:root {
  --bg: #07111f;
  --panel: rgba(11, 22, 38, 0.88);
  --panel-2: rgba(17, 30, 51, 0.95);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(79, 209, 255, 0.28);
  --text: #f5f7fb;
  --muted: #9aa8bf;
  --cyan: #44d9ff;
  --cyan-2: #22b8ff;
  --success: #33d17a;
  --danger: #ff6b81;
  --shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
  --radius-xl: 28px;
  --radius-lg: 20px;
  --radius-md: 16px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  min-height: 100vh;
  font-family: Inter, Arial, Helvetica, sans-serif;
  background:
    radial-gradient(circle at top left, rgba(68, 217, 255, 0.12), transparent 28%),
    radial-gradient(circle at top right, rgba(124, 92, 255, 0.12), transparent 26%),
    linear-gradient(180deg, #06101b 0%, #07111f 50%, #050c16 100%);
  color: var(--text);
}

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

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

.main-content {
  padding: 32px;
}

.topbar,
.topbar-actions,
.btn {
  position: relative;
  z-index: 10;
}

.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 18px;
  margin-bottom: 24px;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--muted);
  font-size: 0.95rem;
}

.breadcrumb a {
  color: var(--cyan);
}

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

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 13px 18px;
  border-radius: 14px;
  border: 1px solid transparent;
  font-weight: 700;
  cursor: pointer;
  transition: 0.25s ease;
}

.btn:disabled {
  opacity: 0.64;
  cursor: wait;
}

.btn.is-loading {
  opacity: 0.72;
  cursor: wait;
}

.btn-primary {
  background: linear-gradient(135deg, var(--cyan), var(--cyan-2));
  color: #04101d;
  box-shadow: 0 12px 35px rgba(34, 184, 255, 0.22);
}

.btn-primary:hover:not(:disabled) {
  transform: translateY(-1px);
  filter: brightness(1.04);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  border-color: var(--border);
}

.btn-secondary:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.08);
}

.btn-block {
  width: 100%;
}

.hero-card,
.panel {
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
}

.hero-card {
  padding: 28px;
  margin-bottom: 22px;
  border-radius: var(--radius-xl);
  background:
    radial-gradient(circle at top right, rgba(68, 217, 255, 0.08), transparent 24%),
    linear-gradient(180deg, rgba(17, 30, 51, 0.95) 0%, rgba(10, 18, 31, 0.98) 100%);
}

.eyebrow,
.panel-label {
  margin: 0 0 10px;
  color: var(--cyan);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  font-size: 0.74rem;
  font-weight: 700;
}

.hero-card h1 {
  margin: 0;
  font-size: clamp(2rem, 3vw, 3rem);
  line-height: 1.04;
}

.hero-description {
  margin: 14px 0 0;
  max-width: 820px;
  color: var(--muted);
  line-height: 1.75;
}

.content-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.7fr) 360px;
  gap: 22px;
}

.main-column,
.side-column {
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.panel {
  padding: 24px;
  border-radius: var(--radius-xl);
  background: var(--panel);
}

.panel__header {
  margin-bottom: 20px;
}

.panel__header--between {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.panel__header h2 {
  margin: 0;
  font-size: 1.35rem;
}

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

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.field--full {
  grid-column: 1 / -1;
}

.field label {
  color: var(--muted);
  font-size: 0.9rem;
  font-weight: 700;
}

.required {
  color: var(--danger);
  margin-left: 2px;
}

.field-hint {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: -2px;
}

.field input,
.field textarea,
.field select {
  width: 100%;
  min-height: 48px;
  border-radius: 14px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.04);
  color: var(--text);
  outline: none;
  padding: 12px 14px;
}

.field textarea {
  min-height: 130px;
  resize: vertical;
}

.field input:focus,
.field textarea:focus,
.field select:focus {
  border-color: var(--border-strong);
  box-shadow: 0 0 0 3px rgba(68, 217, 255, 0.08);
}

