.tutorial-nav,
.tutorial-actions,
.playback-info,
.lesson-meta,
.lesson-row {
  display: flex;
  align-items: center;
}
.tutorial-nav { justify-content: space-between; }
.tutorial-actions { gap: clamp(16px, 3vw, 36px); }
.back-link { font-size: 13px; font-weight: 650; }
.back-link:hover, #external:hover { text-decoration: underline; text-underline-offset: 4px; }
.tutorial-intro { padding-block: clamp(36px, 5vw, 76px) clamp(24px, 3.3vw, 48px); }
.tutorial-intro h1 {
  margin: 0 0 12px;
  color: var(--pine);
  font-size: clamp(46px, 6.4vw, 92px);
  font-weight: 680;
  letter-spacing: -.065em;
  line-height: 1;
}
.tutorial-intro em {
  color: var(--teal);
  font: italic 1.13em/.94 var(--serif);
  letter-spacing: -.045em;
}
.tutorial-intro p { max-width: 640px; color: var(--muted); font-size: clamp(15px, 1.25vw, 19px); }
.tutorial-layout {
  display: grid;
  grid-template-columns: minmax(290px, .78fr) minmax(0, 1.3fr);
  gap: clamp(24px, 4vw, 64px);
  align-items: start;
  padding-block: clamp(26px, 3.1vw, 48px) 60px;
  border-top: 1px solid var(--line);
}
.tutorial-layout h2 { letter-spacing: -.045em; line-height: 1.15; }
.tutorial-catalog h2 { font-size: clamp(23px, 2.2vw, 36px); margin: 0 0 19px; }
.filters { display: flex; flex-wrap: wrap; gap: 8px; }
.search-field, .category-field { flex: 1 1 155px; min-width: 0; }
.search-field { position: relative; }
.search-field svg {
  position: absolute;
  top: 50%;
  left: 11px;
  transform: translateY(-50%);
  width: 16px;
  height: 16px;
  fill: none;
  stroke: var(--muted);
  stroke-width: 1.7;
  pointer-events: none;
}
.search-field input, .category-field select {
  display: block;
  width: 100%;
  height: 42px;
  border: 1px solid #becabf;
  border-radius: 5px;
  background: white;
  color: var(--ink);
  font: 600 13px var(--sans);
}
.search-field input { padding: 0 8px 0 34px; }
.category-field select { padding: 0 7px; }
.category-field select:focus-visible { outline: 3px solid #e47832; outline-offset: 3px; }
.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}
.count, .lesson-meta {
  font: 12px/1.6 var(--mono);
  color: var(--muted);
}
.count { margin: 15px 0 7px; }
#lesson-list {
  margin: 0;
  padding: 0 4px;
  max-height: min(57vh, 530px);
  overflow-y: auto;
  scrollbar-color: #a3b6a8 var(--soft);
  scrollbar-width: thin;
  list-style: none;
  border-block: 1px solid var(--line);
}
.lesson-row {
  width: 100%;
  min-height: 52px;
  text-align: left;
  padding: 10px;
  gap: clamp(8px, 1vw, 16px);
  border-bottom: 1px solid var(--line);
}
#lesson-list li:last-child .lesson-row { border-bottom: 0; }
.lesson-row:hover { background: var(--soft); }
.lesson-row:focus-visible { outline-offset: -3px; }
.lesson-row[aria-current="true"] { background: #deebda; color: var(--pine); }
.lesson-index, .duration { color: var(--muted); font: 12px var(--mono); }
.lesson-name { flex: 1; font-size: 14px; font-weight: 680; line-height: 1.4; }
.lesson-marker { color: var(--teal); font-size: 17px; }
#empty-results { padding: 14px 0; color: var(--muted); font-size: 14px; }
.selected-lesson {
  background: var(--deep);
  color: var(--paper);
  padding: clamp(18px, 2.6vw, 38px);
  border-radius: 12px;
}
.lesson-meta { color: #cedfcf; gap: 9px; flex-wrap: wrap; }
.lesson-meta span + span::before { content: "·"; margin-right: 9px; }
#lesson-title {
  margin: 6px 0 20px;
  font-size: clamp(23px, 2.85vw, 43px);
  font-weight: 620;
}
#lesson-title:focus { outline: 0; }
#video-frame {
  position: relative;
  display: grid;
  place-items: center;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: #e7ece6;
  border-radius: 5px;
}
#video-frame img, #video-frame iframe {
  position: absolute;
  inset: 0;
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  object-fit: contain;
}
#video-frame img[hidden], #watch[hidden] { display: none; }
#watch {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 9px;
  padding: 12px 17px;
  border: 1px solid #aecba8;
  border-radius: 6px;
  background: var(--deep);
  color: #fff;
  font-size: 14px;
  font-weight: 720;
  box-shadow: 0 5px 18px #18312936;
}
#watch:hover { background: #1a5248; }
#watch svg { width: 17px; height: 17px; fill: var(--mint); }
.playback-info { gap: 12px 20px; justify-content: space-between; margin-top: 14px; flex-wrap: wrap; }
.playback-info p { font-size: 12px; color: #d3e1d5; margin: 0; }
#external { font-size: 12px; font-weight: 730; color: var(--mint); }
@media (max-width: 850px) {
  .tutorial-layout { grid-template-columns: minmax(220px, .8fr) minmax(0, 1fr); gap: 20px; }
  .tutorial-actions { gap: 16px; }
}
@media (max-width: 660px) {
  .tutorial-layout { grid-template-columns: 1fr; gap: 22px; padding-bottom: 36px; }
  #lesson-list { max-height: 207px; }
  .tutorial-catalog h2 { margin-bottom: 12px; }
  .selected-lesson { scroll-margin-top: 14px; }
  .tutorial-actions { gap: 13px; }
  .tutorial-actions .back-link { font-size: 12px; }
  .tutorial-actions .nav-cta { display: none; }
}