:root {
  color-scheme: light;
  --bg: var(--tg-theme-bg-color, #f4f7fb);
  --panel: var(--tg-theme-secondary-bg-color, #ffffff);
  --ink: var(--tg-theme-text-color, #182230);
  --muted: var(--tg-theme-hint-color, #667085);
  --line: var(--tg-theme-section-separator-color, #d0d5dd);
  --accent: var(--tg-theme-link-color, #2563eb);
  --study: #b45309;
  --known: #15803d;
}

:root[data-telegram-theme="dark"] {
  color-scheme: dark;
  --study: #fbbf24;
  --known: #86efac;
}

/* PVAR-010: a user-selected appearance overrides Telegram palette only in
   this browser. The auto setting continues to follow Telegram theme variables. */
:root[data-course-theme="light"] {
  color-scheme: light;
  --bg: #f4f7fb; --panel: #ffffff; --ink: #182230;
  --muted: #667085; --line: #d0d5dd; --accent: #2563eb;
  --course-selected-bg: #2563eb; --course-selected-ink: #ffffff;
}
:root[data-course-theme="dark"] {
  color-scheme: dark;
  --bg: #101827; --panel: #1f2937; --ink: #f9fafb;
  --muted: #cbd5e1; --line: #64748b; --accent: #93c5fd;
  --course-selected-bg: #93c5fd; --course-selected-ink: #101827;
}
:root[data-course-reduce-motion="true"] *,
:root[data-course-reduce-motion="true"] *::before,
:root[data-course-reduce-motion="true"] *::after {
  animation-duration: 0.01ms !important;
  animation-iteration-count: 1 !important;
  transition-duration: 0.01ms !important;
  scroll-behavior: auto !important;
}

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

html {
  width: 100%;
  max-width: 100%;
}


body {
  margin: 0;
  min-height: 100vh;
  min-height: 100dvh;
  max-width: 100%;
  overflow-x: clip;
  background: var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

button,
select {
  font: inherit;
}

input,
textarea {
  font: inherit;
}

.app {
  width: min(100%, 760px);
  min-width: 0;
  max-width: 100%;
  min-height: 100vh;
  min-height: var(--app-viewport-height, 100dvh);
  margin: 0 auto;
  padding: 16px;
  padding-top: max(16px, env(safe-area-inset-top, 0px), var(--tg-safe-area-inset-top, 0px), var(--tg-content-safe-area-inset-top, 0px));
  padding-right: max(16px, env(safe-area-inset-right, 0px), var(--tg-safe-area-inset-right, 0px), var(--tg-content-safe-area-inset-right, 0px));
  padding-bottom: max(16px, env(safe-area-inset-bottom, 0px), var(--tg-safe-area-inset-bottom, 0px), var(--tg-content-safe-area-inset-bottom, 0px));
  padding-left: max(16px, env(safe-area-inset-left, 0px), var(--tg-safe-area-inset-left, 0px), var(--tg-content-safe-area-inset-left, 0px));
  display: grid;
  /* Prevent intrinsic card/select widths from expanding the page on phones. */
  grid-template-columns: minmax(0, 1fr);
  grid-auto-rows: max-content;
  align-content: start;
  gap: 12px;
}

.topbar {
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

h1,
h2,
p {
  margin: 0;
}

h1 {
  font-size: 28px;
  line-height: 1.1;
}

#progressText {
  margin-top: 4px;
  color: var(--muted);
  font-size: 14px;
}

.filters {
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

select,
button {
  min-width: 0;
  max-width: 100%;
  min-height: 44px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  color: var(--ink);
  padding: 0 12px;
}

button {
  cursor: pointer;
  font-weight: 650;
}

.card-stage {
  min-height: 0;
  min-width: 0;
  width: 100%;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  align-items: start;
}

.word-card {
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 14px 34px rgba(16, 24, 40, 0.10);
  touch-action: pan-y;
}

.word-card img {
  display: block;
  width: 100%;
  height: auto;
  max-height: min(52dvh, 460px);
  object-fit: contain;
  background: #eef2f6;
}

