:root {
  --tta-red: #c62839;
  --tta-red-soft: #fcebed;
  --tta-navy: #16324f;
  --tta-teal: #0b7a75;
  --tta-amber: #f4a261;
  --tta-ink: #17212f;
  --tta-muted: #64748b;
  --tta-line: #d8e0ea;
  --tta-surface: #ffffff;
  --tta-surface-soft: #f7f9fc;
  --tta-page: #f3f6fb;
  --tta-shadow: 0 20px 50px rgba(18, 32, 53, 0.08);
  --tta-radius: 8px;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--tta-page);
  color: var(--tta-ink);
  font-family: Inter, "Segoe UI", Arial, sans-serif;
  overflow-x: hidden;
}

a {
  text-decoration: none;
}

.site-shell {
  min-height: 100vh;
}

.container-page {
  width: min(100%, 1360px);
  padding-inline: 24px;
}

.shadow-soft {
  box-shadow: var(--tta-shadow);
}

.site-navbar {
  background: rgba(255, 255, 255, 0.94);
  border-bottom: 1px solid var(--tta-line);
  backdrop-filter: blur(10px);
}

.site-navbar > .container-page {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
}

.site-navbar .navbar-collapse {
  flex-basis: 100%;
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  flex: 1 1 auto;
  max-width: 100%;
  min-width: 0;
}

.brand-mark {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  display: inline-grid;
  place-items: center;
  background: linear-gradient(135deg, var(--tta-red), var(--tta-navy));
  color: #fff;
  font-size: 15px;
  font-weight: 700;
}

.brand-text {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.brand-title {
  font-size: 17px;
  line-height: 1.1;
  font-weight: 600;
  color: var(--tta-ink);
}

.brand-subtitle {
  font-size: 12px;
  line-height: 1.2;
  color: var(--tta-muted);
  font-weight: 500;
  overflow-wrap: anywhere;
}

.navbar-toggler-clean {
  border-color: var(--tta-line);
  box-shadow: none !important;
}

.site-nav-list {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-left: auto;
  padding-block: 12px;
  width: 100%;
}

.site-nav-link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-height: 48px;
  max-width: 100%;
  padding: 10px 14px !important;
  border-radius: 999px;
  color: var(--tta-muted);
  font-size: 14px;
  font-weight: 500;
  line-height: 1;
  flex-shrink: 0;
  transition: background-color 0.18s ease, color 0.18s ease, transform 0.18s ease;
}

.site-nav-link:hover,
.site-nav-link.active {
  background: #eef3fb;
  color: var(--tta-navy);
}

.site-nav-icon {
  width: 28px;
  height: 28px;
  border-radius: 999px;
  display: inline-grid;
  place-items: center;
  background: #f1f5fb;
  color: var(--tta-navy);
  flex: 0 0 auto;
}

.site-nav-link.active .site-nav-icon,
.site-nav-link:hover .site-nav-icon {
  background: var(--tta-red-soft);
  color: var(--tta-red);
}

.site-nav-label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.page-section {
  padding: 40px 0;
}

.section-header {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  margin-bottom: 24px;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  color: var(--tta-red);
  font-size: 13px;
  font-weight: 600;
}

.section-title {
  margin: 0;
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1.02;
  font-weight: 700;
  color: var(--tta-ink);
}

.section-copy {
  margin: 0;
  color: var(--tta-muted);
  font-size: 16px;
  max-width: 760px;
}

.hero-shell {
  padding: 36px 0 20px;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.15fr) minmax(320px, 0.85fr);
  gap: 24px;
}

.surface-card {
  background: var(--tta-surface);
  border: 1px solid var(--tta-line);
  border-radius: var(--tta-radius);
  box-shadow: var(--tta-shadow);
}

.hero-panel {
  padding: 36px;
  background:
    linear-gradient(155deg, rgba(198, 40, 57, 0.08), transparent 45%),
    linear-gradient(180deg, rgba(22, 50, 79, 0.03), rgba(22, 50, 79, 0.01)),
    var(--tta-surface);
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 16px;
}

.hero-display {
  margin: 0 0 16px;
  font-size: clamp(40px, 5vw, 66px);
  line-height: 0.98;
  font-weight: 700;
  letter-spacing: 0;
}

.hero-copy {
  margin: 0 0 22px;
  font-size: 17px;
  line-height: 1.7;
  color: var(--tta-muted);
  max-width: 720px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.hero-side-cards {
  display: grid;
  gap: 16px;
}

.info-stack {
  padding: 22px;
}

.info-stack h3,
.stat-card h3,
.lesson-card h3,
.section-card h3 {
  margin: 0 0 8px;
  font-size: 19px;
  line-height: 1.3;
  font-weight: 650;
}

