/* Pfkfks Understanding-First AI Study: Cream / Ink / Green Theme */
:root {
  --bg-page: #faf8f5;
  --bg-card: #ffffff;
  --bg-subtle: #f4efe6;
  --bg-hover: #ece5d8;
  --border-color: #e5dec9;
  --border-subtle: #eee7d7;
  
  --ink-900: #1b1e23;
  --ink-700: #3a4049;
  --ink-500: #636b76;
  --ink-300: #8c95a1;

  --green-800: #14452a;
  --green-700: #1a5937;
  --green-600: #237346;
  --green-200: #b5dec4;
  --green-100: #daf0e2;
  --green-50: #f0f8f3;

  --amber-700: #b45309;
  --amber-100: #fef3c7;
  --amber-50: #fffbeb;

  --red-700: #b91c1c;
  --red-100: #fee2e2;
  --red-50: #fef2f2;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(27, 30, 35, 0.05);
  --shadow-md: 0 4px 12px rgba(27, 30, 35, 0.06);
  --font-base: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Noto Sans KR", "Apple SD Gothic Neo", sans-serif;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: var(--font-base);
  background-color: var(--bg-page);
  color: var(--ink-900);
  line-height: 1.6;
  min-height: 100vh;
  height: 100dvh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

/* Accessibility Focus */
:focus-visible {
  outline: 2px solid var(--green-700);
  outline-offset: 2px;
}

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

.hidden {
  display: none !important;
}

/* Header */
.app-header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  height: 64px;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 40;
}

.header-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-badge {
  background: var(--green-100);
  color: var(--green-800);
  font-size: 0.75rem;
  font-weight: 700;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--ink-900);
}

.header-auth {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.user-info {
  font-size: 0.9rem;
  color: var(--ink-700);
}

.mobile-nav {
  display: none;
  gap: 0.5rem;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: inherit;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.55rem 1rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s ease;
  border: 1px solid transparent;
}

.btn:disabled {
  opacity: 0.55;
  cursor: not-allowed;
}

.btn-primary {
  background: var(--green-700);
  color: #ffffff;
}
.btn-primary:hover:not(:disabled) {
  background: var(--green-800);
}

.btn-secondary {
  background: var(--bg-card);
  border-color: var(--border-color);
  color: var(--ink-900);
}
.btn-secondary:hover:not(:disabled) {
  background: var(--bg-subtle);
}

.btn-outline {
  background: transparent;
  border-color: var(--border-color);
  color: var(--ink-700);
}
.btn-outline:hover:not(:disabled) {
  background: var(--bg-subtle);
  color: var(--ink-900);
}

.btn-lg {
  padding: 0.75rem 1.25rem;
  font-size: 1rem;
}
.btn-sm {
  padding: 0.35rem 0.65rem;
  font-size: 0.8rem;
}
.btn-block {
  width: 100%;
}

.btn-text {
  background: none;
  border: none;
  color: var(--green-700);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
}
.btn-text:hover {
  text-decoration: underline;
}

.btn-icon {
  background: none;
  border: none;
  font-size: 1.25rem;
  color: var(--ink-500);
  cursor: pointer;
  padding: 0.25rem;
  line-height: 1;
}

/* Alert Banner */
.alert-banner {
  background: var(--amber-50);
  border-bottom: 1px solid var(--amber-100);
  color: var(--amber-700);
  padding: 0.75rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}
.alert-banner.error {
  background: var(--red-50);
  border-color: var(--red-100);
  color: var(--red-700);
}
.alert-content {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}
.alert-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Layout */
.learn-layout {
  flex: 1;
  display: grid;
  grid-template-columns: 250px minmax(0, 1fr) 310px;
  grid-template-rows: minmax(0, 1fr);
  min-height: 0;
  overflow: hidden;
}

/* Sidebar */
.sidebar {
  background: var(--bg-card);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  padding: 1.25rem;
  overflow-y: auto;
}

.goal-card {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem;
}

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

.card-title-group {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.card-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ink-700);
}

.privacy-badge {
  font-size: 0.7rem;
  color: var(--green-800);
  background: var(--green-100);
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
  font-weight: 600;
  display: inline-block;
}

.goal-text {
  font-size: 0.88rem;
  color: var(--ink-900);
  white-space: pre-wrap;
}

