/* ─── Sticky mini-video (research §2.2) ─── */

.lesson-video {
  transition: all var(--t-normal) var(--e-out);
}

.lesson-video.is-sticky {
  position: fixed;
  z-index: 95;
  margin: 0;
  box-shadow: 0 20px 50px rgba(0,0,0,0.35);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: #000;
}

/* Desktop: bottom-right corner */
.lesson-video.is-sticky {
  bottom: 24px;
  right: 24px;
  width: 320px;
  max-width: calc(100vw - 48px);
}
.lesson-video.is-sticky video {
  width: 100%;
  height: auto;
  display: block;
}

/* Mobile: top-edge full width with safe insets */
@media (max-width: 768px) {
  .lesson-video.is-sticky {
    top: 0;
    right: 0;
    left: 0;
    width: 100%;
    border-radius: 0;
    box-shadow: 0 6px 16px rgba(0,0,0,0.2);
  }
}

/* Placeholder в потоке: чтобы контент не "прыгал" когда video становится sticky */
.lesson-video-placeholder {
  width: 100%;
  background: var(--c-surface-2);
  border-radius: var(--r-lg);
  display: none;
  margin-bottom: var(--s-6);
  aspect-ratio: 16 / 9;
  border: 1px dashed var(--c-border);
  align-items: center;
  justify-content: center;
  color: var(--c-text-light);
  font-size: var(--fs-sm);
  text-align: center;
}
.lesson-video-placeholder.is-visible { display: flex; }

/* Sticky-mode controls overlay */
.video-sticky-controls {
  position: absolute;
  top: 6px;
  right: 6px;
  display: flex;
  gap: 4px;
  z-index: 2;
  opacity: 0;
  transition: opacity var(--t-fast);
}
.lesson-video.is-sticky:hover .video-sticky-controls,
.lesson-video.is-sticky:focus-within .video-sticky-controls {
  opacity: 1;
}
.video-sticky-controls.is-visible { opacity: 1; }
.video-sticky-btn {
  background: rgba(0,0,0,0.6);
  color: #fff;
  border: none;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background var(--t-fast);
  font-family: inherit;
}
.video-sticky-btn:hover { background: rgba(0,0,0,0.8); }

/* Hide native fullscreen button overlap on mini player */
.lesson-video.is-sticky video::-webkit-media-controls-fullscreen-button { display: none; }