/* Lesson player layout and every block type. */

/* ---------- Player layout ---------- */

.lesson-shell {
  width: min(100% - 2 * var(--gutter), 100rem);
  padding-block: var(--space-l) 0;
}

.lesson-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-l);
}

.lesson-main {
  min-width: 0;
  max-width: 54rem;
  width: 100%;
  margin-inline: auto;
}

.lesson-rail,
.lesson-toc {
  display: none;
}

/* Laptop and up: content + sticky outline on the right. */
@media (min-width: 66rem) {
  .lesson-layout {
    grid-template-columns: minmax(0, 54rem) 15rem;
    justify-content: center;
    gap: clamp(2rem, 4vw, 4.5rem);
  }

  .lesson-toc {
    display: block;
  }

  .toc-mobile {
    display: none;
  }
}

/* Big screens: also show this week's lessons on the left, so wide screens are not empty margins. */
@media (min-width: 96rem) {
  .lesson-layout {
    grid-template-columns: 15rem minmax(0, 54rem) 15rem;
  }

  .lesson-rail {
    display: block;
  }
}

.lesson-aside {
  position: sticky;
  top: 5.75rem;
  max-height: calc(100dvh - 7rem);
  overflow: auto;
  padding-bottom: var(--space-s);
  font-size: var(--step--1);
}

.lesson-aside .annot {
  display: block;
  margin-bottom: var(--space-2xs);
}

.toc__list,
.rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 2px solid var(--line);
}

.toc__list a,
.rail__list a,
.rail__list span.rail__soon {
  display: flex;
  gap: 0.5rem;
  align-items: baseline;
  min-height: 40px;
  padding: 0.45rem 0.75rem;
  margin-left: -2px;
  border-left: 2px solid transparent;
  color: var(--ink-soft);
  text-decoration: none;
  line-height: 1.35;
  transition: color var(--dur-fast) ease, border-color var(--dur-fast) ease, background-color var(--dur-fast) ease;
}

.toc__list a:hover,
.rail__list a:hover {
  color: var(--ink);
  background: var(--sheet-sunk);
}

/* "You are here" in violet. */
.toc__list a.is-active,
.rail__list a[aria-current="page"] {
  color: var(--violet-text);
  border-left-color: var(--violet);
  font-weight: 650;
  background: var(--violet-tint);
}

.toc__n,
.rail__n {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  color: var(--ink-faint);
  flex: none;
}

.rail__list .is-done .rail__n {
  color: var(--ok);
}

.rail__soon {
  opacity: 0.7;
}

.toc-mobile {
  margin-bottom: var(--space-m);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background: var(--sheet);
}

.toc-mobile summary {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  min-height: 48px;
  padding: 0 var(--space-s);
  cursor: pointer;
  font-weight: 650;
  list-style: none;
}

.toc-mobile summary::-webkit-details-marker {
  display: none;
}

.toc-mobile summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  color: var(--violet-text);
}

.toc-mobile[open] summary::after {
  content: "−";
}

.toc-mobile .toc__list {
  margin: 0 var(--space-s) var(--space-s);
}

/* ---------- Lesson header ---------- */

.crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 0.5rem;
  align-items: center;
  margin: 0 0 var(--space-s);
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: var(--step--2);
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

.crumbs li + li::before {
  content: "/";
  margin-right: 0.5rem;
  color: var(--line-strong);
}

.crumbs a {
  color: var(--ink-soft);
  display: inline-flex;
  align-items: center;
  min-height: 32px;
}

.lesson-head h1 {
  font-size: var(--step-4);
  margin-bottom: var(--space-s);
}

.lesson-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 1rem;
  margin: 0 0 var(--space-m);
  color: var(--ink-soft);
  font-size: var(--step--1);
}

.lesson-meta > span {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.lesson-summary {
  font-size: var(--step-1);
  color: var(--ink-soft);
  line-height: 1.5;
  max-width: 42rem;
}

.objectives {
  margin: var(--space-m) 0 var(--space-xl);
  padding: var(--space-m);
}

.objectives__title {
  font-weight: 700;
  margin: 0 0 var(--space-xs);
}

.objectives ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.6rem;
  counter-reset: obj;
}

.objectives li {
  counter-increment: obj;
  display: grid;
  grid-template-columns: 2.25rem 1fr;
  align-items: baseline;
}

.objectives li::before {
  content: counter(obj, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: var(--step--1);
  font-weight: 600;
  color: var(--violet-text);
}

