:root {
  color-scheme: light;
  --bg: #f6f2ea;
  --surface: #fbf8f2;
  --surface-strong: #ffffff;
  --ink: #1f1c17;
  --muted: #6b6257;
  --line: #ddd4c7;
  --accent: #1d5c63;
  --accent-strong: #143f44;
  --accent-soft: #e7f0ef;
  --shadow: 0 10px 24px rgba(40, 32, 18, 0.06);
}

body.theme-dark {
  color-scheme: dark;
  --bg: #141310;
  --surface: #1c1a16;
  --surface-strong: #22201b;
  --ink: #f2ede4;
  --muted: #b2a898;
  --line: #3b352d;
  --accent: #78b2b8;
  --accent-strong: #c6eaed;
  --accent-soft: #203336;
  --shadow: 0 14px 30px rgba(0, 0, 0, 0.3);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: Georgia, "Times New Roman", serif;
  background: var(--bg);
  min-height: 100vh;
}

body:not(.settings-page) {
  height: 100dvh;
  min-height: 100dvh;
  overflow: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

a:focus-visible,
button:focus-visible,
select:focus-visible,
textarea:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid #f4b942;
  outline-offset: 3px;
  box-shadow: 0 0 0 6px rgba(244, 185, 66, 0.24);
}

.app-shell {
  width: 100%;
  margin: 0;
}

body:not(.settings-page) .app-shell {
  height: 100dvh;
  overflow: hidden;
}

.app-shell-with-sidebar {
  display: flex;
  align-items: flex-start;
  gap: 0;
  width: 100%;
  margin: 0;
}

body:not(.settings-page) .app-shell-with-sidebar {
  height: 100dvh;
}

.app-main {
  min-width: 0;
  flex: 1;
  padding-left: 16px;
  padding-right: 12px;
}

body:not(.settings-page) .app-main {
  display: flex;
  flex-direction: column;
  height: 100dvh;
  min-height: 0;
  overflow: hidden;
}

.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  min-height: 34px;
  margin: 0 0 2px;
  padding-top: 4px;
}

.top-brand {
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}

.language-switcher {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 700;
}

.language-switcher select {
  min-width: 132px;
  padding: 0.42rem 0.68rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
}

.site-sidebar {
  width: 42px;
  flex: 0 0 42px;
  margin: 0;
  min-height: calc(100vh - 36px);
  padding: 4px 4px 0 4px;
  border-right: 1px solid var(--line);
  position: sticky;
  top: 0;
}

body:not(.settings-page) .site-sidebar {
  min-height: 100dvh;
}

.site-nav {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}

.sidebar-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--muted);
  padding: 6px 0;
  border-radius: 0;
  position: relative;
  width: 100%;
}

.sidebar-link:hover {
  color: var(--ink);
}

.sidebar-link-icon {
  width: 18px;
  height: 18px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 18px;
}

.sidebar-link-icon svg {
  width: 18px;
  height: 18px;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

.sidebar-link:hover::after {
  content: attr(data-label);
  position: absolute;
  left: calc(100% + 12px);
  top: 50%;
  transform: translateY(-50%);
  padding: 0.32rem 0.6rem;
  border-radius: 999px;
  background: var(--ink);
  color: #fff;
  font-size: 0.84rem;
  line-height: 1;
  white-space: nowrap;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.12);
  z-index: 20;
  pointer-events: none;
}

body.theme-dark .sidebar-link:hover::after {
  background: var(--surface-strong);
  color: var(--ink);
  border: 1px solid var(--line);
}

.primary-action,
.secondary-action,
.auth-form button,
.inline-form button,
.inline-action-form button,
.rating-form button,
.secondary-button,
.danger-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  padding: 0.8rem 1.2rem;
  font-weight: 700;
}

.primary-action,
.auth-form button,
.inline-form button,
.inline-action-form button,
.rating-form button {
  background: var(--accent);
  color: white;
  border: 0;
}

.secondary-action,
.secondary-button {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--ink);
}

.danger-button {
  border: 1px solid rgba(125, 63, 48, 0.22);
  background: #7d3f30;
  color: white;
}

.landing-shell,
.auth-shell,
.dashboard-shell,
.spec-shell {
  width: 100%;
  margin: 0 0 24px;
}

body:not(.settings-page) .landing-shell,
body:not(.settings-page) .auth-shell,
body:not(.settings-page) .dashboard-shell,
body:not(.settings-page) .spec-shell {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-height: 0;
  margin-bottom: 0;
  overflow: hidden;
  overscroll-behavior: contain;
  padding-bottom: 8px;
}

.hero-card,
.auth-card,
.spec-card {
  background: transparent;
  border: 0;
  border-radius: 0;
  box-shadow: none;
}

.hero-card {
  padding: 22px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  align-items: stretch;
  justify-items: center;
}

.hero-copy {
  width: min(920px, 100%);
  margin: 0 auto;
  text-align: center;
}

.hero-copy h1,
.auth-card h1,
.dashboard-hero h1,
.spec-heading h1 {
  margin: 0;
  line-height: 1;
  font-size: clamp(1.7rem, 3.4vw, 3.1rem);
}

.landing-brand {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 14px;
  margin-bottom: 22px;
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--accent-strong);
}

.landing-brand img {
  width: 72px;
  height: 72px;
  object-fit: contain;
  border-radius: 14px;
  background: #fff;
  padding: 8px;
  border: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 6px;
  color: var(--accent);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.hero-text,
.feature-card p,
.dashboard-badge,
.markdown-content p,
.markdown-content li {
  color: var(--muted);
  line-height: 1.65;
  font-size: 1.02rem;
}

.hero-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 26px;
  justify-content: center;
}

.stat-card,
.feature-card,
.dashboard-badge {
  background: transparent;
  border: 0;
  border-radius: 0;
}

.stat-card {
  padding: 0 0 14px;
}

.stat-value {
  display: block;
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent-strong);
}

.stat-label {
  display: block;
  margin-top: 8px;
  color: var(--muted);
}

.dashboard-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 24px 44px;
  margin-top: 26px;
}

