.lesson-2-hero h1 span {
  display: block;
  margin-top: 8px;
  font-size: clamp(1.65rem, 4vw, 3.5rem);
}

.zh-copy {
  color: var(--muted);
}

.compact-header {
  margin-bottom: 14px;
}

.muted-text {
  color: var(--muted);
}

.assistant-journey {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 10px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.journey-step {
  display: grid;
  gap: 8px;
  min-width: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
  color: var(--muted);
}

.journey-step strong {
  color: var(--ink);
  line-height: 1.2;
}

.journey-step span:last-child {
  font-size: 0.88rem;
  font-weight: 750;
}

.journey-number {
  display: inline-grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: var(--radius);
  background: #f1f5f9;
  color: #334155;
  font-weight: 900;
}

.journey-step.is-previous {
  border-color: #b8e8d8;
  background: #f4fbf8;
}

.journey-step.is-current {
  border-color: var(--blue);
  background: #edf4ff;
  box-shadow: 0 10px 24px rgba(36, 107, 253, 0.12);
}

.journey-step.is-current .journey-number {
  background: var(--blue);
  color: #ffffff;
}

.lesson-story {
  max-width: 900px;
}

.example-pair {
  display: grid;
  gap: 8px;
  margin: 18px 0;
  padding: 14px 16px;
  border-left: 6px solid var(--yellow);
  border-radius: var(--radius);
  background: #fffaf0;
}

.example-pair blockquote,
.example-pair p {
  margin: 0;
}

.example-pair blockquote {
  color: var(--ink);
  font-size: 1.12rem;
  font-weight: 900;
}

.lesson-points {
  display: grid;
  gap: 13px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.lesson-points li {
  display: grid;
  gap: 4px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

.lesson-points li:last-child {
  padding-bottom: 0;
  border-bottom: 0;
}

.lesson-points span {
  color: var(--muted);
}

.keyword-card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.keyword-card {
  min-width: 0;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfdff;
}

.keyword-card h3,
.keyword-card p {
  margin: 0;
}

.keyword-card h3 {
  margin-bottom: 8px;
  font-size: 1.05rem;
}

.keyword-card p {
  color: var(--muted);
}

.human-challenge,
.intent-demo,
.setup-panel,
.classifier-panel {
  min-width: 0;
}

.human-challenge {
  display: grid;
  gap: 18px;
}

.intent-category-note {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 8px;
}

.intent-category-note span {
  display: grid;
  gap: 2px;
  min-width: 0;
  min-height: 52px;
  padding: 8px 10px;
  border-radius: var(--radius);
  background: #eef8f5;
  color: #0f6953;
  font-size: 0.9rem;
  font-weight: 850;
}

.intent-category-note strong,
.intent-category-note small {
  min-width: 0;
}

.intent-category-note strong {
  color: #0c5746;
  line-height: 1.2;
}

.intent-category-note small {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 750;
  line-height: 1.25;
}

.challenge-board {
  display: grid;
  grid-template-columns: minmax(240px, 0.7fr) minmax(0, 1.3fr);
  gap: 18px;
  align-items: start;
}

.challenge-message {
  margin: 0;
  padding: 18px;
  border: 1px solid #bfd1e7;
  border-radius: var(--radius);
  background: #edf4ff;
  font-size: clamp(1.2rem, 2vw, 1.55rem);
  font-weight: 900;
  line-height: 1.28;
}

.intent-button-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.intent-choice,
.preset-button,
.suggestion-button {
  min-height: 48px;
  border: 2px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
  color: var(--ink);
  font: inherit;
  font-weight: 850;
  cursor: pointer;
  transition:
    background-color 160ms ease,
    border-color 160ms ease,
    box-shadow 160ms ease;
}

.intent-choice {
  position: relative;
  display: grid;
  gap: 4px;
  padding: 12px 14px;
  text-align: left;
}

.intent-choice span:last-child {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 750;
}

.intent-choice-desc {
  color: #0f6953;
  font-size: 0.86rem;
  font-weight: 800;
  line-height: 1.25;
}

.intent-choice[aria-pressed="true"] {
  border-color: var(--blue);
  background: #edf4ff;
  box-shadow: 0 8px 18px rgba(36, 107, 253, 0.12);
}

.intent-choice.is-correct {
  border-color: #16a34a;
  background: #eafaf0;
}

.intent-choice.is-incorrect {
  border-color: #ffc8c3;
  background: #fff6f5;
}

.intent-choice:hover,
.intent-choice:focus-visible,
.preset-button:hover,
.preset-button:focus-visible,
.preset-button.is-selected,
.suggestion-button:hover,
.suggestion-button:focus-visible {
  border-color: var(--blue);
  background: #edf4ff;
}