.goal-edit-form {
  margin-top: 0.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-help {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--ink-500);
}

.privacy-note {
  color: var(--green-700);
}

.btn-group-sm {
  display: flex;
  gap: 0.5rem;
}

.section-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ink-500);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.75rem;
}

.sessions-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.session-deletion-pending {
  display: flex;
  align-items: center;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.6rem;
  font-size: 0.8rem;
  justify-content: space-between;
  gap: 0.5rem;
  background: var(--bg-card);
}
.session-deletion-pending span { overflow-wrap: anywhere; }

.session-item {
  width: 100%;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  cursor: pointer;
  text-align: left;
  transition: all 0.15s ease;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.session-item:hover {
  border-color: var(--green-600);
  background: var(--green-50);
}
.session-item.active {
  border-color: var(--green-700);
  background: var(--green-50);
  box-shadow: var(--shadow-sm);
}
.session-item-title {
  width: 100%;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink-900);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.session-item-meta {
  width: 100%;
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--ink-500);
}

/* Main Stage */
.main-stage {
  display: flex;
  flex-direction: column;
  background: var(--bg-page);
  overflow: hidden;
  position: relative;
}

/* Setup View */
.setup-view {
  flex: 1;
  overflow-y: auto;
  padding: 2rem 1.5rem;
  display: flex;
  justify-content: center;
}

.setup-card {
  height: fit-content;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  max-width: 760px;
  width: 100%;
  padding: 2rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.setup-intro h2 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--ink-900);
  margin-bottom: 0.3rem;
}
.setup-intro p {
  font-size: 0.95rem;
  color: var(--ink-700);
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

label {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--ink-900);
}

.required {
  color: var(--red-700);
}

.counter, .counter-sm {
  font-size: 0.75rem;
  color: var(--ink-500);
}

.field-help {
  font-size: 0.8rem;
  color: var(--ink-500);
}

.form-control {
  font-family: inherit;
  font-size: 0.95rem;
  color: var(--ink-900);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  transition: border-color 0.15s ease;
  resize: vertical;
}
.form-control:focus {
  border-color: var(--green-700);
}

.file-drop-zone {
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-md);
  background: var(--bg-subtle);
  padding: 1.5rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.15s ease;
}
.file-drop-zone:hover, .file-drop-zone.drag-over {
  border-color: var(--green-600);
  background: var(--green-50);
}
.drop-icon {
  font-size: 2rem;
  display: block;
  margin-bottom: 0.25rem;
}
.drop-primary {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--ink-900);
}
.drop-desc {
  font-size: 0.8rem;
  color: var(--ink-500);
  margin-top: 0.2rem;
}

.file-notice {
  font-size: 0.8rem;
  color: var(--ink-700);
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.85rem;
  line-height: 1.5;
}

.extract-progress-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-top: 0.5rem;
}
.progress-bar-bg {
  height: 8px;
  background: var(--border-color);
  border-radius: 4px;
  overflow: hidden;
}
.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: var(--green-600);
  transition: width 0.2s ease;
}
.progress-text {
  font-size: 0.75rem;
  color: var(--ink-700);
}

.selected-files-list {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  margin-top: 0.5rem;
}
.file-pill {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.4rem 0.75rem;
  font-size: 0.82rem;
}

/* Study View */
.learning-records { margin-top: 1rem; }
.learning-record { border-top: 1px solid var(--border-color); padding: 0.75rem 0; font-size: 0.83rem; }
.learning-record p { margin: 0.35rem 0; overflow-wrap: anywhere; }
.learning-record select { max-width: 100%; margin: 0.35rem 0; }
.study-view {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.study-header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  padding: 0.75rem 1.5rem;
}
.study-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.study-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--ink-900);
}
.study-badges {
  display: flex;
  gap: 0.5rem;
}
.badge {
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.55rem;
  border-radius: 999px;
}
.badge-status {
  background: var(--green-100);
  color: var(--green-800);
}
.badge-progress {
  background: var(--bg-subtle);
  color: var(--ink-700);
  border: 1px solid var(--border-color);
}

/* Chat Stream */
.chat-stream {
  flex: 1;
  overflow-y: auto;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.chat-message {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  max-width: 820px;
  width: 100%;
}
.chat-message.assistant {
  align-self: flex-start;
}
.chat-message.user {
  align-self: flex-end;
}