.feature-card {
  padding: 22px 0 0;
}

body:not(.settings-page) .dashboard-grid {
  gap: 14px 28px;
  margin-top: 14px;
}

body:not(.settings-page) .dashboard-grid,
body:not(.settings-page) .management-grid {
  min-height: 0;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-right: 4px;
}

body:not(.settings-page) .home-progress-grid {
  flex: 1;
  min-height: 0;
  align-items: stretch;
  grid-template-rows: minmax(0, 1fr);
  overflow: hidden;
}

body:not(.settings-page) .known-vocabulary-panel {
  min-height: 0;
  overflow: hidden;
}

body:not(.settings-page) .ai-assessment-panel {
  height: 100%;
  min-height: 0;
  max-height: 100%;
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-right: 4px;
}

body:not(.settings-page) .feature-card {
  padding-top: 12px;
}

body:not(.settings-page) .hero-actions {
  margin-top: 14px;
}

body:not(.settings-page) .dashboard-hero {
  flex: 0 0 auto;
}

body:not(.settings-page) .status-banner {
  flex: 0 0 auto;
  margin-top: 8px;
  padding: 10px 12px;
}

.feature-card h2 {
  margin: 0 0 6px;
  color: var(--accent-strong);
  font-size: 1.28rem;
}

.card-heading {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 16px;
}

.language-total,
.language-pill {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 0.35rem 0.8rem;
  font-size: 0.86rem;
  font-weight: 700;
}

.language-total {
  color: var(--accent-strong);
  background: var(--accent-soft);
}

.language-pill {
  color: var(--accent-strong);
  background: rgba(29, 92, 99, 0.14);
}

.stack-form {
  display: grid;
  gap: 10px;
  margin-top: 18px;
}

.stack-form label {
  font-weight: 700;
  color: var(--accent-strong);
}

.inline-form {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.inline-action-form {
  margin-top: 18px;
}

.inline-form select {
  min-width: 220px;
  flex: 1;
  padding: 0.95rem 1rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
}

.auth-form textarea,
.auth-form select,
.auth-form input[type="file"] {
  width: 100%;
  padding: 0.95rem 1rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
}

.language-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.language-list-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 0;
  background: transparent;
}

.language-name-row {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.language-name {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--accent-strong);
}

.language-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.card-note {
  margin: 10px 0 0;
  color: var(--muted);
  line-height: 1.6;
}

.status-banner {
  margin-top: 18px;
  padding: 14px 18px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: var(--surface-strong);
  font-weight: 700;
}

.status-banner-success {
  color: #1d5c63;
  background: #edf6f5;
}

.status-banner-error {
  color: #7d3f30;
  background: #fff1ee;
}

.theme-fieldset {
  margin: 0;
  padding: 0;
  border: 0;
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.theme-fieldset legend {
  margin: 0 4px 0 0;
  padding: 0;
  color: var(--accent-strong);
  font-weight: 700;
  float: left;
}

.theme-option {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0;
  background: transparent;
}

.theme-option input {
  width: auto;
  margin: 0;
}

.theme-option strong {
  display: block;
}

.auth-shell {
  display: flex;
  justify-content: center;
}

.auth-card {
  width: min(560px, 100%);
  padding: 32px;
}

.auth-form {
  display: grid;
  gap: 10px;
  margin-top: 24px;
}

.auth-form label {
  font-weight: 700;
  color: var(--accent-strong);
}

.auth-form input {
  width: 100%;
  padding: 0.95rem 1rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 16px;
}

.auth-form input:focus {
  outline: 2px solid rgba(29, 92, 99, 0.15);
  border-color: var(--accent);
}

.auth-form textarea:focus,
.auth-form select:focus {
  outline: 2px solid rgba(29, 92, 99, 0.15);
  border-color: var(--accent);
}

.auth-switch {
  margin: 18px 0 0;
  color: var(--muted);
}

.auth-switch a {
  color: var(--accent-strong);
  font-weight: 700;
}

@media (max-width: 900px) {
  body:not(.settings-page) {
    height: auto;
    min-height: 100dvh;
    overflow-x: hidden;
    overflow-y: auto;
  }

  .app-shell {
    width: min(1420px, calc(100vw - 32px));
    margin: 0 auto;
  }

  .app-shell-with-sidebar {
    width: 100%;
    margin: 0;
  }

  body:not(.settings-page) .app-shell,
  body:not(.settings-page) .app-shell-with-sidebar {
    height: auto;
    min-height: 100dvh;
    overflow: visible;
  }

  .app-shell-with-sidebar {
    display: block;
    padding-top: 14px;
  }

  body:not(.settings-page) .app-shell-with-sidebar {
    display: block;
    padding-top: 0;
  }

  .site-sidebar {
    position: static;
    width: 100%;
    min-height: 0;
    padding: 0 0 12px;
    border-right: 0;
  }

  body:not(.settings-page) .site-sidebar {
    flex: 0 0 auto;
    min-height: 0;
    padding: 8px 12px 4px;
    border-right: 0;
  }

  .app-main {
    padding-left: 0;
  }

  body:not(.settings-page) .app-main {
    display: block;
    flex: none;
    height: auto;
    min-height: 0;
    padding: 0 12px 16px;
    overflow: visible;
  }

  .top-bar {
    flex-direction: column;
    align-items: flex-start;
  }

  body:not(.settings-page) .top-bar {
    flex: 0 0 auto;
    flex-direction: row;
    align-items: center;
    gap: 8px;
    min-height: 0;
    margin-bottom: 6px;
    padding-top: 4px;
  }