.info-stack p,
.stat-card p,
.lesson-card p,
.section-card p,
.muted-copy {
  margin: 0;
  color: var(--tta-muted);
  line-height: 1.6;
}

.level-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 28px;
  padding: 0 12px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
}

.level-a1 { background: #fbe5e8; color: #a11c2a; }
.level-a2 { background: #def3f1; color: #0d6763; }
.level-b1 { background: #fdf0df; color: #a35e13; }
.level-b2 { background: #ddf3ee; color: #11776f; }
.level-c1 { background: #e3eef6; color: #355f7c; }
.level-c2 { background: #e8edf5; color: #213851; }

.btn-tta {
  --bs-btn-bg: var(--tta-red);
  --bs-btn-border-color: var(--tta-red);
  --bs-btn-hover-bg: #b11e31;
  --bs-btn-hover-border-color: #b11e31;
  --bs-btn-color: #fff;
  --bs-btn-hover-color: #fff;
  font-weight: 600;
}

.btn-outline-tta {
  --bs-btn-color: var(--tta-red);
  --bs-btn-border-color: var(--tta-red);
  --bs-btn-hover-bg: var(--tta-red);
  --bs-btn-hover-border-color: var(--tta-red);
  --bs-btn-hover-color: #fff;
  font-weight: 600;
}

.section-card,
.lesson-card,
.stream-card,
.admin-card,
.table-shell,
.live-player-card,
.chat-panel,
.sidebar-card {
  background: var(--tta-surface);
  border: 1px solid var(--tta-line);
  border-radius: var(--tta-radius);
  box-shadow: var(--tta-shadow);
}

.section-card,
.lesson-card,
.sidebar-card,
.stream-card {
  padding: 22px;
}

.method-grid,
.level-grid,
.lesson-grid-compact,
.drill-grid,
.object-grid {
  display: grid;
  gap: 16px;
}

.method-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.level-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.lesson-grid-compact,
.drill-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.stat-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.stat-card {
  padding: 20px;
}

.stat-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.stat-icon {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  display: inline-grid;
  place-items: center;
  background: #eef3fb;
  color: var(--tta-navy);
  font-size: 18px;
}

.stat-value {
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1;
  font-weight: 700;
  color: var(--tta-ink);
}

.method-step-index {
  width: 32px;
  height: 32px;
  border-radius: 999px;
  display: inline-grid;
  place-items: center;
  background: #edf2f9;
  color: var(--tta-navy);
  font-size: 13px;
  font-weight: 700;
  margin-bottom: 14px;
}

.badge-soft {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #f2f6fb;
  border: 1px solid var(--tta-line);
  border-radius: 999px;
  padding: 7px 12px;
  color: var(--tta-muted);
  font-size: 12px;
  font-weight: 600;
}

.lesson-filter-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.search-input-lg {
  min-height: 52px;
  border-radius: 12px;
}

.lesson-card-link {
  display: block;
  color: inherit;
  height: 100%;
}

.lesson-meta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-bottom: 12px;
}

.chip-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.audio-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 38px;
  max-width: 100%;
  border-radius: 999px;
  padding: 0 14px;
  background: #eef3fb;
  color: var(--tta-navy);
  font-size: 13px;
  font-weight: 600;
  border: 0;
  flex-shrink: 0;
  transition: background-color 0.18s ease, color 0.18s ease, box-shadow 0.18s ease;
}

.audio-chip.is-playing {
  background: var(--tta-red-soft);
  color: var(--tta-red);
  box-shadow: inset 0 0 0 1px rgba(198, 40, 57, 0.2);
}

.audio-chip[disabled] {
  opacity: 0.55;
  cursor: not-allowed;
}

.object-tile {
  border: 1px solid var(--tta-line);
  border-radius: 8px;
  background: var(--tta-surface-soft);
  padding: 16px;
  height: 100%;
}

.object-top {
  display: flex;
  gap: 14px;
  align-items: start;
  flex-wrap: wrap;
}

.object-thumb {
  width: 72px;
  height: 72px;
  border-radius: 8px;
  background: #fff;
  border: 1px solid var(--tta-line);
  object-fit: contain;
  padding: 10px;
}

.dialogue-list,
.quiz-stack,
.drill-stack,
.related-stack,
.participant-stack,
.stream-stack {
  display: grid;
  gap: 12px;
}

.dialogue-item,
.quiz-item,
.drill-item,
.related-item,
.participant-item,
.stream-item {
  border: 1px solid var(--tta-line);
  border-radius: 8px;
  background: #fff;
  padding: 14px 16px;
}

