:root {
  --bg: #f8fafc;
  --card: #ffffff;
  --primary: #3b82f6;
  --primary-dark: #1e40af;
  --nav: #1e293b;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
  --soft: #f1f5f9;
  --mastered: #10b981;
  --reviewing: #f59e0b;
  --unmastered: #ef4444;
  --shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1);
  --hover-shadow: 0 4px 12px rgb(15 23 42 / 0.08);
  --radius-sm: 8px;
  --radius: 12px;
  --sidebar: 240px;
  --rail: 300px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: Inter, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 14px;
  line-height: 22px;
}

.auth-overlay {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: grid;
  place-items: center;
  padding: 24px;
  background: linear-gradient(135deg, #f8fafc 0%, #eff6ff 48%, #ffffff 100%);
}

.auth-overlay.hidden {
  display: none;
}

.auth-card {
  width: min(420px, 100%);
  padding: 28px;
  border: 1px solid var(--border);
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 24px 80px rgb(15 23 42 / 0.16);
}

.auth-brand {
  color: var(--text);
  margin-bottom: 22px;
}

.auth-brand span {
  color: var(--muted);
}

.auth-tabs {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
  padding: 4px;
  border-radius: 12px;
  background: var(--soft);
  margin-bottom: 18px;
}

.auth-tabs button {
  height: 38px;
  border: 0;
  border-radius: 9px;
  background: transparent;
  color: var(--muted);
  font-weight: 800;
}

.auth-tabs button.active {
  background: #fff;
  color: var(--primary-dark);
  box-shadow: var(--shadow);
}

.auth-form {
  display: grid;
  gap: 12px;
}

.auth-error {
  min-height: 20px;
  margin: 0;
  color: #991b1b;
  font-size: 13px;
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

.app-shell {
  display: grid;
  grid-template-columns: var(--sidebar) minmax(0, 1fr) var(--rail);
  max-width: 1440px;
  min-height: 100vh;
  margin: 0 auto;
}

.sidebar {
  position: sticky;
  top: 0;
  height: 100vh;
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding: 28px 20px;
  background: var(--nav);
  color: #fff;
}

.brand,
.profile-card {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 12px;
  background: var(--primary);
}

.brand strong {
  display: block;
  font-size: 22px;
  line-height: 28px;
}

.brand span,
.profile-card span,
.subject-rail p {
  color: #aab7c8;
  font-size: 12px;
  line-height: 18px;
}

.nav-list {
  display: grid;
  gap: 8px;
}

.nav-item,
.mobile-tab {
  border: 0;
  background: transparent;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  height: 48px;
  padding: 0 14px;
  border-radius: var(--radius-sm);
  color: #aab7c8;
  text-align: left;
}

.nav-item svg,
.mobile-tab svg,
.primary-btn svg,
.secondary-btn svg,
.accent-btn svg,
.text-btn svg {
  width: 20px;
  height: 20px;
  stroke-width: 2.2;
}

.nav-item.active,
.nav-item:hover {
  background: rgb(59 130 246 / 0.14);
  color: #fff;
  box-shadow: inset 4px 0 0 var(--primary);
}

.subject-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.subject-chip,
.tag {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  padding: 4px 10px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-size: 12px;
  font-weight: 600;
  line-height: 18px;
}

.subject-chip {
  border-color: rgb(255 255 255 / 0.12);
  background: rgb(255 255 255 / 0.06);
  color: #dbeafe;
}

.profile-card {
  margin-top: auto;
  padding-top: 20px;
  border-top: 1px solid rgb(255 255 255 / 0.1);
}

.logout-btn {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  margin-left: auto;
  border: 1px solid rgb(255 255 255 / 0.12);
  border-radius: 10px;
  background: rgb(255 255 255 / 0.06);
  color: #cbd5e1;
}

.logout-btn:hover {
  color: #fff;
  background: rgb(255 255 255 / 0.12);
}

.avatar {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: linear-gradient(135deg, #dbeafe, #3b82f6);
  color: #172554;
  font-weight: 800;
}

