.lessons-catalogue { display: grid; gap: 26px; min-width: 0; }
.lessons-page-header { display: grid; grid-template-columns: minmax(0, 1fr) auto; align-items: end; gap: 16px 28px; padding-bottom: 22px; border-bottom: 1px solid var(--border); }
.lessons-header-copy h1 { margin-bottom: 8px; font-size: clamp(2rem, 4vw, 3.25rem); }
.lessons-summary { display: flex; align-items: center; flex-wrap: wrap; gap: 6px 10px; color: var(--text-secondary); font-size: 14px; }
.lessons-summary strong { color: var(--text); font-weight: 540; }
.lessons-summary span[aria-hidden] { color: var(--border-strong); }
.lessons-continue-button { min-height: 44px; }
.lessons-overall-progress { grid-column: 1 / -1; }
.lessons-overall-progress .progress-bar { height: 5px; }
.curriculum-sections { display: grid; }
.curriculum-section { min-width: 0; padding: 26px 0 32px; border-bottom: 1px solid var(--border); }
.curriculum-section:first-child { padding-top: 0; }
.curriculum-heading { display: grid; grid-template-columns: minmax(0, 1fr) minmax(150px, 220px) 22px; align-items: center; gap: 20px; min-height: 66px; cursor: pointer; list-style: none; }
.curriculum-heading::-webkit-details-marker { display: none; }
.curriculum-heading::after { content: "+"; color: var(--text-secondary); font-family: var(--font-mono); font-size: 20px; text-align: right; }
.curriculum-section[open] > .curriculum-heading::after { content: "−"; }
.curriculum-heading-copy { min-width: 0; }
.curriculum-title-line { display: flex; align-items: center; flex-wrap: wrap; gap: 8px 12px; }
.curriculum-heading h2 { margin-bottom: 3px; font-size: 20px; }
.curriculum-heading p { max-width: 680px; font-size: 14px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.module-state-label { color: var(--text-secondary); font-family: var(--font-mono); font-size: 11px; font-weight: 540; letter-spacing: 0.04em; text-transform: uppercase; }
.module-current .module-state-label { color: var(--primary); }
.module-completed .module-state-label { color: var(--success); }
.module-progress-summary { display: grid; gap: 7px; color: var(--text-secondary); font-family: var(--font-mono); font-size: 12px; text-align: right; }
.module-progress-track { display: block; height: 4px; overflow: hidden; border-radius: var(--radius-pill); background: var(--surface-strong); }
.module-progress-track > span { display: block; width: 0; height: 100%; border-radius: inherit; background: var(--success); }
.module-unlock-note { display: flex; align-items: center; gap: 7px; margin-top: 12px; font-size: 13px; }
.module-unlock-note .icon { width: 16px; height: 16px; }
.first-lesson-guide { display: flex; align-items: center; justify-content: space-between; gap: 12px; width: fit-content; margin-top: 16px; padding: 8px 9px 8px 14px; border: 1px solid var(--border-strong); border-radius: var(--radius-pill); background: var(--surface-raised); color: var(--text); box-shadow: var(--shadow-soft); font-size: 13px; font-weight: 540; }
.first-lesson-guide .icon-button { width: 28px; height: 28px; min-height: 28px; font-size: 20px; line-height: 1; }
.lesson-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 16px; max-width: 900px; margin-top: 18px; }
.lesson-tile-shell { position: relative; min-width: 0; aspect-ratio: 1 / 1; }
.lesson-tile { display: grid; grid-template-rows: auto minmax(0, 1fr) auto auto; width: 100%; height: 100%; min-height: 150px; padding: 14px 14px 0; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); color: var(--text); box-shadow: var(--shadow-soft); text-align: left; cursor: pointer; transition: border-color 150ms ease, box-shadow 150ms ease, transform 150ms ease; }
.lesson-tile:hover { border-color: var(--border-strong); background: var(--surface-raised); transform: translateY(-2px); }
.lesson-tile-top { display: flex; align-items: center; justify-content: space-between; min-height: 24px; }
.lesson-tile-number { color: var(--text-secondary); font-family: var(--font-mono); font-size: 13px; font-weight: 540; }
.lesson-tile-status { display: grid; place-items: center; width: 24px; height: 24px; color: var(--text-secondary); }
.lesson-tile-status .icon { width: 18px; height: 18px; }
.lesson-tile-progress { display: grid; place-items: center; min-width: 35px; height: 24px; padding: 0 5px; border: 2px solid var(--primary); border-radius: var(--radius-pill); color: var(--text); font-family: var(--font-mono); font-size: 10px; font-weight: 600; }
.lesson-tile-visual { display: grid; place-items: center; min-height: 52px; color: var(--text); }
.lesson-tile-visual > .icon { width: 44px; height: 44px; stroke-width: 1.45; }
.lesson-tile-symbol { font-family: var(--font-mono); font-size: clamp(1.65rem, 3vw, 2.5rem); font-weight: 600; letter-spacing: 0.04em; text-align: center; }
.lesson-tile-symbol.long { font-size: clamp(1rem, 2vw, 1.45rem); letter-spacing: 0; }
.lesson-tile-priority { align-self: end; justify-self: start; margin-bottom: 7px; padding: 3px 7px; border-radius: var(--radius-pill); background: var(--primary); color: var(--on-primary); font-family: var(--font-mono); font-size: 10px; font-weight: 600; text-transform: uppercase; }
.lesson-tile-footer { display: grid; align-items: center; min-height: 54px; margin: 0 -14px; padding: 8px 46px 8px 13px; border-top: 1px solid var(--border); background: var(--surface-raised); }
.lesson-tile-footer > span { display: -webkit-box; overflow: hidden; color: var(--text); font-size: 13px; font-weight: 540; line-height: 1.25; -webkit-box-orient: vertical; -webkit-line-clamp: 2; }
.lesson-tile-info { position: absolute; right: 5px; bottom: 9px; display: grid; place-items: center; width: 36px; height: 36px; padding: 0; border: 1px solid transparent; border-radius: 50%; background: transparent; color: var(--text-secondary); font-family: var(--font-mono); font-size: 12px; cursor: pointer; }
.lesson-tile-info:hover { border-color: var(--border); background: var(--surface); color: var(--text); }
.lesson-tile-shell.is-recommended .lesson-tile { border-color: var(--primary); box-shadow: 0 0 0 2px var(--primary), var(--shadow-soft); }
.lesson-tile-shell.status-in_progress .lesson-tile { background: var(--surface-raised); }
.lesson-tile-shell.status-available:not(.is-recommended) .lesson-tile { border-color: var(--border-strong); }
.lesson-tile-shell.status-completed .lesson-tile-status,
.lesson-tile-shell.status-perfect .lesson-tile-status { color: var(--success); }
.lesson-tile-shell.status-completed .lesson-tile { background: var(--success-soft); }
.lesson-tile-shell.status-perfect .lesson-tile { border-color: var(--success); background: var(--success-soft); }
.lesson-tile-shell.status-retry_required .lesson-tile { border-color: var(--warning); background: var(--warning-soft); }
.lesson-tile-shell.status-retry_required .lesson-tile-status { color: var(--warning); }
.lesson-tile-shell.status-locked { opacity: 0.7; }
.lesson-tile-shell.status-locked .lesson-tile { box-shadow: none; cursor: not-allowed; }
.lesson-tile-shell.status-locked .lesson-tile:hover { border-color: var(--border); background: var(--surface); transform: none; }
.lessons-loading { display: grid; gap: 18px; }
.lessons-loading .lesson-grid { width: 100%; }
.skeleton-tile { aspect-ratio: 1 / 1; border-radius: var(--radius-md); background: var(--surface-strong); }
.lesson-details-dialog { width: min(560px, calc(100% - 32px)); max-height: min(760px, calc(100vh - 32px)); padding: 0; overflow: auto; border: 1px solid var(--border); border-radius: var(--radius-lg); background: var(--surface-raised); color: var(--text); box-shadow: var(--shadow-modal); }
.lesson-details-dialog::backdrop { background: var(--scrim); }
.lesson-details-content { display: grid; gap: 22px; padding: 26px; }
.lesson-details-heading h2 { margin-bottom: 8px; }
.lesson-details-metrics { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 1px; overflow: hidden; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--border); }
.lesson-details-metrics > div { min-width: 0; padding: 12px; background: var(--surface); }
.lesson-details-metrics dt { color: var(--text-secondary); font-size: 12px; }
.lesson-details-metrics dd { margin: 3px 0 0; color: var(--text); font-family: var(--font-mono); font-size: 14px; font-weight: 540; }
.lesson-details-requirement { display: flex; align-items: center; gap: 8px; padding: 12px; border-radius: var(--radius-md); background: var(--warning-soft); color: var(--text); font-size: 14px; }
.lesson-details-actions { display: flex; justify-content: flex-end; flex-wrap: wrap; gap: 10px; }

