@import url('https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;800&display=swap');

:root {
  --bg: #eef1f5;
  --surface: #ffffff;
  --surface-soft: #f5f7fa;
  --surface-strong: #e9edf2;
  --text: #1c2733;
  --muted: #47586b;
  --border: #d7dee6;
  --border-strong: #c3ccd6;
  --primary: #145da0;
  --primary-dark: #0d4377;
  --primary-darker: #0a2f57;
  --primary-soft: #e6f0fa;
  --secondary: #23364a;
  --accent: #b45309;
  --accent-soft: #fdf0dd;
  --success: #1e7e42;
  --success-soft: #e4f6ea;
  --success-border: #a9dcbb;
  --danger: #c0392b;
  --danger-soft: #fbe9e7;
  --footer-bg: #0a2f57;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  color: var(--text);
  background: var(--bg);
  font-family: 'Manrope', sans-serif;
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.topbar {
  width: 100%;
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.75rem 1.4rem;
  background: var(--primary-darker);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  position: sticky;
  top: 0;
  z-index: 50;
  box-shadow: var(--shadow-md);
}

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

.brand-mark {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: var(--radius-md);
  display: grid;
  place-items: center;
  font-weight: 800;
  color: #fff;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

.topbar-left {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.session-info {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-left: 1.25rem;
  border-left: 1px solid rgba(255, 255, 255, 0.18);
}

.main-nav {
  display: inline-flex;
  align-items: center;
  gap: 0.2rem;
  padding: 0.25rem;
  border: 1px solid rgba(255, 255, 255, 0.18);
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.06);
}

.nav-tab {
  background: transparent;
  color: rgba(255, 255, 255, 0.78);
  padding: 0.42rem 0.85rem;
  border-radius: var(--radius-sm);
  font-weight: 700;
  border: 0;
}

.nav-tab:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.1);
  color: #fff;
  transform: none;
  box-shadow: none;
}

.nav-tab.is-active {
  background: rgba(255, 255, 255, 0.18);
  color: #fff;
  box-shadow: none;
}

.user-pill {
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.28);
  background: rgba(255, 255, 255, 0.1);
  padding: 0.35rem 0.7rem;
  font-size: 0.82rem;
  font-weight: 700;
  color: #fff;
}

.topbar .btn-secondary {
  background: transparent;
  border: 1px solid rgba(255, 255, 255, 0.4);
  color: #fff;
}

.topbar .btn-secondary:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.12);
  box-shadow: none;
}

.brand-name {
  font-weight: 800;
  font-size: 1.1rem;
  line-height: 1.2;
  color: #fff;
}

.app-layout {
  width: min(1400px, calc(100% - 2rem));
  flex: 1;
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 1.2rem;
  padding: 1.2rem 0 1.5rem;
  margin: 0 auto;
}

.site-footer {
  margin-top: auto;
  padding: 1.1rem 1.4rem;
  background: var(--footer-bg);
  color: rgba(255, 255, 255, 0.72);
  text-align: center;
  font-size: 0.82rem;
}

.site-footer p {
  margin: 0;
}

.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  position: sticky;
  top: 88px;
  align-self: start;
  max-height: calc(100vh - 104px);
}

.sidebar .panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.workspace {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-width: 0;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  padding: 1.25rem;
  scroll-margin-top: 96px;
}

.panel-accent {
  border-top: 3px solid var(--primary);
}

.section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.breadcrumb {
  margin: 0 0 0.3rem;
  font-size: 0.78rem;
  color: var(--muted);
  font-weight: 600;
}

h2 {
  margin: 0;
  font-size: 1.25rem;
  font-weight: 800;
}

.badge {
  background: var(--accent-soft);
  color: var(--accent);
  border: 1px solid #f2d4a3;
  border-radius: var(--radius-sm);
  padding: 0.25rem 0.65rem;
  font-size: 0.8rem;
  font-weight: 700;
}

.course-form {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: minmax(280px, 2fr) minmax(130px, 1fr) auto auto;
  gap: 0.65rem;
}

