.learn-shell {
  max-width: 1380px;
  padding: 0 36px;
  margin: auto;
}
.learn-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  min-height: 88px;
  border-bottom: 1px solid var(--line);
}
.learn-topbar nav {
  display: flex;
  align-items: center;
  gap: 30px;
  flex-wrap: wrap;
}
.learn-topbar nav a {
  color: var(--muted);
  padding: 12px 0;
  font-size: 14px;
}
.learn-topbar nav a[aria-current="page"] {
  color: var(--lime);
}
.learning-page main {
  min-height: 70vh;
  padding: 36px 0 50px;
}
#learning-main:focus {
  outline: none;
}
.lab-node::before {
  content: "";
  display: block;
  margin: 0 auto 6px;
  width: 62px;
  height: 59px;
  background: url("./assets/islands-atlas.webp") -2.4px -3px / 184.32px 122.88px;
}
.lab-node[data-node="client"]::before {
  background-position: -68.4px -63.6px;
}
.lab-node[data-node="root"]::before {
  background-position: -70.8px -4.8px;
}
.lab-node[data-node="tld"]::before {
  background-position: -127.2px -12px;
}
.lab-node[data-node="primary"]::before,
.lab-node[data-node="secondary"]::before {
  background-position: -4.8px -64.2px;
}
.check-jump {
  margin-top: 15px;
}
.learning-page h1,
.learning-page h2 {
  font-family: "Barlow Condensed", sans-serif;
  font-weight: 600;
}
.learning-page h1 {
  font-size: 54px;
  line-height: 1.04;
}
.learning-page h2 {
  font-size: 30px;
  line-height: 1.15;
}
.learning-page h3 {
  font-size: 17px;
}
.learning-page p {
  max-width: 70ch;
}

.learn-lead {
  color: var(--muted);
  line-height: 1.65;
  font-size: 17px;
  margin-top: 18px;
  max-width: 60ch;
}
.learning-page .primary-button,
.learning-page .secondary-button {
  width: auto;
  justify-content: center;
  display: inline-flex;
  min-height: 44px;
  padding: 11px 18px;
}
.learn-hero {
  display: grid;
  grid-template-columns: 1fr 320px;
  align-items: center;
  padding: 24px 0 35px;
  gap: 40px;
}
.learn-mascot {
  width: 276px;
  height: 255px;
  background: url("./assets/islands-atlas.webp") -10px -12.5px / 768px 512px;
  margin: auto;
}
.learn-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-top: 24px;
}
.learn-meta {
  display: flex;
  gap: 25px;
  flex-wrap: wrap;
  margin: 24px 0 0;
  font-size: 13px;
  color: var(--muted);
}
.course-progress {
  display: flex;
  align-items: center;
  gap: 22px;
  border-block: 1px solid var(--line);
  padding: 20px 0;
  margin-bottom: 32px;
}
.course-progress progress {
  max-width: 230px;
}
.course-progress a {
  margin-left: auto;
  color: var(--lime);
  font-size: 14px;
}
.curriculum-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px 56px;
}
.course-chapter > h2 {
  margin-bottom: 12px;
  font-size: 27px;
}
.lesson-link {
  display: grid;
  grid-template-columns: 35px 1fr 24px;
  gap: 12px;
  padding: 17px 0;
  border-bottom: 1px solid var(--line);
  align-items: start;
}
.lesson-link:hover {
  color: var(--lime);
}
.lesson-link > span:first-child {
  color: var(--muted);
  font-variant-numeric: tabular-nums;
  padding-top: 1px;
}
.lesson-link strong {
  font-size: 17px;
  font-weight: 500;
}
.lesson-link small {
  display: block;
  font-size: 13px;
  color: var(--muted);
  margin-top: 5px;
}
.lesson-link .lesson-done {
  color: var(--lime);
}
.learn-callout {
  margin-top: 40px;
  padding-top: 25px;
  border-top: 1px solid var(--line);
  display: flex;
  gap: 40px;
  align-items: center;
  justify-content: space-between;
}
.learn-callout p {
  color: var(--muted);
  margin-top: 8px;
}
.learn-back {
  color: var(--muted);
  font-size: 13px;
  display: inline-block;
  margin-bottom: 20px;
}
.lesson-heading {
  display: flex;
  align-items: start;
  justify-content: space-between;
  gap: 30px;
  margin-bottom: 28px;
}
.lesson-heading h1 {
  font-size: 43px;
}