.lesson-player { max-width: var(--typing-width); margin: 0 auto; }
.lesson-player-header { position: relative; display: flex; flex-direction: column; align-items: center; margin-bottom: 28px; }
.lesson-player-header > .button { position: absolute; left: 0; top: 0; }
.lesson-player-heading { text-align: center; max-width: 640px; margin: 0 auto; width: 100%; }
.lesson-player-heading h1 { margin-bottom: 8px; font-size: clamp(2rem, 4vw, 3.25rem); }
.lesson-player-heading > p { display: block; margin: 0 0 14px 0; }
.lesson-exercise-meta { display: flex; flex-wrap: wrap; align-items: center; justify-content: center; gap: 6px 12px; margin: 16px auto 0; text-align: center; color: var(--text-secondary); font-family: var(--font-mono); font-size: 13px; clear: both; }
.lesson-exercise-meta output { color: var(--text); font-weight: 540; }
.lesson-typing-card { min-height: 230px; }
.lesson-player .text-display { text-align: center; }
.lesson-keyboard { margin-top: 22px; }
.lesson-result { max-width: 720px; margin: 40px auto 0; text-align: center; }
.lesson-result .achievement-icon { margin: 0 auto 18px; }
.lesson-result .achievement-icon.passed { border-color: var(--success); background: var(--success-soft); color: var(--success); }
.lesson-results-metrics { max-width: 560px; margin: 28px auto; grid-template-columns: repeat(3, 1fr); }
.lesson-result .button-row { justify-content: center; }
.lesson-result-breakdown { display: flex; flex-direction: column; gap: 12px; max-width: 560px; margin: 20px auto; text-align: left; }
.breakdown-group { padding: 12px 16px; border: 1px solid var(--border); border-radius: var(--radius-md); background: var(--surface); }
.breakdown-group.failed { border-color: var(--warning); background: var(--warning-soft); }
.breakdown-group h3 { margin-bottom: 8px; font-size: 13px; font-family: var(--font-mono); text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-secondary); }
.breakdown-group.failed h3 { color: var(--warning); }
.breakdown-group ul { margin: 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 6px; font-size: 14px; }
.icon-pass { color: var(--success); font-weight: bold; margin-right: 6px; }
.icon-fail { color: var(--error); font-weight: bold; margin-right: 6px; }
.metric-note { color: var(--text-muted); margin-right: 6px; }
.criterion-target { color: var(--text-secondary); font-size: 13px; }