.stack-form {
  display: grid;
  gap: 0.55rem;
}

.login-inline-form {
  grid-template-columns: minmax(180px, 1fr) minmax(180px, 1fr) auto;
  align-items: end;
}

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

input,
select,
textarea {
  border: 1px solid var(--border-strong);
  background: var(--surface);
  border-radius: var(--radius-sm);
  color: var(--text);
  padding: 0.68rem 0.85rem;
}

input:focus,
select:focus,
textarea:focus,
button:focus-visible,
summary:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
}

button {
  border: 0;
  border-radius: var(--radius-sm);
  background: var(--primary);
  color: white;
  cursor: pointer;
  padding: 0.68rem 1rem;
  font-weight: 700;
  transition: background-color 140ms ease, box-shadow 140ms ease;
}

button:hover:not(:disabled) {
  background: var(--primary-dark);
  box-shadow: var(--shadow-sm);
}

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

.btn-secondary {
  background: var(--surface);
  color: var(--secondary);
  border: 1px solid var(--border-strong);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--surface-strong);
  box-shadow: none;
}

.btn-danger {
  background: var(--danger);
  color: white;
}

.btn-danger:hover:not(:disabled) {
  background: #a5291d;
  box-shadow: none;
}

#status {
  min-height: 1.2rem;
  margin-top: 0.75rem;
  color: var(--muted);
}

.courses-grid {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.7rem;
}

.home-courses-grid {
  margin-top: 1rem;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.9rem;
}

.module-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin: 0 0 0.75rem;
  padding: 0.7rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-soft);
}

.module-nav-meta {
  flex: 1;
  text-align: center;
  font-weight: 700;
  color: var(--primary);
}

.module-nav button {
  min-width: 160px;
}

.module-quick-actions,
.module-footer-nav {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin: 0 0 1rem;
  padding: 0.7rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-soft);
}

.module-quick-actions {
  justify-content: flex-end;
}

.module-footer-nav {
  display: flex;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 1rem;
  padding-top: 0.9rem;
  border-top: 1px solid var(--border);
  background: transparent;
  border-left: 0;
  border-right: 0;
  border-bottom: 0;
}

.module-footer-nav button {
  flex: 1;
}

.course-index {
  margin-top: 0.9rem;
  display: grid;
  align-content: start;
  gap: 0.7rem;
  overflow-y: auto;
  flex: 1;
  min-height: 0;
}

.course-index-module {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.75rem;
  background: var(--surface);
  border-left: 3px solid var(--primary);
}

.course-index-certification {
  display: block;
  width: 100%;
  text-align: left;
  cursor: pointer;
  font: inherit;
  color: var(--text);
}

.course-index-certification:hover:not(:disabled) {
  background: var(--surface-strong);
  box-shadow: none;
  transform: none;
}

.course-index-certification .course-index-module-title {
  display: block;
  font-weight: 700;
}

.course-index-module > summary {
  list-style: none;
  cursor: pointer;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.5rem;
}

.course-index-module > summary::-webkit-details-marker {
  display: none;
}

.course-index-module-title {
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.course-index-lessons {
  display: grid;
  gap: 0.35rem;
  margin-top: 0.55rem;
}

.course-index-link {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  text-align: left;
  background: var(--surface-soft);
  color: var(--secondary);
  border: 1px solid var(--border);
  box-shadow: none;
  padding: 0.55rem 0.6rem;
  border-radius: var(--radius-sm);
}

.course-index-link:hover:not(:disabled) {
  background: var(--surface-strong);
  box-shadow: none;
}

.course-index-link:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  background: var(--surface-soft);
}

.course-index-link-text {
  min-width: 0;
}

.course-card {
  width: 100%;
  text-align: left;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  padding: 0.88rem;
  cursor: pointer;
  transition: border-color 140ms ease, box-shadow 140ms ease;
  color: var(--text);
}

