@import url('https://fonts.googleapis.com/css2?family=DM+Sans:wght@400;500;600;700&family=Manrope:wght@400;500;600;650;700;800&display=swap');

:root {
  --ink: #162e3a;
  --muted: #526570;
  --line: #d8e0e3;
  --paper: #fafcfd;
  --green: #b4f1c5;
  --accent: #185c45;
  --navy: #102e3b;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 35px;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: 'DM Sans', Arial, sans-serif;
  font-size: 16px;
  line-height: 1.65;
}

a {
  color: inherit;
  text-decoration: none;
}

a,
button,
input {
  -webkit-tap-highlight-color: transparent;
}

button,
input {
  font: inherit;
}

button,
a,
input {
  touch-action: manipulation;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
summary:focus-visible {
  outline: 3px solid #328568;
  outline-offset: 5px;
}

header {
  max-width: 1376px;
  margin: auto;
  min-height: 96px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 30px;
  padding: 20px 48px;
  border-bottom: 1px solid var(--line);
}

.brand {
  font-family: Manrope, Arial, sans-serif;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 13px;
  letter-spacing: -.6px;
  font-size: 20px;
}

.monogram {
  font-size: 25px;
  border-right: 1px solid var(--line);
  padding-right: 18px;
}

.monogram span {
  color: var(--accent);
}

header nav {
  display: flex;
  gap: 32px;
}

header nav a {
  font-size: 14px;
  font-weight: 600;
  padding: 8px 0;
  position: relative;
}

header nav [aria-current=page]:after {
  content: '';
  position: absolute;
  height: 2px;
  background: var(--accent);
  bottom: 0;
  left: 0;
  right: 0;
}

.header-progress {
  font-size: 13px;
  color: var(--muted);
}

.header-progress span:first-child {
  font-weight: 700;
  color: var(--ink);
}

main {
  max-width: 1280px;
  margin: auto;
  padding: 0 48px;
}

h1,
h2,
h3 {
  font-family: Manrope, Arial, sans-serif;
  line-height: 1.2;
  letter-spacing: -1.3px;
}

h1 {
  font-size: clamp(38px,4.7vw,66px);
  font-weight: 600;
  line-height: 1.12;
  margin: 22px 0;
}

h2 {
  font-size: 30px;
  font-weight: 600;
  margin: 12px 0 20px;
}

h3 {
  font-size: 24px;
  font-weight: 600;
}

p {
  margin: 0 0 20px;
}

.eyebrow {
  font-size: 12px;
  letter-spacing: 1.7px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--accent);
}

.hero {
  display: grid;
  grid-template-columns: 1.25fr 1fr;
  gap: 65px;
  padding: 72px 0 65px;
  align-items: center;
}

.hero h1 em {
  font-style: normal;
  color: var(--accent);
}

.hero-copy {
  font-size: 18px;
  color: var(--muted);
  line-height: 1.75;
  margin: 24px 0 30px;
}

.hero-actions {
  display: flex;
  gap: 25px;
  align-items: center;
  flex-wrap: wrap;
}

.button {
  border: 1px solid var(--navy);
  background: var(--navy);
  color: white;
  padding: 13px 22px;
  border-radius: 5px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 25px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  min-height: 48px;
}

.button:hover {
  background: #204958;
}

.text-link {
  font-size: 14px;
  font-weight: 600;
  border-bottom: 1px solid #85989f;
  padding: 6px 0;
}

.hero-facts {
  display: flex;
  gap: 28px;
  margin-top: 39px;
  font-size: 12px;
  color: var(--muted);
}

.hero-facts strong {
  display: block;
  font-size: 17px;
  color: var(--ink);
  font-weight: 600;
}

.feature {
  background: var(--navy);
  color: #f6fbfd;
  border-radius: 9px;
  padding: 29px 32px;
}

.feature-top {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  font-size: 12px;
  color: #a9bec8;
}

.feature .eyebrow {
  color: var(--green);
  font-size: 12px;
  letter-spacing: 1.2px;
}

.feature h2 {
  font-size: 27px;
  line-height: 1.4;
  letter-spacing: -.6px;
  margin: 25px 0;
}

.feature p {
  font-size: 14px;
  color: #c1d0d6;
  line-height: 1.7;
}

.feature>a {
  font-size: 14px;
  color: var(--green);
  display: flex;
  justify-content: space-between;
  border-top: 1px solid #3e5761;
  padding-top: 18px;
}

.flow {
  display: grid;
  grid-template-columns: 1fr 20px 1fr;
  align-items: center;
  text-align: center;
  margin: 25px 0;
}