@media (max-width: 767px) {
  .lessons-catalogue { gap: 22px; }
  .lessons-page-header { grid-template-columns: 1fr; align-items: start; }
  .lessons-continue-button { width: 100%; }
  .curriculum-section { padding: 22px 0 26px; }
  .curriculum-heading { grid-template-columns: minmax(0, 1fr) 22px; gap: 12px; min-height: 58px; }
  .curriculum-heading p { white-space: normal; }
  .module-progress-summary { grid-column: 1; grid-row: 2; text-align: left; }
  .curriculum-heading::after { grid-column: 2; grid-row: 1 / span 2; }
  .lesson-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 12px; max-width: 460px; }
  .lesson-tile { min-height: 142px; padding: 12px 12px 0; }
  .lesson-tile-footer { min-height: 52px; margin: 0 -12px; padding-left: 11px; }
  .lesson-tile-info { right: 2px; bottom: 5px; width: 44px; height: 44px; }
  .lesson-details-dialog { width: 100%; max-width: none; max-height: 85vh; margin: auto 0 0; border-width: 1px 0 0; border-radius: var(--radius-lg) var(--radius-lg) 0 0; }
  .lesson-details-content { padding: 22px 20px calc(22px + env(safe-area-inset-bottom)); }
  .lesson-player-header { position: static; align-items: flex-start; }
  .lesson-player-header > .button { position: static; margin-bottom: 16px; width: fit-content; }
  .lesson-player-heading { text-align: left; margin: 0; }
}

@media (max-width: 559px) {
  .lesson-results-metrics { grid-template-columns: 1fr; }
}

@media (max-width: 379px) {
  .lesson-grid { grid-template-columns: minmax(0, 220px); }
  .lesson-details-metrics { grid-template-columns: 1fr; }
}

@media (min-width: 768px) and (max-width: 1023px) {
  .lesson-grid { grid-template-columns: repeat(3, minmax(0, 1fr)); max-width: 690px; }
}

@media (min-width: 1200px) {
  .lesson-grid { grid-template-columns: repeat(5, minmax(0, 1fr)); max-width: 1100px; }
}

@media (min-width: 1440px) {
  .lesson-grid { grid-template-columns: repeat(6, minmax(0, 1fr)); max-width: 1260px; }
}

@media (prefers-reduced-motion: reduce) {
  .lesson-tile { transition: none; }
  .lesson-tile:hover { transform: none; }
  .intro-keycap-wrapper.shake { animation: none; }
}