.challenge-feedback {
  min-height: 0;
  margin: 0;
}

.challenge-feedback:not(:empty) {
  padding: 14px 16px;
  border-left: 6px solid var(--teal);
  border-radius: var(--radius);
  background: #f4fbf8;
  font-weight: 800;
}

.challenge-feedback.is-wrong:not(:empty) {
  border-left-color: var(--coral);
  background: #fff6f5;
}

.challenge-actions,
.chat-actions,
.suggestion-list,
.comparison-actions,
.promo-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
}

.intent-demo {
  display: grid;
  gap: 24px;
}

.intent-demo .section-header {
  margin-bottom: 0;
}

.privacy-note,
.demo-disclaimer {
  border-left: 6px solid var(--coral);
  border-radius: var(--radius);
  background: #fff6f5;
  padding: 15px 17px;
}

.privacy-note p,
.demo-disclaimer p {
  margin: 0;
}

.privacy-note p + p,
.demo-disclaimer p + p {
  margin-top: 8px;
}

.intent-demo-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.95fr) minmax(340px, 1.05fr);
  gap: 22px;
  align-items: start;
}

.setup-panel,
.classifier-panel {
  display: grid;
  gap: 20px;
  background: linear-gradient(180deg, #ffffff 0%, #fbfdff 100%);
}

.panel-heading {
  display: grid;
  gap: 7px;
}

.panel-heading h3,
.panel-heading p,
.setup-fields > p {
  margin: 0;
}

.panel-heading > p:last-child {
  color: var(--muted);
}

.step-label,
.chat-kicker {
  margin: 0;
  color: #0f6953;
  font-size: 0.78rem;
  font-weight: 900;
  letter-spacing: 0.08em;
  line-height: 1.2;
  text-transform: uppercase;
}

.setup-fields {
  display: grid;
  gap: 18px;
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.preset-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.preset-list .preset-button:last-child:nth-child(odd) {
  grid-column: 1 / -1;
}

.preset-button {
  position: relative;
  display: grid;
  gap: 3px;
  min-height: 82px;
  padding: 14px 40px 14px 14px;
  text-align: left;
}

.preset-button::after {
  position: absolute;
  top: 16px;
  right: 14px;
  width: 14px;
  height: 14px;
  border: 2px solid #b7c8dc;
  border-radius: 999px;
  background: #ffffff;
  box-shadow: inset 0 0 0 3px #ffffff;
  content: "";
}

.preset-button.is-selected::after {
  border-color: #174dcc;
  background: #174dcc;
}

.preset-title,
.preset-note {
  display: block;
}

.preset-title {
  line-height: 1.2;
}

.preset-note {
  color: var(--muted);
  font-size: 0.88rem;
  font-weight: 700;
  line-height: 1.35;
}

.chat-field,
.chat-input-row,
.suggestion-panel {
  display: grid;
  gap: 8px;
}

.chat-field label,
.chat-label {
  margin: 0;
  font-weight: 900;
  line-height: 1.25;
}

.field-help {
  margin: 0;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.45;
}

.chat-field textarea,
.chat-input-row textarea {
  width: 100%;
  border: 2px solid #cbd8e7;
  border-radius: var(--radius);
  background: #ffffff;
  color: var(--ink);
  font: inherit;
  line-height: 1.45;
  padding: 12px 14px;
  resize: vertical;
  transition:
    border-color 160ms ease,
    box-shadow 160ms ease,
    background-color 160ms ease;
}

.chat-field textarea:focus-visible,
.chat-input-row textarea:focus-visible {
  outline: none;
  border-color: var(--blue);
  background: #ffffff;
  box-shadow: 0 0 0 4px rgba(36, 107, 253, 0.16);
}

.char-count {
  margin: 0;
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 750;
}

.char-count.is-low {
  color: var(--danger);
}

.chat-window-header {
  display: flex;
  align-items: center;
  gap: 12px;
}

.chat-window-header > div:nth-child(2) {
  min-width: 0;
}

.byte-avatar {
  display: grid;
  width: 52px;
  height: 52px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: var(--radius);
  background: var(--ink);
  color: #ffffff;
  font-weight: 900;
}

.chat-window-header h3,
.chat-window-header p {
  margin: 0;
}

.chat-window-header p {
  color: var(--muted);
}

.chat-status {
  display: inline-flex;
  min-height: 34px;
  align-items: center;
  justify-content: center;
  margin-left: auto;
  padding: 6px 10px;
  border-radius: 999px;
  background: #eef8f5;
  color: #0f6953;
  font-size: 0.84rem;
  font-weight: 900;
  white-space: nowrap;
}