.word-body {
  min-width: 0;
  overflow-wrap: anywhere;
  padding: 16px;
}

.episode {
  color: var(--muted);
  font-size: 13px;
}

h2 {
  margin-top: 6px;
  font-size: 34px;
  line-height: 1.05;
}

.translation {
  margin-top: 6px;
  color: var(--accent);
  font-size: 22px;
  font-weight: 700;
}

.association {
  margin-top: 12px;
  color: var(--ink);
  line-height: 1.45;
}

.actions {
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 8px;
}

#studyButton {
  color: var(--study);
}

#knownButton {
  color: var(--known);
}

@media (max-width: 540px) {
  .app {
    padding: 12px;
  }

  .filters,
  .actions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  h2 {
    font-size: 30px;
  }
}

/* Telegram supplies its own accessible primary action at the bottom.
   Keep the normal in-page button for standalone browsers and old clients. */
.tg-main-enabled #knownButton {
  display: none;
}

.tg-main-enabled .actions {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

:where(button, select, input, textarea, summary, [tabindex="-1"]):focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

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

.connection-status {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--panel);
  color: var(--muted);
  font-size: 13px;
  line-height: 1.4;
}
.connection-status[data-kind="error"] { color: var(--study); }
.connection-status p { flex: 1 1 240px; }
.connection-status button, #accountRetry { min-height: 44px; }

@media (max-width: 540px) {
  .tg-main-enabled .actions {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .app {
    padding-top: max(12px, env(safe-area-inset-top, 0px), var(--tg-safe-area-inset-top, 0px), var(--tg-content-safe-area-inset-top, 0px));
    padding-right: max(12px, env(safe-area-inset-right, 0px), var(--tg-safe-area-inset-right, 0px), var(--tg-content-safe-area-inset-right, 0px));
    padding-bottom: max(12px, env(safe-area-inset-bottom, 0px), var(--tg-safe-area-inset-bottom, 0px), var(--tg-content-safe-area-inset-bottom, 0px));
    padding-left: max(12px, env(safe-area-inset-left, 0px), var(--tg-safe-area-inset-left, 0px), var(--tg-content-safe-area-inset-left, 0px));
  }
}

/* Compact learning dashboard: use the Telegram palette, no external UI toolkit. */
.learning-nav {
  min-width: 0;
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 6px;
}
.learning-nav button {
  min-height: 44px;
  padding: 6px 4px;
  font-size: 13px;
  font-weight: 600;
}
.learning-nav button[aria-pressed="true"] {
  border-color: var(--accent);
  background: var(--tg-theme-button-color, #2563eb);
  color: var(--tg-theme-button-text-color, #fff);
}
.learning-status {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
  font-size: 13px;
}
.learning-status span { color: var(--muted); }
[hidden] { display: none !important; }
@media (max-width: 540px) {
  .learning-nav { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .learning-status { display: block; }
  .learning-status span { display: block; margin-top: 3px; }
}

/* Per-device course ownership reminder; readable without opening backup details. */
.course-local-note {
  flex: 0 0 100%;
  margin: 4px 0 0;
  font-size: 12px;
  line-height: 1.5;
  color: var(--muted);
}

/* Optional local-only progress backup controls. */
#storageNotice {
  position: static;
  pointer-events: none;
}
#storageNotice,
#profileBackupNotice {
  width: 100%;
  margin: 8px 0 0;
  padding: 10px 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
  font-size: 13px;
  line-height: 1.35;
  overflow-wrap: anywhere;
  color: var(--study);
  pointer-events: none;
}
#storageNotice[data-kind="info"],
#profileBackupNotice[data-kind="info"] { color: var(--muted); }
.backup-tools { min-width: 0; font-size: 13px; }
.backup-tools summary { cursor: pointer; color: var(--accent); font-weight: 650; }
.backup-buttons { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.backup-buttons button { min-height: 36px; padding: 4px 10px; font-size: 13px; }
.backup-tools p { margin-top: 8px; color: var(--muted); font-size: 12px; line-height: 1.4; }
@media (max-width: 540px) {
  .backup-tools { width: 100%; }
  .backup-tools summary { margin-top: 6px; }
}

