:root {
  --bg: #0f1419;
  --bg-card: #1a2332;
  --bg-elevated: #243044;
  --text: #e8edf4;
  --text-muted: #94a3b8;
  --accent: #38bdf8;
  --accent-hover: #7dd3fc;
  --success: #4ade80;
  --error: #f87171;
  --border: rgba(148, 163, 184, 0.18);
  --shadow: 0 24px 48px rgba(0, 0, 0, 0.35);
  --radius: 14px;
  --touch-min: 44px;
  --gap: 0.65rem;
  --sidebar-w: min(100%, 300px);
  --font: "Outfit", system-ui, sans-serif;
  --font-arabic: "Noto Sans Arabic", "Segoe UI", Tahoma, sans-serif;
  --font-hindi: "Noto Sans Devanagari", "Nirmala UI", sans-serif;
  --font-chinese: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-japanese: "Noto Sans JP", "Yu Gothic", sans-serif;
  --font-korean: "Noto Sans KR", "Malgun Gothic", sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font);
  color: var(--text);
  background:
    radial-gradient(ellipse 80% 60% at 50% -10%, rgba(56, 189, 248, 0.18), transparent),
    radial-gradient(ellipse 60% 50% at 100% 100%, rgba(74, 222, 128, 0.08), transparent),
    var(--bg);
}

.app {
  max-width: 1100px;
  margin: 0 auto;
  padding:
    max(0.75rem, env(safe-area-inset-top))
    max(0.65rem, env(safe-area-inset-right))
    max(0.65rem, env(safe-area-inset-bottom))
    max(0.65rem, env(safe-area-inset-left));
}

html[dir="rtl"] .speed-header,
html[dir="rtl"] .input-row,
html[dir="rtl"] .actions,
html[dir="rtl"] .learn-actions {
  direction: rtl;
}

.header {
  text-align: center;
  margin-bottom: 0.5rem;
}

h1 {
  margin: 0;
  font-size: clamp(1.15rem, 4vw, 1.75rem);
  font-weight: 700;
  line-height: 1.2;
}

.subtitle {
  margin: 0.15rem 0 0;
  color: var(--text-muted);
  line-height: 1.35;
  font-size: 0.78rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.75rem;
  box-shadow: var(--shadow);
}

.app-layout {
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}

.app-sidebar {
  display: flex;
  flex-direction: column;
  gap: var(--gap);
  min-width: 0;
}

.app-main {
  min-width: 0;
  flex: 1;
}

.setup-panel {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg-elevated);
}

.setup-panel-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--touch-min);
  padding: 0 0.85rem;
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  touch-action: manipulation;
}

.setup-panel-summary::-webkit-details-marker {
  display: none;
}

.setup-panel-summary::after {
  content: "▾";
  color: var(--accent);
  font-size: 0.9rem;
  transition: transform 0.15s ease;
}

.setup-panel[open] .setup-panel-summary::after {
  transform: rotate(180deg);
}

.setup-panel-body {
  display: flex;
  flex-direction: column;
  gap: var(--gap);
  padding: 0 0.75rem 0.75rem;
}

.controls-row {
  display: flex;
  flex-direction: column;
  gap: var(--gap);
}

.saved-state {
  padding: 0.55rem 0.65rem;
  border-radius: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
}

.saved-state-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.45rem;
}

.saved-state-title {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.saved-state-lang {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--accent);
}

.saved-state-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.35rem;
}

.saved-stat {
  padding: 0.35rem 0.2rem;
  border-radius: 8px;
  background: var(--bg);
  text-align: center;
}

.saved-stat .stat-label {
  font-size: 0.58rem;
  line-height: 1.2;
  margin-bottom: 0.1rem;
}

.saved-stat .stat-value {
  font-size: 0.95rem;
}

.state-summary {
  display: none;
  margin: 0.45rem 0 0;
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.35;
}

.mode-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.35rem;
  padding: 0.3rem;
  border-radius: 10px;
  background: var(--bg);
  border: 1px solid var(--border);
  flex-shrink: 0;
}

.mode-tab {
  border: none;
  border-radius: 10px;
  min-height: var(--touch-min);
  padding: 0.75rem 1rem;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  cursor: pointer;
  touch-action: manipulation;
  transition: background 0.15s ease, color 0.15s ease;
}

.mode-tab.active {
  color: #0f172a;
  background: var(--accent);
}

.mode-section.hidden {
  display: none;
}

.level-picker {
  margin: 0;
}

.level-hint {
  margin: 0.3rem 0 0;
  font-size: 0.72rem;
  line-height: 1.35;
  color: var(--text-muted);
}