.course-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-sm);
}

.course-card h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.dashboard-course-card {
  width: 100%;
  text-align: left;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  padding: 1rem;
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
  min-height: 180px;
  color: var(--text);
  transition: border-color 140ms ease, box-shadow 140ms ease;
}

.dashboard-course-card::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 4px;
  background: var(--border-strong);
}

.dashboard-course-card.is-progress::before {
  background: var(--primary);
}

.dashboard-course-card.is-complete::before {
  background: var(--success);
}

.dashboard-course-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-md);
}

.dashboard-card-head h3,
.dashboard-course-card h3,
.dashboard-course-card .meta-line,
.dashboard-course-card strong,
.dashboard-course-card p {
  color: var(--text);
}

.card-tags {
  display: flex;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-top: 0.3rem;
}

.pill {
  display: inline-block;
  border-radius: var(--radius-sm);
  padding: 0.16rem 0.5rem;
  font-size: 0.74rem;
  font-weight: 700;
  border: 1px solid transparent;
  line-height: 1.4;
}

.pill-neutral {
  background: var(--surface-strong);
  color: var(--secondary);
  border-color: var(--border-strong);
}

.pill-warning {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: #f2d4a3;
}

.pill-success {
  background: var(--success-soft);
  color: var(--success);
  border-color: var(--success-border);
}

.dashboard-course-card .meta-line {
  color: var(--muted);
}

.dashboard-card-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 0.8rem;
}

.dashboard-course-card h3 {
  margin: 0 0 0.35rem;
  font-size: 1.02rem;
}

.dashboard-percent {
  font-size: 1.1rem;
  color: var(--primary);
  font-weight: 800;
}

.dashboard-card-cover {
  width: 100%;
  height: 94px;
  border-radius: var(--radius-sm);
  background-size: cover;
  background-position: center;
  margin-bottom: 0.9rem;
  border: 1px solid var(--border);
  background-color: var(--surface-soft);
}

.progress-bar {
  width: 100%;
  height: 0.5rem;
  background: var(--surface-strong);
  border-radius: 999px;
  overflow: hidden;
  margin: 0.85rem 0 0.6rem;
}

.progress-bar span {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: var(--primary);
}

.meta-line {
  margin: 0;
  color: var(--muted);
  font-size: 0.84rem;
}

.module {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  margin: 0.9rem 0;
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.module > summary {
  list-style: none;
  cursor: pointer;
  padding: 0.82rem 0.95rem;
  font-weight: 700;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  background: var(--surface-soft);
}

.module > summary::-webkit-details-marker,
.lesson > summary::-webkit-details-marker {
  display: none;
}

.summary-note {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 600;
}

.module-content {
  padding: 0.55rem 0.75rem 0.85rem;
}

.objectives {
  margin: 0.4rem 0 0.8rem;
  padding: 0 0 0 1.1rem;
  color: var(--muted);
}

.lesson {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  margin-top: 0.55rem;
  scroll-margin-top: 96px;
}

.lesson.is-locked {
  border-style: dashed;
  opacity: 0.86;
}

.lesson.is-locked > summary {
  cursor: not-allowed;
}

.lesson > summary {
  list-style: none;
  cursor: pointer;
  padding: 0.62rem 0.75rem;
  font-weight: 600;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.8rem;
  background: var(--surface-soft);
}

.lesson-tree-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  min-width: 0;
  flex: 1;
}

.lesson-tree-title {
  min-width: 0;
}

.lesson-tree-checks {
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
  flex-shrink: 0;
}

.lesson-check {
  width: 1.3rem;
  height: 1.3rem;
  border-radius: 999px;
  display: inline-grid;
  place-items: center;
  border: 1px solid var(--border-strong);
  background: var(--surface-soft);
  color: #94a3b8;
  font-size: 0.8rem;
  line-height: 1;
}

.lesson-check.is-done {
  border-color: var(--success-border);
  background: var(--success-soft);
  color: var(--success);
}

