.lesson {
  background-color: var(--background-lesson);
  padding: 0 1em;
}
.lesson * {
  color: var(--background-light);
}
.lesson h2 {
  margin: 0;
  margin-bottom: .25em;
  padding-top: 1em;
  text-transform: uppercase;
}

@media (min-width: 67.5em) {
  .video-player {
    display: flex;
  }
}

.video-player__container {
  margin-bottom: 2em;
}
@media (min-width: 67.5em) {
  .video-player__container {
    flex: 3;
  }
}
.video-player__container figure {
  border: 1px solid var(--foreground);
  width: 100%;
  height: auto;
}
.video-player__container img {
  filter: hue-rotate(45deg) saturate(45%);
}

.lesson__current {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  white-space: nowrap;
}
.lesson__current > small {
  color: var(--foreground);
  flex: 4;
  margin-bottom: .5em;
  padding-right: 5em;
}

.lesson__skip {
  display: flex;
  flex: 1;
  justify-content: space-between;
  margin-bottom: .5em;
}

.lesson__current .skip-previous {
  cursor: pointer;
}
.lesson__current .skip-next {
  cursor: pointer;
  margin-left: 2em;
}
.lesson__current .skip-previous svg,
.lesson__current .skip-next svg {
  width: auto;
  height: 1.2em;
}
.lesson__current .skip-previous path,
.lesson__current .skip-next path {
  fill: var(--background-light);
}
.lesson__current .skip-previous:hover,
.lesson__current .skip-next:hover {
  color: var(--foreground);
}
.lesson__current .skip-previous:hover path,
.lesson__current .skip-next:hover path {
  fill: var(--foreground);
}

.video {
  position: relative;
}
.control-panel {
  background-color: hsla(32, 100%, 45%, .4);
  display: flex;
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 10%;
}
.play-pause {
  align-items: center;
  background-color: hsla(32, 100%, 45%, .2);
  cursor: pointer;
  display: flex;
  width: 80px;
  max-width: 10%;
  height: 100%;
}
.play-pause svg {
  fill: var(--foreground);
  margin: 0 10px;
  width: 100%;
  height: 50%;
}

.video-player__nav {
  display: flex;
  flex-direction: column;
}
@media (min-width: 67.5em) {
  .video-player__nav {
    flex: 2;
    margin-left: 2em;
  }
}

.nav-element__label {
  align-items: center;
  background-color: var(--main);
  cursor: pointer;
  display: flex;
  column-gap: 1.2em;
  font-weight: bold;
  justify-content: space-between;
  padding: .5em;
}
.label__name {
  display: flex;
  flex-direction: column;
  flex: 1;
}
.label__name::before {
  content: attr(data-course);
  font-size: .75rem;
}
.nav-element__label.greyed-out {
  cursor: not-allowed;
  filter: saturate(.5) blur(1px);
  pointer-events: none;
}
.nav-element__label button {
  align-self: center;
  border: 1px solid var(--background-light);
  color: var(--background-light);
  line-height: .68;
  padding: .2em;
  padding-top: .3em;
  width: 1.2em;
}
.nav-element__label:hover :is(sup, span, button),
.nav-element__label button:focus-visible {
  border-color: var(--foreground);
  color: var(--foreground);
}

.nav-element :is(.graduated, .favourite) {
  align-items: center;
  display: flex;
  justify-content: center;
  position: relative;
  width: auto;
  height: 1.2lh;
}
.nav-element .graduated g {
  fill: none;
  stroke: var(--background-light);
}
.nav-element .graduated.filled g {
  stroke: limegreen;
}
.nav-element :is(.favourite, .graduated) svg {
  stroke: var(--background-light);
  stroke-width: 38;
  fill: none;
  width: auto;
  height: 100%;
}
.nav-element .favourite.filled svg {
  fill: var(--background-light);
}

.nav-element .graduated:hover::before,
.nav-element .favourite:hover::before {
  background-color: var(--heading);
  color: var(--background-lighter);
  content: attr(data-hintempty);
  font-size: .8rem;
  font-weight: normal;
  padding: .25em .5em;
  position: absolute;
  top: -150%;
  right: 0;
  width: auto;
  height: 1.5lh;
  white-space: nowrap;
}
.nav-element .graduated.filled:hover::before,
.nav-element .favourite.filled:hover::before {
  content: attr(data-hintfilled);
}
.nav-element .graduated:hover::after,
.nav-element .favourite:hover::after {
  border-color: var(--heading);
  border-right-color: transparent;
  border-bottom-color: transparent;
  border-left-color: transparent;
  border-style: solid;
  border-width: .5em;
  content: "";
  position: absolute;
  top: -50%;
  right: .25em;
  width: 1em;
  height: 1em;
}

.nav-element + .nav-element {
  margin-top: .1em;
}
.nav-element ul {
  background-color: #382E3C;
  margin: 0;
  overflow: hidden;
  transition: all 180ms ease;
  visibility: hidden;
  height: 0;
}
.nav-element ul.is-open {
  visibility: visible;
}
.nav-element li {
  display: flex;
  padding: .4em;
}
.nav-element li:hover *:not(.no-fill) {
  color: var(--foreground);
  fill: var(--foreground);
}
.nav-element li .no-fill {
  fill: var(--background-light);
}
.nav-element li + li {
  border-top: 1.5px solid var(--main);
}
.nav-element ul svg {
  align-self: center;
  fill: var(--background-light);
  flex: 1;
  margin-left: 1em;
  width: auto;
  height: 1em;
}
.nav-element ul button {
  flex: 6;
  margin-right: 2.5em;
  text-align: left;
}
.nav-element a {
  align-self: center;
  padding: .75em;
}
.nav-element a svg {
  margin: 0;
}
.nav-element a:hover path {
  fill: var(--foreground);
}

