/* Learning Experience Redesign
   Scope: learning.html, courses.html, topics.html, exercise.html */

:root {
  --lrn-bg-a: #f3faff;
  --lrn-bg-b: #eef6ff;
  --lrn-bg-c: #fff7ef;
  --lrn-surface: rgba(255, 255, 255, 0.72);
  --lrn-surface-strong: rgba(255, 255, 255, 0.9);
  --lrn-line: rgba(76, 111, 166, 0.24);
  --lrn-text: #102542;
  --lrn-muted: #587099;
  --lrn-brand: #2f7bff;
  --lrn-brand-2: #16b9a4;
  --lrn-accent: #ff8b5e;
  --lrn-good: #11a779;
  --lrn-radius-xl: 26px;
  --lrn-radius-lg: 18px;
  --lrn-radius-md: 12px;
  --lrn-shadow: 0 22px 46px rgba(39, 67, 110, 0.18);
}

[data-page="learning"],
[data-page="courses"],
[data-page="topics"],
[data-page="exercise"] {
  background:
    radial-gradient(circle at 0% 0%, #dff2ff 0%, transparent 32%),
    radial-gradient(circle at 100% 12%, #ffe9d8 0%, transparent 34%),
    radial-gradient(circle at 78% 100%, #dbf9f2 0%, transparent 30%),
    linear-gradient(130deg, var(--lrn-bg-a), var(--lrn-bg-b) 48%, var(--lrn-bg-c));
}

[data-page="learning"] .app-shell,
[data-page="courses"] .app-shell,
[data-page="topics"] .app-shell,
[data-page="exercise"] .app-shell {
  max-width: 1180px;
}

/* Shared blocks */
.learning-shell {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.lrn-card {
  border: 1px solid var(--lrn-line);
  border-radius: var(--lrn-radius-xl);
  background: var(--lrn-surface);
  box-shadow: var(--lrn-shadow);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.lrn-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  margin: 0;
  padding: 0.35rem 0.78rem;
  border-radius: 999px;
  border: 1px solid rgba(47, 123, 255, 0.24);
  color: #1f4f98;
  background: linear-gradient(115deg, rgba(47, 123, 255, 0.14), rgba(22, 185, 164, 0.14));
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

.lrn-hero {
  padding: clamp(1rem, 3.2vw, 2rem);
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(220px, 0.8fr);
  gap: 1rem;
  position: relative;
  overflow: hidden;
}

.lrn-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(145deg, rgba(47, 123, 255, 0.08), rgba(22, 185, 164, 0.08));
  pointer-events: none;
}

.lrn-hero-content {
  position: relative;
  z-index: 1;
}

.lrn-hero-title {
  margin: 0.8rem 0 0.52rem;
  font-size: clamp(1.45rem, 3.2vw, 2.35rem);
  line-height: 1.14;
  color: var(--lrn-text);
}

.lrn-hero-sub {
  margin: 0;
  color: var(--lrn-muted);
  font-size: clamp(0.9rem, 1.4vw, 1rem);
  max-width: 620px;
}

.lrn-hero-art {
  position: relative;
  z-index: 1;
  border-radius: 20px;
  min-height: 160px;
  background:
    radial-gradient(circle at 24% 22%, rgba(255, 255, 255, 0.6), transparent 40%),
    linear-gradient(135deg, rgba(47, 123, 255, 0.9), rgba(22, 185, 164, 0.8) 55%, rgba(255, 139, 94, 0.9));
  border: 1px solid rgba(255, 255, 255, 0.3);
  overflow: hidden;
}

.lrn-hero-art::after {
  content: "";
  position: absolute;
  width: 120px;
  height: 120px;
  right: -18px;
  top: -22px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.2);
}

[data-page="learning"] .learning-hero-art {
  min-height: 192px;
  display: grid;
  place-items: center;
  isolation: isolate;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.34), 0 16px 32px rgba(27, 74, 133, 0.26);
}

[data-page="learning"] .learning-hero-art::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 24% 16%, rgba(255, 255, 255, 0.34) 0%, transparent 36%),
    linear-gradient(135deg, rgba(7, 28, 63, 0.18), rgba(7, 28, 63, 0) 45%);
  z-index: 0;
}

[data-page="learning"] .learning-hero-icon-orb {
  width: clamp(76px, 9vw, 114px);
  height: clamp(76px, 9vw, 114px);
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at 35% 22%, rgba(255, 255, 255, 0.9), rgba(219, 248, 243, 0.36) 58%, rgba(22, 185, 164, 0.26) 100%);
  border: 1px solid rgba(255, 255, 255, 0.6);
  box-shadow: 0 18px 30px rgba(8, 30, 66, 0.24), inset 0 1px 0 rgba(255, 255, 255, 0.7);
  position: relative;
  z-index: 2;
}