.message-header {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  color: var(--ink-500);
}
.chat-message.user .message-header {
  justify-content: flex-end;
}
.role-badge {
  font-weight: 700;
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
  font-size: 0.72rem;
}
.chat-message.assistant .role-badge {
  background: var(--green-100);
  color: var(--green-800);
}
.chat-message.user .role-badge {
  background: var(--bg-subtle);
  color: var(--ink-700);
}

.message-card {
  padding: 1.1rem 1.25rem;
  border-radius: var(--radius-md);
  line-height: 1.65;
  box-shadow: var(--shadow-sm);
  word-break: break-word;
}
.chat-message.assistant .message-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-left: 4px solid var(--green-700);
}
.chat-message.user .message-card {
  background: var(--green-50);
  border: 1px solid var(--green-200);
}

.block-intro-banner {
  background: var(--bg-subtle);
  border-left: 3px solid var(--green-600);
  padding: 0.4rem 0.75rem;
  margin-bottom: 0.75rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: 0.82rem;
  color: var(--ink-700);
}

/* Safe Markdown Typography */
.markdown-body h1, .markdown-body h2, .markdown-body h3, .markdown-body h4 {
  color: var(--ink-900);
  margin: 1rem 0 0.5rem 0;
}
.markdown-body h1:first-child, .markdown-body h2:first-child, .markdown-body h3:first-child {
  margin-top: 0;
}
.markdown-body p {
  margin-bottom: 0.75rem;
}
.markdown-body p:last-child {
  margin-bottom: 0;
}
.markdown-body ul, .markdown-body ol {
  margin: 0.5rem 0 0.75rem 1.5rem;
}
.markdown-body code {
  font-family: ui-monospace, SFMono-Regular, Consolas, monospace;
  background: var(--bg-subtle);
  color: var(--green-800);
  padding: 0.15rem 0.35rem;
  border-radius: 4px;
  font-size: 0.88em;
}
.markdown-body pre {
  background: #1b1e23;
  color: #f7f9fa;
  padding: 0.85rem;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 0.75rem 0;
}
.markdown-body pre code {
  background: none;
  color: inherit;
  padding: 0;
}
.markdown-body blockquote {
  border-left: 3px solid var(--border-color);
  padding-left: 0.75rem;
  color: var(--ink-500);
  margin: 0.75rem 0;
}
.markdown-body table {
  border-collapse: collapse;
  width: 100%;
  margin: 0.75rem 0;
}
.markdown-body th, .markdown-body td {
  border: 1px solid var(--border-color);
  padding: 0.4rem 0.65rem;
  text-align: left;
  font-size: 0.88rem;
}
.markdown-body th {
  background: var(--bg-subtle);
}
.katex-display {
  overflow-x: auto;
  overflow-y: hidden;
  padding: 0.35rem 0;
}

/* Workspace Dock */
.workspace-dock {
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  padding: 1rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.block-controls {
  display: flex;
  justify-content: center;
}

.btn-group-actions {
  display: flex;
  gap: 0.65rem;
  width: 100%;
  max-width: 820px;
}
.btn-group-actions .btn-primary {
  flex: 2;
}
.btn-group-actions .btn-secondary {
  flex: 1;
}

.completed-banner {
  background: var(--green-50);
  border: 1px solid var(--green-200);
  color: var(--green-800);
  padding: 0.65rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  text-align: center;
  width: 100%;
  max-width: 820px;
}

.question-form {
  max-width: 820px;
  margin: 0 auto;
  width: 100%;
}

.question-input-wrap {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.question-textarea {
  width: 100%;
  resize: none;
  border-radius: var(--radius-md);
}

.question-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Right Panel */
.right-panel {
  background: var(--bg-card);
  border-left: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  height: 100%;
  overflow: hidden;
}

.panel-tabs {
  display: flex;
  border-bottom: 1px solid var(--border-color);
  background: var(--bg-subtle);
}

.panel-tab-btn {
  flex: 1;
  padding: 0.75rem 0.5rem;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  font-family: inherit;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--ink-500);
  cursor: pointer;
}
.panel-tab-btn.active {
  color: var(--green-800);
  background: var(--bg-card);
  border-bottom-color: var(--green-700);
}