.backup-text-panel { width: 100%; margin-top: 10px; }
.backup-text-panel label { display: block; margin-bottom: 6px; font-weight: 650; }
.backup-text-panel textarea {
  display: block;
  width: 100%;
  max-width: 100%;
  min-height: 132px;
  padding: 10px;
  resize: vertical;
  font: 12px/1.4 ui-monospace, SFMono-Regular, Consolas, monospace;
  color: var(--ink);
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow-wrap: anywhere;
}

/* Learning V2: avoid answer leakage until the user explicitly reveals it. */
.training-controls { display: grid; grid-template-columns: auto minmax(0, 1fr); align-items: center; gap: 10px; }
.training-controls label { font-size: 13px; color: var(--muted); font-weight: 600; }
.training-prompt { font-size: 14px; font-weight: 600; color: var(--muted); text-align: center; }
.reveal-answer { width: 100%; border-color: var(--accent); color: var(--accent); }
@media (max-width: 540px) {
  .training-controls { grid-template-columns: minmax(0, 1fr); gap: 5px; }
}

.filters:has(#episodeFilter[hidden]) { grid-template-columns: minmax(0, 1fr); }


/* PVAR-015 account plane: server data stays separate from browser-local course progress. */
.account-switch { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 5px; }
.account-switch button { min-height: 44px; font-weight: 700; }
.account-switch button[aria-pressed="true"] {
  background: var(--course-selected-bg, var(--tg-theme-button-color, #2563eb));
  color: var(--course-selected-ink, var(--tg-theme-button-text-color, #fff));
  border-color: var(--accent);
}
#courseSurface { display: grid; gap: 12px; min-width: 0; }
.account-surface { display: grid; gap: 14px; min-width: 0; }
.account-header { display: grid; gap: 5px; }
.account-header h1 { margin: 0; }
.account-header p { margin: 0; }
#accountStatus { font-size: 13px; color: var(--muted); }
#accountStatus[role="alert"] { color: var(--study); }
.account-warning, .account-conflict {
  margin: 0; padding: 10px 12px; border: 1px solid var(--study);
  border-radius: 9px; color: var(--study); background: var(--panel);
}
.account-panel {
  min-width: 0; display: grid; gap: 10px; padding: 14px;
  border: 1px solid var(--line); border-radius: 12px; background: var(--panel);
}
.account-panel h2, .account-panel h3 { margin: 0; font-size: 20px; line-height: 1.2; }
.account-panel h3 { font-size: 16px; }
.account-optional { color: var(--muted); font-weight: 400; }
.account-form { display: grid; gap: 9px; }
.account-form label { font-weight: 600; font-size: 13px; }
.account-form input, .account-form textarea, .account-filter-form input {
  width: 100%; min-width: 0; box-sizing: border-box;
  min-height: 44px; padding: 9px 12px; border-radius: 9px;
  border: 1px solid var(--line); color: var(--ink); background: var(--panel);
}
.account-form textarea { min-height: 138px; resize: vertical; line-height: 1.45; }
.account-form button, .account-controls button { min-height: 44px; }
.account-filter-form { display: grid; gap: 9px; }
.account-filter-form > label, .account-filter-row label {
  display: grid; gap: 5px; min-width: 0; font-size: 13px; font-weight: 600;
}
.account-filter-row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.account-filter-row select { width: 100%; }
.account-stats {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 8px; margin: 0;
}
.account-stats > div { min-width: 0; padding: 9px; border: 1px solid var(--line); border-radius: 9px; }
.account-stats dt { color: var(--muted); font-size: 11px; }
.account-stats dd { margin: 3px 0 0; font-size: 19px; font-weight: 700; }
.account-controls { display: grid; gap: 6px; }
.account-word-list { margin: 0; padding: 0; list-style: none; display: grid; gap: 8px; }
.account-word { display: flex; justify-content: space-between; align-items: center;
  gap: 8px; overflow-wrap: anywhere; border: 1px solid var(--line); background: var(--bg);
  padding: 10px; border-radius: 9px; }
.account-word span { min-width: 0; }
.account-word button { flex-shrink: 0; }
.account-empty { padding: 12px; border: 1px dashed var(--line); border-radius: 9px; color: var(--muted); }