[data-page="learning"] .learning-hero-icon {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1;
  filter: drop-shadow(0 6px 12px rgba(8, 30, 66, 0.24));
}

[data-page="learning"] .learning-hero-chip {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 2;
  padding: 0.35rem 0.72rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.2);
  color: #eef7ff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  backdrop-filter: blur(6px);
}

[data-page="learning"] .learning-hero-grid {
  position: absolute;
  inset: auto 10px 10px auto;
  width: 110px;
  height: 56px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  background:
    linear-gradient(rgba(255, 255, 255, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.22) 1px, transparent 1px);
  background-size: 14px 14px;
  opacity: 0.5;
  z-index: 1;
}

[data-page="courses"] .course-hero-art {
  min-height: 192px;
  display: grid;
  place-items: center;
  isolation: isolate;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.34), 0 16px 32px rgba(27, 74, 133, 0.26);
}

[data-page="courses"] .course-hero-art::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 22% 18%, rgba(255, 255, 255, 0.35) 0%, transparent 36%),
    linear-gradient(130deg, rgba(8, 30, 66, 0.16), rgba(8, 30, 66, 0) 45%);
  z-index: 0;
}

[data-page="courses"] .course-hero-icon-orb {
  width: clamp(74px, 9vw, 112px);
  height: clamp(74px, 9vw, 112px);
  border-radius: 999px;
  display: grid;
  place-items: center;
  background: radial-gradient(circle at 35% 24%, rgba(255, 255, 255, 0.88), rgba(223, 245, 255, 0.35) 58%, rgba(95, 131, 255, 0.25) 100%);
  border: 1px solid rgba(255, 255, 255, 0.55);
  box-shadow: 0 18px 30px rgba(8, 30, 66, 0.24), inset 0 1px 0 rgba(255, 255, 255, 0.65);
  position: relative;
  z-index: 2;
}

[data-page="courses"] .course-hero-icon {
  font-size: clamp(2rem, 4vw, 3rem);
  line-height: 1;
  filter: drop-shadow(0 6px 12px rgba(8, 30, 66, 0.24));
}

[data-page="courses"] .course-hero-chip {
  position: absolute;
  top: 12px;
  left: 12px;
  z-index: 2;
  padding: 0.35rem 0.72rem;
  border-radius: 999px;
  border: 1px solid rgba(255, 255, 255, 0.42);
  background: rgba(255, 255, 255, 0.2);
  color: #eef7ff;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  backdrop-filter: blur(6px);
}

[data-page="courses"] .course-hero-grid {
  position: absolute;
  inset: auto 10px 10px auto;
  width: 110px;
  height: 56px;
  border-radius: 14px;
  border: 1px solid rgba(255, 255, 255, 0.24);
  background:
    linear-gradient(rgba(255, 255, 255, 0.22) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.22) 1px, transparent 1px);
  background-size: 14px 14px;
  opacity: 0.5;
  z-index: 1;
}

.learning-stats {
  margin-top: 0.95rem;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.55rem;
}

.learning-stat {
  border: 1px solid rgba(76, 111, 166, 0.24);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.72);
  padding: 0.72rem 0.75rem;
  text-align: center;
}

.learning-stat-link {
  text-decoration: none;
  transition: 0.24s ease;
  cursor: pointer;
}

.learning-stat-link:hover {
  transform: translateY(-2px);
  border-color: rgba(47, 123, 255, 0.4);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 8px 18px rgba(36, 65, 106, 0.18);
}

.learning-stat-number {
  display: block;
  color: #123c77;
  font-size: clamp(1.08rem, 2vw, 1.4rem);
  font-weight: 700;
  line-height: 1.08;
}

.learning-stat-label {
  display: block;
  margin-top: 0.18rem;
  color: var(--lrn-muted);
  font-size: 0.74rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.learning-search-bar {
  margin-top: 0.82rem;
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.learning-search-input {
  flex: 1;
  min-width: 0;
  border: 1px solid rgba(76, 111, 166, 0.3);
  border-radius: 999px;
  padding: 0.56rem 0.82rem;
  background: rgba(255, 255, 255, 0.86);
  color: #123767;
  font-size: 0.84rem;
  outline: none;
}

.learning-search-input:focus {
  border-color: rgba(47, 123, 255, 0.5);
  box-shadow: 0 0 0 3px rgba(47, 123, 255, 0.12);
}