.thumbnail-preview {
  margin-top: 10px;
  border-radius: 14px;
  overflow: hidden;
  border: 1px solid var(--border);
}

.thumbnail-preview img {
  width: 100%;
  height: 180px;
  object-fit: cover;
  display: block;
}

#modulesContainer {
  display: flex;
  flex-direction: column;
  gap: 12px;
  counter-reset: module-counter;
}

#modulesContainer:empty::before {
  content: "Aún no hay módulos. Presiona \"+ Agregar módulo\" para comenzar.";
  display: block;
  padding: 28px 20px;
  text-align: center;
  color: var(--muted);
  font-size: 0.9rem;
  border: 1px dashed rgba(255, 255, 255, 0.1);
  border-radius: 16px;
  line-height: 1.6;
}

.module-card {
  counter-increment: module-counter;
  position: relative;
  padding: 18px 48px 18px 54px;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
  transition: border-color 0.2s ease, background 0.2s ease, box-shadow 0.2s ease;
}

.module-card:hover {
  border-color: rgba(68, 217, 255, 0.22);
  background: rgba(68, 217, 255, 0.03);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.18);
}

.module-card::before {
  content: counter(module-counter);
  position: absolute;
  left: 16px;
  top: 18px;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  background: rgba(68, 217, 255, 0.1);
  border: 1px solid rgba(68, 217, 255, 0.2);
  color: var(--cyan);
  font-weight: 800;
  font-size: 0.8rem;
  text-align: center;
  line-height: 26px;
}

.module-card::after {
  content: "⋮";
  position: absolute;
  right: 16px;
  top: 18px;
  color: rgba(255, 255, 255, 0.18);
  font-size: 1.2rem;
  cursor: grab;
  line-height: 1;
  letter-spacing: 1px;
}

.module-card:hover::after {
  color: rgba(255, 255, 255, 0.38);
}

.module-card__desc {
  margin-top: 12px;
}

.module-card__actions {
  margin-top: 12px;
  display: flex;
  justify-content: flex-end;
}

.summary-box {
  display: grid;
  gap: 14px;
}

.summary-box > div,
.info-box {
  padding: 16px;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.05);
  background: rgba(255, 255, 255, 0.03);
}

.summary-box span,
.info-box p {
  display: block;
  margin: 0 0 8px;
  color: var(--muted);
}

.summary-box strong,
.info-box strong {
  color: var(--text);
}

.readiness-card {
  display: grid;
  gap: 16px;
}

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

.readiness-card__hint {
  margin: 0;
  color: var(--muted);
  line-height: 1.6;
}

.readiness-pill {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 62px;
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  font-size: 0.82rem;
  font-weight: 800;
  border: 1px solid rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.05);
}

.readiness-pill.is-ready {
  color: #7ef0b3;
  border-color: rgba(126, 240, 179, 0.28);
  background: rgba(0, 200, 120, 0.12);
}

.readiness-pill.is-pending {
  color: #ffd27a;
  border-color: rgba(255, 210, 122, 0.22);
  background: rgba(255, 190, 60, 0.11);
}

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

.readiness-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.06);
  background: rgba(255, 255, 255, 0.03);
}

.readiness-item.is-ready {
  border-color: rgba(126, 240, 179, 0.2);
  background: rgba(0, 200, 120, 0.08);
}

.readiness-item.is-missing {
  border-color: rgba(255, 210, 122, 0.18);
  background: rgba(255, 190, 60, 0.08);
}

.readiness-item__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 24px;
  height: 24px;
  border-radius: 999px;
  flex-shrink: 0;
  font-size: 0.72rem;
  font-weight: 900;
  letter-spacing: 0.02em;
}

.readiness-item.is-ready .readiness-item__icon {
  color: #02160d;
  background: #7ef0b3;
}

.readiness-item.is-missing .readiness-item__icon {
  color: #221300;
  background: #ffd27a;
}