.flow span {
  padding: 14px 6px;
  background: #264552;
  border: 1px solid #4a6875;
  font-size: 12px;
  border-radius: 4px;
}

.flow b {
  font-size: 18px;
  font-weight: 400;
  color: #b6ced7;
}

.flow b:nth-of-type(2) {
  grid-column: 1/4;
  padding: 2px;
}

.flow .flow-result {
  grid-column: 1/4;
  background: var(--green);
  color: var(--navy);
  font-size: 14px;
  font-weight: 600;
  border: 0;
}

.section {
  padding: 40px 0 64px;
  border-top: 1px solid var(--line);
}

.section-heading {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 40px;
  margin-bottom: 28px;
}

.section-heading h2 {
  font-size: 28px;
  margin-bottom: 0;
}

.section-heading p:not(.eyebrow) {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

.level-grid {
  display: grid;
  grid-template-columns: repeat(3,1fr);
  gap: 20px;
}

.level-card {
  display: block;
  border: 1px solid var(--line);
  border-radius: 6px;
  padding: 26px 24px 20px;
  background: white;
  transition: border-color .15s, transform .15s;
}

.level-card:hover {
  border-color: var(--accent);
  transform: translateY(-3px);
}

.level-card .eyebrow {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-size: 12px;
}

.level-card .eyebrow span {
  font-weight: 400;
  color: var(--muted);
  letter-spacing: .6px;
}

.level-card h3 {
  margin: 25px 0 12px;
}

.level-card p {
  font-size: 14px;
  color: var(--muted);
  min-height: 46px;
}

.card-bottom {
  display: flex;
  justify-content: space-between;
  margin-top: 26px;
  font-size: 12px;
  color: var(--muted);
}

.track {
  height: 3px;
  background: #e8edef;
  margin-top: 14px;
}

.track span {
  display: block;
  background: var(--accent);
  height: 100%;
  width: 0;
}

.reading-band {
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  padding: 44px 0 55px;
}

.reading-band h2 {
  font-size: 27px;
}

.reading-band>p {
  color: var(--muted);
  font-size: 16px;
  margin: 0;
}

footer {
  max-width: 1280px;
  margin: 0 auto;
  padding: 30px 48px 40px;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--line);
  gap: 16px;
}

footer .brand {
  font-size: 16px;
}

footer p,
footer small {
  font-size: 12px;
  color: var(--muted);
  margin: 0;
}

.page-intro {
  padding: 60px 0 42px;
  max-width: 850px;
}

.page-intro h1 {
  font-size: 48px;
}

.page-intro>p:not(.eyebrow) {
  color: var(--muted);
  font-size: 18px;
}

.curriculum-layout {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 64px;
  padding-bottom: 70px;
}

.curriculum-sidebar {
  align-self: start;
  position: sticky;
  top: 30px;
}

.progress-panel {
  border: 1px solid var(--line);
  padding: 24px;
  background: white;
  border-radius: 5px;
}

.progress-panel strong {
  font-size: 32px;
  display: block;
  margin: 12px 0;
}

.progress-panel small {
  display: block;
  font-size: 12px;
  color: var(--muted);
  margin: 8px 0 20px;
}

.progress-panel .button {
  width: 100%;
  padding: 12px;
}

progress {
  height: 6px;
  width: 100%;
  appearance: none;
  border: none;
  border-radius: 3px;
  background: #dce6e3;
}

progress::-webkit-progress-bar {
  background: #dce6e3;
  border-radius: 3px;
}

progress::-webkit-progress-value {
  background: var(--accent);
}

progress::-moz-progress-bar {
  background: var(--accent);
}

.curriculum-sidebar nav {
  display: flex;
  flex-direction: column;
  margin-top: 26px;
}

.curriculum-sidebar nav a {
  font-size: 14px;
  padding: 10px 0;
}

.curriculum-sidebar nav a span {
  color: var(--accent);
  font-size: 12px;
  margin-right: 12px;
}

.curriculum-level {
  margin-bottom: 56px;
}

.curriculum-level>p:not(.eyebrow) {
  color: var(--muted);
}

.curriculum-level h2 {
  font-size: 29px;
}

.lesson-list {
  border-top: 1px solid var(--line);
}

.lesson-row {
  display: grid;
  grid-template-columns: 28px 1fr 67px;
  align-items: center;
  gap: 16px;
  padding: 19px 5px;
  border-bottom: 1px solid var(--line);
}