.learning-search-btn {
  border: 0;
  border-radius: 999px;
  padding: 0.58rem 0.95rem;
  background: linear-gradient(115deg, #5f83ff, #3cc8a7);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  font-family: "Outfit", sans-serif;
  cursor: pointer;
  transition: 0.22s ease;
}

.learning-search-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 18px rgba(52, 102, 189, 0.26);
}

.lrn-section {
  padding: 1rem;
}

.lrn-section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.65rem;
  margin-bottom: 0.9rem;
  flex-wrap: wrap;
}

.lrn-section-title {
  margin: 0;
  font-size: clamp(1.02rem, 2vw, 1.35rem);
  color: var(--lrn-text);
}

.lrn-pill {
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  border: 1px solid rgba(22, 185, 164, 0.28);
  background: rgba(22, 185, 164, 0.12);
  color: #0f6f63;
  font-size: 0.75rem;
  font-weight: 600;
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.42rem;
  flex-wrap: wrap;
  margin: 0 0 0.75rem;
  padding: 0;
  color: #44608d;
  font-size: 0.82rem;
}

.breadcrumb a {
  color: #2359a7;
  font-weight: 500;
}

.breadcrumb span {
  opacity: 0.82;
}

/* Learning home: categories */
[data-page="learning"] .categories-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 0.8rem;
}

[data-page="learning"] .category-card {
  border: 1px solid rgba(76, 111, 166, 0.2);
  border-radius: var(--lrn-radius-lg);
  background: var(--lrn-surface-strong);
  padding: 1rem;
  position: relative;
  overflow: hidden;
  transition: 0.24s ease;
  box-shadow: 0 12px 28px rgba(36, 65, 106, 0.14);
}

[data-page="learning"] .category-card::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  background: linear-gradient(130deg, rgba(47, 123, 255, 0.12), rgba(22, 185, 164, 0.1));
  opacity: 0;
  transition: 0.24s ease;
}

[data-page="learning"] .category-card:hover {
  transform: translateY(-4px);
  border-color: rgba(47, 123, 255, 0.34);
}

[data-page="learning"] .category-card:hover::before {
  opacity: 1;
}

[data-page="learning"] .category-card > * {
  position: relative;
  z-index: 1;
}

[data-page="learning"] .category-icon {
  font-size: 2.2rem;
  line-height: 1;
  display: inline-flex;
  margin-bottom: 0.62rem;
}

[data-page="learning"] .category-name {
  margin: 0;
  font-size: 1.04rem;
  line-height: 1.22;
  color: #10294d;
}

[data-page="learning"] .category-description {
  margin: 0.45rem 0 0.78rem;
  color: var(--lrn-muted);
  font-size: 0.86rem;
  line-height: 1.52;
}

[data-page="learning"] .category-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.38rem;
  font-size: 0.74rem;
  color: #355682;
}

[data-page="learning"] .category-meta span {
  border-radius: 999px;
  border: 1px solid rgba(76, 111, 166, 0.24);
  background: rgba(255, 255, 255, 0.8);
  padding: 0.22rem 0.55rem;
}

/* Courses */
[data-page="courses"] .courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 0.88rem;
}

[data-page="courses"] .course-card {
  border: 1px solid rgba(76, 111, 166, 0.2);
  border-radius: var(--lrn-radius-lg);
  background: var(--lrn-surface-strong);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: 0.24s ease;
  box-shadow: 0 12px 28px rgba(36, 65, 106, 0.14);
}

[data-page="courses"] .course-card.course-card-enrolled {
  border-color: rgba(17, 167, 121, 0.36);
}

[data-page="courses"] .course-card:hover {
  transform: translateY(-4px);
  border-color: rgba(47, 123, 255, 0.34);
}

[data-page="courses"] .course-banner {
  height: 200px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3.5rem;
  position: relative;
  overflow: hidden;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

[data-page="courses"] .course-banner-image {
  width: 100%;
  height: 100%;
  object-fit: contain;
  object-position: center;
  position: absolute;
  inset: 0;
  display: block;
  background: inherit;
}

[data-page="courses"] .course-banner-icon {
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

[data-page="courses"] .course-banner::after {
  content: "";
  position: absolute;
  width: 72px;
  height: 72px;
  right: -12px;
  top: -16px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.18);
}

[data-page="courses"] .course-body {
  padding: 0.85rem 0.92rem 0.9rem;
}

[data-page="courses"] .course-card-link {
  display: block;
  color: inherit;
  text-decoration: none;
}