/* ---------- Lesson body rhythm ---------- */

.lesson-body {
  counter-reset: section;
}

.lesson-body > * + * {
  margin-top: var(--space-l);
}

.lesson-body > .block--text + .block--text {
  margin-top: var(--space-s);
}

/* Prose (markdown output) */
.prose > :last-child {
  margin-bottom: 0;
}

.prose h2 {
  font-size: var(--step-3);
  margin-top: var(--space-xl);
  scroll-margin-top: 6rem;
}

.lesson-body .prose h2::before {
  counter-increment: section;
  content: "§ " counter(section);
  display: block;
  margin-bottom: 0.4rem;
  font-family: var(--font-mono);
  font-size: var(--step--2);
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--violet-text);
}

.lesson-body > .block--text:first-child .prose h2:first-child,
.lesson-body > .block--text:first-child > h2:first-child {
  margin-top: 0;
}

.prose h3 {
  margin-top: var(--space-l);
}

.prose p,
.prose li {
  max-width: 68ch;
}

.prose ul,
.prose ol {
  padding-left: 1.4rem;
  margin: 0 0 var(--space-s);
}

.prose li {
  margin-bottom: 0.35rem;
}

.prose ul li::marker {
  color: var(--violet);
}

.prose ol li::marker {
  font-family: var(--font-mono);
  font-size: 0.85em;
  color: var(--violet-text);
}

.prose code {
  padding: 0.08em 0.35em;
  border-radius: 4px;
  background: var(--sheet-sunk);
  border: 1px solid var(--line);
  font-size: 0.86em;
  overflow-wrap: anywhere;
}

.prose strong {
  font-weight: 700;
}

/* ---------- Finish line + prev/next ---------- */

.finish {
  margin-top: var(--space-2xl);
  padding: var(--space-m);
  display: grid;
  gap: var(--space-s);
  border-top: 3px solid var(--violet);
}

.finish__row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-s);
}

.finish__title {
  margin: 0;
  font-size: var(--step-2);
}

.finish__note {
  margin: 0;
  color: var(--ink-soft);
  font-size: var(--step--1);
}

.finish.is-done {
  border-top-color: var(--ok);
}

.btn--done {
  --btn-bg: var(--ok-tint);
  --btn-fg: var(--ok);
  --btn-border: var(--ok);
}

.pager {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr));
  gap: var(--space-s);
  margin-top: var(--space-m);
}

.pager__link {
  display: grid;
  gap: 0.2rem;
  padding: var(--space-s) var(--space-m);
  border: 1px solid var(--line);
  border-radius: var(--radius-m);
  background: var(--sheet);
  color: var(--ink);
  text-decoration: none;
  box-shadow: var(--shadow-s);
  transition: border-color var(--dur-fast) ease, transform var(--dur-fast) var(--ease-out), box-shadow var(--dur-fast) ease;
}

.pager__link:hover {
  border-color: var(--violet);
  transform: translateY(-2px);
  box-shadow: var(--shadow-m);
}

.pager__link--next {
  text-align: right;
}

.pager__title {
  font-weight: 700;
  line-height: 1.3;
}

/* ---------- Locked / missing states ---------- */

.state-card {
  max-width: 44rem;
  margin: var(--space-xl) auto;
  padding: var(--space-l);
  display: grid;
  gap: var(--space-s);
  justify-items: start;
}

.state-card__art {
  width: 7rem;
  height: auto;
  color: var(--violet);
}

.state-card h1 {
  font-size: var(--step-3);
  margin: 0;
}

.state-card p {
  margin: 0;
  color: var(--ink-soft);
}

.waitlist {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem 0.75rem;
}

.waitlist__note {
  font-size: var(--step--1);
  color: var(--ink-soft);
}

.lesson-loading {
  display: grid;
  gap: var(--space-s);
  max-width: 54rem;
  margin-inline: auto;
}

.lesson-loading .skeleton:nth-child(1) { height: 1rem; width: 40%; }
.lesson-loading .skeleton:nth-child(2) { height: 3.2rem; width: 85%; }
.lesson-loading .skeleton:nth-child(3) { height: 1.2rem; width: 60%; }
.lesson-loading .skeleton:nth-child(4) { height: 12rem; }

.rail__week {
  margin: 0 0 var(--space-xs);
  font-weight: 700;
  line-height: 1.3;
}

.toc-mobile summary .annot {
  margin-left: 0.25rem;
}