.lesson-body {
  padding: 0 0.75rem 0.75rem;
}

.phase-switcher {
  display: flex;
  gap: 1.3rem;
  flex-wrap: wrap;
  margin: 0.7rem 0 0.9rem;
  border-bottom: 1px solid var(--border);
}

.phase-tab {
  background: transparent;
  color: var(--muted);
  border: 0;
  border-bottom: 2px solid transparent;
  border-radius: 0;
  box-shadow: none;
  padding: 0.55rem 0.05rem;
  margin-bottom: -1px;
}

.phase-tab:hover:not(:disabled) {
  background: transparent;
  color: var(--text);
  box-shadow: none;
}

.phase-tab.is-active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.tab-check {
  display: inline-grid;
  place-items: center;
  width: 15px;
  height: 15px;
  border-radius: 999px;
  background: var(--success-soft);
  color: var(--success);
  font-size: 0.62rem;
  vertical-align: middle;
}

.workflow-step {
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface-soft);
  color: var(--muted);
  padding: 0.18rem 0.55rem;
  font-size: 0.78rem;
  font-weight: 700;
}

.workflow-step.is-done,
.phase-state.is-done {
  background: var(--success-soft);
  border-color: var(--success-border);
  color: var(--success);
}

.phase-block {
  border-top: 1px solid var(--border);
  padding-top: 0.7rem;
  margin-top: 0.7rem;
}

.phase-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.6rem;
  margin-bottom: 0.45rem;
  flex-wrap: wrap;
}

.phase-head h4 {
  margin: 0;
  font-size: 0.98rem;
  font-weight: 800;
}

.phase-state {
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-strong);
  background: var(--surface-soft);
  color: var(--muted);
  padding: 0.2rem 0.55rem;
  font-size: 0.77rem;
  font-weight: 700;
}

.lesson-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 0.8rem;
  padding: 0.55rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-soft);
}

.exercises-actions,
.quiz-actions {
  margin-bottom: 0.8rem;
}

.lesson-next-steps {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
  margin-top: 0.8rem;
  padding: 0.7rem 0.9rem;
  border: 1px solid #bcd6ef;
  border-radius: var(--radius-md);
  background: var(--primary-soft);
}

.lesson-next-steps:empty {
  display: none;
}

.lesson-next-steps .meta-line {
  font-weight: 700;
  color: var(--primary-dark);
}

.icon-action {
  width: 2.5rem;
  min-width: 2.5rem;
  padding: 0.5rem 0.4rem;
  font-size: 1rem;
  line-height: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.lesson-editor-modal {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.48);
  display: grid;
  place-items: center;
  padding: 1rem;
  z-index: 2000;
}

.generation-progress-overlay {
  position: fixed;
  inset: 0;
  background: rgba(15, 23, 42, 0.48);
  display: grid;
  place-items: center;
  padding: 1rem;
  z-index: 2100;
}

.generation-progress-dialog {
  width: min(640px, 96vw);
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: 0 24px 48px rgba(15, 23, 42, 0.22);
  padding: 1.25rem;
}

.generation-progress-dialog h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.generation-progress-message {
  min-height: 1.2rem;
}

.generation-progress-bar {
  margin: 0.8rem 0;
}

.generation-progress-preview {
  max-height: 260px;
  overflow-y: auto;
  margin: 0;
  padding: 0.75rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-soft);
  font: 0.8rem/1.5 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--muted);
}

.lesson-editor-dialog {
  width: min(920px, 96vw);
  background: var(--surface);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  box-shadow: 0 24px 48px rgba(15, 23, 42, 0.22);
  padding: 1rem;
}

.lesson-editor-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.8rem;
}

.lesson-editor-header h3 {
  margin: 0;
  font-size: 1.05rem;
}

.lesson-editor-dialog textarea {
  width: 100%;
  min-height: 420px;
  resize: vertical;
  padding: 1rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-strong);
  background: var(--surface-soft);
  color: var(--text);
  font: 0.84rem/1.55 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  box-sizing: border-box;
}