  .site-nav {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
  }

  body:not(.settings-page) .site-nav {
    flex-wrap: nowrap;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  body:not(.settings-page) .sidebar-link {
    width: auto;
    min-width: 38px;
    min-height: 38px;
    padding: 8px;
  }

  body:not(.settings-page) .sidebar-link-icon,
  body:not(.settings-page) .sidebar-link-icon svg {
    width: 20px;
    height: 20px;
  }

  body:not(.settings-page) .language-switcher {
    margin-left: auto;
    min-width: 0;
  }

  body:not(.settings-page) .language-switcher select {
    min-width: 0;
    width: min(48vw, 180px);
    padding: 0.4rem 0.58rem;
    font-size: 0.78rem;
  }

  body:not(.settings-page) .landing-shell,
  body:not(.settings-page) .auth-shell,
  body:not(.settings-page) .dashboard-shell,
  body:not(.settings-page) .spec-shell {
    display: block;
    flex: none;
    min-height: 0;
    margin-bottom: 16px;
    overflow: visible;
    padding-bottom: 16px;
  }

  body:not(.settings-page) .dashboard-grid,
  body:not(.settings-page) .management-grid,
  body:not(.settings-page) .home-progress-grid,
  body:not(.settings-page) .conversation-layout,
  body:not(.settings-page) .grammar-topic-layout {
    min-height: 0;
    overflow: visible;
  }

  body:not(.settings-page) .home-progress-grid {
    grid-template-rows: auto;
  }

  body:not(.settings-page) .ai-assessment-panel {
    height: auto;
    max-height: none;
    overflow: visible;
  }

  body:not(.settings-page) .known-vocabulary-panel {
    overflow: visible;
  }

  body:not(.settings-page) .live-chat-card,
  body:not(.settings-page) .grammar-chat-card {
    height: auto;
    overflow: visible;
  }

  body:not(.settings-page) .live-chat-thread {
    flex: none;
    height: clamp(260px, 52dvh, 420px);
  }

  body:not(.settings-page) .grammar-chat-thread {
    flex: none;
    height: clamp(240px, 48dvh, 400px);
  }

  body:not(.settings-page) .grammar-lesson-card {
    overflow: visible;
  }

  body:not(.settings-page) .grammar-lesson-content {
    max-height: min(58dvh, 520px);
    overflow-y: auto;
  }

  body:not(.settings-page) .grammar-topic-list-card {
    display: block;
    flex: none;
    overflow: visible;
  }

  body:not(.settings-page) .topic-list-scroll {
    max-height: none;
    overflow: visible;
    padding-right: 0;
  }

  body:not(.settings-page) .conversation-history-sidebar {
    position: static;
    padding-top: 0;
  }

  body:not(.settings-page) .conversation-history-sidebar .conversation-history-scroll,
  body:not(.settings-page) .conversation-history-scroll {
    max-height: min(48dvh, 320px);
  }

  .sidebar-link::after {
    display: none;
  }

  .hero-card,
  .feature-grid,
  .dashboard-grid {
    grid-template-columns: 1fr;
  }

  .card-heading,
  .language-list-item,
  .conversation-list-item,
  .topic-list-item {
    flex-direction: column;
    align-items: flex-start;
  }
}

.form-error {
  margin-top: 18px;
  padding: 14px 16px;
  color: #7f1d1d;
  background: #fce7e7;
  border: 1px solid #e7b7b7;
  border-radius: 16px;
}

.dashboard-hero {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 12px;
  padding: 0 0 2px;
}

.dashboard-badge {
  padding: 0;
  min-width: 0;
  text-align: right;
  color: var(--muted);
  font-weight: 700;
}

.conversation-header-meta {
  display: grid;
  gap: 2px;
  justify-items: end;
}

body.theme-dark .inline-form select,
body.theme-dark .auth-form textarea,
body.theme-dark .auth-form select,
body.theme-dark .auth-form input[type="file"],
body.theme-dark .auth-form input,
body.theme-dark .deck-search-input,
body.theme-dark .timescale-form select,
body.theme-dark .language-switcher select,
body.theme-dark .flashcard-face,
body.theme-dark .flashcard-answer,
body.theme-dark .chat-message-assistant,
body.theme-dark .landing-brand img {
  background: var(--surface-strong);
}

body.theme-dark .chat-message-user {
  background: rgba(120, 178, 184, 0.12);
}

body.theme-dark .status-banner-success {
  color: #a8e1e4;
  background: #183034;
}

body.theme-dark .status-banner-error {
  color: #f1b5a8;
  background: #39211c;
}

body.theme-dark .form-error {
  color: #f7cac4;
  background: #3b2222;
  border-color: #6e3c3c;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  margin-top: 18px;
}

body:not(.settings-page) .stats-grid {
  gap: 12px;
  margin-top: 10px;
}

.vocabulary-grid {
  align-items: start;
}

.compact-form {
  margin-top: 12px;
}

.auto-import-form {
  padding-top: 14px;
  border-top: 1px solid var(--line);
}

.stack-actions {
  display: grid;
  gap: 12px;
  margin-top: 18px;
}

.vocabulary-list-card {
  margin-top: 18px;
}

body:not(.settings-page) .vocabulary-list-card,
body:not(.settings-page) .review-workspace-card {
  margin-top: 10px;
}

.review-workspace-card {
  margin-top: 18px;
  padding-top: 0;
}

.review-workspace-card .review-queue-list {
  margin-top: 2px;
}

.vocabulary-header-actions {
  align-items: center;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.vocabulary-header-actions .dashboard-badge {
  white-space: nowrap;
}

.fullscreen-workspace-exit {
  display: none;
}

.flashcard-direction-form {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  margin: 0 0 10px;
  flex-wrap: wrap;
}

.flashcard-direction-form > .secondary-button {
  min-height: 40px;
  padding: 0.56rem 0.86rem;
  font: inherit;
  cursor: pointer;
}

.segmented-control,
.settings-radio-group {
  margin: 0;
  padding: 0;
  border: 0;
}

.segmented-control {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.segmented-control legend,
.settings-radio-group legend {
  margin: 0 8px 0 0;
  padding: 0;
  color: var(--accent-strong);
  font-weight: 700;
}

.segmented-control legend {
  float: left;
  line-height: 2.35;
}

.segmented-control label,
.settings-radio-group label {
  position: relative;
  display: inline-flex;
  align-items: center;
  cursor: pointer;
}

.segmented-control input,
.settings-radio-group input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

.segmented-control span,
.settings-radio-group span {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--ink);
  background: transparent;
  font-weight: 700;
}