/* ── Concept Introduction Screen & Keycap Components ────── */
.lesson-player-nav-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  margin-bottom: 12px;
}

.lesson-introduction-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100%;
  max-width: 820px;
  margin: 0 auto;
  padding: 16px;
  box-sizing: border-box;
  min-height: calc(100vh - var(--header-height, 56px) - 32px);
}

@supports (min-height: 100dvh) {
  .lesson-introduction-screen {
    min-height: calc(100dvh - var(--header-height, 56px) - 32px);
  }
}

.intro-card {
  width: 100%;
  max-width: 760px;
  background-color: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px 32px;
  box-shadow: var(--shadow-modal);
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
}

.intro-header-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.intro-heading-eyebrow {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.intro-header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.intro-step-indicator {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-muted);
}

.intro-skip-btn {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-decoration: none;
  cursor: pointer;
  background: transparent;
  border: none;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  transition: color 0.15s ease, background-color 0.15s ease;
}

.intro-skip-btn:hover {
  color: var(--text);
  background-color: var(--surface);
}

.intro-skip-btn:focus-visible {
  outline: 2px solid var(--focus);
  outline-offset: 2px;
}

.intro-body {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.intro-main-title {
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
  margin: 0 0 8px;
}

.intro-supporting-text {
  font-size: 0.9375rem;
  line-height: 1.5;
  color: var(--text-secondary);
  margin: 0 0 16px;
  max-width: 520px;
}

.intro-keycap-wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 12px 0 16px;
  min-height: 110px;
}

.intro-keycap-group {
  display: flex;
  align-items: center;
  gap: 16px;
}

.intro-keycap-plus {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-muted);
}

.intro-keycap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 104px;
  height: 104px;
  padding: 0 16px;
  font-size: 2.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text);
  background-color: var(--surface-raised);
  border: 2px solid var(--border-strong);
  border-radius: 14px;
  box-shadow: 0 6px 0 var(--border-strong);
  user-select: none;
  box-sizing: border-box;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background-color 0.12s ease, border-color 0.12s ease, color 0.12s ease;
}

.intro-keycap-label {
  display: block;
  line-height: 1;
  color: inherit;
}

.intro-keycap--wide {
  width: auto;
  min-width: 140px;
  padding: 0 24px;
  font-size: 1.5rem;
}

.intro-keycap--space {
  width: auto;
  min-width: 220px;
  padding: 0 32px;
  font-size: 1.5rem;
}

.intro-keycap--pressed {
  transform: translateY(3px);
  box-shadow: 0 2px 0 var(--success);
  border-color: var(--success);
  color: var(--success);
}

.intro-keycap--error {
  border-color: var(--error);
  color: var(--error);
}

.intro-keycap-technique-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 88px;
  height: 88px;
  border-radius: 50%;
  background-color: var(--surface);
  color: var(--primary);
  border: 2px solid var(--border-strong);
}

.intro-keycap-technique-icon .icon {
  width: 44px;
  height: 44px;
  stroke-width: 2;
}

.intro-finger-guidance {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin-top: 4px;
  margin-bottom: 16px;
}

.intro-finger-text {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text);
}

.intro-home-return-text {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.intro-secondary-text {
  font-size: 0.9375rem;
  color: var(--text-muted);
  margin: 8px 0 0;
  max-width: 520px;
}

.intro-footer-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  padding-top: 16px;
  margin-top: 12px;
  border-top: 1px solid var(--border);
}

.intro-prompt-hint {
  font-size: 1rem;
  color: var(--text-secondary);
  margin: 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

.intro-prompt-hint kbd {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  background-color: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  padding: 2px 8px;
  color: var(--text);
  box-shadow: 0 2px 0 var(--border);
}

.intro-keyboard {
  width: 100%;
  max-width: 580px;
  margin-top: 12px;
}

.ki-key.ki-key--muted {
  opacity: 0.3;
}

.ki-key.intro-key-highlight {
  opacity: 1;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--primary);
}

@keyframes shakeKeycap {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

.intro-keycap-wrapper.shake {
  animation: shakeKeycap 0.3s ease-in-out;
}

@media (max-width: 640px) {
  .intro-card {
    padding: 16px 20px;
    border-radius: 8px;
  }
  .intro-main-title {
    font-size: 1.25rem;
  }
  .intro-keycap {
    width: 80px;
    height: 80px;
    font-size: 2rem;
    border-radius: 10px;
  }
  .intro-keycap--wide {
    min-width: 110px;
    font-size: 1.25rem;
  }
  .intro-keycap--space {
    min-width: 160px;
    font-size: 1.25rem;
  }
  .intro-keyboard {
    transform: scale(0.9);
    margin-top: 4px;
  }
}

