.lesson-dialogue__sidebar {
  grid-area: plan; min-height: 0; min-width: 0; overflow-y: auto;
  padding: 1rem 1.25rem; border-left: 1px solid var(--border-muted);
  border-radius: 0 0 var(--radius-lg, 12px) 0; background: var(--surface-2);
}
.lesson-dialogue__plan-heading { display: flex; justify-content: space-between; align-items: center; gap: 1rem; }
.lesson-dialogue__neighbors { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 0.5rem; margin-top: 0.75rem; font-size: var(--font-size-caption); }
.lesson-dialogue__neighbors:empty { display: none; }
.lesson-dialogue__neighbors a { padding: 0.25rem 0; }
.lesson-dialogue__continue { display: grid; gap: 0.25rem; margin-top: 0.75rem; padding: 0.75rem; border: 1px solid var(--reader-link); border-radius: var(--radius-md, 10px); background: var(--surface-1); }
.lesson-dialogue__continue span { font-size: var(--font-size-caption); }
.lesson-dialogue__continue strong { font-family: var(--site-font-display); font-size: var(--font-size-body-lg); color: var(--text-primary); }
.lesson-dialogue__continue:hover { background: var(--surface-hover); }
.lesson-dialogue__plan-overview { position: sticky; top: -1rem; z-index: 1; padding: 1rem 0 0.75rem; margin-top: -1rem; background: var(--surface-2); border-bottom: 1px solid var(--border-muted); }
.lesson-dialogue__plan-update { margin: 0.625rem 0 0; color: var(--text-primary); font-size: var(--font-size-caption); line-height: var(--line-height-body); border-left: 3px solid var(--success); padding-left: 0.625rem; }
.lesson-dialogue__plan-heading h2 {
  margin: 0; color: var(--text-heading); font-family: var(--site-font-display);
  font-size: var(--font-size-title-md); font-weight: 600; line-height: var(--line-height-heading);
}
.lesson-dialogue__plan-heading .lesson-dialogue__navigation { flex-shrink: 0; }
.lesson-dialogue__mastery-count { margin: 0.75rem 0 0.5rem; font-size: var(--font-size-body-sm); font-weight: 600; color: var(--text-primary); }
.lesson-dialogue__mastery {
  display: block; appearance: none; width: 100%; height: 0.5rem; overflow: hidden; border: 0;
  border-radius: var(--radius-pill, 999px); background: var(--border-muted); color: var(--success); accent-color: var(--success);
}
.lesson-dialogue__mastery::-webkit-progress-bar { background: var(--border-muted); }
.lesson-dialogue__mastery::-webkit-progress-value { background: var(--success); border-radius: var(--radius-pill, 999px); transition: width 250ms ease; }
.lesson-dialogue__mastery::-moz-progress-bar { background: var(--success); border-radius: var(--radius-pill, 999px); }
.lesson-dialogue__plan-hint, .lesson-dialogue__plan-note {
  color: var(--text-secondary); font-size: var(--font-size-caption); line-height: var(--line-height-body); margin: 0.625rem 0;
}
.lesson-dialogue__plan-list { display: grid; gap: 0.25rem; margin: 0; padding: 0; list-style: none; }
.lesson-dialogue__objective-link { display: block; width: 100%; padding: 0.25rem 0; border: 0; background: transparent; color: inherit; font: inherit; text-align: left; cursor: pointer; }
.lesson-dialogue__objective-link > span { font-family: var(--site-font-body); }
.lesson-dialogue__objective-link:hover > span { color: var(--reader-link); text-decoration: underline; text-underline-offset: 0.2em; }
.lesson-dialogue__objective-link:focus-visible { outline: 2px solid var(--reader-link); outline-offset: 3px; }
.lesson-dialogue__plan-section > summary { font-family: var(--site-font-body); display: flex; justify-content: space-between; gap: 0.5rem; padding: 0.375rem 0; cursor: pointer; color: var(--text-primary); font-size: var(--font-size-body-sm); font-weight: 600; }
.lesson-dialogue__plan-section > summary > span:first-child { text-decoration-color: transparent; text-decoration-thickness: 1px; transition: text-decoration-color 950ms ease-out; }
.lesson-dialogue__plan-section > summary > span:last-child { color: var(--text-secondary); white-space: nowrap; font-weight: 400; }
.lesson-dialogue__objectives { display: grid; gap: 0.25rem; margin: 0.25rem 0 0.375rem; padding: 0 0 0 1.25rem; }
.lesson-dialogue__objectives li { font-size: var(--font-size-body-sm); color: var(--text-primary); }
.lesson-dialogue__objectives small { display: block; margin-top: 0; font-size: var(--font-size-caption); color: var(--text-secondary); }
.lesson-dialogue__objectives [data-objective-status="mastered"]::marker { content: '✓  '; color: var(--success); }
.lesson-dialogue__objectives [data-objective-status="mastered"] .lesson-dialogue__objective-link > span { text-decoration: line-through; text-decoration-color: var(--success); text-decoration-thickness: 1px; }
.lesson-dialogue__objectives [data-objective-status="mastered"] small { color: var(--success); }
.lesson-dialogue__objectives [data-objective-status="developing"] { border-left: 2px solid var(--reader-link); padding-left: 0.5rem; }
.lesson-dialogue__plan-section[data-section-complete="true"] > summary > span:first-child { text-decoration-line: line-through; text-decoration-color: var(--success); }
