:root {
  --bg: #f7faf8;
  --panel: #ffffff;
  --ink: #101513;
  --muted: #5b6763;
  --line: #dbe5e0;
  --green: #137c5b;
  --teal: #0b8c95;
  --coral: #d84f4f;
  --yellow: #e1b84d;
  --shadow: 0 18px 50px rgb(16 21 19 / 10%);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

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

button,
input {
  font: inherit;
}

.site-header {
  align-items: center;
  display: flex;
  justify-content: space-between;
  padding: 22px clamp(20px, 5vw, 72px);
}

.brand {
  align-items: center;
  display: flex;
  gap: 12px;
}

.brand-mark {
  align-items: center;
  background: var(--ink);
  border-radius: 8px;
  color: #ffffff;
  display: inline-flex;
  font-weight: 800;
  height: 40px;
  justify-content: center;
  width: 40px;
}

.brand small {
  color: var(--muted);
  display: block;
  font-size: 12px;
  margin-top: 2px;
}

.nav-links,
.hero-actions,
.course-tile-top,
.course-header,
.lesson-row,
.chapter-heading,
.metrics {
  align-items: center;
  display: flex;
}

.nav-links {
  gap: 20px;
}

.link-button {
  background: none;
  border: 0;
  color: var(--ink);
  cursor: pointer;
  padding: 0;
}

.button {
  background: var(--green);
  border: 1px solid var(--green);
  border-radius: 8px;
  color: #ffffff;
  cursor: pointer;
  display: inline-flex;
  font-weight: 800;
  justify-content: center;
  padding: 12px 18px;
}

.button.secondary {
  background: #ffffff;
  color: var(--green);
}

.hero {
  align-items: stretch;
  display: grid;
  gap: clamp(24px, 4vw, 52px);
  grid-template-columns: minmax(0, 1fr) minmax(300px, 0.8fr);
  min-height: calc(100vh - 110px);
  padding: 28px clamp(20px, 5vw, 72px) 72px;
}

.hero-copy {
  align-self: center;
  max-width: 760px;
}

.eyebrow {
  color: var(--teal);
  font-size: 13px;
  font-weight: 900;
  margin: 0 0 14px;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  font-size: clamp(44px, 8vw, 92px);
  line-height: 0.95;
  margin: 0;
  max-width: 820px;
}

h2,
h3 {
  margin: 0;
}

.lead {
  color: var(--muted);
  font-size: 20px;
  line-height: 1.6;
  max-width: 680px;
}

.hero-actions {
  gap: 18px;
  margin-top: 32px;
}

.hero-actions span,
.next-step,
.muted {
  color: var(--muted);
}

.hero-image-wrap {
  border: 1px solid var(--line);
  border-radius: 8px;
  min-height: 420px;
  overflow: hidden;
}

.hero-image-wrap img {
  display: block;
  height: 100%;
  object-fit: cover;
  width: 100%;
}

.principles,
.page-intro,
.course-grid,
.chapter-list,
.auth-panel,
.description-band {
  padding: 56px clamp(20px, 5vw, 72px);
}

.principles {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.principles article,
.metrics article,
.course-tile,
.chapter-block,
.auth-form,
.empty-state,
.description-band {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 8px;
  box-shadow: var(--shadow);
}

.principles article {
  padding: 24px;
}

.principles span,
.chapter-heading span,
.lesson-row span {
  color: var(--coral);
  font-size: 12px;
  font-weight: 900;
  text-transform: uppercase;
}

.page-intro h1,
.course-header h1,
.auth-panel h1 {
  font-size: clamp(38px, 6vw, 72px);
}

.page-intro p,
.course-header p,
.auth-panel p,
.description-band p {
  color: var(--muted);
  line-height: 1.6;
  max-width: 760px;
}

.metrics {
  gap: 16px;
  padding: 0 clamp(20px, 5vw, 72px) 24px;
}

.metrics article {
  min-width: 160px;
  padding: 20px;
}

.metrics span {
  color: var(--green);
  display: block;
  font-size: 34px;
  font-weight: 900;
}

.metrics p {
  color: var(--muted);
  margin: 4px 0 0;
}

.course-grid {
  display: grid;
  gap: 18px;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  padding-top: 18px;
}

.course-tile {
  min-height: 240px;
  padding: 24px;
}

.course-tile-top,
.course-header,
.lesson-row,
.chapter-heading {
  justify-content: space-between;
}

.course-tile-top p {
  color: var(--teal);
  font-size: 12px;
  font-weight: 900;
  margin: 0;
  text-transform: uppercase;
}

.course-tile-top strong {
  color: var(--green);
}

.course-tile h2 {
  font-size: 28px;
  margin: 28px 0 12px;
}

.course-tile > p {
  color: var(--muted);
  line-height: 1.5;
}

.next-step {
  display: block;
  margin-top: 24px;
}

.empty-state {
  grid-column: 1 / -1;
  padding: 32px;
}

.course-header {
  gap: 24px;
  padding: 42px clamp(20px, 5vw, 72px);
}

.course-header > div {
  flex: 1;
}

.progress-ring {
  align-items: center;
  aspect-ratio: 1;
  background: #ffffff;
  border: 8px solid var(--yellow);
  border-radius: 50%;
  display: flex;
  flex: 0 0 150px;
  flex-direction: column;
  justify-content: center;
}

.progress-ring span {
  font-size: 34px;
  font-weight: 900;
}

.progress-ring small {
  color: var(--muted);
}

.description-band {
  margin: 0 clamp(20px, 5vw, 72px) 20px;
  padding: 24px;
}

.chapter-list {
  display: grid;
  gap: 22px;
  padding-top: 24px;
}

.chapter-block {
  overflow: hidden;
}

.chapter-heading {
  gap: 24px;
  padding: 24px;
}

.chapter-heading p {
  color: var(--muted);
  margin: 6px 0 0;
}

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

.lesson-row {
  gap: 18px;
  padding: 20px 24px;
}

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

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

.lesson-row.is-complete {
  background: #eef8f1;
}

.lesson-row strong {
  color: var(--green);
}

.auth-panel {
  align-items: start;
  display: grid;
  gap: 32px;
  grid-template-columns: minmax(0, 1fr) minmax(280px, 420px);
}

.auth-form {
  display: grid;
  gap: 10px;
  padding: 24px;
}

.auth-form input {
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 12px;
  width: 100%;
}

.auth-form label {
  font-weight: 800;
}

@media (max-width: 840px) {
  .site-header,
  .nav-links,
  .hero-actions,
  .course-header,
  .lesson-row,
  .chapter-heading,
  .metrics {
    align-items: flex-start;
    flex-direction: column;
  }

  .hero,
  .principles,
  .auth-panel {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

  .hero-image-wrap {
    min-height: 280px;
  }

  .progress-ring {
    flex-basis: 132px;
  }
}