/* Keep the model-owned course identity beside the design-owned navigation. */
:root { --hero-header-height: 144px; }
html { scroll-padding-top: calc(var(--hero-header-height) + 20px); }
.course-header { position: sticky; top: 0; z-index: 50; background: var(--paper); }
.course-header .site-header { position: static; }
.course-identity {
  display: grid;
  grid-template-columns: 64px minmax(0, 1fr) auto;
  align-items: center;
  gap: 16px;
  min-height: 68px;
  padding: 12px max(32px, calc((100vw - 1240px) / 2));
  border-bottom: 1px solid var(--line);
}
.course-identity img { width: 64px; height: 40px; object-fit: cover; }
.course-identity-title { color: var(--ink); font-size: 14px; font-weight: 700; text-decoration: none; overflow-wrap: anywhere; }
.course-identity-title:hover { text-decoration: underline; text-underline-offset: 4px; }
.course-identity-enroll { padding: 10px 16px; background: var(--blue); color: white; font-size: 14px; font-weight: 700; text-decoration: none; }
.course-identity-enroll:hover { background: var(--ink); }
@media (min-width: 721px) {
  .learn-heading, .description-heading, .faq-heading { top: calc(var(--hero-header-height) + 36px); }
}
@media (min-width: 1021px) {
  .lesson-player { top: calc(var(--hero-header-height) + 36px); }
}
@media (max-width: 1020px) {
  .course-identity { padding-inline: 20px; }
  .lesson-player { top: 0; }
}
@media (max-width: 720px) {
  :root { --hero-header-height: 134px; }
  .course-identity { grid-template-columns: 48px minmax(0, 1fr) auto; gap: 10px; padding-inline: 16px; }
  .course-identity img { width: 48px; height: 36px; }
  .course-identity-title { font-size: 13px; }
  .course-identity-enroll { padding-inline: 12px; }
}

.player-media {
  position: absolute;
  inset: 0;
  z-index: 3;
  display: none;
  background: #071117;
}

.player-screen.has-media .player-media {
  display: block;
}

.player-media iframe,
.player-media video {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  object-fit: contain;
}

.player-screen.has-media .player-topline {
  z-index: 4;
}

.player-screen.has-media > :not(.player-media) {
  pointer-events: none;
}

.player-error {
  position: absolute;
  z-index: 5;
  right: 24px;
  bottom: 22px;
  left: 24px;
  margin: 0;
  border: 1px solid #40515a;
  border-radius: 8px;
  background: rgba(7, 17, 23, 0.94);
  color: #e8efec;
  padding: 12px 16px;
  text-align: center;
  font-size: 13px;
}

.lesson-enroll-link {
  width: 100%;
  text-decoration: none;
}

.lesson-enroll-link:hover { color: var(--lime); }

.lesson-lock {
  display: inline-flex;
  color: #71827b;
}

.lesson-lock svg {
  width: 16px;
  height: 16px;
  fill: none;
  stroke: currentColor;
  stroke-linecap: round;
  stroke-linejoin: round;
  stroke-width: 1.5;
}

.faq-answer {
  max-width: 66ch;
  margin: -8px 0 28px;
  color: var(--ink-soft);
}

.faq-answer > :first-child,
.subscribe-status > :first-child {
  margin-top: 0;
}

.faq-answer > :last-child,
.subscribe-status > :last-child {
  margin-bottom: 0;
}