.main-stage {
  min-width: 0;
  padding: 24px;
}

.right-rail {
  display: grid;
  align-content: start;
  gap: 20px;
  padding: 24px 24px 24px 0;
}

.view {
  display: none;
}

.view.active {
  display: block;
}

.hero-panel,
.panel,
.rail-card,
.metric-card,
.streak-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--card);
  box-shadow: var(--shadow);
}

.hero-panel {
  display: flex;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 30px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--primary);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 8px;
  font-size: 24px;
  font-weight: 800;
  line-height: 32px;
}

h2 {
  margin-bottom: 0;
  font-size: 18px;
  font-weight: 750;
  line-height: 24px;
}

h3 {
  font-size: 15px;
  line-height: 22px;
}

.hero-panel p,
.page-head p,
.muted {
  color: var(--muted);
}

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

.primary-btn,
.secondary-btn,
.accent-btn,
.text-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 40px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  transition: transform 160ms ease, box-shadow 160ms ease, border-color 160ms ease;
}

.primary-btn {
  border: 1px solid var(--primary);
  background: var(--primary);
  color: white;
  padding: 0 16px;
}

.secondary-btn {
  border: 1px solid var(--border);
  background: #fff;
  color: var(--text);
  padding: 0 16px;
}

.accent-btn {
  border: 1px solid #d97706;
  background: #fbbf24;
  color: #422006;
  padding: 0 16px;
}

.text-btn {
  border: 0;
  background: transparent;
  color: var(--primary-dark);
  padding: 0 4px;
}

.primary-btn:hover,
.secondary-btn:hover,
.accent-btn:hover {
  transform: translateY(-1px);
  box-shadow: var(--hover-shadow);
}

.full {
  width: 100%;
}

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

.span-4 {
  grid-column: span 4;
}

.span-6 {
  grid-column: span 6;
}

.span-8 {
  grid-column: span 8;
}

.panel {
  padding: 20px;
}

.section-head,
.page-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

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

.page-head {
  margin-bottom: 16px;
}

.task-list,
.reason-list,
.weak-list,
.mistake-list,
.knowledge-map {
  display: grid;
  gap: 12px;
}

.task-card,
.mistake-card,
.knowledge-card,
.reason-row {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
}

.task-card,
.mistake-card,
.knowledge-card {
  padding: 14px;
}

.task-card {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
}

.task-icon {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 12px;
  background: var(--soft);
}

.task-card strong,
.mistake-card strong {
  display: block;
}

.task-card span,
.mistake-card span,
.knowledge-card span,
.similar-card span {
  color: var(--muted);
  font-size: 12px;
}

.line-chart {
  margin-top: 16px;
}

.line-chart svg {
  width: 100%;
  height: 220px;
  border-radius: var(--radius-sm);
  background: linear-gradient(180deg, #f8fafc, #eff6ff);
}

.chart-axis {
  display: flex;
  justify-content: space-between;
  margin-top: 8px;
  color: var(--muted);
  font-size: 12px;
}

.reason-row {
  padding: 12px;
}

.reason-row header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 8px;
  font-weight: 700;
}

.progress-track,
.mini-progress {
  position: relative;
  overflow: hidden;
  height: 8px;
  border-radius: 999px;
  background: #e9e3ee;
}

.progress-track b,
.mini-progress b {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--primary);
}

.weak-list .knowledge-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.streak-card {
  position: relative;
  overflow: hidden;
  min-height: 112px;
  padding: 20px;
  background: linear-gradient(135deg, #fde68a, #f59e0b);
  color: #422006;
}

.streak-card span,
.streak-card strong {
  display: block;
}

.streak-card strong {
  margin-top: 8px;
  font-size: 28px;
  line-height: 36px;
}

.streak-card svg {
  position: absolute;
  right: 20px;
  bottom: 18px;
  width: 42px;
  height: 42px;
  opacity: 0.45;
}

.rail-card h2 {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 16px;
}

.rail-card {
  padding: 20px;
}

.mini-progress {
  height: auto;
  margin-top: 14px;
  padding-top: 26px;
  background: transparent;
}

.mini-progress::before {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  height: 6px;
  border-radius: 999px;
  background: #e2e8f0;
}