.segmented-control span {
  padding: 0.56rem 0.86rem;
}

.settings-radio-group {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.settings-radio-group legend {
  width: 100%;
}

.settings-radio-group span {
  padding: 0.72rem 1rem;
}

.segmented-control input:checked + span,
.settings-radio-group input:checked + span {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.segmented-control input:focus-visible + span,
.settings-radio-group input:focus-visible + span {
  outline: 3px solid #f4b942;
  outline-offset: 3px;
  box-shadow: 0 0 0 6px rgba(244, 185, 66, 0.24);
}


.dashboard-hero-compact {
  align-items: flex-start;
}

.hero-actions-left {
  justify-content: flex-start;
}

.hero-action-form {
  margin: 0;
}

.hero-action-form button {
  font: inherit;
  cursor: pointer;
}

.home-stats-grid {
  margin-top: 12px;
}

.home-grid {
  align-items: start;
}

.home-progress-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(340px, 0.92fr);
  gap: 34px 52px;
  margin-top: 30px;
  align-items: start;
}

.known-vocabulary-total {
  margin: 6px 0 0;
  color: var(--muted);
  font-weight: 700;
}

.timescale-form {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-weight: 700;
}

.timescale-form select {
  padding: 0.55rem 0.8rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
}

.known-chart-frame {
  margin-top: 24px;
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 10px;
  align-items: stretch;
}

.known-y-axis {
  position: relative;
  height: 240px;
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.known-y-axis span {
  position: absolute;
  right: 0;
  transform: translateY(-50%);
}

.known-line-chart {
  height: 240px;
  min-width: 0;
}

.known-line-chart svg {
  display: block;
  width: 100%;
  height: 100%;
  overflow: visible;
}

.known-line {
  fill: none;
  stroke: var(--accent);
  stroke-width: 2.8;
  stroke-linecap: round;
  stroke-linejoin: round;
  vector-effect: non-scaling-stroke;
}

.known-chart-labels {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-left: 44px;
  margin-top: 10px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 700;
}

.known-vocabulary-panel.is-loading {
  opacity: 0.72;
}

.ai-assessment-panel .inline-action-form {
  margin-top: 24px;
}

.settings-panel {
  margin-top: 12px;
  padding-top: 0;
}

.settings-shell .auth-form,
.settings-shell .compact-form,
.settings-shell .stack-form,
.settings-shell .inline-action-form {
  margin-top: 7px;
}

.settings-shell .auth-form {
  gap: 6px;
}

.settings-shell .auth-form input,
.settings-shell .auth-form textarea,
.settings-shell .auth-form select,
.settings-shell .auth-form input[type="file"],
.settings-shell .inline-form select {
  padding: 0.58rem 0.7rem;
  border-radius: 10px;
}

.settings-single-panel {
  display: grid;
  gap: 0;
}

.settings-action {
  min-width: fit-content;
  position: relative;
  justify-self: end;
}

.settings-action summary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: fit-content;
  cursor: pointer;
  list-style: none;
  padding: 0.55rem 0.75rem;
  border: 1px solid rgba(29, 92, 99, 0.18);
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-weight: 700;
  line-height: 1;
}

.settings-action summary::-webkit-details-marker {
  display: none;
}

.settings-action[open] summary {
  display: flex;
  width: fit-content;
  background: transparent;
  color: var(--accent-strong);
  font-size: 0;
  margin-bottom: 7px;
  margin-left: auto;
}

.settings-action[open] summary::after {
  content: "Close";
  font-size: 0.9rem;
}

.settings-action form {
  min-width: min(680px, calc(100vw - 96px));
}

.settings-shell .card-note {
  margin-top: 3px;
  line-height: 1.35;
  font-size: 0.9rem;
}

.settings-shell h2 {
  font-size: 1.08rem;
  margin-bottom: 2px;
}

.settings-shell .language-name {
  font-size: 1.02rem;
}

.settings-shell .language-total,
.settings-shell .language-pill {
  padding: 0.22rem 0.52rem;
  font-size: 0.76rem;
}

.settings-row,
.settings-language-row {
  display: grid;
  grid-template-columns: minmax(220px, 1fr) auto;
  gap: 12px;
  align-items: start;
  padding: 9px 0;
  border-top: 1px solid var(--line);
}

.settings-row:first-child {
  border-top: 0;
}

.settings-row-danger {
  border-top-color: rgba(125, 63, 48, 0.28);
}

.settings-actions {
  display: flex;
  align-items: flex-start;
  justify-content: flex-end;
  gap: 6px;
  flex-wrap: wrap;
}

.settings-language-list {
  display: grid;
  gap: 0;
  padding-bottom: 4px;
}

.settings-language-row {
  margin-left: 18px;
  padding: 7px 0;
  grid-template-columns: minmax(220px, 1fr) auto;
}

.settings-shell .language-actions {
  gap: 6px;
}

.settings-shell .language-actions button,
.settings-shell .language-actions a,
.settings-shell .inline-action-form button,
.settings-shell .inline-action-form a,
.settings-shell .inline-form button,
.settings-shell .auth-form button {
  padding: 0.55rem 0.75rem;
}

.settings-form-grid {
  grid-template-columns: minmax(120px, 180px) minmax(0, 1fr);
  align-items: center;
  max-width: 760px;
}

.settings-form-grid > button {
  grid-column: 2;
  justify-self: start;
}

.settings-theme-form {
  grid-template-columns: minmax(0, 1fr) auto;
  align-items: end;
}

.settings-theme-form > button {
  grid-column: 2;
}

.settings-inline-add {
  display: flex;
  align-items: center;
  gap: 10px;
}

.settings-inline-add label {
  white-space: nowrap;
}

.settings-inline-add .inline-form {
  flex: 1;
}

.activity-list {
  list-style: none;
  margin: 16px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

body:not(.settings-page) .activity-list {
  gap: 6px;
  margin-top: 8px;
}

.activity-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  padding: 14px 0;
}

body:not(.settings-page) .activity-item {
  padding: 8px 0;
}

.activity-title,
.activity-detail {
  display: block;
}

.activity-title {
  color: var(--accent-strong);
  font-weight: 700;
}

.activity-detail,
.activity-item time {
  color: var(--muted);
  line-height: 1.5;
}