.language-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.45rem;
  direction: ltr;
}

.language-field {
  min-width: 0;
}

.language-select {
  width: 100%;
  min-height: 40px;
  padding: 0.45rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background-color: var(--bg-card);
  color: var(--text);
  font-family: inherit;
  font-size: 0.82rem;
  font-weight: 500;
}

.language-select option {
  color: #0f1419;
  background-color: #e8edf4;
}

.language-select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.speed-picker {
  margin: 0;
}

.speed-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.5rem;
}

.speed-header .input-label {
  margin-bottom: 0;
}

.speed-value {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent);
}

.speed-slider {
  display: block;
  width: 100%;
  height: 5px;
  margin: 0.35rem 0 0;
  accent-color: var(--accent);
  cursor: pointer;
}

.cycle-feedback,
.learn-progress {
  margin-bottom: var(--gap);
  padding: 0.55rem 0.65rem;
  border-radius: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
}

.cycle-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.4rem;
}

.cycle-range-label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.cycle-count {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--accent);
  white-space: nowrap;
}

.cycle-bar-track {
  height: 7px;
  border-radius: 999px;
  background: var(--bg);
  overflow: hidden;
}

.cycle-bar-fill {
  height: 100%;
  width: 0%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), #4ade80);
  transition: width 0.35s ease;
}

.cycle-remaining {
  margin: 0.55rem 0 0;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.cycle-notice {
  margin: 0.75rem 0 0;
  padding: 0.7rem 0.85rem;
  border-radius: 10px;
  font-size: 0.88rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--success);
  background: rgba(74, 222, 128, 0.12);
  border: 1px solid rgba(74, 222, 128, 0.25);
}

.cycle-feedback.cycle-complete .cycle-count {
  color: var(--success);
}

.scoreboard {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.35rem;
  margin-bottom: var(--gap);
}

.stat {
  background: var(--bg-elevated);
  border-radius: 8px;
  padding: 0.4rem 0.25rem;
  text-align: center;
}

.stat-label {
  display: block;
  font-size: 0.75rem;
  line-height: 1.3;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
  overflow-wrap: anywhere;
}

.stat-value {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--accent);
}

.prompt-area {
  min-height: 2rem;
  margin-bottom: var(--gap);
  text-align: center;
}

.status-text {
  margin: 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.answer-reveal {
  margin-top: var(--gap);
  padding: 0.55rem 0.65rem;
  border-radius: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
}

.answer-reveal-title {
  margin: 0 0 0.75rem;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.numerals-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.45rem;
  margin-bottom: 0.45rem;
}

.numeral-block {
  padding: 0.45rem;
  border-radius: 8px;
  background: var(--bg);
  text-align: center;
}

.digit-answer {
  display: block;
  margin-top: 0.15rem;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--accent);
}

.arabic-numeral {
  font-family: var(--font-arabic);
}

.words-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  align-items: start;
}

.word-block {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  min-width: 0;
}

.answer-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.word-value {
  display: flex;
  align-items: center;
  min-height: 1.75rem;
}

.answer-source,
.answer-native {
  font-size: 0.9rem;
  line-height: 1.4;
  color: var(--text);
}

.answer-native {
  font-weight: 600;
  letter-spacing: 0.02em;
}

.answer-native.font-arabic {
  font-family: var(--font-arabic);
}

.answer-native.font-hindi {
  font-family: var(--font-hindi);
}

.answer-native.font-chinese {
  font-family: var(--font-chinese);
}

.answer-native.font-japanese {
  font-family: var(--font-japanese);
}

.answer-native.font-korean {
  font-family: var(--font-korean);
}

.learn-card {
  margin-bottom: var(--gap);
}

.learn-option {
  margin-bottom: 0.4rem;
}

.learn-continue {
  width: 100%;
  margin-bottom: 0.45rem;
}

.practice-options {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  margin-bottom: var(--gap);
  padding: 0.45rem 0.55rem;
  border-radius: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
}

.option-toggle {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 36px;
  padding: 0.2rem 0;
  font-size: 0.8rem;
  line-height: 1.4;
  color: var(--text);
  cursor: pointer;
  touch-action: manipulation;
}

.option-toggle input {
  width: 1.2rem;
  height: 1.2rem;
  margin: 0;
  accent-color: var(--accent);
  flex-shrink: 0;
}

.actions.learn-actions {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.35fr) minmax(0, 1fr);
  gap: 0.65rem;
}