.dialogue-top,
.quiz-top,
.stream-item-top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: start;
  flex-wrap: wrap;
}

.lesson-page-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(320px, 0.85fr);
  gap: 24px;
  padding: 28px 0 40px;
}

.lesson-hero-card {
  padding: 28px;
}

.lesson-hero-title {
  margin: 0 0 12px;
  font-size: clamp(34px, 4vw, 50px);
  line-height: 1.02;
  font-weight: 700;
  overflow-wrap: anywhere;
}

.lesson-summary {
  margin: 0;
  font-size: 17px;
  line-height: 1.7;
  color: var(--tta-muted);
}

.lesson-media {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 8px;
  overflow: hidden;
  background: #0f1b2b;
}

.lesson-media video,
.lesson-media iframe {
  width: 100%;
  height: 100%;
  display: block;
}

.lesson-media-empty {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 8px;
  background: #eef3fb;
  border: 1px dashed var(--tta-line);
  display: grid;
  place-items: center;
  color: var(--tta-muted);
  text-align: center;
  padding: 24px;
}

.info-list {
  display: grid;
  gap: 14px;
}

.info-list dt {
  margin-bottom: 6px;
  font-size: 13px;
  font-weight: 700;
  color: var(--tta-navy);
}

.info-list dd {
  margin: 0;
  color: var(--tta-muted);
}

.method-list {
  margin: 0;
  padding-left: 20px;
  display: grid;
  gap: 8px;
  color: var(--tta-muted);
}

.task-type-badge {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  background: #eff4fb;
  color: var(--tta-navy);
  font-size: 12px;
  font-weight: 600;
}

.task-option-list,
.pair-grid {
  display: grid;
  gap: 10px;
}

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

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

.site-footer {
  margin-top: 48px;
  padding: 32px 0 40px;
  border-top: 1px solid var(--tta-line);
  background: #fff;
}

.footer-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
}

.footer-logo-row {
  display: flex;
  align-items: center;
  gap: 14px;
}

.footer-title {
  font-size: 16px;
  font-weight: 650;
}

.footer-copy {
  color: var(--tta-muted);
  font-size: 14px;
}

.footer-stat-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.footer-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 38px;
  padding: 0 14px;
  border: 1px solid var(--tta-line);
  border-radius: 999px;
  color: var(--tta-muted);
  background: var(--tta-surface-soft);
  font-size: 13px;
  font-weight: 600;
}

.modal-eyebrow {
  font-size: 12px;
  font-weight: 700;
  color: var(--tta-red);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.live-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(340px, 0.85fr);
  gap: 24px;
  padding: 28px 0 40px;
}

.live-left-stack,
.live-right-stack {
  display: grid;
  gap: 18px;
}

.live-player-card {
  padding: 20px;
}

.live-player {
  width: 100%;
  aspect-ratio: 16 / 9;
  border-radius: 8px;
  overflow: hidden;
  background: #0f1b2b;
}

.live-player video,
.live-player iframe {
  width: 100%;
  height: 100%;
  display: block;
}

.chat-panel {
  display: grid;
  grid-template-rows: auto auto 1fr auto;
  min-height: 780px;
  overflow: hidden;
}

.chat-panel-head,
.chat-panel-sub,
.chat-panel-foot {
  padding: 18px;
}

.chat-panel-head {
  border-bottom: 1px solid var(--tta-line);
}

.chat-panel-sub {
  border-bottom: 1px solid var(--tta-line);
  background: #f9fbfe;
}

.chat-feed {
  overflow-y: auto;
  padding: 16px 18px;
  background: #fbfcff;
  display: grid;
  align-content: start;
  gap: 12px;
}

.chat-item {
  border: 1px solid var(--tta-line);
  border-radius: 8px;
  background: #fff;
  padding: 12px 14px;
}

.chat-item.self {
  border-color: #f3cad0;
  background: #fff8f8;
}

.chat-item-head {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 6px;
  color: var(--tta-muted);
  font-size: 12px;
}

.chat-item-body {
  white-space: pre-wrap;
  word-break: break-word;
}

.sticker-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 10px;
}

.sticker-btn {
  min-height: 54px;
  border: 1px solid var(--tta-line);
  border-radius: 8px;
  background: #fff;
  font-size: 26px;
}

.poll-card {
  border: 1px solid #cfe3e0;
  border-radius: 8px;
  background: #f3fbfa;
  padding: 14px;
}

.poll-option {
  width: 100%;
  text-align: left;
  border: 1px solid var(--tta-line);
  border-radius: 8px;
  background: #fff;
  padding: 10px 12px;
}

