:root {
  color-scheme: light;
  font-family: Arial, Helvetica, sans-serif;
  color: #102f4d;
  background: #eef3f7;
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
  margin: 0;
}

body {
  padding: 18px;
  background: #eef3f7;
}

button {
  font: inherit;
}

.lesson-player {
  width: min(100%, 1180px);
  margin: 0 auto;
  overflow: hidden;
  border: 1px solid #d8cdb7;
  border-radius: 16px;
  background: #fffdf8;
  box-shadow: 0 10px 30px rgb(16 47 77 / 10%);
}

.lesson-player__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 18px 22px;
  border-bottom: 1px solid #e5dccb;
}

.lesson-player__heading {
  min-width: 0;
}

.lesson-player__eyebrow {
  margin: 0 0 5px;
  color: #54708a;
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.lesson-player__title {
  margin: 0;
  font-size: clamp(1.25rem, 2.2vw, 1.75rem);
  line-height: 1.2;
}

.lesson-player__counter {
  flex: 0 0 auto;
  padding: 9px 14px;
  border-radius: 999px;
  color: #fff;
  background: #176493;
  font-weight: 700;
}

.lesson-player__progress {
  padding: 14px 22px;
  border-bottom: 1px solid #e5dccb;
  background: #f8fafc;
}

.lesson-player__task-list {
  display: flex;
  gap: 12px;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  list-style: none;
}

.lesson-player__progress-strip {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: stretch;
  gap: 8px;
}

.lesson-player__progress-viewport {
  min-width: 0;
  overflow-x: auto;
  overscroll-behavior-inline: contain;
  scrollbar-width: none;
  scroll-snap-type: inline proximity;
}

.lesson-player__progress-viewport::-webkit-scrollbar {
  display: none;
}

.lesson-player__progress--adaptive .lesson-player__task-list {
  width: max-content;
  overflow: visible;
}

.lesson-player__progress--adaptive .lesson-player__task {
  flex: 0 0 clamp(190px, 22vw, 240px);
  scroll-snap-align: center;
}

.lesson-player__progress-arrow {
  width: 42px;
  min-height: 52px;
  padding: 0;
  border: 1px solid #b8ccdc;
  border-radius: 10px;
  color: #176493;
  background: #fff;
  font-size: 2rem;
  font-weight: 700;
  line-height: 1;
  cursor: pointer;
}

.lesson-player__progress-arrow:hover:not(:disabled),
.lesson-player__progress-view-all:hover {
  background: #edf6fb;
}

.lesson-player__progress-arrow:focus-visible,
.lesson-player__progress-view-all:focus-visible,
.lesson-player__progress-viewport:focus-visible {
  outline: 3px solid #e8b913;
  outline-offset: 2px;
}

.lesson-player__progress-arrow:disabled {
  cursor: not-allowed;
  opacity: 0.35;
}

.lesson-player__progress-view-all {
  display: block;
  margin: 9px auto 0;
  padding: 5px 10px;
  border: 0;
  border-radius: 7px;
  color: #176493;
  background: transparent;
  font-size: 0.82rem;
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 2px;
  cursor: pointer;
}

.lesson-player__progress--expanded .lesson-player__progress-strip {
  display: block;
}

.lesson-player__progress--expanded .lesson-player__progress-arrow {
  display: none;
}

.lesson-player__progress--expanded .lesson-player__progress-viewport {
  overflow: visible;
}

.lesson-player__progress--expanded .lesson-player__task-list {
  display: grid;
  width: auto;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.lesson-player__progress--expanded .lesson-player__task {
  width: auto;
}

.lesson-player__task {
  display: grid;
  grid-template-columns: 32px minmax(130px, 1fr);
  flex: 1 0 190px;
  align-items: center;
  gap: 10px;
  min-width: 0;
  padding: 9px 11px;
  border: 1px solid #d2dce5;
  border-radius: 12px;
  color: #597086;
  background: #fff;
  cursor: pointer;
}

.lesson-player__task:hover {
  background: #f3f8fb;
}

.lesson-player__task:focus-visible {
  outline: 3px solid #e8b913;
  outline-offset: 2px;
}

.lesson-player__task--current {
  border-color: #176493;
  color: #102f4d;
  background: #edf6fb;
  box-shadow: inset 0 0 0 1px #176493;
}

.lesson-player__task--complete {
  border-color: #79b58a;
  color: #205f33;
  background: #edf8f0;
}

.lesson-player__task-marker {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  border: 2px solid #b9c7d3;
  border-radius: 50%;
  background: #fff;
  font-weight: 700;
}