.activity-item time {
  flex: 0 0 auto;
  font-size: 0.9rem;
  white-space: nowrap;
}

.embedded-flashcard-card {
  margin-top: 18px;
}

.deck-stats-grid {
  margin-top: 22px;
}

.deck-search-label {
  display: block;
  margin-top: 18px;
  color: var(--accent-strong);
  font-weight: 700;
}

.deck-contents-card summary {
  cursor: pointer;
  color: var(--accent-strong);
  font-size: 1.18rem;
  font-weight: 700;
  list-style-position: inside;
}

.deck-contents-scroll {
  max-height: 560px;
  overflow-y: auto;
  padding-right: 8px;
}

.deck-search-input {
  width: 100%;
  margin-top: 8px;
  padding: 0.9rem 1rem;
  font: inherit;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 999px;
}

.deck-table {
  margin-top: 18px;
}

.deck-table-head,
.deck-row summary {
  display: grid;
  grid-template-columns: 1.1fr 1.2fr 0.7fr 1fr 0.45fr;
  gap: 14px;
  align-items: center;
}

.deck-table-head {
  padding-bottom: 10px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.deck-row summary {
  padding: 14px 0;
  cursor: pointer;
  list-style: none;
}

.deck-row summary::-webkit-details-marker {
  display: none;
}

.deck-word {
  color: var(--accent-strong);
  font-weight: 700;
}

.deck-row-open {
  color: var(--accent);
  font-weight: 700;
  text-align: right;
}

.deck-row[open] .deck-row-open {
  color: var(--muted);
}

.deck-row-detail {
  padding: 0 0 12px;
}

.deck-edit-form {
  max-width: 680px;
}

.narrow-shell {
  max-width: 760px;
}

.confirmation-card {
  margin-top: 18px;
}

.edit-grid {
  margin-top: 18px;
  padding-top: 18px;
}

.empty-state-card {
  margin-top: 18px;
}

.summary-list {
  margin: 18px 0 0;
  padding-left: 1.2rem;
  color: var(--muted);
  line-height: 1.8;
}

.chat-card {
  margin-top: 10px;
}

.conversation-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(250px, 320px);
  gap: 24px;
  align-items: start;
}

body:not(.settings-page) .conversation-layout {
  flex: 1;
  align-items: stretch;
  min-height: 0;
  overflow: hidden;
}

.conversation-layout:has(.conversation-history-sidebar:not([open])) {
  grid-template-columns: minmax(0, 1fr) max-content;
  gap: 10px;
}

.conversation-live-panel {
  min-width: 0;
}

.chat-card .auth-form textarea {
  padding: 0.58rem 0.7rem;
}

.live-chat-card {
  display: flex;
  flex-direction: column;
  min-height: 0;
}

body:not(.settings-page) .live-chat-card {
  height: 100%;
  overflow: hidden;
}

body:not(.settings-page) .conversation-live-panel {
  align-self: stretch;
}

.conversation-end-form {
  display: flex;
  justify-content: flex-end;
  margin-top: 8px;
}

.conversation-history-card {
  margin-top: 10px;
}

.conversation-history-card summary {
  cursor: pointer;
  color: var(--accent-strong);
  font-size: 1.18rem;
  font-weight: 700;
  list-style-position: inside;
}

.conversation-history-sidebar {
  position: sticky;
  top: 44px;
  min-width: 0;
  padding-top: 10px;
  overflow: hidden;
}

.conversation-history-sidebar:not([open]) {
  justify-self: end;
  width: max-content;
}

.conversation-history-sidebar:not([open]) summary {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  white-space: nowrap;
}

.conversation-history-sidebar .conversation-list {
  margin-top: 10px;
  gap: 8px;
}

.conversation-history-sidebar .conversation-history-scroll {
  max-height: calc(100dvh - 120px);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-right: 4px;
}

.conversation-history-sidebar .conversation-list-item {
  flex-direction: column;
  gap: 8px;
  padding: 10px 0;
}

.conversation-history-sidebar .language-actions {
  gap: 8px;
}

.conversation-history-sidebar .language-actions a {
  min-height: 32px;
  padding: 0.48rem 0.72rem;
  font-size: 0.9rem;
}

.conversation-detail-card summary {
  cursor: pointer;
  color: var(--accent-strong);
  font-size: 1.18rem;
  font-weight: 700;
  list-style-position: inside;
}

.conversation-detail-card h2 {
  margin-bottom: 8px;
}

.conversation-detail-actions button,
.conversation-detail-actions a {
  min-height: 42px;
  padding: 0.72rem 1rem;
  font: inherit;
  font-weight: 700;
  line-height: 1;
}

.conversation-detail-scroll {
  max-height: min(52vh, 520px);
  overflow-y: auto;
  padding-right: 8px;
}

.conversation-detail-card .chat-thread {
  gap: 8px;
  margin-top: 8px;
}

.conversation-detail-card .chat-message {
  padding: 10px 12px;
  border-radius: 12px;
}

.conversation-detail-card .chat-role {
  margin-bottom: 3px;
  font-size: 0.74rem;
}

.conversation-detail-card .chat-text {
  line-height: 1.45;
}

.conversation-history-scroll {
  max-height: calc(100dvh - 120px);
  overflow-y: auto;
  padding-right: 4px;
}

.conversation-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.conversation-list-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  padding: 18px 0;
  background: transparent;
}

.conversation-title,
.conversation-meta {
  display: block;
}

.conversation-title {
  color: var(--accent-strong);
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.35;
}

.conversation-meta {
  margin-top: 5px;
  color: var(--muted);
  line-height: 1.5;
}

.chat-thread {
  display: grid;
  gap: 4px;
  margin-top: 4px;
  max-height: min(56vh, 560px);
  overflow-y: auto;
  padding-right: 4px;
}