.lesson-heading .learn-lead {
  font-size: 15px;
  margin-top: 10px;
}
.lesson-heading .text-button {
  min-height: 44px;
  text-decoration: underline;
  text-underline-offset: 3px;
  white-space: nowrap;
}
.lab-layout {
  display: grid;
  grid-template-columns: 310px minmax(0, 1fr);
  gap: 28px;
  align-items: start;
}
.lesson-brief {
  padding: 23px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 10px;
}
.lesson-brief > p {
  color: var(--muted);
  margin: 14px 0 22px;
  line-height: 1.65;
}
.task-list {
  list-style: none;
  margin: 14px 0 18px;
  padding: 0;
}
.task-list li {
  display: flex;
  gap: 10px;
  align-items: start;
  margin: 13px 0;
  font-size: 14px;
  line-height: 1.55;
}
.task-list .task-state {
  color: var(--muted);
  width: 16px;
  flex-shrink: 0;
}
.task-list .met .task-state {
  color: var(--lime);
}
.lesson-brief .text-button {
  font-size: 13px;
  min-height: 44px;
}
.lab-hint {
  padding-top: 12px;
  font-size: 14px;
  color: var(--apricot);
}
.lesson-brief details {
  margin-top: 16px;
  font-size: 14px;
  color: var(--muted);
}
.lesson-brief summary {
  cursor: pointer;
  color: var(--ink);
}
.lesson-brief details p {
  margin-top: 12px;
}
.source-links {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 18px;
  font-size: 12px;
}
.source-links a {
  text-decoration: underline;
  text-underline-offset: 3px;
  color: var(--muted);
}
.lab-panel {
  min-width: 0;
}
.lab-toolbar {
  display: flex;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 14px;
}
.lab-clock {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}
.lab-form {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 110px auto;
  align-items: end;
  gap: 12px;
}
.lab-form label {
  font-size: 13px;
  color: var(--muted);
}
.lab-form select {
  margin-top: 7px;
  display: block;
  width: 100%;
  min-height: 46px;
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 9px 10px;
}
.lab-tools {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
  margin: 16px 0;
}
.lab-tools button {
  background: var(--raised);
  border: 1px solid var(--line);
  border-radius: 5px;
  min-height: 42px;
  padding: 8px 11px;
  font-size: 13px;
}
.lab-tools .offline {
  color: var(--apricot);
}
.lab-network {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 18px;
  margin-top: 22px;
}
.lab-nodes {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 8px;
}
.lab-node {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 12px 5px;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
  transition:
    background-color 0.18s,
    border-color 0.18s;
}
.lab-node b {
  display: block;
  font-size: 20px;
  color: var(--ink);
  margin-bottom: 6px;
  font-family: "Barlow Condensed", sans-serif;
}
.lab-node.current {
  border-color: var(--lime);
  background: color-mix(in oklch, var(--lime) 8%, var(--surface));
  color: var(--ink);
}
.lab-node.current b {
  color: var(--lime);
}
.lab-network > p {
  color: var(--muted);
  font-size: 12px;
  margin-top: 14px;
}
.lab-journey {
  margin-top: 22px;
}
.journey-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.journey-heading span {
  color: var(--muted);
  font-size: 13px;
}
.trace-list {
  padding-left: 24px;
  margin: 16px 0;
}
.trace-details {
  margin-top: 16px;
}
.trace-details summary {
  cursor: pointer;
  color: var(--lime);
  min-height: 36px;
  font-size: 14px;
}
.trace-list li {
  padding: 5px 0 8px 7px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.6;
}
.trace-list li:last-child {
  color: var(--ink);
}
.trace-list li::marker {
  color: var(--lime);
  font-variant-numeric: tabular-nums;
}
.lab-empty {
  padding: 28px 0;
  color: var(--muted);
  font-size: 15px;
}
.lab-answer {
  padding: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  margin-top: 20px;