.lesson-player__task--current .lesson-player__task-marker {
  border-color: #176493;
  color: #fff;
  background: #176493;
}

.lesson-player__task--complete .lesson-player__task-marker {
  border-color: #2f7b45;
  color: #fff;
  background: #2f7b45;
}

.lesson-player__task-copy {
  min-width: 0;
}

.lesson-player__task-title,
.lesson-player__task-status {
  display: block;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-player__task-title {
  font-size: 0.92rem;
  font-weight: 700;
}

.lesson-player__task-status {
  margin-top: 2px;
  font-size: 0.78rem;
}

.lesson-player__stage {
  position: relative;
  height: min(74vh, 760px);
  min-height: 560px;
  background: #fff;
}

.lesson-player__frame {
  display: block;
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
}

.lesson-player__notice-region:empty {
  display: none;
}

.lesson-player__notice {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin: 0;
  padding: 14px 22px;
  border-top: 1px solid;
}

.lesson-player__notice--complete {
  border-color: #acd5b6;
  color: #205f33;
  background: #edf8f0;
}

.lesson-player__notice-copy {
  margin: 0;
  line-height: 1.4;
}

.lesson-player__gate {
  width: min(calc(100% - 32px), 560px);
  padding: 24px;
  border: 2px solid #d0a800;
  border-radius: 14px;
  color: #102f4d;
  background: #fffdf8;
  box-shadow: 0 18px 50px rgb(16 47 77 / 28%);
}

.lesson-player__gate::backdrop {
  background: rgb(16 47 77 / 48%);
}

.lesson-player__gate-heading {
  margin: 0 0 10px;
  font-size: 1.35rem;
  line-height: 1.25;
}

.lesson-player__gate-copy {
  margin: 0 0 20px;
  line-height: 1.5;
}

.lesson-player__notice-actions {
  display: flex;
  flex: 0 0 auto;
  gap: 10px;
}

.lesson-player__footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 22px;
  border-top: 1px solid #e5dccb;
}

.lesson-player__item-title {
  min-width: 0;
  margin: 0;
  overflow: hidden;
  color: #102f4d;
  font-weight: 700;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.lesson-player__nav {
  display: flex;
  flex: 0 0 auto;
  gap: 10px;
}

.lesson-player__button {
  min-height: 44px;
  padding: 10px 17px;
  border: 1px solid #b8ccdc;
  border-radius: 10px;
  color: #102f4d;
  background: #f5f9fc;
  font-weight: 700;
  cursor: pointer;
}

.lesson-player__button--primary {
  border-color: #176493;
  color: #fff;
  background: #176493;
}

.lesson-player__button:hover:not(:disabled) {
  filter: brightness(0.96);
}

.lesson-player__button:focus-visible {
  outline: 3px solid #e8b913;
  outline-offset: 2px;
}

.lesson-player__button:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.lesson-player__error {
  margin: 0;
  padding: 28px;
  color: #7a2222;
  font-weight: 700;
}

@media (max-width: 900px) {
  .lesson-player__progress--expanded .lesson-player__task-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 680px) {
  body {
    padding: 0;
  }

  .lesson-player {
    border-right: 0;
    border-left: 0;
    border-radius: 0;
  }

  .lesson-player__header,
  .lesson-player__footer {
    align-items: stretch;
    padding: 14px;
  }

  .lesson-player__header {
    align-items: center;
  }

  .lesson-player__footer {
    flex-direction: column;
  }

  .lesson-player__progress {
    padding: 12px 14px;
  }

  .lesson-player__task {
    flex-basis: 170px;
  }

  .lesson-player__progress--adaptive .lesson-player__task {
    flex-basis: min(78vw, 220px);
  }

  .lesson-player__progress-arrow {
    width: 38px;
  }

  .lesson-player__progress--expanded .lesson-player__task-list {
    grid-template-columns: 1fr;
  }

  .lesson-player__notice {
    align-items: stretch;
    flex-direction: column;
    padding: 13px 14px;
  }

  .lesson-player__notice-actions,
  .lesson-player__notice-actions .lesson-player__button {
    width: 100%;
  }

  .lesson-player__gate {
    padding: 20px;
  }

  .lesson-player__gate .lesson-player__notice-actions {
    flex-direction: column;
  }

  .lesson-player__stage {
    height: 70vh;
    min-height: 520px;
  }

  .lesson-player__nav,
  .lesson-player__button {
    width: 100%;
  }
}