.live-chat-thread {
  height: clamp(150px, calc(100dvh - 285px), 430px);
  max-height: none;
  min-height: 0;
  overscroll-behavior: contain;
  overflow-anchor: none;
  scroll-behavior: auto;
}

body:not(.settings-page) .live-chat-thread {
  flex: 1;
  height: auto;
}

.chat-message {
  width: fit-content;
  max-width: min(82%, 820px);
  padding: 6px 8px;
  border-radius: 8px;
  border: 1px solid var(--line);
}

.chat-message-user {
  justify-self: end;
  text-align: right;
  background: rgba(29, 92, 99, 0.08);
}

.chat-message-assistant {
  justify-self: start;
  background: rgba(255, 255, 255, 0.72);
}

.chat-role {
  display: none;
}

.chat-message .chat-text {
  margin: 0;
  white-space: pre-wrap;
  font-size: 0.94rem;
  line-height: 1.22;
}

.saved-chat-thread {
  max-height: none;
}

.grammar-topic-layout {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(420px, 1.1fr);
  gap: 28px;
  align-items: start;
}

body:not(.settings-page) .grammar-topic-layout {
  align-items: stretch;
  flex: 1;
  min-height: 0;
  overflow: hidden;
}

.grammar-topic-layout.lesson-collapsed {
  grid-template-columns: 1fr;
  gap: 18px;
}

.grammar-topic-layout.lesson-collapsed .grammar-lesson-card {
  grid-column: 1 / -1;
  grid-row: 2;
}

.grammar-topic-layout.lesson-collapsed .grammar-practice-panel {
  grid-column: 1 / -1;
  grid-row: 1;
}

.grammar-practice-panel {
  grid-column: 2;
  grid-row: 1;
  position: static;
  min-width: 0;
}

body:not(.settings-page) .grammar-practice-panel,
body:not(.settings-page) .grammar-chat-card {
  min-height: 0;
}

body:not(.settings-page) .grammar-practice-panel {
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

body:not(.settings-page) .grammar-chat-card {
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.grammar-lesson-card {
  grid-column: 1;
  grid-row: 1;
  padding-top: 10px;
}

body:not(.settings-page) .grammar-lesson-card {
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.grammar-lesson-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  color: var(--accent-strong);
  font-weight: 700;
}

.grammar-lesson-title {
  font-size: 1.28rem;
}

.grammar-content-toggle {
  flex: 0 0 auto;
  min-height: 38px;
  padding: 0.56rem 0.82rem;
}

.grammar-lesson-content {
  margin-top: 16px;
  max-height: calc(100dvh - 150px);
  overflow-y: auto;
  padding-right: 8px;
}

.grammar-lesson-content > h1:first-child,
.grammar-lesson-content > h2:first-child,
.grammar-lesson-content > h3:first-child {
  display: none;
}

body:not(.settings-page) .grammar-lesson-content {
  flex: 1;
  max-height: none;
  min-height: 0;
}

.grammar-lesson-actions {
  margin-top: 18px;
}

.grammar-chat-card {
  margin-top: 0;
}

.grammar-chat-heading {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  margin-bottom: 10px;
}

.grammar-chat-heading h2 {
  margin-bottom: 0;
}

.grammar-chat-heading .topic-last-practiced {
  flex: 0 1 auto;
  margin: 0;
  text-align: right;
}

.grammar-chat-thread {
  height: clamp(150px, calc(100dvh - 315px), 360px);
  max-height: none;
  overflow-y: auto;
  padding-right: 4px;
}

body:not(.settings-page) .grammar-chat-thread {
  flex: 1;
  height: auto;
  min-height: 120px;
}

.grammar-thread-actions {
  justify-content: flex-end;
  margin-top: 8px;
}

.grammar-topic-list-card {
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

body:not(.settings-page) .grammar-topic-list-card {
  flex: 1;
}

.topic-list-scroll {
  flex: 1;
  min-height: 0;
  max-height: min(68vh, 720px);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-right: 8px;
}

body:not(.settings-page) .topic-list-scroll {
  max-height: none;
}

.topic-group + .topic-group {
  margin-top: 18px;
}

.topic-group-title {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 0.86rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.topic-list {
  list-style: none;
  margin: 18px 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
  max-height: min(68vh, 720px);
  overflow-y: auto;
  padding-right: 8px;
}

.grammar-topic-list-card .topic-list {
  max-height: none;
  margin: 0;
  overflow: visible;
  padding-right: 0;
}

body:not(.settings-page) .topic-list {
  max-height: calc(100dvh - 145px);
  gap: 8px;
  margin-top: 10px;
}

body:not(.settings-page) .grammar-topic-list-card .topic-list {
  max-height: none;
  margin-top: 0;
}

.topic-list-item {
  padding: 0;
  background: transparent;
}

.topic-details {
  padding: 14px 0;
}

body:not(.settings-page) .topic-details {
  padding: 8px 0;
}

.topic-summary {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

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

.topic-expand-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  flex: 0 0 28px;
  margin-left: 4px;
  padding: 0;
  border: 0;
  background: transparent;
  color: var(--accent-strong);
  cursor: pointer;
  font: inherit;
  font-weight: 800;
}

.topic-last-practiced {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 600;
}

.topic-detail-body {
  margin-top: 12px;
}

button:disabled,
textarea:disabled {
  cursor: not-allowed;
  opacity: 0.55;
}

.conversation-vocabulary-card {
  margin-top: 18px;
}

.suggestion-form {
  margin-top: 18px;
}

.suggestion-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.suggestion-item {
  padding: 16px 0;
  background: transparent;
}

.suggestion-item-added,
.suggestion-item-skipped {
  opacity: 0.72;
}

.suggestion-choice {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.suggestion-choice input {
  margin-top: 6px;
}

.suggestion-title,
.suggestion-meta,
.suggestion-example,
.suggestion-source {
  display: block;
}

.suggestion-title {
  color: var(--accent-strong);
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.35;
}

.suggestion-meta {
  margin-top: 4px;
  color: var(--muted);
  line-height: 1.5;
}

.suggestion-example,
.suggestion-source {
  margin-top: 8px;
  color: var(--muted);
  line-height: 1.55;
}