.intro-keycap-group {
  display: flex;
  align-items: center;
  gap: 16px;
}

.intro-keycap-plus {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--text-muted);
}

.intro-keycap {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 104px;
  height: 104px;
  padding: 0 16px;
  font-size: 2.75rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text);
  background-color: var(--surface-raised);
  border: 2px solid var(--border-strong);
  border-radius: 14px;
  box-shadow: 0 6px 0 var(--border-strong);
  user-select: none;
  box-sizing: border-box;
  transition: transform 0.12s ease, box-shadow 0.12s ease, background-color 0.12s ease, border-color 0.12s ease, color 0.12s ease;
}

.intro-keycap-label {
  display: block;
  line-height: 1;
  color: inherit;
}

.intro-keycap--wide {
  width: auto;
  min-width: 140px;
  padding: 0 24px;
  font-size: 1.5rem;
}

.intro-keycap--space {
  width: auto;
  min-width: 220px;
  padding: 0 32px;
  font-size: 1.5rem;
}

.intro-keycap--pressed {
  transform: translateY(3px);
  box-shadow: 0 2px 0 var(--success);
  border-color: var(--success);
  color: var(--success);
}

.intro-keycap--error {
  border-color: var(--error);
  color: var(--error);
}

.intro-keycap-technique-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 88px;
  height: 88px;
  border-radius: 50%;
  background-color: var(--surface);
  color: var(--primary);
  border: 2px solid var(--border-strong);
}

.intro-keycap-technique-icon .icon {
  width: 44px;
  height: 44px;
  stroke-width: 2;
}

.intro-finger-guidance {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 4px;
  margin-top: 4px;
  margin-bottom: 16px;
}

.intro-finger-text {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text);
}

.intro-home-return-text {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.intro-secondary-text {
  font-size: 0.9375rem;
  color: var(--text-muted);
  margin: 8px 0 0;
  max-width: 520px;
}

.intro-footer-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  padding-top: 16px;
  margin-top: 12px;
  border-top: 1px solid var(--border);
}

.intro-prompt-hint {
  font-size: 1rem;
  color: var(--text-secondary);
  margin: 0;
  display: flex;
  align-items: center;
  gap: 6px;
}

.intro-prompt-hint kbd {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  font-weight: 700;
  background-color: var(--surface);
  border: 1px solid var(--border-strong);
  border-radius: 4px;
  padding: 2px 8px;
  color: var(--text);
  box-shadow: 0 2px 0 var(--border);
}

.intro-keyboard {
  width: 100%;
  max-width: 580px;
  margin-top: 12px;
}

.ki-key.ki-key--muted {
  opacity: 0.3;
}

.ki-key.intro-key-highlight {
  opacity: 1;
  border-color: var(--primary);
  box-shadow: 0 0 0 2px var(--primary);
}

@keyframes shakeKeycap {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

.intro-keycap-wrapper.shake {
  animation: shakeKeycap 0.3s ease-in-out;
}

@media (max-width: 640px) {
  .intro-card {
    padding: 16px 20px;
    border-radius: 8px;
  }
  .intro-main-title {
    font-size: 1.25rem;
  }
  .intro-keycap {
    width: 80px;
    height: 80px;
    font-size: 2rem;
    border-radius: 10px;
  }
  .intro-keycap--wide {
    min-width: 110px;
    font-size: 1.25rem;
  }
  .intro-keycap--space {
    min-width: 160px;
    font-size: 1.25rem;
  }
  .intro-keyboard {
    transform: scale(0.9);
    margin-top: 4px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .intro-keycap {
    transition: none;
  }
  .intro-keycap-wrapper.shake {
    animation: none;
  }
}

/* Exercise Transition / Rest Overlay */
.exercise-transition-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--scrim);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  padding: 24px;
  animation: fadeIn 0.15s ease-out;
}

.exercise-transition-card {
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  max-width: 440px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow-modal);
}

.exercise-transition-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 16px;
  background: var(--success-soft);
  color: var(--success);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

.exercise-transition-card h2 {
  font-size: 1.5rem;
  font-weight: 700;
  margin: 0 0 8px;
  color: var(--text);
}

.exercise-transition-card p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin: 0 0 24px;
}

.exercise-transition-actions {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.exercise-transition-actions .button {
  width: 100%;
  justify-content: center;
}

.kbd-shortcut {
  font-size: 0.8em;
  opacity: 0.7;
  margin-left: 6px;
}