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

.participant-name {
  font-weight: 600;
}

.admin-shell {
  display: grid;
  grid-template-columns: 280px minmax(0, 1fr);
  min-height: calc(100vh - 73px);
}

.admin-sidebar {
  background: var(--tta-navy);
  color: #fff;
  padding: 24px 18px;
  border-right: 1px solid rgba(255, 255, 255, 0.08);
}

.admin-sidebar .brand-subtitle {
  color: rgba(255, 255, 255, 0.72);
}

.admin-nav {
  margin-top: 28px;
  display: grid;
  gap: 8px;
}

.admin-nav-link {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 46px;
  padding: 0 14px;
  border-radius: 8px;
  color: rgba(255, 255, 255, 0.78);
  font-size: 14px;
  font-weight: 500;
}

.admin-nav-link:hover,
.admin-nav-link.active {
  background: rgba(255, 255, 255, 0.12);
  color: #fff;
}

.admin-main {
  padding: 22px;
}

.admin-head {
  display: flex;
  flex-wrap: wrap;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 18px;
}

.admin-stat-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
  margin-bottom: 18px;
}

.admin-toolbar,
.filter-toolbar,
.pagination-bar,
.table-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.filter-toolbar {
  padding: 16px 18px;
  border-bottom: 1px solid var(--tta-line);
  background: #fafcff;
}

.table-shell {
  overflow: hidden;
}

.table-wrap {
  overflow-x: auto;
}

.table-sticky {
  margin: 0;
}

.table-sticky thead th {
  position: sticky;
  top: 0;
  z-index: 2;
  background: #f8fbff;
  vertical-align: middle;
  white-space: nowrap;
  font-size: 13px;
}

.table-sticky td,
.table-sticky th {
  border-color: var(--tta-line);
  vertical-align: middle;
}

.table-title {
  font-weight: 600;
  color: var(--tta-ink);
}

.row-meta {
  color: var(--tta-muted);
  font-size: 12px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  padding: 0 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 700;
}

.status-published,
.status-live,
.status-ready,
.status-active {
  background: #e4f6f1;
  color: #127463;
}

.status-draft,
.status-scheduled {
  background: #eef3fb;
  color: #355b7d;
}

.status-missing,
.status-ended,
.status-inactive {
  background: #fcebed;
  color: #b12a39;
}

.table-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.empty-state {
  padding: 28px;
  text-align: center;
  color: var(--tta-muted);
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: 16px;
}

.form-field {
  display: grid;
  gap: 8px;
}

.form-field label {
  font-size: 13px;
  font-weight: 700;
  color: var(--tta-navy);
}

.field-error {
  color: #b12a39;
  font-size: 12px;
}

.upload-card {
  border: 1px dashed var(--tta-line);
  border-radius: 8px;
  padding: 14px;
  background: #fbfcff;
}

.upload-preview {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
}

.upload-preview img {
  width: 72px;
  height: 72px;
  object-fit: cover;
  border: 1px solid var(--tta-line);
  border-radius: 8px;
}

.audio-audit-grid {
  display: grid;
  gap: 8px;
  color: var(--tta-muted);
  font-size: 13px;
}

.login-page {
  min-height: calc(100vh - 73px);
  display: grid;
  place-items: center;
  padding: 30px 0 50px;
}

.login-card {
  width: min(100%, 460px);
  padding: 28px;
}

@media (max-width: 1199.98px) {
  .hero-grid,
  .lesson-page-grid,
  .live-layout,
  .admin-shell {
    grid-template-columns: 1fr;
  }

  .method-grid,
  .level-grid,
  .lesson-grid-compact,
  .drill-grid,
  .admin-stat-grid,
  .stat-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .admin-sidebar {
    padding-bottom: 12px;
  }

  .brand-subtitle {
    display: none;
  }
}

@media (max-width: 767.98px) {
  .container-page {
    padding-inline: 16px;
  }

  .hero-panel,
  .section-card,
  .lesson-card,
  .stream-card,
  .sidebar-card,
  .live-player-card,
  .chat-panel-head,
  .chat-panel-sub,
  .chat-panel-foot,
  .login-card {
    padding: 18px;
  }

  .method-grid,
  .level-grid,
  .lesson-grid-compact,
  .drill-grid,
  .admin-stat-grid,
  .pair-grid,
  .stat-grid {
    grid-template-columns: 1fr;
  }

  .site-nav-list {
    padding-top: 12px;
    width: 100%;
  }

  .site-nav-link {
    width: 100%;
    justify-content: flex-start;
    border-radius: 14px;
  }

  .brand-lockup {
    max-width: calc(100% - 64px);
  }

  .chat-panel {
    min-height: 640px;
  }
}