.lesson-editor-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.7rem;
  margin-top: 0.9rem;
}

.lesson-completion-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  margin-left: auto;
  padding: 0.46rem 0.8rem;
  border: 1px solid var(--success-border);
  border-radius: var(--radius-sm);
  background: var(--success-soft);
  color: var(--success);
  font-weight: 700;
  cursor: pointer;
}

.lesson-completion-toggle input {
  width: 1rem;
  height: 1rem;
  accent-color: var(--success);
  margin: 0;
}

.lesson-actions button,
.quiz-footer button,
.export-btn {
  padding: 0.5rem 0.75rem;
  font-size: 0.86rem;
}

.lesson-actions .export-btn,
.lesson-actions button:not(.phase-tab) {
  min-width: 92px;
}

.export-btn {
  min-width: 86px;
}

.lesson-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-top: 0.65rem;
  padding: 0.8rem 0.9rem;
  font-size: 0.92rem;
  line-height: 1.62;
  overflow-x: auto;
}

#course-detail .section-head {
  padding-bottom: 0.35rem;
  border-bottom: 1px solid var(--border);
  margin-bottom: 0.75rem;
}

.lesson-content h1,
.lesson-content h2,
.lesson-content h3,
.lesson-content h4 {
  margin: 0.8rem 0 0.4rem;
  line-height: 1.3;
  font-weight: 800;
}

.lesson-content p {
  margin: 0.55rem 0;
}

.lesson-content ul,
.lesson-content ol {
  margin: 0.45rem 0 0.6rem;
  padding-left: 1.15rem;
}

.lesson-content code {
  background: var(--surface-strong);
  border-radius: var(--radius-sm);
  padding: 0.08rem 0.32rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  font-size: 0.88em;
}

.lesson-content pre {
  position: relative;
  background: var(--primary-darker);
  color: #eaf1fb;
  border-radius: var(--radius-md);
  padding: 0.7rem;
  padding-right: 2.6rem;
  overflow-x: auto;
}

.lesson-content pre code {
  background: transparent;
  color: inherit;
  padding: 0;
}

.code-copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  width: 1.9rem;
  height: 1.9rem;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.2);
  background: rgba(255, 255, 255, 0.08);
  color: #eaf1fb;
  font-size: 0.9rem;
  line-height: 1;
  opacity: 0.75;
  transition: opacity 140ms ease, background-color 140ms ease;
}

.lesson-content pre:hover .code-copy-btn {
  opacity: 1;
}

.code-copy-btn:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.18);
  box-shadow: none;
}

.code-copy-btn.is-copied {
  background: var(--success);
  border-color: var(--success);
  opacity: 1;
}

.lesson-content table {
  border-collapse: collapse;
  width: 100%;
  margin: 0.65rem 0;
}

.lesson-content th,
.lesson-content td {
  border: 1px solid var(--border);
  padding: 0.45rem 0.5rem;
  text-align: left;
}

.lesson-content th {
  background: var(--surface-soft);
}

.mini-list {
  margin: 0.65rem 0 0;
  padding: 0;
  list-style: none;
}

.mini-list li {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-soft);
  padding: 0.62rem;
  margin: 0.38rem 0;
}

.mini-list li ul {
  margin: 0.4rem 0 0;
  padding-left: 1rem;
}

.exercise-prompt {
  margin-top: 0;
}

.exercise-solution {
  margin-top: 0.6rem;
}

.exercise-solution > summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--primary);
  list-style: none;
}

.exercise-solution > summary::-webkit-details-marker {
  display: none;
}

.exercise-solution .lesson-content {
  margin-top: 0.5rem;
}

.quiz-options {
  display: grid;
  gap: 0.35rem;
  margin-top: 0.5rem;
}

.quiz-option {
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  padding: 0.5rem 0.62rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
}

.quiz-option.is-correct {
  background: var(--success-soft);
  border-color: var(--success-border);
  color: var(--success);
  font-weight: 700;
}