.lesson-row:hover {
  background: #edf4f1;
}

.lesson-number {
  font-size: 12px;
  color: var(--muted);
}

.lesson-row strong {
  font-size: 16px;
  font-weight: 500;
}

.row-description {
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
  display: block;
  margin-top: 4px;
}

.row-meta {
  font-size: 12px;
  display: flex;
  gap: 12px;
  align-items: center;
  color: var(--muted);
}

.completion {
  font-size: 20px;
}

.is-complete .completion {
  color: var(--accent);
}

.breadcrumbs {
  display: flex;
  gap: 14px;
  font-size: 13px;
  color: var(--muted);
  padding: 32px 0;
  border-bottom: 1px solid var(--line);
  flex-wrap: wrap;
}

.breadcrumbs a:hover {
  text-decoration: underline;
}

.lesson-layout {
  display: grid;
  grid-template-columns: 230px minmax(0,720px);
  gap: 62px;
  padding: 46px 0 70px;
  justify-content: space-between;
}

.lesson-sidebar {
  position: sticky;
  top: 32px;
  align-self: start;
}

.lesson-sidebar nav {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 22px 0;
}

.lesson-sidebar nav a {
  font-size: 14px;
  color: var(--muted);
}

.lesson-sidebar nav a:hover {
  color: var(--accent);
}

.sidebar-meta {
  font-size: 12px;
  color: var(--muted);
  padding-top: 22px;
  border-top: 1px solid var(--line);
  margin: 28px 0 18px;
}

.lesson-title {
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 36px;
}

.lesson-title h1 {
  font-size: 46px;
  line-height: 1.18;
}

.lesson-deck {
  font-size: 21px;
  color: var(--muted);
  margin: 20px 0 0;
}

.lesson-section {
  margin: 32px 0;
}

.lesson-section h2,
.reflection h2,
.related h2,
.sources h2 {
  font-size: 22px;
  letter-spacing: -.6px;
  margin-bottom: 15px;
}

.lesson-section p {
  font-size: 17px;
  line-height: 1.9;
  color: #334b57;
  margin: 0;
}

.example {
  padding: 25px 30px;
  background: #edf4f1;
  border-left: 3px solid #44816b;
  border-radius: 0 5px 5px 0;
}

.remember {
  background: var(--navy);
  color: #fff;
  padding: 29px 32px;
  border-radius: 5px;
  margin: 40px 0 32px;
}

.remember .eyebrow {
  color: var(--green);
}

blockquote {
  font-family: Manrope, Arial, sans-serif;
  font-size: 24px;
  line-height: 1.55;
  letter-spacing: -.4px;
  margin: 16px 0 0;
}

.reflection {
  padding: 0 0 30px;
  border-bottom: 1px solid var(--line);
}

.reflection p {
  color: var(--muted);
  margin-bottom: 0;
}

.related {
  margin: 30px 0;
}

.related>div {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.related a {
  font-size: 14px;
  border: 1px solid var(--line);
  background: white;
  border-radius: 4px;
  padding: 8px 12px;
}

.related a:hover {
  border-color: var(--accent);
}

.sources a {
  display: block;
  text-decoration: underline;
  font-size: 14px;
  margin: 8px 0;
}

.sources small {
  font-size: 12px;
  color: var(--muted);
}

.complete-panel {
  padding: 25px 0;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  align-items: center;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  margin: 36px 0 25px;
  flex-wrap: wrap;
}

.complete-panel h2 {
  font-size: 18px;
  letter-spacing: -.4px;
  margin: 0 0 5px;
}

.complete-panel p {
  font-size: 13px;
  color: var(--muted);
  margin: 0;
}

.complete-panel button[aria-pressed=true] {
  background: #e2f3e9;
  color: var(--accent);
  border-color: #aad5bc;
}

.lesson-pager {
  display: flex;
  justify-content: space-between;
  gap: 20px;
}

.lesson-pager a {
  font-size: 16px;
  max-width: 48%;
}

.lesson-pager a:last-child {
  text-align: right;
}

.lesson-pager small {
  display: block;
  font-size: 12px;
  letter-spacing: 1px;
  color: var(--muted);
  margin-bottom: 8px;
}

.search-label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  margin: 30px 0 8px;
}

input[type=search] {
  padding: 15px 18px;
  border: 1px solid #a6b7bf;
  border-radius: 5px;
  background: white;
  color: var(--ink);
  width: 100%;
  max-width: 600px;
}

.glossary {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 55px;
  padding-bottom: 60px;
}

