.DemoLessonHeader_root__SEgqE{display:flex;flex-direction:column;gap:var(--ch-space-2,8px)}.DemoLessonHeader_meta__8y92N{color:var(--ch-text-muted,#5b6472);font-size:var(--ch-font-sm,14px);font-weight:700}.DemoLessonHeader_title__dEYpB{margin:0;font-size:var(--ch-font-xl,28px);line-height:1.15}.DemoLessonHeader_credit__s2WCQ{color:var(--ch-text-muted,#5b6472);font-size:var(--ch-font-sm,14px)}.DisclosureGroup_group__uGsZW{display:flex;flex-direction:column}.DisclosureGroup_item__CApXf{border-bottom:1px solid var(--ch-line-soft,#e6e7f0)}.DisclosureGroup_heading__ffc02{margin:0}.DisclosureGroup_button__G1to1{display:flex;align-items:center;gap:10px;width:100%;min-height:60px;padding:0 4px;border:0;background:transparent;color:var(--ch-ink,#1a1446);font-family:var(--ch-font-display,Arial,sans-serif);font-size:16px;font-weight:700;letter-spacing:.01em;text-align:left;text-transform:uppercase;cursor:pointer}.DisclosureGroup_button__G1to1:focus-visible{outline:2px solid var(--ch-brand,#4f46e5);outline-offset:2px}.DisclosureGroup_label__i6Un4{display:flex;align-items:center;flex:1 1;gap:10px}.DisclosureGroup_label__i6Un4>*{font-family:var(--ch-font-body,Arial,sans-serif);text-transform:none}.DisclosureGroup_chevron__dtk31{display:flex;align-items:center;justify-content:center;flex-shrink:0;width:32px;height:32px;border-radius:50%;background:var(--ch-ground,#f5f6fb);transition:transform .16s var(--ch-ease,ease)}.DisclosureGroup_chevron__dtk31 svg{width:14px;height:14px}.DisclosureGroup_open__XWnNt .DisclosureGroup_chevron__dtk31{background:var(--ch-brand,#4f46e5);color:var(--ch-on-brand,#ffffff);transform:rotate(180deg)}.DisclosureGroup_region__oq0Ao{display:flex;flex-direction:column;padding:0 4px 14px}.DisclosureGroup_region__oq0Ao[hidden]{display:none}@media (prefers-reduced-motion:reduce){.DisclosureGroup_chevron__dtk31{transition:none}}.DemoSwitchPlaque_root__dX4UR{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:var(--ch-space-4,16px);padding:var(--ch-space-6,24px);border:2px solid var(--ch-brand,#4f46e5);border-radius:var(--ch-radius-card,24px);background:var(--ch-surface,#ffffff)}.DemoSwitchPlaque_text__1oYsw{display:flex;flex:1 1 320px;flex-direction:column;gap:var(--ch-space-1,4px);color:var(--ch-text-muted,#5b6472)}.DemoSwitchPlaque_title__XT4HH{margin:0;color:var(--ch-ink,#1a1446);font-size:var(--ch-font-lg,18px)}.DemoSwitchPlaque_actions__hMNE_{display:flex;flex-wrap:wrap;gap:var(--ch-space-3,12px)}.DemoResult_root__vqP6v{display:flex;flex-direction:column;gap:var(--ch-space-3,12px)}.DemoResult_actions__0GDZk{display:flex;flex-wrap:wrap;justify-content:flex-end;gap:var(--ch-space-3,12px)}.Notice_notice__pYlct{display:flex;align-items:flex-start;gap:var(--ch-space-3,12px);box-sizing:border-box;padding:var(--ch-space-3,12px) var(--ch-space-4,16px);border-radius:var(--ch-radius-md,16px);font-size:var(--ch-text-md,15px);line-height:var(--ch-leading-body,1.55)}.Notice_info__WzXHV{background:var(--ch-brand-soft,#ecebff);color:var(--ch-ink,#1a1446)}.Notice_attention__QCflt{background:var(--ch-attention-soft,#fff4c7);color:var(--ch-attention-ink,#6b4a00)}.Notice_danger__BSZeI{background:var(--ch-danger-soft,#fdecef);color:#8f1a2c}.Notice_success__zLHTs{background:var(--ch-success-soft,#d8f5ee);color:var(--ch-success-ink,#0e5e4e)}.Notice_icon__6BBXP{flex-shrink:0;width:22px;height:22px;margin-top:1px}.Notice_text__6zLm0{flex:1 1;min-width:0}.Notice_title__Ify0Q{margin:0;font-weight:800}.Notice_body__T4ail{overflow-wrap:anywhere}.Notice_action__AAXtF{flex-shrink:0;align-self:center;font-weight:700}.Notice_hidden__4t_5S{position:absolute;width:1px;height:1px;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}@media (max-width:639px){.Notice_notice__pYlct{flex-wrap:wrap}.Notice_action__AAXtF{flex-basis:100%;text-align:right}}.DemoStudentSide_root__bDif4{display:flex;flex-direction:column;gap:var(--ch-space-4,16px)}.DemoStudentSide_actions__Y6zFf{display:flex;justify-content:flex-end;flex-wrap:wrap;gap:var(--ch-space-3,12px)}.DemoStudentSide_open__GG30Y{color:var(--ch-text-muted,#5b6472);font-size:var(--ch-font-sm,14px)}.SegmentedTabs_list__6zf_S{display:inline-flex;flex-wrap:wrap;gap:var(--ch-space-1,4px);padding:var(--ch-space-1,4px);border-radius:var(--ch-radius-pill,999px);background:var(--ch-ground-cool,#eef0f7)}.SegmentedTabs_onDark__B6cui{background:var(--ch-on-brand-panel,rgba(255,255,255,.1))}.SegmentedTabs_tab__3Y5fi{display:inline-flex;align-items:center;gap:var(--ch-space-2,8px);min-height:44px;padding:0 var(--ch-space-5,20px);border:0;border-radius:var(--ch-radius-pill,999px);background:transparent;color:var(--ch-ink,#1a1446);font:inherit;font-weight:700;cursor:pointer}.SegmentedTabs_onDark__B6cui .SegmentedTabs_tab__3Y5fi{color:var(--ch-on-brand,#ffffff)}.SegmentedTabs_selected___WvEc{background:var(--ch-surface,#ffffff);color:var(--ch-ink,#1a1446)}.SegmentedTabs_onDark__B6cui .SegmentedTabs_selected___WvEc{background:var(--ch-on-brand,#ffffff);color:var(--ch-ink,#1a1446)}.SegmentedTabs_count__mgP_L{font-size:var(--ch-text-sm,13px);opacity:.7}.SegmentedTabs_tab__3Y5fi:focus-visible{outline:2px solid var(--ch-brand,#4f46e5);outline-offset:2px}.SegmentedTabs_onDark__B6cui .SegmentedTabs_tab__3Y5fi:focus-visible{outline-color:var(--ch-accent,#ffd54a)}.DemoBlockCard_head__DU9a8{display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:var(--ch-space-3,12px);margin-bottom:var(--ch-space-3,12px)}.DemoBlockCard_title__ccbIB{margin:0;font-size:var(--ch-font-lg,18px)}.SurfaceCard_card__cA_pP{display:flex;flex-direction:column;min-width:0;overflow:hidden;border-radius:var(--ch-radius-card,24px);background:var(--ch-surface,#ffffff);box-shadow:var(
    --ch-shadow-card,0 1px 2px rgba(26,20,70,.06),0 10px 28px rgba(26,20,70,.07)
  );color:var(--ch-ink,#1a1446)}.SurfaceCard_padded__4Ovtt{padding:var(--ch-space-6,24px)}.SurfaceCard_link__h0UBb{text-decoration:none;transition:transform var(--ch-duration,.18s) var(--ch-ease,ease)}.SurfaceCard_link__h0UBb:hover{color:var(--ch-ink,#1a1446);box-shadow:var(
    --ch-shadow-raised,0 2px 4px rgba(26,20,70,.06),0 24px 48px rgba(26,20,70,.14)
  )}@media (prefers-reduced-motion:no-preference){.SurfaceCard_link__h0UBb:hover{transform:translateY(-2px)}}.SurfaceCard_link__h0UBb:focus-visible{outline:2px solid var(--ch-brand,#4f46e5);outline-offset:2px}.Chip_chip__EbrGT{display:inline-flex;align-items:center;height:var(--ch-chip-h,26px);padding:0 10px;border:1px solid;border-radius:var(--ch-radius-chip,6px);font-family:var(--ch-font-body,Arial,sans-serif);font-size:var(--ch-text-xs,12px);font-weight:700;line-height:1;letter-spacing:.03em;text-transform:uppercase;white-space:nowrap}.Chip_ink__2eMw6{color:var(--ch-ink,#1a1446)}.Chip_on-brand__A2Jsm{color:var(--ch-on-brand,#ffffff);border-color:var(--ch-on-brand-line,rgba(255,255,255,.22))}.DemoTeacherSide_root__HLge2{display:flex;flex-direction:column;gap:var(--ch-space-4,16px)}.DemoTeacherSide_toolbar__am3FD{justify-content:space-between}.DemoTeacherSide_group__kGW_U,.DemoTeacherSide_toolbar__am3FD{display:flex;flex-wrap:wrap;gap:var(--ch-space-3,12px)}.demo_page__VNjDt{display:flex;flex-direction:column;gap:var(--ch-space-4,16px);max-width:880px;margin:0 auto;padding:var(--ch-space-6,24px) var(--ch-space-4,16px) var(--ch-space-8,48px)}.demo_title__3R1aW{margin:0;font-size:var(--ch-font-2xl,32px)}.demo_lead__gn7NR,.demo_note__P_lKJ{margin:0;color:var(--ch-text-muted,#5b6472)}.demo_note__P_lKJ{font-size:var(--ch-font-sm,14px)}