.actions.learn-actions .btn {
  width: 100%;
  min-width: 0;
}

#learn-prev {
  grid-column: 1;
  grid-row: 1;
}

#learn-hear {
  grid-column: 2;
  grid-row: 1;
}

#learn-next {
  grid-column: 3;
  grid-row: 1;
}

.actions.learn-actions .btn-primary {
  font-size: 1rem;
}

.actions.learn-actions .btn-secondary {
  padding: 0.75rem 0.65rem;
  font-size: 0.9rem;
}

.actions {
  display: flex;
  gap: 0.45rem;
  margin-bottom: var(--gap);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  min-height: var(--touch-min);
  border: none;
  border-radius: 10px;
  padding: 0.55rem 0.75rem;
  font-family: inherit;
  font-size: 0.88rem;
  font-weight: 600;
  cursor: pointer;
  touch-action: manipulation;
  transition: background 0.15s ease, transform 0.1s ease, opacity 0.15s ease;
}

.btn:active:not(:disabled) {
  transform: scale(0.98);
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.btn-primary {
  flex: 1;
  background: var(--accent);
  color: #0f172a;
}

.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
}

.btn-secondary {
  background: var(--bg-elevated);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover:not(:disabled) {
  background: #2d3d56;
}

.btn-accent {
  background: #22c55e;
  color: #052e16;
  white-space: nowrap;
}

.btn-accent:hover:not(:disabled) {
  background: #4ade80;
}

.answer-form {
  margin-bottom: 0.5rem;
}

.input-label {
  display: block;
  margin-bottom: 0.3rem;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--text-muted);
}

.input-row {
  display: flex;
  gap: 0.45rem;
}

input[type="number"] {
  flex: 1;
  width: 100%;
  min-height: var(--touch-min);
  padding: 0.55rem 0.65rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg);
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
}

input[type="number"]:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

input[type="number"]:disabled {
  opacity: 0.5;
}

input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  opacity: 1;
}

.feedback {
  margin: 1rem 0 0;
  padding: 0.85rem 1rem;
  border-radius: 12px;
  font-weight: 500;
  line-height: 1.45;
}

.feedback.success {
  background: rgba(74, 222, 128, 0.12);
  color: var(--success);
  border: 1px solid rgba(74, 222, 128, 0.25);
}

.feedback.error {
  background: rgba(248, 113, 113, 0.12);
  color: var(--error);
  border: 1px solid rgba(248, 113, 113, 0.25);
}

.hidden {
  display: none;
}

.footer {
  margin-top: 0.5rem;
  text-align: center;
}

.footer p {
  margin: 0;
  font-size: 0.72rem;
  color: var(--text-muted);
  line-height: 1.35;
}

.footer p + p {
  margin-top: 0.25rem;
}

.footer-tip {
  display: none;
}

.voice-status {
  font-weight: 500;
  color: var(--success);
}

.voice-status.warning {
  color: var(--error);
}

.server-notice {
  color: var(--accent);
  font-weight: 500;
}

.server-notice code {
  font-size: 0.82rem;
  background: var(--bg-elevated);
  padding: 0.1rem 0.35rem;
  border-radius: 6px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.keyboard-shortcuts {
  margin: 0 0 0.5rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.info-page {
  max-width: 640px;
}

.info-card {
  text-align: left;
}

.info-card h2 {
  margin: 1.5rem 0 0.5rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text);
}

.info-card h2:first-child {
  margin-top: 0;
}

.info-card p,
.info-card li {
  margin: 0 0 0.75rem;
  color: var(--text-muted);
  line-height: 1.6;
  font-size: 0.95rem;
}

.info-card ul,
.info-card ol {
  margin: 0 0 0.75rem;
  padding-left: 1.35rem;
}

.info-card li {
  margin-bottom: 0.35rem;
}

.info-card a {
  color: var(--accent);
}

.info-card a:hover {
  color: var(--accent-hover);
}

.info-card code {
  font-size: 0.85rem;
  background: var(--bg-elevated);
  padding: 0.1rem 0.35rem;
  border-radius: 6px;
}

.info-muted {
  font-size: 0.85rem;
  color: var(--text-muted);
}

.back-link {
  display: inline-block;
  margin-bottom: 1rem;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}

.back-link:hover {
  color: var(--accent-hover);
}

.info-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem 1.25rem;
  margin: 0 0 0.75rem;
}

.info-nav a {
  color: var(--accent);
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 500;
}

.info-nav a:hover {
  color: var(--accent-hover);
}

.info-nav a[aria-current="page"] {
  color: var(--text);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.license-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.88rem;
  margin: 0.75rem 0 1rem;
}