[data-page="courses"] .course-card-link.is-clickable {
  cursor: pointer;
}

[data-page="courses"] .course-card-link.is-clickable:hover .course-name {
  color: #0f7256;
}

[data-page="courses"] .course-name {
  margin: 0;
  color: #10294d;
  font-size: 1rem;
  line-height: 1.25;
}

[data-page="courses"] .course-desc {
  margin: 0.45rem 0 0.7rem;
  color: var(--lrn-muted);
  font-size: 0.84rem;
  line-height: 1.5;
}

[data-page="courses"] .course-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.32rem;
}

[data-page="courses"] .catalog-search {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.8rem;
}

[data-page="courses"] .catalog-search-input {
  flex: 1;
  min-width: 0;
  border: 1px solid rgba(76, 111, 166, 0.3);
  border-radius: 999px;
  padding: 0.56rem 0.84rem;
  background: rgba(255, 255, 255, 0.9);
  color: #123767;
  font-size: 0.84rem;
  outline: none;
}

[data-page="courses"] .catalog-search-input:focus {
  border-color: rgba(47, 123, 255, 0.5);
  box-shadow: 0 0 0 3px rgba(47, 123, 255, 0.12);
}

[data-page="courses"] .catalog-search-btn {
  border: 0;
  border-radius: 999px;
  padding: 0.58rem 0.95rem;
  background: linear-gradient(115deg, #5f83ff, #3cc8a7);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  font-family: "Outfit", sans-serif;
  cursor: pointer;
}

[data-page="courses"] .courses-catalog-groups {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

[data-page="courses"] .course-category-group {
  border: 1px solid rgba(76, 111, 166, 0.2);
  border-radius: 16px;
  padding: 0.78rem;
  background: rgba(255, 255, 255, 0.5);
}

[data-page="courses"] .course-category-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.66rem;
  flex-wrap: wrap;
}

[data-page="courses"] .course-category-title {
  margin: 0;
  color: #10294d;
  font-size: 0.95rem;
}

[data-page="courses"] .course-category-count {
  border-radius: 999px;
  border: 1px solid rgba(76, 111, 166, 0.26);
  background: rgba(255, 255, 255, 0.84);
  padding: 0.24rem 0.6rem;
  color: #355682;
  font-size: 0.72rem;
  font-weight: 700;
}

[data-page="courses"] .courses-grid-group {
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
}

[data-page="courses"] .course-actions {
  display: flex;
  gap: 0.5rem;
  padding: 0 0.92rem 0.9rem;
  margin-top: auto;
}

[data-page="courses"] .course-enroll-btn {
  flex: 1;
  border: none;
  border-radius: 999px;
  padding: 0.55rem 0.8rem;
  font-size: 0.78rem;
  font-weight: 700;
  font-family: "Outfit", sans-serif;
  cursor: pointer;
  background: linear-gradient(115deg, #5f83ff, #3cc8a7);
  color: #fff;
  transition: 0.22s ease;
}

[data-page="courses"] .course-enroll-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(52, 102, 189, 0.25);
}

[data-page="courses"] .course-enroll-btn.login-required {
  background: linear-gradient(115deg, #6f77e7, #875bd7);
}

[data-page="courses"] .course-enroll-btn.enrolled,
[data-page="courses"] .course-enroll-btn.enrolled:hover {
  background: linear-gradient(115deg, #18a773, #118f64);
}

[data-page="courses"] .course-enroll-btn:disabled {
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
  opacity: 0.78;
}

[data-page="courses"] .course-share-btn {
  border: 1px solid rgba(76, 111, 166, 0.25);
  border-radius: 999px;
  padding: 0.55rem 0.82rem;
  font-size: 0.78rem;
  font-weight: 700;
  color: #355682;
  background: rgba(255, 255, 255, 0.88);
  cursor: pointer;
  transition: 0.22s ease;
}

[data-page="courses"] .course-share-btn:hover:not(:disabled) {
  transform: translateY(-2px);
  box-shadow: 0 8px 18px rgba(52, 102, 189, 0.14);
}

[data-page="courses"] .course-open-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: 1px solid rgba(76, 111, 166, 0.25);
  border-radius: 999px;
  padding: 0.55rem 0.82rem;
  font-size: 0.78rem;
  font-weight: 700;
  color: #355682;
  background: rgba(255, 255, 255, 0.88);
  text-decoration: none;
}