[data-type=wav] {
  cursor: default;
  display: flex;
  flex-wrap: wrap;
  row-gap: 1em;
}
.audio-player {
  align-items: center;
  display: flex;
  flex-basis: 100%;
  gap: 1em;
}
[data-type=wav] .audio-player svg {
  cursor: pointer;
  margin: 0;
  width: auto;
  height: 1.5lh;
}
.audio-player__start-stop:hover path {
  fill: var(--foreground);
}
.invisible {
  display: none;
}
.audio-player__progress-bar {
  flex: 1;
}

.audio-player input[type=range] {
  -webkit-appearance: none;
  background-color: transparent;
  height: 1.5lh;
}
.audio-player input[type=range]::-webkit-slider-runnable-track {
  background-color: #444;
  border-radius: 1px;
  cursor: pointer;
  width: 100%;
  height: 5px;
}
.audio-player input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  background-color: var(--foreground);
  border-radius: 50%;
  cursor: pointer;
  margin-top: -2.5px;
  width: .7lh;
  height: .7lh;
}
.audio-player input[type=range]:focus::-webkit-slider-runnable-track {
  background-color: #444;
}
.audio-player input[type=range]::-moz-range-track {
  background-color: #444;
  border-radius: 1px;
  cursor: pointer;
  height: 5px;
}
.audio-player input[type=range]::-moz-range-thumb {
  background: var(--foreground);
  border: none;
  border-radius: 50%;
  cursor: pointer;
  width: .7lh;
  height: .7lh;
}

.lesson-details {
  background-color: var(--background-lighter);
  background-image: url(../img/background-bright.png);
  padding: 0 1em 2em;
}
@media (min-width: 67.5em) {
  .lesson-details {
    padding: 0 3em 2em;
  }
}
.lesson-details nav {
  border-bottom: 2px solid var(--background-light);
  margin-bottom: 1.5em;
}
.lesson-details ul {
  display: flex;
  list-style: none;
  margin: 0;
  padding-top: 2.5em;
  padding-left: 0;
}
.lesson-details li {
  cursor: pointer;
  font-family: 'Franklin Sub', sans-serif;
  font-size: 1.5rem;
  padding: .8em 1em .1em;
}
.lesson-details li + li {
  margin-left: 1em;
}
.lesson-details li:first-child.active {
  background-color: var(--background-light);
  clip-path: polygon(5% 0, 95% 33%, 100% 100%, 0 100%);
}
.lesson-details li:last-child.active {
  background-color: var(--background-light);
  clip-path: polygon(5% 33%, 95% 15%, 100% 100%, 0 100%);
}
.lesson-details li:first-child.active:focus-visible,
.lesson-details li:last-child.active:focus-visible {
  background-color: var(--badge-02);
  color: var(--background-lighter);
}

.course-articles {
  display: flex;
  width: 200%;
}

.course-articles-overview {
  display: flex;
  flex-basis: 100%;
  flex-direction: column;
  transform: translateX(-100%);
  transition: all 300ms ease;
  visibility: hidden;
}
.course-articles-overview.active {
  transform: translateX(0);
  transition: all 300ms ease;
  visibility: visible;
}
.course-articles-lesson {
  flex-basis: 100%;
  transform: translateX(0);
  transition: all 300ms ease;
  visibility: hidden;
}
.course-articles-lesson.active {
  transform: translateX(-100%);
  transition: all 300ms ease;
  visibility: visible;
}

.lesson-details p {
  max-width: 72ch;
}

.course-articles-overview p:first-child {
  margin-top: 0;
}
@media (min-width: 67.5em) {
  .course-articles-overview {
    flex-direction: row;
  }
  .course-articles-overview > section:last-child {
    flex: 2;
  }
}

.article__info {
  padding: 1em;
}
.article__info:last-child {
  padding-bottom: 0;
}
.article__info figure {
  display: block;
  float: left;
  margin-right: 1em;
  width: 2.8em;
  height: 2.8em;
}
.article__info img {
  width: 100%;
  height: 100%;
}
.article__info p {
  color: var(--heading);
  font-size: 1rem;
  font-weight: bold;
  margin: 0;
  text-transform: uppercase;
}
.article__info span {
  color: var(--heading);
}

.course-articles-lesson {
  clear: both;
}

.lesson-details__lesson h4 {
  color: var(--main);
  font-family: 'Franklin Paragraph', sans-serif;
  font-size: 1.15rem;
  font-weight: bold;
  margin: 1.5em 0 .2em;
}
.lesson-details__lesson:first-child h4 {
  margin-top: 0;
}
.lesson-details__lesson h4 > span {
  text-transform: uppercase;
}
.lesson-details__lesson h4 > span::after {
  content: ": ";
}
.lesson-details__lesson > span {
  font-family: 'Franklin Sub', sans-serif;
}
.lesson-details__lesson time {
  margin-left: .3em;
}
.lesson-details__lesson p {
  margin: .2em 0 1em;
}

.lesson-details__lesson + .lesson-details__lesson {
  border-top: 2px solid var(--background-light);
}