.suggestion-source {
  font-size: 0.94rem;
  font-style: italic;
}

.form-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.flashcard-card,
.review-summary-card {
  margin-top: 10px;
  padding: 18px;
}

.card-progress {
  margin: 0 0 8px;
  color: var(--accent);
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.86rem;
}

.flashcard-face,
.flashcard-answer {
  padding: 16px;
  border-radius: 18px;
  border: 1px solid var(--line);
  background: var(--surface-strong);
}

.flashcard-answer {
  margin-top: 18px;
  background: rgba(219, 236, 235, 0.42);
}

.flashcard-answer-pop {
  animation: answer-pop 180ms ease-out;
}

@keyframes answer-pop {
  from {
    opacity: 0;
    transform: translateY(8px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.flashcard-label {
  margin: 0 0 8px;
  color: var(--accent);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.8rem;
}

.flashcard-face h2,
.flashcard-answer-text {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.4rem);
  line-height: 1.05;
  color: var(--accent-strong);
}

.rating-form {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.rating-form button {
  gap: 0.55rem;
}

.rating-shortcut {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.55rem;
  height: 1.55rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.24);
  font-size: 0.82rem;
  line-height: 1;
}

.secondary-button .rating-shortcut {
  background: var(--surface-strong);
  color: var(--accent-strong);
}

.fullscreen-toggle-button {
  cursor: pointer;
  font: inherit;
}

#review-workspace:fullscreen {
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  width: 100vw;
  min-height: 100vh;
  padding: clamp(20px, 5vw, 72px);
  background: var(--bg);
  overflow-y: auto;
}

#review-workspace:fullscreen .fullscreen-workspace-exit {
  display: inline-flex;
  align-self: flex-end;
  margin-bottom: 12px;
}

#review-workspace:fullscreen .card-heading {
  position: absolute;
  top: 24px;
  left: clamp(20px, 5vw, 72px);
  right: clamp(20px, 5vw, 72px);
}

#review-workspace:fullscreen .embedded-flashcard-card,
#review-workspace:fullscreen .review-summary-card,
#review-workspace:fullscreen .review-queue-list,
#review-workspace:fullscreen > .inline-action-form {
  width: min(920px, 100%);
  margin-left: auto;
  margin-right: auto;
}

#review-workspace:fullscreen .embedded-flashcard-card {
  margin-top: clamp(28px, 6vh, 64px);
  padding: 0;
}

#review-workspace:fullscreen .flashcard-face,
#review-workspace:fullscreen .flashcard-answer {
  padding: clamp(24px, 5vw, 56px);
}

.flashcard-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.flashcard-fullscreen-shell {
  min-height: calc(100vh - 32px);
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
}

.fullscreen-flashcard-card {
  margin-top: 0;
  min-height: auto;
  display: flex;
  flex-direction: column;
  justify-content: flex-start;
  padding: 18px 40px 32px;
}

.fullscreen-card-only {
  border: 0;
  background: transparent;
  box-shadow: none;
}

.fullscreen-exit-button {
  position: fixed;
  top: 18px;
  right: 18px;
  z-index: 10;
}

.fullscreen-launch-card,
.fullscreen-summary-card {
  max-width: 520px;
  margin-inline: auto;
  text-align: center;
}

body.fullscreen-review-page .site-sidebar,
body.fullscreen-review-page .stats-grid,
body.fullscreen-review-page .management-grid,
body.fullscreen-review-page .deck-contents-card,
body.fullscreen-review-page .dashboard-hero,
body.fullscreen-review-page .status-banner {
  display: none;
}

body.fullscreen-review-page .app-shell-with-sidebar {
  display: block;
  padding-top: 0;
}

body.fullscreen-review-page .fullscreen-vocabulary-shell {
  width: 100%;
  margin-top: 0;
}

body.fullscreen-review-page .card-progress {
  margin-bottom: 8px;
}

body.fullscreen-review-page {
  background: var(--bg);
}

.spec-card {
  padding: 30px 24px 40px;
}

.spec-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  padding-bottom: 18px;
  margin-bottom: 20px;
}

.spec-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
}

.markdown-content {
  width: min(760px, 100%);
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
  color: var(--accent-strong);
  line-height: 1.12;
  margin-top: 1.4em;
}

.markdown-content h1:first-child,
.markdown-content h2:first-child,
.markdown-content h3:first-child {
  margin-top: 0;
}

.markdown-content h2 {
  font-size: 1.7rem;
}

.markdown-content p + p,
.markdown-content p + ul,
.markdown-content ul + p,
.markdown-content ul + h2,
.markdown-content p + h2 {
  margin-top: 1rem;
}

.markdown-content ul,
.markdown-content ol {
  padding-left: 1.4rem;
}

.markdown-content li + li {
  margin-top: 0.45rem;
}

.markdown-content code {
  background: #f0e6d7;
  padding: 0.12rem 0.35rem;
  border-radius: 4px;
}

@media (max-width: 900px) {
  .hero-card,
  .feature-grid,
  .dashboard-grid,
  .home-progress-grid,
  .vocabulary-import-layout,
  .stats-grid {
    grid-template-columns: 1fr;
  }

  body:not(.settings-page) .home-progress-grid {
    grid-template-rows: auto minmax(0, 1fr);
  }

  .dashboard-hero {
    flex-direction: column;
    align-items: flex-start;
  }

  .spec-heading {
    flex-direction: column;
    align-items: flex-start;
  }

  .vocabulary-item-head {
    flex-direction: column;
  }

  .deck-shortcut-panel {
    position: static;
  }

  .deck-table-head {
    display: none;
  }

  .deck-row summary {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .deck-row-open {
    text-align: left;
  }

  .activity-item {
    flex-direction: column;
    gap: 6px;
  }
}

@media (max-width: 640px) {
  .landing-shell,
  .auth-shell,
  .dashboard-shell,
  .spec-shell {
    width: min(100vw - 20px, 1180px);
  }