.meta-badge,
.level-badge {
  display: inline-flex;
  align-items: center;
  border-radius: 999px;
  padding: 0.22rem 0.56rem;
  font-size: 0.72rem;
  font-weight: 600;
  border: 1px solid rgba(76, 111, 166, 0.24);
  background: rgba(255, 255, 255, 0.84);
  color: #355682;
}

.level-beginner {
  background: rgba(17, 167, 121, 0.14);
  border-color: rgba(17, 167, 121, 0.3);
  color: #0f7256;
}

.level-intermediate {
  background: rgba(255, 139, 94, 0.17);
  border-color: rgba(255, 139, 94, 0.35);
  color: #94441e;
}

.level-advanced {
  background: rgba(47, 123, 255, 0.14);
  border-color: rgba(47, 123, 255, 0.35);
  color: #1f4f98;
}

/* Topics */
[data-page="topics"] .topics-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 0.75rem;
}

[data-page="topics"] .topic-card {
  border: 1px solid rgba(76, 111, 166, 0.2);
  border-radius: var(--lrn-radius-lg);
  background: var(--lrn-surface-strong);
  padding: 0.88rem;
  box-shadow: 0 10px 24px rgba(36, 65, 106, 0.12);
  transition: 0.24s ease;
}

[data-page="topics"] .topic-card:hover {
  transform: translateY(-3px);
  border-color: rgba(22, 185, 164, 0.34);
}

[data-page="topics"] .topic-header {
  display: flex;
  align-items: flex-start;
  gap: 0.56rem;
  margin-bottom: 0.46rem;
}

[data-page="topics"] .topic-number {
  width: 30px;
  height: 30px;
  flex-shrink: 0;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: linear-gradient(130deg, var(--lrn-brand), var(--lrn-brand-2));
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
}

[data-page="topics"] .topic-name {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.24;
  color: #10294d;
}

[data-page="topics"] .topic-desc {
  margin: 0 0 0.6rem;
  color: var(--lrn-muted);
  font-size: 0.82rem;
  line-height: 1.52;
  padding-left: 2.28rem;
}

[data-page="topics"] .topic-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 0.32rem;
  padding-left: 2.28rem;
}

[data-page="topics"] .meta-item {
  border-radius: 999px;
  border: 1px solid rgba(76, 111, 166, 0.24);
  background: rgba(255, 255, 255, 0.84);
  padding: 0.2rem 0.54rem;
  font-size: 0.72rem;
  color: #355682;
}

/* Exercise page */
[data-page="exercise"] .exercise-layout {
  display: grid;
  grid-template-columns: minmax(220px, 280px) minmax(0, 1fr);
  gap: 0.86rem;
}

[data-page="exercise"] .exercise-sidebar {
  border: 1px solid rgba(76, 111, 166, 0.24);
  border-radius: var(--lrn-radius-xl);
  background: var(--lrn-surface);
  box-shadow: 0 12px 28px rgba(36, 65, 106, 0.14);
  padding: 0.85rem;
  max-height: calc(100vh - 130px);
  overflow-y: auto;
  position: sticky;
  top: 86px;
}

[data-page="exercise"] .sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.68rem;
}

[data-page="exercise"] .sidebar-header h3 {
  margin: 0;
  font-size: 0.95rem;
  color: #123565;
}

[data-page="exercise"] .close-sidebar {
  display: none;
  width: 30px;
  height: 30px;
  border-radius: 9px;
  border: 1px solid rgba(76, 111, 166, 0.24);
  background: rgba(255, 255, 255, 0.84);
  color: #42628f;
  font-size: 1rem;
  cursor: pointer;
}

[data-page="exercise"] .exercises-nav {
  display: flex;
  flex-direction: column;
  gap: 0.34rem;
}

[data-page="exercise"] .exercise-nav-item {
  border-radius: 10px;
  border: 1px solid rgba(76, 111, 166, 0.2);
  background: rgba(255, 255, 255, 0.8);
  color: #284b78;
  padding: 0.42rem 0.55rem;
  font-size: 0.78rem;
  font-weight: 500;
  transition: 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.42rem;
}

[data-page="exercise"] .exercise-nav-item:hover {
  border-color: rgba(47, 123, 255, 0.35);
}

[data-page="exercise"] .exercise-nav-item.active {
  background: linear-gradient(130deg, rgba(47, 123, 255, 0.16), rgba(22, 185, 164, 0.13));
  border-color: rgba(47, 123, 255, 0.35);
  color: #1f4f98;
  font-weight: 700;
}

[data-page="exercise"] .exercise-nav-item.completed {
  border-color: rgba(17, 167, 121, 0.35);
  background: linear-gradient(130deg, rgba(17, 167, 121, 0.08), rgba(22, 185, 164, 0.08));
}

