:root {
  color-scheme: light;
  --academy-bg: #f3f6fb;
  --academy-surface: #ffffff;
  --academy-surface-2: #e9eef7;
  --academy-ink: #172033;
  --academy-muted: #56627a;
  --academy-line: #d7deea;
  --academy-accent: #245fd6;
  --academy-accent-strong: #1848aa;
  --academy-accent-soft: #e8efff;
  --academy-success: #147a50;
  --academy-success-soft: #e2f5ec;
  --academy-danger: #b5363d;
  --academy-danger-soft: #fbe8ea;
  --academy-warning: #915f00;
  --academy-warning-soft: #fff2ce;
  --academy-radius: 14px;
  --academy-header-height: 64px;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
}

* {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

html {
  min-height: 100%;
  background: var(--academy-bg);
}

body {
  min-height: 100vh;
  margin: 0;
  background: var(--academy-bg);
  color: var(--academy-ink);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

button,
input,
select {
  font: inherit;
}

button,
a,
input,
select {
  -webkit-tap-highlight-color: transparent;
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible {
  outline: 3px solid rgba(36, 95, 214, 0.35);
  outline-offset: 2px;
}

button[disabled] {
  cursor: not-allowed;
  opacity: 0.48;
}

.academy-skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 50;
  padding: 10px 14px;
  transform: translateY(-140%);
  border-radius: 8px;
  background: var(--academy-ink);
  color: white;
  text-decoration: none;
}

.academy-skip-link:focus {
  transform: translateY(0);
}

.academy-header {
  position: sticky;
  top: 0;
  z-index: 20;
  min-height: var(--academy-header-height);
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 10px max(16px, calc((100vw - 1280px) / 2));
  border-bottom: 1px solid var(--academy-line);
  background: rgba(255, 255, 255, 0.96);
}

.academy-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  flex: 0 0 auto;
  color: var(--academy-ink);
  font-weight: 750;
  letter-spacing: -0.02em;
  text-decoration: none;
}

.academy-brand-mark {
  width: 34px;
  height: 34px;
  display: grid;
  place-items: center;
  border-radius: 9px;
  background: var(--academy-ink);
  color: white;
  font-size: 18px;
}

.academy-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  min-width: 0;
}

.academy-nav a {
  min-height: 40px;
  display: inline-flex;
  align-items: center;
  padding: 0 13px;
  border-radius: 9px;
  color: var(--academy-muted);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
  white-space: nowrap;
}

.academy-nav a:hover {
  background: var(--academy-surface-2);
  color: var(--academy-ink);
}

.academy-nav a[aria-current="page"] {
  background: var(--academy-accent-soft);
  color: var(--academy-accent-strong);
}

.academy-home-link {
  margin-left: auto;
  color: var(--academy-muted);
  font-size: 14px;
  font-weight: 650;
  text-decoration: none;
}

.academy-shell {
  width: min(1280px, 100%);
  margin: 0 auto;
  padding: 24px 20px 56px;
}

.academy-title-row {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 20px;
}

.academy-title-row h1 {
  margin: 0;
  max-width: 18ch;
  font-size: 28px;
  line-height: 1.18;
  letter-spacing: -0.025em;
  text-wrap: balance;
}

.academy-title-row p {
  max-width: 60ch;
  margin: 5px 0 0;
  color: var(--academy-muted);
  font-size: 15px;
  text-wrap: pretty;
}

.academy-goal {
  min-width: 220px;
  display: grid;
  gap: 7px;
}

.academy-goal-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--academy-muted);
  font-size: 13px;
  font-weight: 650;
}

.academy-progress-track {
  height: 8px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--academy-surface-2);
}

.academy-progress-bar {
  height: 100%;
  width: 0;
  border-radius: inherit;
  background: var(--academy-accent);
  transition: width 200ms ease-out;
}

.academy-layout {
  display: grid;
  grid-template-columns: 240px minmax(0, 1fr);
  gap: 20px;
  align-items: start;
}

.academy-sidebar,
.academy-workspace,
.lookup-workspace {
  border: 1px solid var(--academy-line);
  border-radius: var(--academy-radius);
  background: var(--academy-surface);
}

.academy-sidebar {
  position: sticky;
  top: calc(var(--academy-header-height) + 18px);
  overflow: hidden;
}

.academy-side-section {
  padding: 17px;
}

.academy-side-section + .academy-side-section {
  border-top: 1px solid var(--academy-line);
}

.academy-side-title {
  margin: 0 0 10px;
  color: var(--academy-muted);
  font-size: 12px;
  font-weight: 750;
}

.academy-mode-list {
  display: grid;
  gap: 6px;
}

.academy-mode {
  width: 100%;
  min-height: 44px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  padding: 8px 10px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--academy-muted);
  text-align: left;
  cursor: pointer;
}

.academy-mode:hover {
  background: var(--academy-surface-2);
  color: var(--academy-ink);
}