.account-preview { display: grid; gap: 8px; padding: 12px; border: 1px solid var(--accent); border-radius: 10px; }
.account-preview > strong { font-size: 22px; overflow-wrap: anywhere; }
.account-preview audio, .account-detail audio { width: 100%; max-width: 100%; }
.account-example-list, .account-batch-list { margin: 0; padding-left: 22px; display: grid; gap: 7px; }
.account-example-list li { display: grid; gap: 2px; overflow-wrap: anywhere; }
.account-example-list li span:last-child { color: var(--muted); font-size: 13px; }
.account-batch-list li { overflow-wrap: anywhere; }
.account-action-row, .account-title-row {
  display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px;
}
.account-action-row > button { flex: 1 1 180px; }
.account-title-row h2 { flex: 1 1 220px; }
.account-detail { scroll-margin-top: 12px; }
.account-danger { color: #b42318; border-color: #b42318; }
.account-conflict { display: grid; gap: 9px; }
.account-conflict p { line-height: 1.45; }
.account-training { display: grid; gap: 9px; border: 1px solid var(--line);
  border-radius: 12px; padding: 16px; background: var(--panel); text-align: center; }
#accountPrompt { font-size: 24px; font-weight: 700; }
#accountAnswer { color: var(--accent); font-size: 20px; }
.account-training-modes {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 7px;
  margin: 0; padding: 10px; border: 1px solid var(--line); border-radius: 9px;
}
.account-training-modes legend { padding: 0 5px; font-weight: 700; }
.account-training-modes label {
  min-height: 44px; display: flex; align-items: center; justify-content: center;
  gap: 6px; padding: 6px; border: 1px solid var(--line); border-radius: 8px;
}
.account-training progress { width: 100%; min-height: 12px; }
.account-training-choices { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.account-training-choices button { min-height: 48px; overflow-wrap: anywhere; }
.account-match-board { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.account-match-board section { min-width: 0; display: grid; align-content: start; gap: 8px; }
.account-match-board h3 { margin: 0; font-size: 14px; }
.account-match-column { display: grid; gap: 8px; }
.account-match-column button { min-height: 48px; overflow-wrap: anywhere; }
.account-match-column button.is-selected { border-color: var(--accent); box-shadow: 0 0 0 2px var(--accent); }
.account-match-column button.is-incorrect { border-color: #b42318; color: #b42318; }
.account-match-column button.is-matched {
  border-color: var(--known); color: var(--known); text-decoration: line-through; opacity: 0.72;
}
.account-training :focus-visible { outline: 3px solid var(--accent); outline-offset: 2px; }
button:disabled { cursor: not-allowed; opacity: 0.58; }
@media (max-width: 540px) {
  .account-panel { padding: 12px; }
  .account-word { align-items: flex-start; flex-wrap: wrap; }
  .account-word button { width: 100%; }
  .account-filter-row, .account-stats, .account-training-modes,
  .account-training-choices { grid-template-columns: minmax(0, 1fr); }
  .account-stats > div { display: flex; align-items: baseline; justify-content: space-between; gap: 8px; }
  .account-form :where(input, textarea), .account-filter-form input { scroll-margin-bottom: 45dvh; }
}
@media (max-width: 380px) {
  .account-match-board { grid-template-columns: minmax(0, 1fr); }
}

.account-note { margin: 4px 0; font-size: 12px; line-height: 1.5; color: var(--muted); }

/* Every hidden HTML control must remain visually hidden even under display:grid. */
[hidden] { display: none !important; }

/* PVAR-010: controls are separated from course/backups and have 44px targets. */
.profile-settings { display: grid; gap: 10px; }
.profile-settings h2 { margin: 0; font-size: 18px; }
.profile-setting { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; font-size: 14px; }
.profile-setting input[type="checkbox"] { width: 20px; height: 20px; accent-color: var(--accent); }
.profile-setting select { flex: 1 1 190px; min-height: 44px; }
#profileSettingsReset { min-height: 44px; }
#profileSettingsNotice[role="alert"] { color: var(--study); }