}
.answer-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 15px;
}
.answer-top h3 {
  font-size: 17px;
}
.answer-top span {
  color: var(--lime);
  font-size: 12px;
}
.record-row {
  border-top: 1px solid var(--line);
  padding: 12px 0;
  display: grid;
  grid-template-columns: 65px 1fr auto;
  gap: 12px;
  align-items: center;
}
.record-row b {
  color: var(--lilac);
  font-size: 13px;
}
.record-row code {
  display: block;
  overflow-wrap: anywhere;
  font-size: 14px;
}
.record-row small {
  color: var(--muted);
  font-size: 12px;
}
.answer-note {
  color: var(--muted);
  font-size: 13px;
}
.lab-cache {
  margin-top: 22px;
}
.lab-cache h3 {
  font-size: 14px;
  margin-bottom: 10px;
}
.cache-lines {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.cache-line {
  font-size: 12px;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 5px;
  padding: 8px 10px;
  overflow-wrap: anywhere;
}
.cache-line b {
  color: var(--ink);
  font-weight: 500;
}
.learning-check {
  border-top: 1px solid var(--line);
  margin-top: 30px;
  padding-top: 26px;
}
.learning-check > p {
  color: var(--muted);
  margin-top: 12px;
}
.check-question {
  margin: 20px 0 14px;
  font-size: 17px;
  font-weight: 500;
}
.check-choices {
  display: grid;
  gap: 10px;
}
.check-choice {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 14px 16px;
  text-align: left;
  font-size: 15px;
  line-height: 1.5;
  min-height: 48px;
}
.check-choice:hover {
  border-color: var(--lime);
}
.check-choice.correct {
  border-color: var(--lime);
  color: var(--lime);
}
.check-choice.incorrect {
  border-color: var(--apricot);
}
.check-feedback {
  padding: 14px 0 0;
  line-height: 1.65;
  color: var(--apricot);
}
.check-feedback.correct {
  color: var(--lime);
}
.lesson-complete {
  border-top: 1px solid var(--line);
  margin-top: 25px;
  padding-top: 25px;
}
.lesson-complete p {
  margin-top: 10px;
  color: var(--muted);
}
.lab-announcement {
  min-height: 22px;
  color: var(--lime);
  font-size: 13px;
  margin-top: 12px;
}
.raw-response {
  margin-top: 22px;
  color: var(--muted);
  font-size: 13px;
}
.raw-response summary {
  cursor: pointer;
}
.raw-response pre {
  white-space: pre-wrap;
  overflow-wrap: anywhere;
  background: var(--surface);
  padding: 16px;
  border-radius: 6px;
  font-size: 12px;
}
.teaching-layout {
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(220px, 1fr);
  gap: 60px;
  margin-top: 34px;
}
.teaching-layout section {
  margin-bottom: 35px;
}
.teaching-layout p,
.teaching-layout li {
  margin-top: 12px;
  color: var(--muted);
  line-height: 1.7;
}
.teaching-layout h3 {
  margin-top: 20px;
}
.teaching-layout ol,
.teaching-layout ul {
  padding-left: 22px;
}
.teaching-layout a {
  color: var(--lime);
  text-decoration: underline;
  text-underline-offset: 3px;
}
.teaching-layout aside {
  border-left: 1px solid var(--line);
  padding-left: 28px;
}
.teaching-layout aside h2 {
  font-size: 27px;
}
.teaching-layout .source-links {
  gap: 12px;
}
.report-summary {
  margin: 30px 0;
  padding: 22px 0;
  border-block: 1px solid var(--line);
  display: flex;
  gap: 45px;
  flex-wrap: wrap;
}
.report-summary strong {
  font-family: "Barlow Condensed", sans-serif;
  font-size: 38px;
}
.report-summary span {
  display: block;
  color: var(--muted);
  font-size: 13px;
}
.report-table-wrap {
  overflow-x: auto;
}
.report-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  text-align: left;
  font-size: 14px;
}
.report-table th,
.report-table td {
  border-bottom: 1px solid var(--line);
  padding: 14px 12px 14px 0;
  vertical-align: top;
}
.report-table th {
  color: var(--muted);
  font-weight: 500;
}
.report-table td small {
  display: block;
  color: var(--muted);