  .hero-card,
  .auth-card,
  .spec-card {
    border-radius: 22px;
  }

  .hero-card,
  .auth-card,
  .spec-card {
    padding: 16px 14px;
  }

  .brand span {
    display: none;
  }
}

@media (max-width: 720px) {
  .app-shell,
  .app-shell-with-sidebar {
    width: 100%;
  }

  .app-shell-with-sidebar {
    display: block;
    padding-top: 0;
  }

  .site-sidebar {
    position: static;
    width: 100%;
    min-height: 0;
    padding: 8px 12px 4px;
    border-right: 0;
  }

  .site-nav {
    display: flex;
    flex-wrap: nowrap;
    gap: 8px;
    overflow-x: auto;
    padding-bottom: 4px;
  }

  .sidebar-link {
    width: auto;
    min-width: 38px;
    min-height: 38px;
    padding: 8px;
  }

  .sidebar-link-icon,
  .sidebar-link-icon svg {
    width: 20px;
    height: 20px;
  }

  .app-main {
    padding: 0 12px 24px;
  }

  .top-bar {
    flex-direction: row;
    align-items: center;
    gap: 8px;
    min-height: 0;
    margin-bottom: 8px;
    padding-top: 4px;
  }

  .top-brand {
    font-size: 0.72rem;
    letter-spacing: 0.1em;
  }

  .language-switcher {
    margin-left: auto;
    min-width: 0;
  }

  .language-switcher select {
    min-width: 0;
    width: min(48vw, 180px);
    padding: 0.4rem 0.58rem;
    font-size: 0.78rem;
  }

  .dashboard-shell,
  .spec-shell {
    width: 100%;
    margin-bottom: 20px;
  }

  .dashboard-hero {
    gap: 6px;
    padding-bottom: 2px;
  }

  .hero-copy h1,
  .auth-card h1,
  .dashboard-hero h1,
  .spec-heading h1 {
    font-size: clamp(1.55rem, 8vw, 2.35rem);
    line-height: 0.98;
  }

  .hero-actions,
  .hero-actions-left,
  .language-actions,
  .form-actions,
  .rating-form {
    width: 100%;
    gap: 8px;
  }

  .hero-actions > a,
  .hero-actions > form,
  .hero-actions button,
  .language-actions > a,
  .language-actions > form,
  .language-actions button,
  .inline-action-form button,
  .inline-action-form a,
  .secondary-button,
  .danger-button,
  .primary-action,
  .secondary-action {
    width: 100%;
  }

  .home-progress-grid,
  .vocabulary-import-layout,
  .dashboard-grid,
  .stats-grid {
    grid-template-columns: 1fr;
    gap: 22px;
  }

  .settings-form-grid,
  .settings-theme-form,
  .settings-row,
  .settings-language-row {
    grid-template-columns: 1fr;
  }

  .settings-row,
  .settings-language-row {
    gap: 8px;
  }

  .settings-language-row {
    margin-left: 0;
  }

  .settings-actions {
    justify-content: stretch;
  }

  .settings-action form {
    min-width: 0;
  }

  .settings-form-grid > button,
  .settings-theme-form > button {
    grid-column: auto;
  }

  .settings-inline-add {
    align-items: stretch;
    flex-direction: column;
    gap: 6px;
  }

  .grammar-topic-layout {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .conversation-layout {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .conversation-history-sidebar {
    position: static;
  }

  .conversation-history-scroll {
    max-height: 280px;
  }

  .grammar-practice-panel {
    grid-column: auto;
    grid-row: auto;
    position: static;
  }

  .grammar-lesson-card,
  .grammar-topic-layout.lesson-collapsed .grammar-lesson-card,
  .grammar-topic-layout.lesson-collapsed .grammar-practice-panel {
    grid-column: auto;
    grid-row: auto;
  }

  .grammar-chat-thread {
    height: clamp(145px, calc(100dvh - 305px), 320px);
    max-height: none;
  }

  .grammar-lesson-content {
    max-height: 420px;
  }

  .grammar-chat-heading {
    align-items: flex-start;
    flex-direction: column;
    gap: 4px;
  }

  .grammar-chat-heading .topic-last-practiced {
    text-align: left;
  }

  .card-heading {
    flex-direction: column;
    gap: 10px;
  }

  .known-chart-frame {
    grid-template-columns: 28px minmax(0, 1fr);
    gap: 8px;
    margin-top: 16px;
  }

  .known-y-axis,
  .known-line-chart {
    height: 180px;
  }

  .known-chart-labels {
    margin-left: 36px;
    font-size: 0.78rem;
  }

  .timescale-form {
    width: 100%;
    justify-content: space-between;
  }

  .timescale-form select {
    width: 150px;
  }

  .flashcard-card,
  .review-summary-card {
    padding: 18px 0;
  }

  .flashcard-face,
  .flashcard-answer {
    padding: 18px;
    border-radius: 18px;
  }

  .flashcard-face h2,
  .flashcard-answer-text {
    font-size: clamp(1.8rem, 11vw, 2.7rem);
    overflow-wrap: anywhere;
  }

  .deck-table-head {
    display: none;
  }

  .deck-row summary {
    grid-template-columns: 1fr;
    gap: 6px;
    padding: 12px 0;
  }

  .deck-edit-form,
  .edit-grid {
    grid-template-columns: 1fr;
  }

  .language-list-item,
  .conversation-list-item {
    flex-direction: column;
    align-items: stretch;
    gap: 12px;
  }

  .chat-message {
    max-width: 92%;
    padding: 6px 8px;
    border-radius: 8px;
  }

  .live-chat-thread {
    height: clamp(145px, calc(100dvh - 280px), 360px);
  }

  .chat-text,
  .markdown-content {
    overflow-wrap: anywhere;
  }

  .topic-summary {
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 8px;
  }

  .topic-summary,
  .topic-last-practiced,
  .topic-details .language-name-row {
    width: 100%;
  }

  .topic-last-practiced {
    margin-left: 0;
    font-size: 0.84rem;
  }

  .topic-expand-button {
    margin-left: auto;
  }

  .summary-list {
    padding-left: 1rem;
  }
}