.typing-indicator {
  width: fit-content;
  min-height: 32px;
  margin: 0;
  padding: 5px 10px;
  border-radius: 999px;
  background: #f1f5f9;
  color: var(--muted);
  font-weight: 800;
}

.chat-error {
  margin: 0;
  color: var(--danger);
  font-weight: 850;
}

.chat-error:not(:empty) {
  min-height: 44px;
  padding: 9px 12px;
  border: 1px solid #ffc8c3;
  border-radius: var(--radius);
  background: #fff2f1;
}

.chat-actions .button:disabled {
  opacity: 0.58;
  cursor: not-allowed;
  box-shadow: none;
}

.preset-button:disabled,
.suggestion-button:disabled {
  cursor: wait;
  opacity: 0.7;
}

.intent-choice:disabled {
  cursor: default;
}

.suggestion-button {
  padding: 10px 14px;
  text-align: left;
}

.rule-test {
  display: grid;
  gap: 2px;
}

.rule-test span:first-child {
  color: var(--danger);
  font-size: 0.82rem;
  font-weight: 900;
}

.rule-test span:last-child {
  color: var(--ink);
}

.intent-result-card {
  display: grid;
  gap: 16px;
  padding: 16px;
  border: 1px solid #bfd1e7;
  border-radius: var(--radius);
  background: #f7fbff;
}

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

.intent-badge {
  display: grid;
  width: 52px;
  height: 52px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: var(--radius);
  background: var(--ink);
  color: #ffffff;
  font-size: 0.86rem;
  font-weight: 900;
}

.intent-badge.intent-question {
  background: var(--blue);
}

.intent-badge.intent-recommendation {
  background: var(--teal);
}

.intent-badge.intent-reminder {
  background: var(--violet);
}

.intent-badge.intent-plan {
  background: #9a5a00;
}

.intent-badge.intent-preference {
  background: #0f6953;
}

.intent-badge.intent-other {
  background: #334155;
}

.result-heading h3,
.result-detail h4,
.result-detail p {
  margin: 0;
}

.result-detail {
  display: grid;
  gap: 4px;
}

.result-detail h4 {
  font-size: 1rem;
}

.result-detail p {
  color: var(--muted);
}

.instruction-demo {
  display: grid;
  gap: 14px;
}

.instruction-compare {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.instruction-compare article {
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #fbfdff;
}

.instruction-compare h3,
.instruction-compare p {
  margin: 0;
}

.instruction-compare p + p {
  margin-top: 8px;
}

.comparison-panel {
  display: grid;
  gap: 12px;
}

.comparison-panel[hidden],
.intent-result-card[hidden] {
  display: none;
}

.comparison-feedback {
  margin: 0;
  color: var(--muted);
  font-weight: 800;
}

.comparison-feedback:not(:empty) {
  padding: 12px 14px;
  border-radius: var(--radius);
  background: #eef8f5;
  color: #0f6953;
}

.routing-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.routing-grid article {
  display: grid;
  gap: 8px;
  padding: 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #ffffff;
}

.routing-grid strong,
.routing-grid span {
  min-width: 0;
}

.routing-grid span {
  color: #174dcc;
  font-weight: 900;
}

.routing-note {
  margin: 16px 0 0;
  color: var(--muted);
}

.project-card h3 {
  margin-bottom: 8px;
}

.lesson-next-panel {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.lesson-cta {
  display: grid;
  gap: 18px;
}

.button.is-disabled,
.button.is-disabled:hover {
  border-color: var(--line);
  background: #f1f5f9;
  color: #64748b;
  box-shadow: none;
  cursor: default;
}

@media (prefers-reduced-motion: reduce) {
  .intent-choice,
  .preset-button,
  .suggestion-button,
  .chat-field textarea,
  .chat-input-row textarea {
    transition: none;
  }
}

@media (max-width: 1024px) {
  .assistant-journey {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .intent-category-note {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (max-width: 900px) {
  .challenge-board,
  .intent-demo-grid,
  .instruction-compare {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .assistant-journey,
  .keyword-card-grid,
  .intent-category-note,
  .intent-button-grid,
  .preset-list,
  .routing-grid {
    grid-template-columns: 1fr;
  }

  .lesson-2-hero .hero-actions .button,
  .challenge-actions .button,
  .chat-actions .button,
  .suggestion-button,
  .comparison-actions .button,
  .promo-cta .button,
  .lesson-nav .button {
    width: 100%;
  }

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

  .chat-status {
    margin-left: 0;
  }

  .lesson-next-panel {
    align-items: flex-start;
    flex-direction: column;
  }

  .lesson-next-panel .button {
    width: 100%;
  }
}