.academy-mode[aria-pressed="true"] {
  background: var(--academy-accent-soft);
  color: var(--academy-accent-strong);
  font-weight: 700;
}

.academy-mode small {
  color: inherit;
  font-size: 11px;
  opacity: 0.75;
}

.academy-stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
}

.academy-stat strong {
  display: block;
  font-size: 20px;
  line-height: 1.15;
}

.academy-stat span {
  color: var(--academy-muted);
  font-size: 12px;
}

.academy-weak-list {
  min-height: 28px;
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.academy-chip {
  min-height: 28px;
  display: inline-flex;
  align-items: center;
  padding: 3px 9px;
  border-radius: 999px;
  background: var(--academy-warning-soft);
  color: var(--academy-warning);
  font-size: 12px;
  font-weight: 700;
}

.academy-empty-small {
  color: var(--academy-muted);
  font-size: 12px;
}

.academy-workspace {
  min-width: 0;
  overflow: hidden;
}

.academy-session-bar {
  min-height: 56px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--academy-line);
}

.academy-session-status {
  display: flex;
  align-items: center;
  gap: 14px;
  color: var(--academy-muted);
  font-size: 13px;
  font-weight: 650;
}

.academy-session-status strong {
  color: var(--academy-ink);
}

.academy-question {
  min-height: 300px;
  display: grid;
  place-items: center;
  padding: 32px 24px 26px;
  text-align: center;
}

.academy-question-inner {
  width: min(560px, 100%);
}

.academy-prompt-label {
  margin: 0 0 8px;
  color: var(--academy-muted);
  font-size: 13px;
  font-weight: 700;
}

.academy-character {
  min-height: 112px;
  display: grid;
  place-items: center;
  font-family: "Noto Sans TC", "PingFang TC", "Microsoft JhengHei", sans-serif;
  font-size: 84px;
  font-weight: 650;
  line-height: 1;
  letter-spacing: -0.04em;
}

.academy-answer {
  min-height: 54px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-top: 16px;
}

.academy-answer-slot {
  min-width: 46px;
  height: 50px;
  display: grid;
  place-items: center;
  border-bottom: 3px solid var(--academy-line);
  color: var(--academy-ink);
  font-size: 24px;
  font-weight: 750;
}

.academy-answer-slot.is-filled {
  border-color: var(--academy-accent);
}

.academy-feedback {
  min-height: 50px;
  margin-top: 14px;
  color: var(--academy-muted);
  font-size: 14px;
}

.academy-feedback strong {
  color: var(--academy-ink);
}

.academy-feedback[data-tone="success"] {
  color: var(--academy-success);
}

.academy-feedback[data-tone="danger"] {
  color: var(--academy-danger);
}

.academy-actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 12px;
}

.academy-button {
  min-height: 42px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 8px 14px;
  border: 1px solid var(--academy-line);
  border-radius: 9px;
  background: white;
  color: var(--academy-ink);
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
  transition: background 160ms ease-out, border-color 160ms ease-out, color 160ms ease-out, transform 120ms ease-out;
}

.academy-button:hover {
  border-color: #aab5c8;
  background: var(--academy-surface-2);
}

.academy-button:active {
  transform: translateY(1px);
}

.academy-button.primary {
  border-color: var(--academy-accent);
  background: var(--academy-accent);
  color: white;
}

.academy-button.primary:hover {
  border-color: var(--academy-accent-strong);
  background: var(--academy-accent-strong);
}

.academy-button.danger {
  border-color: var(--academy-danger-soft);
  color: var(--academy-danger);
}

.academy-keyboard-wrap {
  padding: 18px;
  border-top: 1px solid var(--academy-line);
  background: #edf1f7;
}

.academy-keyboard-hint {
  margin: 0 0 12px;
  color: var(--academy-muted);
  font-size: 12px;
  text-align: center;
}

.academy-keyboard {
  display: grid;
  gap: 7px;
  justify-content: center;
}

.academy-key-row {
  display: flex;
  justify-content: center;
  gap: 7px;
}

.academy-key {
  width: clamp(42px, 5vw, 58px);
  min-height: 54px;
  display: grid;
  place-items: center;
  padding: 3px;
  border: 1px solid #cbd3df;
  border-bottom-width: 3px;
  border-radius: 8px;
  background: white;
  color: var(--academy-ink);
  cursor: pointer;
  user-select: none;
}

.academy-key:hover {
  border-color: #9ba8bb;
  background: #f8faff;
}

.academy-key:active,
.academy-key.is-active {
  transform: translateY(2px);
  border-bottom-width: 1px;
  background: var(--academy-accent-soft);
  color: var(--academy-accent-strong);
}

.academy-key.is-hint {
  border-color: var(--academy-warning);
  background: var(--academy-warning-soft);
  color: var(--academy-warning);
}

.academy-key .latin {
  color: var(--academy-muted);
  font-size: 10px;
  line-height: 1;
}