.mini-progress b {
  position: absolute;
  bottom: 0;
  left: 0;
  height: 6px;
  background: var(--unmastered);
}

.ai-chip {
  display: inline-flex;
  padding: 2px 6px;
  border-radius: 4px;
  background: #dbeafe;
  color: var(--primary-dark);
  font-size: 12px;
  font-weight: 700;
}

.stepper {
  display: inline-flex;
  gap: 8px;
}

.stepper span {
  padding: 5px 10px;
  border-radius: 999px;
  background: var(--soft);
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.stepper .active {
  background: #dbeafe;
  color: var(--primary-dark);
}

.stepper .done {
  background: #dcfce7;
  color: #166534;
}

.input-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 16px;
}

.mistake-composer {
  display: grid;
  gap: 12px;
  margin-top: 16px;
  padding: 14px;
  border: 1px solid #bfdbfe;
  border-radius: 16px;
  background: linear-gradient(180deg, #ffffff, #f8fbff);
  box-shadow: 0 10px 30px rgb(59 130 246 / 0.08);
}

.composer-textarea {
  min-height: 180px;
  border: 0;
  background: transparent;
  font-size: 16px;
  line-height: 26px;
}

.composer-textarea:focus {
  border-color: transparent;
  background: transparent;
  box-shadow: none;
}

.composer-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding-top: 12px;
  border-top: 1px solid var(--border);
}

.composer-tools {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.composer-attachments {
  margin-top: 0;
}

.analysis-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 390px;
  gap: 16px;
}

.upload-zone {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 240px;
  padding: 24px;
  border: 1px dashed #93c5fd;
  border-radius: var(--radius);
  background: #eff6ff;
  color: var(--primary-dark);
  text-align: center;
}

.upload-zone input {
  position: absolute;
  inset: 0;
  z-index: 2;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
}

.upload-zone svg {
  width: 40px;
  height: 40px;
  margin-bottom: 8px;
}

.upload-zone span {
  color: var(--muted);
}

.preview-strip {
  display: flex;
  gap: 12px;
  margin-top: 12px;
  overflow-x: auto;
}

.preview-strip img,
.preview-placeholder {
  width: 112px;
  height: 82px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  object-fit: cover;
  background: var(--soft);
}

.file-preview {
  display: grid;
  place-items: center;
  width: 160px;
  min-width: 160px;
  height: 82px;
  padding: 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--muted);
  text-align: center;
  font-size: 12px;
  line-height: 16px;
}

.manual-grid,
.ai-form {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

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

label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  background: var(--soft);
  color: var(--text);
  outline: none;
}

input,
select {
  height: 44px;
  padding: 0 12px;
}

textarea {
  min-height: 110px;
  padding: 12px;
  resize: vertical;
}

input:focus,
select:focus,
textarea:focus {
  border-color: var(--primary);
  background: #fff;
  box-shadow: 0 0 0 3px rgb(59 130 246 / 0.16);
}

.ai-form {
  grid-template-columns: 1fr 1fr;
}

.field-block {
  margin-top: 18px;
}

.field-title {
  margin-bottom: 8px;
  font-weight: 800;
}

.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tag {
  background: #f1f5f9;
  color: #475569;
}

.tag.selected,
.tag:hover {
  border-color: #fecaca;
  background: #fee2e2;
  color: #991b1b;
}

.explain-card {
  margin-bottom: 10px;
  padding: 12px;
  border-left: 4px solid var(--primary);
  border-radius: var(--radius-sm);
  background: #eff6ff;
}

.explain-card.warning {
  border-color: var(--unmastered);
  background: #fef2f2;
}

.empty-analysis {
  display: grid;
  place-items: center;
  gap: 8px;
  min-height: 190px;
  padding: 20px;
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  background: #f8fafc;
  color: var(--muted);
  text-align: center;
}

.empty-analysis svg {
  width: 34px;
  height: 34px;
  color: var(--primary);
}

.empty-analysis p {
  margin-bottom: 0;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  padding: 4px 10px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 800;
}