.glossary-entry {
  padding: 25px 0;
  border-top: 1px solid var(--line);
}

.glossary-entry h2 {
  font-size: 22px;
  letter-spacing: -.6px;
}

.glossary-entry h2 span {
  font-size: 18px;
  color: var(--accent);
}

.glossary-entry p {
  font-size: 16px;
  color: var(--muted);
}

.glossary-entry small {
  font-size: 12px;
  color: var(--muted);
}

/* Collapsible lesson sections ------------------------------------------- */

.lesson-details {
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.lesson-details + .lesson-details {
  border-top: 0;
  margin-top: -32px;
}

.lesson-details summary {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 48px;
  padding: 14px 0;
  cursor: pointer;
  list-style: none;
}

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

.lesson-details summary h2 {
  margin: 0;
}

.lesson-details summary:hover h2 {
  color: var(--accent);
}

.chevron {
  font-family: Manrope, Arial, sans-serif;
  font-size: 26px;
  line-height: 1;
  color: var(--accent);
  transition: transform .15s ease;
}

.lesson-details[open] .chevron {
  transform: rotate(90deg);
}

.lesson-details > p {
  padding-bottom: 24px;
}

/* Check your understanding ---------------------------------------------- */

.quiz {
  margin: 0 0 36px;
  padding: 29px 32px;
  border: 1px solid var(--line);
  border-radius: 5px;
  background: white;
}

.quiz .quiz-prompt {
  font-size: 21px;
  line-height: 1.4;
  letter-spacing: -.4px;
  margin: 10px 0 20px;
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.quiz-option {
  display: grid;
  grid-template-columns: 30px 1fr;
  gap: 4px 12px;
  align-items: start;
  width: 100%;
  min-height: 48px;
  padding: 12px 16px;
  text-align: left;
  color: var(--ink);
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 5px;
  line-height: 1.5;
}

.quiz[data-ready] .quiz-option:not(:disabled) {
  cursor: pointer;
}

.quiz[data-ready] .quiz-option:not(:disabled):hover {
  border-color: var(--accent);
}

.quiz-option:disabled {
  opacity: 1;
}

.quiz-letter {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border: 1px solid #a6b7bf;
  border-radius: 50%;
  font-size: 12px;
  font-weight: 700;
}

.quiz-mark {
  grid-column: 2;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .4px;
}

.quiz-mark:empty {
  display: none;
}

.quiz-option.is-correct {
  background: #e2f3e9;
  border-color: #44816b;
}

.quiz-option.is-correct .quiz-letter {
  background: var(--accent);
  border-color: var(--accent);
  color: white;
}

.quiz-option.is-correct .quiz-mark {
  color: var(--accent);
}

.quiz-option.is-incorrect {
  background: #fbeeed;
  border-color: #c0605a;
}

.quiz-option.is-incorrect .quiz-letter {
  background: #9b2f28;
  border-color: #9b2f28;
  color: white;
}

.quiz-option.is-incorrect .quiz-mark {
  color: #9b2f28;
}

.quiz-reveal {
  margin-top: 18px;
}

.quiz-reveal > summary {
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  padding: 6px 0;
}

.quiz[data-ready] .quiz-reveal > summary {
  display: none;
}

.quiz-feedback {
  padding-top: 12px;
}

.quiz[data-ready] .quiz-feedback {
  padding-top: 0;
}

.quiz-feedback:focus {
  outline: none;
}

.quiz-feedback:focus-visible {
  outline: 3px solid #328568;
  outline-offset: 5px;
}

.quiz-verdict {
  margin-bottom: 6px;
}

.quiz-explanation {
  color: #334b57;
  margin-bottom: 0;
}

.quiz-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 22px;
}

.quiz-actions:not(:empty) {
  margin-top: 18px;
}

.text-button {
  font-size: 14px;
  font-weight: 600;
  color: var(--ink);
  background: none;
  border: 0;
  border-bottom: 1px solid #85989f;
  padding: 6px 0;
  cursor: pointer;
}

.quiz-done {
  font-size: 14px;
  font-weight: 600;
  color: var(--accent);
}

.quiz-done:focus {
  outline: none;
}

[hidden] {
  display: none!important;
}

.sr-only {
  position: absolute;
  clip: rect(0,0,0,0);
  width: 1px;
  height: 1px;
  overflow: hidden;
}

.skip {
  position: absolute;
  left: 20px;
  top: -100px;
  z-index: 100;
  background: var(--navy);
  color: white;
  padding: 10px;
}

.skip:focus {
  top: 10px;
}

@media (min-width: 1450px) {
  .hero {
    padding-top: 90px;
    padding-bottom: 85px;
  }
}

