 0.75rem;
    border-right: 0;
    border-bottom: 1px solid var(--er-line);
    text-align: left;
  }

  .er-lab-result__actions {
    grid-column: auto;
  }
}

@media (prefers-reduced-motion: reduce) {
  .er-lab *,
  .er-lab *::before,
  .er-lab *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}