.panel-body {
  flex: 1;
  overflow-y: auto;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.panel-sub-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ink-700);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 0.5rem;
}
.panel-sub-desc {
  font-size: 0.78rem;
  color: var(--ink-500);
  margin-bottom: 0.75rem;
}

.map-overview-card {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  font-size: 0.85rem;
  color: var(--ink-700);
  line-height: 1.5;
}

.map-blocks-container {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.map-block-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}
.map-block-card.active {
  border-color: var(--green-700);
  background: var(--green-50);
}
.map-block-card.completed {
  border-color: var(--green-200);
  opacity: 0.9;
}
.map-block-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.map-block-title {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--ink-900);
}
.map-block-badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}
.map-block-card.active .map-block-badge {
  background: var(--green-700);
  color: #fff;
}
.map-block-card.completed .map-block-badge {
  background: var(--green-100);
  color: var(--green-800);
}
.map-block-card.pending .map-block-badge {
  background: var(--bg-subtle);
  color: var(--ink-500);
}
.map-block-refs {
  font-size: 0.73rem;
  color: var(--ink-500);
}

.legend {
  display: flex;
  gap: 0.75rem;
  font-size: 0.75rem;
  color: var(--ink-700);
  margin-bottom: 0.5rem;
}
.legend-item {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}
.dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
}
.dot-known { background: #3b82f6; }
.dot-exposed { background: var(--green-600); }
.dot-upcoming { background: var(--border-color); }

.map-concepts-container {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.concept-row {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.65rem;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}
.concept-row.known {
  border-left: 3px solid #3b82f6;
}
.concept-row.exposed {
  border-left: 3px solid var(--green-600);
  background: var(--green-50);
}
.concept-row.upcoming {
  border-left: 3px solid var(--border-color);
  opacity: 0.75;
}
.concept-main {
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.concept-name {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ink-900);
}
.concept-status-pill {
  font-size: 0.68rem;
  font-weight: 600;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}
.concept-prereqs {
  font-size: 0.72rem;
  color: var(--ink-500);
}

.sources-container {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.source-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  overflow: hidden;
}
.source-card-header {
  background: var(--bg-subtle);
  padding: 0.5rem 0.75rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--ink-900);
}
.source-units-list {
  display: flex;
  flex-direction: column;
}
.source-unit-item {
  padding: 0.5rem 0.75rem;
  border-top: 1px solid var(--border-subtle);
  font-size: 0.78rem;
}
.source-unit-item.active-ref {
  background: var(--green-50);
  border-left: 3px solid var(--green-700);
}
.unit-label {
  font-weight: 600;
  color: var(--ink-700);
  margin-bottom: 0.15rem;
}
.unit-preview {
  color: var(--ink-500);
  line-height: 1.4;
  max-height: 60px;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* Settings Panel */
.settings-section {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.settings-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.settings-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}
.settings-title {
  min-width: 0;
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--ink-900);
  overflow-wrap: anywhere;
}
.settings-danger-zone {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--border-color);
}
.btn.danger, .btn-outline.danger {
  color: var(--red-700);
  border-color: var(--red-100);
}
.btn-outline.danger:hover:not(:disabled) {
  background: var(--red-50);
  border-color: var(--red-700);
  color: var(--red-700);
}
.pending-deletions-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.settings-title-row .btn-text, .session-deletion-pending .btn-text { flex-shrink: 0; }

/* Responsive */
@media (max-width: 1100px) {
  .learn-layout {
    grid-template-columns: 200px minmax(0, 1fr) 260px;
  }
}