.form-message {
  margin-top: 14px;
  padding: 13px 14px;
  border-radius: 14px;
  border: 1px solid rgba(51, 209, 122, 0.24);
  background: rgba(51, 209, 122, 0.1);
  color: #90f7bd;
  line-height: 1.55;
}

.form-message.error {
  border-color: rgba(255, 107, 129, 0.28);
  background: rgba(255, 107, 129, 0.1);
  color: #ffb3bf;
}

.hidden {
  display: none !important;
}

.overlay,
.sidebar::before,
.sidebar::after {
  pointer-events: none;
}

@media (max-width: 1180px) {
  .content-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .main-content {
    padding: 18px;
  }

  .topbar,
  .panel__header--between {
    align-items: stretch;
    flex-direction: column;
  }

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

#thumbnailPreview.hidden {
  display: none;
}

.course-thumb-preview-card {
  margin-top: 10px;
  border-radius: 18px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.08);
  background: rgba(255,255,255,0.03);
}

.course-thumb-preview-card img {
  width: 100%;
  max-height: 220px;
  object-fit: cover;
  display: block;
}

.course-lesson-preview {
  display: grid;
  grid-template-columns: 56px 1fr auto;
  gap: 14px;
  align-items: center;
  padding: 14px;
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: 18px;
  background: rgba(255,255,255,0.03);
  margin-bottom: 12px;
}

.course-lesson-preview__order {
  width: 56px;
  height: 56px;
  border-radius: 16px;
  display: grid;
  place-items: center;
  font-weight: 700;
  background: rgba(255,255,255,0.06);
}

.course-lesson-preview__main {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.course-lesson-preview__main strong {
  font-size: 15px;
}

.course-lesson-preview__main span {
  font-size: 13px;
  opacity: 0.8;
}

.course-lesson-preview__stats {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

.lesson-status {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 34px;
  padding: 0 12px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
}

.lesson-status--published {
  background: rgba(0, 200, 120, 0.15);
  color: #7ef0b3;
  border: 1px solid rgba(126, 240, 179, 0.25);
}

.lesson-status--draft {
  background: rgba(255, 190, 60, 0.12);
  color: #ffd27a;
  border: 1px solid rgba(255, 210, 122, 0.22);
}

@media (max-width: 900px) {
  .course-lesson-preview {
    grid-template-columns: 1fr;
  }

  .course-lesson-preview__order {
    width: 44px;
    height: 44px;
  }
}

select,
input,
textarea {
  color: #f5f7fb;
  background: rgba(12, 18, 30, 0.92);
}

select option {
  color: #f5f7fb;
  background: #0f1726;
}

/* skeleton loader */
.lesson-skeleton {
  display: grid;
  gap: 18px;
}

.lesson-skeleton.hidden {
  display: none;
}

.lesson-skeleton__hero {
  height: 170px;
  border-radius: 28px;
}

.lesson-skeleton__grid {
  display: grid;
  grid-template-columns: 1.8fr 0.9fr;
  gap: 24px;
}

.lesson-skeleton__main,
.lesson-skeleton__side {
  display: grid;
  gap: 18px;
}

.lesson-skeleton__card {
  min-height: 240px;
  border-radius: 26px;
}

.shimmer {
  background: linear-gradient(90deg, rgba(255,255,255,.04) 25%, rgba(255,255,255,.08) 50%, rgba(255,255,255,.04) 75%);
  background-size: 400% 100%;
  animation: shimmer 1.6s infinite;
}

@keyframes shimmer {
  0% { background-position: 100% 0; }
  100% { background-position: -100% 0; }
}

/* ── Lecciones agrupadas por módulo ───────────────────────── */

.lessons-toolbar {
  display: flex;
  justify-content: flex-end;
  margin-bottom: 10px;
}