.license-table th,
.license-table td {
  text-align: left;
  padding: 0.55rem 0.65rem;
  border-bottom: 1px solid var(--border);
  vertical-align: top;
}

.license-table th {
  color: var(--text);
  font-weight: 600;
}

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

.license-table a {
  color: var(--accent);
  word-break: break-word;
}

/* Phone landscape & short viewports: side-by-side layout */
@media (orientation: landscape) and (max-height: 520px) {
  .subtitle {
    display: none;
  }

  .app-layout {
    display: grid;
    grid-template-columns: minmax(220px, 34%) 1fr;
    align-items: start;
    gap: 0.5rem;
  }

  .saved-state-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .setup-panel {
    border: none;
    background: transparent;
  }

  .setup-panel-summary {
    display: none;
  }

  .setup-panel-body {
    display: flex;
    padding: 0;
  }

  .controls-row {
    flex-direction: column;
  }

  .words-row,
  .numerals-row {
    grid-template-columns: 1fr 1fr;
  }

  .footer-tip,
  .keyboard-shortcuts {
    display: none;
  }
}

/* Tablet portrait & larger phones */
@media (min-width: 600px) and (orientation: portrait) {
  .app {
    padding:
      max(1rem, env(safe-area-inset-top))
      max(1rem, env(safe-area-inset-right))
      max(1rem, env(safe-area-inset-bottom))
      max(1rem, env(safe-area-inset-left));
  }

  .card {
    padding: 1rem;
  }

  .subtitle {
    display: block;
    font-size: 0.85rem;
  }

  .state-summary {
    display: block;
  }

  .setup-panel {
    border: none;
    background: transparent;
  }

  .setup-panel-summary {
    display: none;
  }

  .setup-panel-body {
    padding: 0;
  }

  .controls-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--gap);
  }

  .footer-tip {
    display: block;
  }
}

/* Tablet landscape & small desktop landscape */
@media (min-width: 700px) and (orientation: landscape) {
  .app-layout {
    display: grid;
    grid-template-columns: var(--sidebar-w) 1fr;
    align-items: start;
    gap: 0.85rem;
  }

  .card {
    padding: 1rem 1.1rem;
  }

  .subtitle {
    display: block;
    font-size: 0.85rem;
  }

  .state-summary {
    display: block;
  }

  .setup-panel {
    border: none;
    background: transparent;
  }

  .setup-panel-summary {
    display: none;
  }

  .setup-panel-body {
    padding: 0;
  }

  .controls-row {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--gap);
  }

  .footer-tip {
    display: block;
  }
}

/* Desktop portrait (tall narrow window) */
@media (min-width: 600px) and (orientation: portrait) and (min-height: 900px) {
  .app {
    max-width: 480px;
  }
}

/* Desktop landscape & wide screens */
@media (min-width: 900px) {
  .app {
    padding:
      max(1.25rem, env(safe-area-inset-top))
      max(1.5rem, env(safe-area-inset-right))
      max(1.25rem, env(safe-area-inset-bottom))
      max(1.5rem, env(safe-area-inset-left));
  }

  .card {
    padding: 1.25rem;
  }

  .app-layout {
    grid-template-columns: 320px 1fr;
    gap: 1.25rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  .digit-answer {
    font-size: 1.85rem;
  }
}

/* Mobile portrait: collapsible settings, compact learn buttons */
@media (max-width: 599px) and (orientation: portrait) {
  .subtitle {
    display: none;
  }

  .language-field .input-label {
    font-size: 0.68rem;
    margin-bottom: 0.2rem;
  }

  .actions.learn-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.4rem;
  }

  .actions.learn-actions #learn-hear {
    grid-column: 1 / -1;
    grid-row: 1;
  }

  .actions.learn-actions #learn-prev {
    grid-column: 1;
    grid-row: 2;
  }

  .actions.learn-actions #learn-next {
    grid-column: 2;
    grid-row: 2;
  }

  .actions:not(.learn-actions) {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.4rem;
  }

  .actions:not(.learn-actions) .btn-primary {
    grid-column: 1 / -1;
  }

  .input-row {
    flex-direction: row;
  }

  .input-row .btn-accent {
    flex-shrink: 0;
    width: auto;
    min-width: 5.5rem;
  }
}

@media (max-width: 599px) and (orientation: portrait) and (pointer: coarse) {
  .keyboard-shortcuts {
    display: none;
  }
}

/* Very narrow: stack numerals */
@media (max-width: 360px) {
  .words-row,
  .numerals-row {
    grid-template-columns: 1fr;
  }

  .saved-state-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}