/* PVAR-010 local-only progress summary (no server-side account data). */
.profile-summary { display: grid; gap: 10px; }
.profile-summary h2 { margin: 0; font-size: 18px; }
.profile-stats { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; margin: 0; }
.profile-stats > div {
  display: grid; gap: 6px; border: 1px solid var(--line);
  border-radius: 10px; padding: 12px; min-width: 0; background: var(--panel);
}
.profile-stats dt { font-size: 12px; color: var(--muted); }
.profile-stats dd { margin: 0; font-size: 22px; font-weight: 700; }
.profile-subheading { margin: 4px 0 0; font-size: 16px; }
.profile-modes { display: grid; gap: 6px; margin: 0; }
.profile-modes > div {
  display: flex; align-items: baseline; justify-content: space-between;
  flex-wrap: wrap; gap: 8px; min-width: 0; padding: 10px 12px;
  border: 1px solid var(--line); border-radius: 9px;
}
.profile-modes dt { font-size: 13px; }
.profile-modes dd { margin: 0; font-weight: 650; white-space: nowrap; font-variant-numeric: tabular-nums; }
@media (max-width: 340px) { .profile-stats { grid-template-columns: minmax(0, 1fr); } }

/* PVAR-010: the browser cannot verify an external backup was saved. */
.backup-reminder { margin: 4px 0 8px; line-height: 1.5; font-size: 13px;
  color: var(--ink); overflow-wrap: anywhere; }
#confirmBackupSavedButton { min-height: 44px; width: 100%; text-align: start; }

/* PVAR-010: achievements are read-only projections of the local course. */
.profile-achievements-section { display: grid; gap: 10px; }
.profile-achievements-section h2 { margin: 0; font-size: 18px; }
.profile-achievements { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.profile-achievements li {
  display: flex; justify-content: space-between; align-items: center;
  flex-wrap: wrap; gap: 8px; padding: 12px;
  border: 1px solid var(--line); border-radius: 10px; background: var(--panel);
}
.profile-achievements li > span:first-child { display: grid; gap: 4px; min-width: 0; }
.profile-achievements small { color: var(--muted); font-size: 12px; line-height: 1.4; }
.achievement-status { font-size: 12px; font-weight: 650; color: var(--muted); }
.achievement-status[data-earned="true"] { color: var(--known); }

/* PVAR-008 shell: explicit [hidden] handling wins over display:grid.
   A hidden page must never remain keyboard- or screen-reader-visible. */
#homeSurface[hidden], #courseSurface[hidden], #accountSurface[hidden],
#profileSurface[hidden], #accountTraining[hidden] { display: none !important; }
.home-surface, .profile-surface { display: grid; gap: 14px; min-width: 0; }
.product-header { display: grid; gap: 6px; }
.product-header h1, .product-header p { margin: 0; }
.home-actions { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 10px; }
.home-actions button, #profileReset { min-height: 44px; }
.account-switch {
  display: grid; grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 5px; position: sticky; bottom: 0; z-index: 2;
  padding: 8px 0 max(8px, env(safe-area-inset-bottom, 0px));
  background: var(--bg);
}
.account-switch button { min-width: 0; padding: 8px 2px; font-size: 12px; overflow-wrap: anywhere; }
@media (max-width: 350px) {
  .account-switch button { font-size: 11px; }
  .home-actions { grid-template-columns: minmax(0, 1fr); }
}

/* PVAR-009: local quiz controls; no user-entered answers are placed in HTML. */
.course-interactive { display: grid; gap: 10px; }
.choice-answers { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
.choice-answers button { min-height: 48px; overflow-wrap: anywhere; text-align: start; }
#spellingForm label { font-weight: 600; font-size: 14px; }
#spellingInput {
  width: 100%; box-sizing: border-box; min-height: 44px; border: 1px solid var(--line);
  background: var(--panel); color: var(--ink); border-radius: 9px; padding: 10px 12px;
}
#spellingForm button, #interactiveNext { min-height: 44px; }
.course-feedback { margin: 0; padding: 10px 12px; border-radius: 9px; background: var(--panel); }
@media (max-width: 400px) {
  .choice-answers { grid-template-columns: minmax(0, 1fr); }
}