[data-page="exercise"] .exercise-nav-main {
  min-width: 0;
  display: inline-flex;
  align-items: center;
  gap: 0.36rem;
}

[data-page="exercise"] .exercise-nav-title {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

[data-page="exercise"] .exercise-nav-check {
  width: 20px;
  height: 20px;
  border-radius: 999px;
  border: 1px solid rgba(17, 167, 121, 0.4);
  background: rgba(17, 167, 121, 0.16);
  color: #0f7256;
  font-size: 0.74rem;
  font-weight: 800;
  display: inline-grid;
  place-items: center;
  flex-shrink: 0;
}

[data-page="exercise"] .exercise-main {
  min-width: 0;
}

[data-page="exercise"] .toggle-sidebar {
  display: none;
  margin-bottom: 0.55rem;
  border: 1px solid rgba(76, 111, 166, 0.24);
  border-radius: 999px;
  padding: 0.44rem 0.8rem;
  font-size: 0.8rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.86);
  color: #234f8c;
}

[data-page="exercise"] .exercise-progress-wrap {
  margin-top: 0.7rem;
}

[data-page="exercise"] .exercise-progress-meta {
  font-size: 0.78rem;
  color: #365685;
  font-weight: 600;
  margin-bottom: 0.36rem;
}

[data-page="exercise"] .exercise-progress-track {
  width: 100%;
  height: 8px;
  border-radius: 999px;
  background: rgba(76, 111, 166, 0.18);
  overflow: hidden;
}

[data-page="exercise"] .exercise-progress-fill {
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, #11a779, #16b9a4);
  transition: width 0.25s ease;
}

[data-page="exercise"] .exercise-content {
  border: 1px solid rgba(76, 111, 166, 0.24);
  border-radius: var(--lrn-radius-xl);
  background: var(--lrn-surface-strong);
  box-shadow: 0 12px 28px rgba(36, 65, 106, 0.14);
  padding: clamp(0.95rem, 2vw, 1.55rem);
  margin-bottom: 0.78rem;
  line-height: 1.65;
  color: #2b446e;
  min-width: 0;
  overflow: hidden;
  word-break: break-word;
  overflow-wrap: anywhere;
}

[data-page="exercise"] .exercise-content h1 {
  margin: 0 0 0.75rem;
  font-size: clamp(1.12rem, 2vw, 1.55rem);
  line-height: 1.22;
  color: #112f59;
}

[data-page="exercise"] .exercise-content h2,
[data-page="exercise"] .exercise-content h3 {
  margin-top: 1rem;
  margin-bottom: 0.52rem;
  color: #123a6f;
  font-size: clamp(0.98rem, 1.6vw, 1.22rem);
}

[data-page="exercise"] .exercise-content p {
  margin: 0 0 0.75rem;
}

[data-page="exercise"] .exercise-content pre,
[data-page="exercise"] .exercise-content code {
  font-family: "Fira Code", "Roboto Mono", monospace;
}

[data-page="exercise"] .exercise-content pre {
  background: #1e1e1e;
  border: 1px solid #3e4451;
  border-radius: 14px;
  padding: 0;
  overflow-x: auto;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.16);
  color: #d4d4d4;
  position: relative;
}

[data-page="exercise"] .exercise-content pre code {
  display: block;
  padding: 1.05rem;
  background: transparent;
  color: #d4d4d4;
  line-height: 1.7;
  font-size: 0.9rem;
}

[data-page="exercise"] .exercise-content pre.ql-syntax {
  color: #d4d4d4;
  white-space: pre;
}

[data-page="exercise"] .exercise-content :not(pre) > code {
  background: rgba(221, 235, 255, 0.5);
  border-radius: 4px;
  padding: 0.1rem 0.35rem;
  color: #1a355f;
  font-size: 0.9em;
}

[data-page="exercise"] .exercise-content img {
  max-width: 100% !important;
  width: auto !important;
  height: auto !important;
  border-radius: 12px;
  border: 1px solid rgba(76, 111, 166, 0.2);
  cursor: zoom-in;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

[data-page="exercise"] .exercise-content img:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 28px rgba(20, 43, 74, 0.2);
}

[data-page="exercise"] .exercise-content table,
[data-page="exercise"] .exercise-content iframe,
[data-page="exercise"] .exercise-content video,
[data-page="exercise"] .exercise-content canvas {
  max-width: 100% !important;
}

[data-page="exercise"] .exercise-content table {
  display: block;
  width: 100% !important;
  overflow-x: auto;
}