.quiz-option.is-wrong {
  background: var(--danger-soft);
  border-color: var(--danger);
  color: var(--danger);
}

.certification-result-banner {
  padding: 0.6rem 0.8rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.certification-result-banner.is-passed {
  background: var(--success-soft);
  border-color: var(--success-border);
  color: var(--success);
}

.certification-result-banner.is-failed {
  background: var(--danger-soft);
  border-color: var(--danger);
  color: var(--danger);
}

.quiz-footer {
  margin-top: 0.75rem;
  display: flex;
  gap: 0.75rem;
  align-items: center;
  flex-wrap: wrap;
}

.spaced-block {
  margin-top: 1rem;
}

.certification-exam {
  margin-top: 1rem;
}

.certification-section {
  margin-top: 2rem;
  padding: 1.25rem;
  border: 1px solid var(--border);
  border-top: 3px solid var(--primary);
  border-radius: var(--radius-lg);
  background: var(--surface-soft);
  scroll-margin-top: 96px;
}

.certification-section .section-head {
  margin-bottom: 0.5rem;
}

.course-progress-card {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-soft);
  padding: 0.75rem;
  margin-bottom: 1rem;
}

.course-admin-actions,
.course-editor-actions {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.edit-course-status {
  min-height: 1.2rem;
  margin: 0.5rem 0 0;
  color: var(--muted);
  font-size: 0.85rem;
}

.course-editor-form {
  margin-top: 1rem;
}

.course-restructure-panel {
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}

.course-restructure-panel h3 {
  margin: 0 0 0.4rem;
  font-size: 1.02rem;
}

.course-restructure-panel textarea {
  width: 100%;
  margin: 0.6rem 0;
  box-sizing: border-box;
}

.course-restructure-panel.is-blocked textarea,
.course-restructure-panel.is-blocked button {
  opacity: 0.6;
  cursor: not-allowed;
}

.image-upload-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 0.6rem;
  align-items: center;
}

.course-editor-grid {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  gap: 1rem;
}

.course-editor-column {
  display: grid;
  gap: 0.65rem;
}

.course-editor-row {
  display: grid;
  gap: 0.4rem;
}

.course-editor-preview {
  min-height: 150px;
  border: 1px dashed var(--border-strong);
  border-radius: var(--radius-md);
  background: var(--surface-soft);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.course-editor-preview img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.lesson-version-panel {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--border);
}

.lesson-version-list {
  display: grid;
  gap: 0.65rem;
  margin-top: 0.7rem;
}

.lesson-version-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 0.7rem;
  padding: 0.75rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface-soft);
}

.lesson-version-item strong {
  display: block;
  font-size: 0.85rem;
}

.lesson-version-item small {
  display: block;
  color: var(--secondary);
  margin-top: 0.2rem;
}

.lesson-version-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  justify-content: flex-end;
}

.mermaid {
  margin: 1rem 0;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow-x: auto;
}

.chartjs-wrapper {
  position: relative;
  width: 100%;
  min-height: 260px;
  margin: 1rem 0;
  padding: 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
}

.chartjs-wrapper canvas {
  display: block;
  width: 100% !important;
  height: 320px !important;
}

.mermaid svg {
  max-width: 100%;
  height: auto;
}

label {
  font-weight: 700;
  color: var(--secondary);
  font-size: 0.85rem;
}

.users-list {
  margin-top: 0.8rem;
  display: grid;
  gap: 0.45rem;
}

.users-list h3 {
  margin: 0;
  font-size: 0.95rem;
}

.user-row {
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.55rem 0.65rem;
  display: flex;
  justify-content: space-between;
  gap: 0.6rem;
  flex-wrap: wrap;
  background: var(--surface-soft);
  font-size: 0.85rem;
}

#certification-result .lesson {
  padding: 0.62rem;
}

@media (max-width: 840px) {
  .app-layout {
    grid-template-columns: 1fr;
    width: min(100% - 1rem, 1200px);
  }

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

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

  #course-detail .section-head {
    align-items: flex-start;
  }
}