.status-pill.reviewing {
  background: #fef3c7;
  color: #92400e;
}

.status-pill.unmastered {
  background: #fee2e2;
  color: #991b1b;
}

.status-pill.mastered {
  background: #d1fae5;
  color: #065f46;
}

.filter-bar {
  display: grid;
  grid-template-columns: 150px 150px 150px minmax(0, 1fr);
  gap: 12px;
  margin-bottom: 16px;
}

.notebook-layout {
  display: grid;
  grid-template-columns: 360px minmax(0, 1fr);
  gap: 16px;
}

.mistake-card.active {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgb(59 130 246 / 0.12);
}

.mistake-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

.problem-surface {
  margin-top: 16px;
  padding: 18px;
  border-radius: var(--radius-sm);
  background: #f8fafc;
  font-size: 16px;
  line-height: 26px;
}

.analysis-block {
  margin-top: 16px;
}

.analysis-block ol {
  padding-left: 20px;
}

.similar-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.similar-card {
  display: grid;
  gap: 8px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
}

.similar-card button {
  height: 32px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--primary-dark);
  font-weight: 700;
}

.visual-export {
  margin-top: 18px;
  padding-top: 18px;
  border-top: 1px solid var(--border);
}

.visual-canvas {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 260px;
  margin-top: 12px;
  overflow: hidden;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #f8fafc;
}

.visual-canvas img {
  display: none;
  width: 100%;
  max-height: 520px;
  object-fit: contain;
}

.visual-canvas.ready img {
  display: block;
}

.visual-canvas.ready .visual-loading {
  display: none;
}

.visual-loading {
  display: grid;
  place-items: center;
  gap: 10px;
  color: var(--muted);
  text-align: center;
}

.visual-loading svg {
  width: 32px;
  height: 32px;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

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

.knowledge-card header {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.knowledge-children {
  display: grid;
  gap: 8px;
}

.knowledge-item {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  background: var(--soft);
}

.metric-card {
  grid-column: span 4;
  padding: 20px;
}

.metric-card svg {
  width: 38px;
  height: 38px;
  padding: 8px;
  border-radius: var(--radius-sm);
  background: #dbeafe;
  color: var(--primary-dark);
}

.metric-card span,
.metric-card small {
  display: block;
  color: var(--muted);
}

.metric-card strong {
  display: block;
  margin: 10px 0 4px;
  font-size: 34px;
  line-height: 38px;
}

.bar-chart {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  align-items: end;
  gap: 14px;
  height: 280px;
  padding-top: 20px;
  border-bottom: 1px solid var(--border);
}

.bar-group {
  display: grid;
  align-items: end;
  grid-template-columns: 1fr 1fr;
  gap: 4px;
  height: 220px;
}

.bar {
  min-height: 12px;
  border-radius: 6px 6px 0 0;
  background: var(--primary);
}

.bar.added {
  background: #cbd5e1;
}

.bar-label {
  grid-column: 1 / -1;
  color: var(--muted);
  text-align: center;
}

.legend {
  display: inline-flex;
  gap: 8px;
  align-items: center;
  color: var(--muted);
}

.legend i {
  display: inline-block;
  width: 12px;
  height: 12px;
  border-radius: 3px;
  background: var(--primary);
}

.legend i + i {
  background: #cbd5e1;
}

.ai-weekly {
  background: #eff6ff;
}

.ai-weekly h2 {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--primary-dark);
}

.distribution {
  display: grid;
  gap: 10px;
}

.distribution-row {
  display: grid;
  grid-template-columns: 84px minmax(0, 1fr) 44px;
  gap: 12px;
  align-items: center;
}

.mobile-tabs {
  display: none;
}

.toast {
  position: fixed;
  right: 24px;
  bottom: 24px;
  transform: translateY(140px);
  opacity: 0;
  pointer-events: none;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  background: var(--nav);
  color: #fff;
  box-shadow: 0 10px 25px rgb(15 23 42 / 0.18);
  transition: transform 220ms ease, opacity 220ms ease;
  z-index: 20;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
}