[data-page="exercise"] .exercise-content .exercise-body.ql-editor {
  padding: 0;
  border: 0;
}

[data-page="exercise"] .exercise-content .exercise-code-wrap {
  position: relative;
}

[data-page="exercise"] .exercise-content .exercise-copy-btn {
  position: absolute;
  top: 0.5rem;
  right: 0.5rem;
  border: 1px solid rgba(95, 131, 255, 0.4);
  background: rgba(255, 255, 255, 0.95);
  color: #214070;
  border-radius: 8px;
  padding: 0.34rem 0.62rem;
  font-size: 0.73rem;
  font-weight: 700;
  cursor: pointer;
  transition: 0.2s ease;
}

[data-page="exercise"] .exercise-content .exercise-copy-btn:hover {
  background: rgba(95, 131, 255, 0.18);
  border-color: rgba(95, 131, 255, 0.55);
}

[data-page="exercise"] .exercise-actions {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.45rem;
}

[data-page="exercise"] .btn-action {
  border-radius: 999px;
  border: 1px solid rgba(76, 111, 166, 0.28);
  padding: 0.48rem 0.6rem;
  font-size: 0.79rem;
  font-weight: 600;
  background: rgba(255, 255, 255, 0.86);
  color: #244e8c;
  transition: 0.2s ease;
}

[data-page="exercise"] .btn-action:hover:not(:disabled) {
  transform: translateY(-1px);
  border-color: rgba(47, 123, 255, 0.36);
}

[data-page="exercise"] .btn-action:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

[data-page="exercise"] .btn-complete {
  background: linear-gradient(125deg, rgba(22, 185, 164, 0.2), rgba(17, 167, 121, 0.2));
  border-color: rgba(17, 167, 121, 0.34);
  color: #0e7159;
}

.empty-state,
.loading,
.loading-state {
  border: 1px dashed rgba(76, 111, 166, 0.3);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.78);
  color: var(--lrn-muted);
  padding: 1.05rem;
  text-align: center;
  font-size: 0.9rem;
}

.empty-icon,
.empty-state-icon {
  font-size: 2rem;
  line-height: 1;
  display: block;
  margin-bottom: 0.4rem;
}

.exercise-nav-overlay {
  display: none;
}

[data-page="exercise"] .image-zoom-overlay {
  position: fixed;
  inset: 0;
  z-index: 3000;
  background: rgba(4, 9, 18, 0.94);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transition: opacity 0.2s ease;
  cursor: zoom-out;
  padding: 1rem;
}

[data-page="exercise"] .image-zoom-overlay.active {
  opacity: 1;
}

[data-page="exercise"] .image-zoom-content {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  touch-action: none;
}

[data-page="exercise"] .image-zoom-content img {
  max-width: 100%;
  max-height: 94vh;
  width: auto;
  height: auto;
  border-radius: 12px;
  border: 0;
  box-shadow: 0 22px 70px rgba(0, 0, 0, 0.45);
  cursor: grab;
  will-change: transform;
  transform-origin: center center;
  transition: transform 0.15s ease;
}

[data-page="exercise"] .image-zoom-content img.dragging {
  cursor: grabbing;
}

[data-page="exercise"] .image-zoom-close {
  position: fixed;
  top: 1rem;
  right: 1rem;
  width: 44px;
  height: 44px;
  border: 0;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.95);
  color: #193962;
  font-size: 1.4rem;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
  display: grid;
  place-items: center;
  box-shadow: 0 10px 22px rgba(8, 15, 28, 0.35);
}

[data-page="exercise"] .image-zoom-controls {
  position: fixed;
  left: 50%;
  bottom: 1.2rem;
  transform: translateX(-50%);
  z-index: 3001;
  display: inline-flex;
  gap: 0.4rem;
  padding: 0.4rem;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 10px 22px rgba(8, 15, 28, 0.35);
}

[data-page="exercise"] .image-zoom-btn {
  min-width: 38px;
  height: 38px;
  border: 1px solid rgba(47, 123, 255, 0.28);
  border-radius: 999px;
  background: rgba(47, 123, 255, 0.1);
  color: #193962;
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1;
  padding: 0 0.58rem;
  cursor: pointer;
  transition: 0.18s ease;
}

[data-page="exercise"] .image-zoom-btn:hover {
  background: rgba(47, 123, 255, 0.18);
  border-color: rgba(47, 123, 255, 0.4);
}

/* Responsive */
@media (max-width: 980px) {
  .lrn-hero {
    grid-template-columns: 1fr;
  }

