:root {
  --learn-navy: #04221f;
  --learn-teal: #0d9488;
  --learn-mint: #5ee6c8;
  --learn-orange: #f5821f;
  --learn-paper: #f3f7f6;
  --learn-muted: #60706d;
  --learn-border: #dbe7e4;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--learn-paper);
  color: var(--learn-navy);
  font-family: 'Prompt', sans-serif;
}

.learning-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 76px;
  padding: 14px clamp(20px, 6vw, 88px);
  background: var(--learn-navy);
  color: #fff;
}
.learning-header img { display: block; width: auto; height: 34px; max-width: 54vw; }
.learning-header-actions { display: flex; align-items: center; gap: 12px; }
.back-link { color: #d8efea; font-size: 0.9rem; text-decoration: none; }
.back-link:hover { color: #fff; }

.learning-shell { width: min(1160px, calc(100% - 40px)); margin: 0 auto; padding: 52px 0 80px; }
.learning-kicker {
  color: var(--learn-teal);
  font-family: 'IBM Plex Mono', monospace;
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.learning-title { margin: 8px 0 10px; font-size: clamp(2rem, 5vw, 3.4rem); line-height: 1.15; }
.learning-intro { max-width: 720px; margin: 0; color: var(--learn-muted); line-height: 1.75; }
.all-courses-link {
  display: inline-flex;
  margin-top: 14px;
  color: var(--learn-teal);
  font-size: .9rem;
  font-weight: 600;
  text-decoration: none;
}
.all-courses-link[hidden] { display: none; }
.all-courses-link:hover { text-decoration: underline; }
.learner-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 22px;
  padding: 8px 14px;
  border: 1px solid var(--learn-border);
  border-radius: 999px;
  background: #fff;
  color: var(--learn-muted);
  font-size: 0.85rem;
}

.status-panel {
  margin-top: 36px;
  padding: 22px 24px;
  border: 1px solid var(--learn-border);
  border-radius: 14px;
  background: #fff;
  color: var(--learn-muted);
  line-height: 1.65;
}
.status-panel.error { border-color: #f5b4ad; background: #fff7f6; color: #9f2921; }
.status-panel[hidden] { display: none; }

.course-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 24px; margin-top: 36px; }
.course-panel {
  overflow: hidden;
  border: 1px solid var(--learn-border);
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 16px 45px -36px rgba(4, 34, 31, 0.55);
}
.course-head { padding: 26px 28px; background: linear-gradient(135deg, #07342f, #0d655c); color: #fff; }
.course-head.marketing { background: linear-gradient(135deg, #6b300c, #dd6d1b); }
.course-head h2 { margin: 0 0 8px; font-size: 1.45rem; }
.course-head p { margin: 0; color: rgba(255,255,255,.78); font-size: .9rem; line-height: 1.6; }
.progress-copy { margin-top: 13px; color: var(--learn-mint); font: 500 .78rem 'IBM Plex Mono', monospace; }
.lesson-list { margin: 0; padding: 0; list-style: none; }
.lesson-item { border-top: 1px solid var(--learn-border); }
.lesson-link {
  display: grid;
  grid-template-columns: 42px 1fr auto;
  gap: 14px;
  align-items: center;
  padding: 18px 22px;
  color: inherit;
  text-decoration: none;
  transition: background .15s ease;
}
.lesson-link:hover { background: #f1faf8; }
.lesson-number {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: #e5f5f2;
  color: var(--learn-teal);
  font-weight: 700;
}
.lesson-copy strong { display: block; font-size: .98rem; }
.lesson-copy span { display: block; margin-top: 3px; color: var(--learn-muted); font-size: .78rem; }
.lesson-state { color: var(--learn-muted); font-size: .78rem; white-space: nowrap; }
.lesson-state.complete { color: #07805e; font-weight: 600; }
.empty-lessons { padding: 22px 28px; color: var(--learn-muted); }

.lesson-layout { display: grid; grid-template-columns: minmax(0, 1.7fr) minmax(280px, .7fr); gap: 28px; margin-top: 32px; }
.lesson-layout.no-activities { grid-template-columns: minmax(0, 1fr); }
.video-card, .test-panel {
  border: 1px solid var(--learn-border);
  border-radius: 18px;
  background: #fff;
  box-shadow: 0 16px 45px -36px rgba(4, 34, 31, 0.55);
}
.video-frame { position: relative; overflow: hidden; width: 100%; aspect-ratio: 16 / 9; border-radius: 18px 18px 0 0; background: #061a18; }
#youtube-player, #youtube-player iframe { width: 100%; height: 100%; }
.test-panel { align-self: start; padding: 24px; }
.test-panel[hidden] { display: none; }
.test-panel h2 { margin: 0 0 8px; font-size: 1.2rem; }
.test-help { margin: 0 0 18px; color: var(--learn-muted); font-size: .84rem; line-height: 1.6; }
.test-card { padding: 16px 0; border-top: 1px solid var(--learn-border); }
.test-card strong { display: block; margin-bottom: 5px; }
.test-card p { margin: 0 0 12px; color: var(--learn-muted); font-size: .8rem; line-height: 1.5; }
.form-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 16px;
  border: 0;
  border-radius: 9px;
  background: var(--learn-orange);
  color: #271607;
  cursor: pointer;
  font: 600 .86rem 'Prompt', sans-serif;
  text-decoration: none;
}
.form-link.locked { pointer-events: none; background: #e3e8e7; color: #798481; }
.test-actions { display: flex; flex-wrap: wrap; gap: 8px; }
.seek-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  padding: 10px 12px;
  border: 1px solid var(--learn-border);
  border-radius: 9px;
  background: #fff;
  color: var(--learn-navy);
  cursor: pointer;
  font: 600 .82rem 'Prompt', sans-serif;
}
.seek-button:hover { background: #edf8f6; border-color: var(--learn-teal); }
.activity-opened { margin-top: 8px; color: #07805e; font-size: .76rem; }

@media (max-width: 880px) {
  .course-grid, .lesson-layout { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
  .learning-header { align-items: flex-start; flex-direction: column; }
  .learning-header-actions { width: 100%; justify-content: space-between; }
  .learning-shell { width: min(100% - 28px, 1160px); padding-top: 36px; }
  .course-grid { gap: 16px; }
  .lesson-link { grid-template-columns: 38px 1fr; }
  .lesson-state { grid-column: 2; }
}