@media (max-width: 1000px) {
  header {
    padding: 20px 30px;
    gap: 15px;
  }

  .progress-caption {
    display: none;
  }

  main {
    padding: 0 30px;
  }

  .hero {
    gap: 32px;
  }

  .hero-facts {
    gap: 16px;
  }

  .hero-actions {
    gap: 14px;
  }

  .feature {
    padding: 25px;
  }

  .level-grid {
    gap: 14px;
  }

  .level-card {
    padding: 22px 18px;
  }

  .level-card h3 {
    font-size: 21px;
  }

  .curriculum-layout {
    gap: 32px;
    grid-template-columns: 210px 1fr;
  }

  .lesson-layout {
    grid-template-columns: 185px minmax(0,1fr);
    gap: 32px;
  }

  footer {
    padding: 30px;
  }

  .section-heading {
    align-items: start;
  }

  .section-heading>p {
    max-width: 260px;
  }
}

@media (max-width: 740px) {
  header {
    padding: 16px 20px;
    flex-wrap: wrap;
    gap: 12px;
    min-height: 0;
  }

  .brand {
    font-size: 18px;
  }

  .monogram {
    padding-right: 12px;
  }

  header nav {
    order: 3;
    width: 100%;
    gap: 27px;
    border-top: 1px solid var(--line);
    padding-top: 7px;
  }

  header nav a {
    font-size: 14px;
  }

  .header-progress {
    margin-left: auto;
  }

  main {
    padding: 0 22px;
  }

  .hero {
    grid-template-columns: 1fr;
    padding: 38px 0;
    gap: 32px;
  }

  .hero h1 {
    font-size: 46px;
  }

  .hero-copy {
    font-size: 17px;
  }

  .hero-facts {
    justify-content: space-between;
  }

  .feature {
    padding: 25px 26px;
  }

  .feature h2 {
    font-size: 26px;
  }

  .section {
    padding: 30px 0 38px;
  }

  .section-heading {
    display: block;
  }

  .section-heading h2 {
    font-size: 28px;
    margin-bottom: 16px;
  }

  .section-heading>p {
    max-width: none;
  }

  .level-grid {
    grid-template-columns: 1fr;
  }

  .level-card {
    padding: 25px;
  }

  .level-card h3 {
    font-size: 25px;
    margin-top: 17px;
  }

  .level-card p {
    min-height: 0;
  }

  .card-bottom {
    margin-top: 20px;
  }

  .reading-band {
    grid-template-columns: 1fr;
    gap: 12px;
    padding: 32px 0;
  }

  .reading-band h2 {
    font-size: 26px;
  }

  footer {
    padding: 24px 22px;
    display: block;
  }

  footer p {
    margin: 12px 0;
  }

  .page-intro {
    padding: 36px 0 25px;
  }

  .page-intro h1 {
    font-size: 38px;
  }

  .page-intro>p:not(.eyebrow) {
    font-size: 16px;
  }

  .curriculum-layout {
    display: block;
  }

  .curriculum-sidebar {
    position: static;
  }

  .curriculum-sidebar nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4px 16px;
    margin: 20px 0 36px;
  }

  .progress-panel {
    padding: 18px;
  }

  .progress-panel strong {
    font-size: 25px;
    margin: 6px 0;
  }

  .progress-panel .button {
    width: auto;
  }

  .lesson-row {
    grid-template-columns: 24px 1fr 56px;
    gap: 10px;
  }

  .row-description {
    display: none;
  }

  .row-meta {
    gap: 7px;
  }

  .lesson-layout {
    display: block;
    padding-top: 30px;
  }

  .lesson-sidebar {
    display: none;
  }

  .breadcrumbs {
    font-size: 12px;
    padding: 23px 0;
    gap: 8px;
  }

  .lesson-title h1 {
    font-size: 38px;
    overflow-wrap: anywhere;
  }

  .lesson-deck {
    font-size: 19px;
  }

  .lesson-section p {
    font-size: 17px;
  }

  .example {
    padding: 22px;
  }

  .remember {
    padding: 24px;
  }

  blockquote {
    font-size: 22px;
  }

  .complete-panel {
    display: block;
  }

  .complete-panel button {
    margin-top: 18px;
  }

  .glossary {
    grid-template-columns: 1fr;
  }

  .glossary-entry h2 {
    font-size: 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition: none!important;
  }
}

@media (max-width: 740px) {
  .quiz {
    padding: 24px 20px;
  }

  .quiz .quiz-prompt {
    font-size: 19px;
  }

  .quiz-option {
    padding: 12px 14px;
  }
}