  .lrn-hero-art {
    min-height: 120px;
  }

  [data-page="learning"] .learning-hero-art {
    min-height: 164px;
  }

  [data-page="learning"] .learning-hero-chip {
    top: 10px;
    left: 10px;
    padding: 0.28rem 0.6rem;
    font-size: 0.66rem;
  }

  [data-page="learning"] .learning-hero-grid {
    width: 92px;
    height: 48px;
    background-size: 12px 12px;
  }

  [data-page="courses"] .course-hero-art {
    min-height: 164px;
  }

  [data-page="courses"] .course-hero-chip {
    top: 10px;
    left: 10px;
    padding: 0.28rem 0.6rem;
    font-size: 0.66rem;
  }

  [data-page="courses"] .course-hero-grid {
    width: 92px;
    height: 48px;
    background-size: 12px 12px;
  }

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

  .learning-search-bar {
    flex-wrap: wrap;
  }

  [data-page="exercise"] .exercise-layout {
    grid-template-columns: 1fr;
  }

  [data-page="exercise"] .exercise-sidebar {
    position: fixed;
    left: 0;
    top: 4.4rem;
    bottom: 0.75rem;
    width: min(86vw, 320px);
    max-height: none;
    border-radius: 0 16px 16px 0;
    transform: translateX(-105%);
    transition: transform 0.25s ease;
    z-index: 1200;
  }

  [data-page="exercise"] .exercise-sidebar.active {
    transform: translateX(0);
  }

  [data-page="exercise"] .close-sidebar {
    display: grid;
    place-items: center;
  }

  [data-page="exercise"] .toggle-sidebar {
    display: inline-flex;
    align-items: center;
    gap: 0.36rem;
    cursor: pointer;
  }

  .exercise-nav-overlay {
    position: fixed;
    inset: 0;
    background: rgba(15, 28, 49, 0.4);
    z-index: 1190;
    opacity: 0;
    visibility: hidden;
    transition: 0.2s ease;
  }

  .exercise-nav-overlay.show {
    display: block;
    opacity: 1;
    visibility: visible;
  }
}

@media (max-width: 760px) {
  [data-page="learning"],
  [data-page="courses"],
  [data-page="topics"],
  [data-page="exercise"] {
    padding-bottom: 5.9rem;
  }

  .lrn-hero,
  .lrn-section {
    padding: 0.82rem;
  }

  .learning-stats {
    gap: 0.42rem;
  }

  .learning-search-bar {
    flex-direction: column;
    align-items: stretch;
  }

  .learning-search-btn {
    width: 100%;
  }

  [data-page="learning"] .categories-grid,
  [data-page="courses"] .courses-grid,
  [data-page="topics"] .topics-list {
    grid-template-columns: 1fr;
  }

  [data-page="courses"] .course-banner {
    height: 180px;
  }

  [data-page="courses"] .course-actions {
    flex-direction: column;
  }

  [data-page="courses"] .catalog-search {
    flex-direction: column;
    align-items: stretch;
  }

  [data-page="courses"] .catalog-search-btn {
    width: 100%;
  }

  [data-page="learning"] .learning-hero-art {
    min-height: 148px;
    border-radius: 16px;
  }

  [data-page="learning"] .learning-hero-icon-orb {
    width: 78px;
    height: 78px;
  }

  [data-page="learning"] .learning-hero-icon {
    font-size: 2.1rem;
  }

  [data-page="learning"] .learning-hero-grid {
    right: 8px;
    bottom: 8px;
    width: 78px;
    height: 40px;
  }

  [data-page="courses"] .course-hero-art {
    min-height: 148px;
    border-radius: 16px;
  }

  [data-page="courses"] .course-hero-icon-orb {
    width: 78px;
    height: 78px;
  }

  [data-page="courses"] .course-hero-icon {
    font-size: 2.1rem;
  }

  [data-page="courses"] .course-hero-grid {
    right: 8px;
    bottom: 8px;
    width: 78px;
    height: 40px;
  }

  [data-page="exercise"] .exercise-actions {
    grid-template-columns: 1fr;
  }

  [data-page="exercise"] .exercise-sidebar {
    top: 3.9rem;
    bottom: 5.4rem;
    width: min(92vw, 340px);
  }

  [data-page="exercise"] .image-zoom-close {
    width: 40px;
    height: 40px;
    font-size: 1.2rem;
  }

  [data-page="exercise"] .image-zoom-controls {
    bottom: 0.85rem;
  }

  [data-page="exercise"] .image-zoom-btn {
    min-width: 36px;
    height: 36px;
  }
}