.tutor-dialog {
  width: min(720px, calc(100vw - 32px));
  max-height: min(760px, calc(100vh - 32px));
  padding: 0;
  border: 0;
  border-radius: 16px;
  box-shadow: 0 24px 80px rgb(15 23 42 / 0.28);
}

.tutor-dialog::backdrop {
  background: rgb(15 23 42 / 0.36);
  backdrop-filter: blur(3px);
}

.tutor-shell {
  display: grid;
  grid-template-rows: auto auto minmax(260px, 1fr) auto auto;
  max-height: min(760px, calc(100vh - 32px));
  background: #fff;
}

.tutor-head {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 20px 20px 14px;
  border-bottom: 1px solid var(--border);
}

.icon-btn {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--text);
}

.tutor-context,
.quick-prompts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  background: #f8fafc;
}

.chat-log {
  display: grid;
  align-content: start;
  gap: 12px;
  padding: 20px;
  overflow-y: auto;
}

.chat-message {
  max-width: 86%;
  padding: 12px 14px;
  border-radius: 14px;
}

.chat-message p {
  margin-bottom: 0;
  white-space: pre-wrap;
}

.chat-message.assistant {
  justify-self: start;
  background: #eff6ff;
  color: #172554;
}

.chat-message.user {
  justify-self: end;
  background: var(--primary);
  color: #fff;
}

.quick-prompts button {
  min-height: 32px;
  border: 1px solid #bfdbfe;
  border-radius: 999px;
  background: #eff6ff;
  color: var(--primary-dark);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 10px;
}

.chat-form {
  display: grid;
  gap: 10px;
  padding: 14px 20px 20px;
}

.quality-toggle {
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--muted);
}

.quality-toggle input {
  width: 16px;
  height: 16px;
}

.chat-input-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 10px;
}

.chat-input-row textarea {
  min-height: 54px;
  max-height: 150px;
}

@media (max-width: 1180px) {
  .app-shell {
    grid-template-columns: var(--sidebar) minmax(0, 1fr);
  }

  .right-rail {
    display: none;
  }

  .analysis-layout {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 767px) {
  body {
    padding-bottom: 72px;
  }

  .app-shell {
    display: block;
    min-height: auto;
  }

  .sidebar {
    display: none;
  }

  .main-stage {
    padding: 16px;
  }

  .hero-panel,
  .page-head,
  .section-head {
    display: grid;
  }

  .hero-panel {
    padding: 20px;
  }

  .hero-actions,
  .filter-bar,
  .manual-grid,
  .optional-fields,
  .ai-form,
  .notebook-layout,
  .similar-grid,
  .knowledge-map,
  .content-grid,
  .analytics-grid {
    grid-template-columns: 1fr;
  }

  .detail-actions {
    justify-content: start;
  }

  .hero-actions {
    display: grid;
  }

  .composer-toolbar {
    align-items: stretch;
    flex-direction: column;
  }

  .composer-tools {
    align-items: stretch;
  }

  .span-4,
  .span-6,
  .span-8,
  .metric-card {
    grid-column: auto;
  }

  .filter-bar {
    display: grid;
  }

  .mistake-detail {
    display: block;
  }

  .stepper {
    overflow-x: auto;
  }

  .mobile-tabs {
    position: fixed;
    right: 0;
    bottom: 0;
    left: 0;
    z-index: 10;
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    height: 64px;
    border-top: 1px solid var(--border);
    background: #fff;
  }

  .mobile-tab {
    display: grid;
    place-items: center;
    align-content: center;
    gap: 2px;
    color: var(--muted);
    font-size: 11px;
  }

  .mobile-tab.active {
    color: var(--primary);
  }

  .mobile-tab svg {
    width: 21px;
    height: 21px;
  }

  .toast {
    right: 16px;
    bottom: 80px;
    left: 16px;
  }

  .tutor-dialog {
    width: 100vw;
    max-width: 100vw;
    max-height: 100vh;
    height: 100vh;
    border-radius: 0;
  }

  .tutor-shell {
    max-height: 100vh;
    height: 100vh;
  }

  .chat-input-row {
    grid-template-columns: 1fr;
  }

  .chat-message {
    max-width: 94%;
  }
}