.academy-key .symbol {
  font-size: 20px;
  font-weight: 750;
  line-height: 1.1;
}

.academy-key.utility {
  width: clamp(54px, 7vw, 74px);
  color: var(--academy-muted);
  font-size: 13px;
  font-weight: 750;
}

.academy-dialog {
  width: min(480px, calc(100% - 32px));
  padding: 0;
  border: 0;
  border-radius: 16px;
  background: white;
  color: var(--academy-ink);
}

.academy-dialog::backdrop {
  background: rgba(12, 18, 31, 0.58);
}

.academy-dialog-body {
  padding: 24px;
}

.academy-dialog h2 {
  margin: 0;
  font-size: 24px;
  letter-spacing: -0.02em;
}

.academy-dialog p {
  color: var(--academy-muted);
}

.academy-summary {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
  margin: 20px 0;
}

.academy-summary div {
  padding: 13px;
  border-radius: 10px;
  background: var(--academy-surface-2);
  text-align: center;
}

.academy-summary strong {
  display: block;
  font-size: 22px;
}

.academy-summary span {
  color: var(--academy-muted);
  font-size: 12px;
}

.academy-dialog-actions {
  display: flex;
  justify-content: flex-end;
  gap: 8px;
}

.academy-toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 40;
  max-width: min(420px, calc(100% - 32px));
  padding: 11px 15px;
  transform: translate(-50%, 16px);
  border-radius: 9px;
  background: var(--academy-ink);
  color: white;
  font-size: 14px;
  font-weight: 650;
  opacity: 0;
  pointer-events: none;
  transition: opacity 160ms ease-out, transform 160ms ease-out;
}

.academy-toast.is-visible {
  transform: translate(-50%, 0);
  opacity: 1;
}

.academy-toast[data-tone="success"] {
  background: var(--academy-success);
}

.academy-toast[data-tone="danger"] {
  background: var(--academy-danger);
}

.academy-info {
  margin-top: 28px;
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(260px, 0.8fr);
  gap: 20px;
  padding: 22px;
  border-top: 1px solid var(--academy-line);
  color: var(--academy-muted);
}

.academy-info h2,
.academy-info h3 {
  margin: 0 0 8px;
  color: var(--academy-ink);
  letter-spacing: -0.015em;
}

.academy-info h2 {
  font-size: 18px;
}

.academy-info h3 {
  font-size: 15px;
}

.academy-info p,
.academy-info li {
  max-width: 70ch;
  font-size: 14px;
  line-height: 1.65;
}

.academy-info ul {
  margin: 8px 0 0;
  padding-left: 20px;
}

@media (max-width: 900px) {
  .academy-header {
    overflow-x: auto;
    padding-inline: 14px;
  }

  .academy-brand span:last-child,
  .academy-home-link {
    display: none;
  }

  .academy-layout {
    grid-template-columns: 1fr;
  }

  .academy-sidebar {
    position: static;
    display: grid;
    grid-template-columns: 1.2fr 1fr 1fr;
  }

  .academy-side-section + .academy-side-section {
    border-top: 0;
    border-left: 1px solid var(--academy-line);
  }
}

@media (max-width: 640px) {
  :root {
    --academy-header-height: 58px;
  }

  .academy-header {
    gap: 8px;
    min-height: var(--academy-header-height);
    padding-block: 8px;
  }

  .academy-brand-mark {
    width: 32px;
    height: 32px;
  }

  .academy-nav a {
    min-height: 38px;
    padding-inline: 10px;
    font-size: 13px;
  }

  .academy-shell {
    padding: 18px 12px 40px;
  }

  .academy-title-row {
    align-items: stretch;
    flex-direction: column;
    gap: 14px;
  }

  .academy-title-row h1 {
    font-size: 23px;
  }

  .academy-goal {
    min-width: 0;
  }

  .academy-sidebar {
    display: block;
  }

  .academy-side-section + .academy-side-section {
    border-top: 1px solid var(--academy-line);
    border-left: 0;
  }

  .academy-side-section:nth-child(n + 2) {
    display: none;
  }

  .academy-session-bar {
    align-items: flex-start;
    flex-direction: column;
    gap: 6px;
  }

  .academy-question {
    min-height: 270px;
    padding: 24px 14px 20px;
  }

  .academy-character {
    min-height: 92px;
    font-size: 70px;
  }

  .academy-keyboard-wrap {
    padding: 14px 7px;
  }

  .academy-keyboard,
  .academy-key-row {
    gap: 4px;
  }

  .academy-key {
    width: min(9.2vw, 44px);
    min-width: 30px;
    min-height: 50px;
    border-radius: 7px;
  }

  .academy-key.utility {
    width: min(14vw, 58px);
  }

  .academy-key .symbol {
    font-size: 17px;
  }

  .academy-info {
    grid-template-columns: 1fr;
    padding: 18px 14px;
  }

  .academy-summary {
    grid-template-columns: 1fr;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}