  margin-top: 4px;
}
.report-table .complete-label {
  color: var(--lime);
}
.report-note {
  color: var(--muted);
  font-size: 13px;
  margin-top: 18px;
}
.learn-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  padding: 22px 0;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
}
.learning-save-warning {
  margin-top: 15px;
  color: var(--apricot);
}
.learning-page .danger-link {
  color: var(--apricot);
  background: none;
  text-decoration: underline;
  font-size: 13px;
  min-height: 44px;
}
@media (max-width: 1000px) {
  .learn-shell {
    padding-inline: 24px;
  }
  .lab-layout {
    grid-template-columns: 270px minmax(0, 1fr);
    gap: 20px;
  }
  .lab-form {
    grid-template-columns: 1fr 90px;
  }
  .lab-form .primary-button {
    grid-column: 1/-1;
  }
  .lab-nodes {
    grid-template-columns: repeat(3, 1fr);
  }
  .learn-topbar nav {
    gap: 18px;
  }
}
@media (max-width: 760px) {
  .learn-shell {
    padding-inline: 18px;
  }
  .learn-topbar {
    align-items: start;
    flex-direction: column;
    gap: 8px;
    padding-top: 20px;
  }
  .learn-topbar nav {
    width: 100%;
    justify-content: space-between;
    gap: 10px;
  }
  .learn-topbar nav a {
    font-size: 12px;
  }
  .learning-page main {
    padding-top: 25px;
  }
  .learn-hero {
    grid-template-columns: 1fr;
    gap: 0;
    padding-top: 0;
  }
  .learn-mascot {
    display: none;
  }
  .learning-page h1 {
    font-size: 43px;
  }
  .learn-lead {
    font-size: 16px;
  }
  .learn-meta {
    gap: 12px 20px;
  }
  .course-progress {
    flex-wrap: wrap;
    gap: 13px;
    font-size: 14px;
  }
  .course-progress progress {
    max-width: none;
    flex: 1;
    min-width: 90px;
  }
  .course-progress a {
    flex-basis: 100%;
  }
  .curriculum-grid {
    grid-template-columns: 1fr;
    gap: 30px;
  }
  .learn-callout {
    flex-direction: column;
    align-items: start;
    gap: 15px;
  }
  .lesson-heading {
    gap: 15px;
  }
  .lesson-heading h1 {
    font-size: 35px;
  }
  .lesson-heading .text-button {
    font-size: 12px;
  }
  .lab-layout {
    grid-template-columns: 1fr;
  }
  .lesson-brief {
    padding: 20px;
  }
  .lab-network {
    padding: 14px;
  }
  .lab-form {
    grid-template-columns: minmax(0, 1fr) 90px;
  }
  .lab-form select {
    font-size: 14px;
  }
  .lab-answer {
    padding: 16px;
  }
  .record-row {
    grid-template-columns: 48px 1fr;
    gap: 10px;
  }
  .record-row > small {
    grid-column: 2;
  }
  .lab-toolbar {
    font-size: 12px;
  }
  .teaching-layout {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  .teaching-layout aside {
    border: 0;
    padding: 0;
  }
  .learn-footer {
    flex-wrap: wrap;
    font-size: 11px;
  }
  .learn-footer > span {
    order: 3;
  }
  .report-summary {
    gap: 28px;
  }
  .report-table {
    min-width: 530px;
  }
}
@media print {
  :root {
    color-scheme: light;
    --ink: #111;
    --muted: #444;
    --line: #bbb;
    --lime: #244500;
    --surface: #fff;
  }
  .learning-page {
    background: #fff;
    color: #111;
  }
  .learn-shell {
    max-width: none;
    padding: 0;
  }
  .learn-topbar,
  .learn-footer,
  .learn-actions,
  .learn-back,
  .danger-link,
  .learning-save-warning {
    display: none !important;
  }
  .learning-page main {
    padding: 0;
  }
  .learning-page h1 {
    font-size: 30px;
  }
  .teaching-layout {
    display: block;
  }
  .teaching-layout section,
  .report-table tr {
    break-inside: avoid;
  }
  .teaching-layout aside {
    border: 0;
    padding: 0;
  }
  .report-table-wrap {
    overflow: visible;
  }
  .report-table {
    min-width: 0;
    font-size: 11px;
  }
  a {
    color: #111 !important;
  }
}

.lesson-meta {
  font-size: 14px;
  color: var(--muted);
  margin: 12px 0 0;
}