@media (max-width: 860px) {
  .app-header {
    height: auto;
    min-height: 108px;
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    padding: 10px 14px;
    gap: 8px;
  }
  .header-brand { min-width: 0; gap: 8px; }
  .brand-badge { white-space: nowrap; }
  .brand-title { font-size: 15px; white-space: nowrap; }
  .model-label, .user-info { display: none; }
  .header-auth { grid-column: 2; grid-row: 1; }
  .header-auth .btn { padding: 7px 10px; font-size: 12px; white-space: nowrap; }
  .mobile-nav {
    display: flex;
    grid-column: 1 / -1;
    grid-row: 2;
    gap: 4px;
    flex-wrap: nowrap;
  }
  .mobile-nav .tab-btn { flex: 1; min-width: 0; white-space: nowrap; padding: 0.35rem 0.3rem; font-size: 0.74rem; text-align: center; }
  .main-stage { min-width: 0; }
  .study-header, .chat-stream, .workspace-dock { padding-left: 14px; padding-right: 14px; }
  .btn-group-actions { display: flex; gap: 6px; }
  .btn-group-actions .btn { white-space: nowrap; padding: 10px 9px; font-size: 12px; }
  .study-title { font-size: 16px; }
  .learn-layout {
    display: flex;
    flex-direction: column;
  }
  .sidebar, .main-stage, .right-panel {
    display: none;
    height: 100%;
    overflow-y: auto;
  }
  .learn-layout.view-main .main-stage { display: flex; }
  .learn-layout.view-map .right-panel { display: flex; }
  .learn-layout.view-map #panel-map { display: flex; }
  .learn-layout.view-map #panel-sources { display: none; }
  .learn-layout.view-map #panel-settings { display: none; }
  .learn-layout.view-sources .right-panel { display: flex; }
  .learn-layout.view-sources #panel-sources { display: flex; }
  .learn-layout.view-sources #panel-map { display: none; }
  .learn-layout.view-sources #panel-settings { display: none; }
  .learn-layout.view-settings .right-panel { display: flex; }
  .learn-layout.view-settings #panel-settings { display: flex; }
  .learn-layout.view-settings #panel-map { display: none; }
  .learn-layout.view-settings #panel-sources { display: none; }
  .learn-layout.view-sessions .sidebar { display: flex; }
  
  .tab-btn {
    padding: 0.35rem 0.65rem;
    background: none;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--ink-700);
    cursor: pointer;
  }
  .tab-btn.active {
    background: var(--green-700);
    color: #fff;
    border-color: var(--green-700);
  }
}

/* Constrain the workspace to the viewport: map length never pushes the composer away. */
.app-header, .alert-banner, .study-header, .workspace-dock, .panel-tabs { flex-shrink: 0; }
.sidebar, .main-stage, .right-panel, .study-view, .chat-stream, .panel-body, .setup-view { min-height: 0; min-width: 0; }
.study-meta { flex-wrap: wrap; gap: .5rem; }
.study-title { overflow-wrap: anywhere; flex: 1; min-width: 0; }
.study-badges { flex-wrap: wrap; }
.study-header { max-height: 30%; overflow-y: auto; }
.workspace-dock { max-height: 45%; overflow-y: auto; }
.map-section { flex-shrink: 0; }
.map-disclosure { border: 1px solid var(--border-color); border-radius: var(--radius-sm); padding: .7rem; }
.map-disclosure > summary { cursor: pointer; margin: 0; text-transform: none; }
.map-disclosure[open] > summary { margin-bottom: .75rem; }
.title-edit-form { display: flex; flex-direction: column; gap: .5rem; margin-top: .75rem; }
.legend { flex-wrap: wrap; }
@media (max-width: 860px) {
  .study-meta { display: grid; grid-template-columns: auto minmax(0, 1fr); }
  .study-title { grid-column: 1 / -1; }
  .study-badges { justify-content: flex-end; }
}
/* Source-backed curriculum details keep long transcripts contained on mobile. */
.curriculum-section { margin-top: 1rem; padding: .75rem; border: 1px solid var(--border-color, #d8dce4); border-radius: .65rem; min-width: 0; overflow-wrap: anywhere; }
.curriculum-section:empty { display: none; }
.curriculum-section details, .curriculum-extras details { margin: .65rem 0; }
.curriculum-section summary, .curriculum-extras summary { cursor: pointer; font-weight: 600; }
.curriculum-section button, .curriculum-extras button { margin: .4rem .3rem .2rem 0; white-space: normal; }
.perspective-card { padding: .75rem 0; border-bottom: 1px solid var(--border-color, #d8dce4); }
.perspective-card blockquote { margin: .5rem 0; padding-left: .65rem; border-left: 3px solid #879dc7; }
.perspective-unit-text { white-space: pre-wrap; overflow-wrap: anywhere; max-height: 20rem; overflow: auto; font: inherit; }
.curriculum-question { font-weight: 600; margin: .6rem 0; }
.preparation-item { margin: .7rem 0; }