.lesson-dialogue__plan-section[data-section-complete="true"] > summary > span:last-child { color: var(--success); }
.lesson-dialogue__plan-section[data-section-complete="true"] > summary > span:last-child::before { content: '✓ '; }
.lesson-dialogue__plan-section[data-section-current="true"] > summary { color: var(--reader-link); }
.lesson-dialogue__objectives .is-progress-updated { animation: objective-progress-reveal 1400ms ease-out both; }
.lesson-dialogue__objectives [data-objective-status="mastered"].is-progress-pending .lesson-dialogue__objective-link > span { text-decoration: none; }
.lesson-dialogue__objectives [data-objective-status="mastered"].is-progress-updated .lesson-dialogue__objective-link > span {
  text-decoration: none; box-decoration-break: clone; -webkit-box-decoration-break: clone;
  background-image: linear-gradient(var(--success), var(--success)); background-position: left 55%; background-repeat: no-repeat;
  background-size: 100% 1px; animation: objective-strike 950ms cubic-bezier(0.22, 1, 0.36, 1) both;
}
@keyframes objective-progress-reveal { from { background: var(--success-surface); } to { background: transparent; } }
@keyframes objective-strike { from { background-size: 0% 1px; } to { background-size: 100% 1px; } }
.lesson-dialogue__objectives [data-objective-status="reinforce"] small { color: var(--warning); }
.lesson-dialogue__plan-note { display: flex; align-items: flex-start; gap: 0.5rem; margin: 1.25rem 0 0; }
.lesson-dialogue__topic {
  display: none;
}
.lesson-dialogue__achievement {
  position: fixed; bottom: max(1rem, env(safe-area-inset-bottom)); right: max(1rem, env(safe-area-inset-right)); z-index: 1000; width: min(22rem, calc(100vw - 2rem)); box-sizing: border-box;
  overflow: hidden; display: grid; gap: 0.375rem; margin: 0; padding: 1rem 2.75rem 1rem 1rem;
  box-shadow: var(--shadow-popover); animation: dialogue-achievement-enter 220ms ease-out;
  border: 1px solid var(--success); border-radius: var(--radius-md, 10px); background: var(--surface-2); color: var(--text-primary);
}
.lesson-dialogue__achievement > i { font-size: var(--font-size-title-md); }
.lesson-dialogue__achievement > strong { font-size: var(--font-size-body); }
.lesson-dialogue__achievement > span { color: var(--text-primary); font-size: var(--font-size-body-sm); }
.lesson-dialogue__achievement-close { position: absolute; top: 0.25rem; right: 0.25rem; width: 2.25rem; height: 2.25rem; border: 0; border-radius: var(--radius-sm, 6px); background: transparent; color: var(--text-primary); font: inherit; cursor: pointer; }
.lesson-dialogue__achievement-close:hover { background: var(--surface-hover); }
.lesson-dialogue__achievement-close:focus-visible { outline: 2px solid var(--focus); outline-offset: -2px; }
@keyframes dialogue-achievement-enter { from { opacity: 0; transform: translateY(0.5rem); } to { opacity: 1; transform: translateY(0); } }
.lesson-dialogue__burst { position: absolute; inset: 0; pointer-events: none; }
.lesson-dialogue__burst span { position: absolute; top: 40%; left: 50%; width: 0.375rem; height: 0.625rem; opacity: 0; background: var(--success); }
.lesson-dialogue__burst span:nth-child(even) { background: var(--reader-link); border-radius: 50%; }
.is-celebrating .lesson-dialogue__burst span { animation: dialogue-confetti 900ms ease-out both; }
@keyframes dialogue-confetti {
  0% { opacity: 0; transform: rotate(calc(var(--piece) * 36deg)) translateY(0); }
  20% { opacity: 1; }
  100% { opacity: 0; transform: rotate(calc(var(--piece) * 36deg)) translateY(-7rem) rotate(150deg); }
}
@media (prefers-reduced-motion: reduce) {
  .lesson-dialogue__achievement { animation: none; }
  .lesson-dialogue__plan-section > summary > span:first-child { transition: none; }
  .lesson-dialogue__objectives .is-progress-updated, .lesson-dialogue__objectives [data-objective-status="mastered"].is-progress-updated .lesson-dialogue__objective-link > span { animation: none; }
  .lesson-dialogue__mastery::-webkit-progress-value { transition: none; }
  .is-celebrating .lesson-dialogue__burst span { animation: none; }
}
@media (max-width: 760px) {
  .lesson-dialogue__plan-overview { top: -0.75rem; padding-top: 0.75rem; margin-top: -0.75rem; }
  .lesson-dialogue__sidebar { max-height: 40dvh; padding: 0.75rem 1rem; border-left: 0; border-bottom: 1px solid var(--border-muted); border-radius: 0; }
  .lesson-dialogue__plan-heading h2 { font-size: var(--font-size-body); margin: 0; }
  .lesson-dialogue__plan-note { display: none; }
  .lesson-dialogue__menu > ol { max-height: calc(40dvh - 4rem); }
  .lesson-dialogue__mastery-count { margin: 0.25rem 0 0.375rem; }
  .lesson-dialogue__plan-hint { margin: 0.5rem 0; }
  .lesson-dialogue__plan-list { gap: 0.25rem; }
  .lesson-dialogue__objective-link { min-height: 2.75rem; }
  .lesson-dialogue__achievement { padding: 0.75rem 2.75rem 0.75rem 0.75rem; }
  .lesson-dialogue__achievement > i { display: none; }
}