.module-group {
  border: 1px solid rgba(255,255,255,.08);
  border-radius: 20px;
  overflow: hidden;
  margin-bottom: 10px;
  background: rgba(255,255,255,.02);
  transition: border-color .15s;
}

.module-group:hover {
  border-color: rgba(255,255,255,.13);
}

.module-group__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  width: 100%;
  padding: 15px 20px;
  background: none;
  border: none;
  color: inherit;
  cursor: pointer;
  text-align: left;
  transition: background .15s;
  font-family: inherit;
}

.module-group__header:hover {
  background: rgba(255,255,255,.04);
}

.module-group__left {
  display: flex;
  align-items: center;
  gap: 10px;
}

.module-group__right {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.module-group__chevron {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--muted, #9aa8bf);
  transition: transform .2s ease;
  flex-shrink: 0;
}

.module-group:not(.is-open) .module-group__chevron {
  transform: rotate(-90deg);
}

.module-group__name {
  font-size: 15px;
  font-weight: 700;
}

.module-group__pill {
  font-size: 11px;
  color: var(--muted, #9aa8bf);
  background: rgba(255,255,255,.07);
  padding: 3px 10px;
  border-radius: 999px;
}

/* body: oculto cuando colapsado */
.module-group__body {
  display: none;
  border-top: 1px solid rgba(255,255,255,.06);
}

.module-group.is-open .module-group__body {
  display: block;
}

/* filas de lección */
.module-group__lessons {
  padding: 4px 0;
}

.lesson-row {
  display: grid;
  grid-template-columns: 44px 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 11px 20px;
  border-bottom: 1px solid rgba(255,255,255,.04);
  transition: background .12s;
}

.lesson-row:last-child {
  border-bottom: none;
}

.lesson-row:hover {
  background: rgba(255,255,255,.03);
}

.lesson-row__order {
  width: 38px;
  height: 38px;
  border-radius: 11px;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 13px;
  background: rgba(255,255,255,.07);
  flex-shrink: 0;
}

.lesson-row__title {
  font-size: 14px;
  font-weight: 600;
  line-height: 1.35;
}

.lesson-row__actions {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.module-group__footer {
  padding: 10px 20px 14px;
  border-top: 1px solid rgba(255,255,255,.05);
}

/* badges de estado */
.lesson-badge {
  display: inline-flex;
  align-items: center;
  padding: 3px 9px;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 700;
  white-space: nowrap;
}

.lesson-badge--pub {
  background: rgba(0,200,120,.14);
  color: #7ef0b3;
  border: 1px solid rgba(126,240,179,.22);
}

.lesson-badge--draft {
  background: rgba(255,190,60,.11);
  color: #ffd27a;
  border: 1px solid rgba(255,210,122,.2);
}

/* botones de tamaño pequeño */
.btn-sm {
  padding: 6px 13px !important;
  font-size: 12px !important;
  border-radius: 10px !important;
}

.btn-ghost {
  background: transparent;
  border: 1px solid rgba(255,255,255,.11);
  color: var(--muted, #9aa8bf);
  border-radius: 10px;
  padding: 7px 14px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s, color .15s, border-color .15s;
  font-family: inherit;
}

.btn-ghost:hover {
  background: rgba(255,255,255,.06);
  color: var(--text, #f5f7fb);
  border-color: rgba(255,255,255,.18);
}

/* estado vacío */
.lessons-empty {
  padding: 28px 20px;
  border: 1px dashed rgba(255,255,255,.12);
  border-radius: 16px;
  text-align: center;
}

.lessons-empty h3 {
  margin: 0 0 6px;
  font-size: 16px;
}

.lessons-empty p {
  margin: 0;
  opacity: .65;
  font-size: 14px;
}

@media (max-width: 600px) {
  .lesson-row {
    grid-template-columns: 38px 1fr;
    row-gap: 8px;
  }

  .lesson-row__actions {
    grid-column: 1 / -1;
    padding-left: 50px;
  }

  .module-group__right {
    display: none;
  }
}