:root {
  color-scheme: light;
  --ink: #17212a;
  --muted: #607080;
  --paper: #f5f7f4;
  --sheet: #fffefa;
  --line: #cfd8df;
  --blue: #234056;
  --blue-soft: #dfeaf1;
  --green: #3f735a;
  --gold: #d6a23e;
  --rose: #b85a48;
  --field: #ffffff;
  --shadow: 0 16px 36px rgba(23, 33, 42, 0.12);
  font-family: "Aptos", "Segoe UI", "Helvetica Neue", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background:
    linear-gradient(90deg, rgba(35, 64, 86, 0.05) 1px, transparent 1px),
    linear-gradient(0deg, rgba(35, 64, 86, 0.045) 1px, transparent 1px),
    var(--paper);
  background-size: 28px 28px;
  color: var(--ink);
}

button,
input,
select,
textarea {
  font: inherit;
}

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

h1,
h2,
h3,
p,
dd,
dt,
button,
a,
input,
select,
textarea {
  overflow-wrap: anywhere;
}

.lesson-topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 12px clamp(16px, 4vw, 44px);
  border-bottom: 1px solid rgba(207, 216, 223, 0.95);
  background: rgba(245, 247, 244, 0.94);
  backdrop-filter: blur(14px);
}

.lesson-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: 0;
  font-weight: 900;
}

.lesson-brand span {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 7px;
  background: var(--blue);
  color: #fff1ad;
}

.lesson-topbar nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px;
}

.lesson-topbar nav a {
  padding: 9px 10px;
  color: var(--muted);
  font-weight: 850;
}

.lesson-hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(300px, 420px);
  gap: clamp(22px, 5vw, 62px);
  align-items: end;
  min-height: 54vh;
  padding: clamp(30px, 5vw, 62px) clamp(16px, 5vw, 58px) clamp(22px, 4vw, 42px);
  border-bottom: 1px solid var(--line);
  background:
    linear-gradient(120deg, rgba(63, 115, 90, 0.14), transparent 35%),
    linear-gradient(0deg, rgba(255, 254, 250, 0.72), rgba(255, 254, 250, 0));
}

.eyebrow {
  margin: 0;
  color: var(--rose);
  font-size: 0.76rem;
  font-weight: 950;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1 {
  max-width: 1040px;
  margin: 9px 0 14px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(2.8rem, 7vw, 7rem);
  line-height: 0.9;
  letter-spacing: 0;
}

h2 {
  margin: 8px 0 10px;
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(1.8rem, 4vw, 3.3rem);
  line-height: 0.98;
  letter-spacing: 0;
}

h3 {
  margin: 0 0 8px;
  font-size: 1rem;
}

.lede {
  max-width: 880px;
  color: var(--muted);
  font-size: clamp(1.04rem, 1.8vw, 1.28rem);
  line-height: 1.56;
}

.hero-actions,
.form-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

button,
.lesson-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0 15px;
  border: 1px solid var(--blue);
  border-radius: 7px;
  background: transparent;
  color: var(--blue);
  cursor: pointer;
  font-weight: 850;
  transition: transform 140ms ease-out, box-shadow 140ms ease-out, background 140ms ease-out;
}

button:hover,
.lesson-button:hover {
  transform: translateY(-1px);
  box-shadow: 0 9px 18px rgba(23, 33, 42, 0.15);
}

button:active,
.lesson-button:active {
  transform: translateY(0);
}

.primary,
.form-actions button:first-child {
  background: var(--blue);
  color: var(--sheet);
}

button:focus-visible,
a:focus-visible,
input:focus,
select:focus,
textarea:focus {
  outline: 3px solid rgba(63, 115, 90, 0.3);
  outline-offset: 2px;
}

.lesson-ledger,
.lesson-panel,
.lesson-sheet,
.validation-panel {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 254, 250, 0.97);
  box-shadow: var(--shadow);
}

.lesson-ledger {
  padding: 20px;
}

.lesson-ledger dl {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 16px 0 0;
}

.lesson-ledger div {
  min-height: 92px;
  padding: 14px;
  border: 1px solid rgba(207, 216, 223, 0.9);
  border-radius: 7px;
  background: #f8fbfd;
}

.lesson-ledger dt {
  color: var(--muted);
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
}

.lesson-ledger dd {
  margin: 6px 0 0;
  color: var(--green);
  font: 900 1.85rem/1 Georgia, "Times New Roman", serif;
}

.lesson-workflow {
  display: grid;
  grid-template-columns: minmax(340px, 540px) minmax(0, 1fr);
  gap: clamp(18px, 4vw, 34px);
  align-items: start;
  padding: clamp(18px, 5vw, 58px);
}

.lesson-panel {
  padding: clamp(16px, 3vw, 24px);
}

fieldset {
  margin: 0 0 20px;
  padding: 0;
  border: 0;
}

legend {
  margin-bottom: 12px;
  font: 900 1.15rem/1.2 Georgia, "Times New Roman", serif;
}

label {
  display: grid;
  gap: 6px;
  color: var(--muted);
  font-weight: 850;
}

input,
select,
textarea {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 7px;
  background: var(--field);
  color: var(--ink);
}

input,
select {
  min-height: 42px;
  padding: 0 10px;
}

textarea {
  min-height: 92px;
  padding: 10px;
  resize: vertical;
}

.field-pair {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin-bottom: 12px;
}

.field-pair.thirds {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.day-list {
  display: grid;
  gap: 12px;
}

.day-card {
  display: grid;
  grid-template-columns: minmax(86px, 0.7fr) minmax(130px, 1fr) minmax(180px, 1.3fr);
  gap: 10px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f8fbfd;
}

.day-card .wide {
  grid-column: span 2;
}

.status-message {
  min-height: 24px;
  margin: 14px 0 0;
  color: var(--green);
  font-weight: 900;
}

.fine-print {
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.9rem;
  line-height: 1.5;
}

.lesson-sheet {
  min-height: 720px;
  overflow: hidden;
}

.sheet-label {
  padding: 10px 16px;
  border-bottom: 1px solid var(--line);
  background: var(--blue-soft);
  color: var(--blue);
  font-size: 0.78rem;
  font-weight: 950;
  text-transform: uppercase;
}

.plan-document {
  padding: clamp(18px, 4vw, 34px);
  background:
    linear-gradient(90deg, rgba(214, 162, 62, 0.12) 0 8px, transparent 8px),
    var(--sheet);
}

.plan-header {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 18px;
  border-bottom: 3px solid var(--blue);
}

.plan-header span {
  align-self: start;
  padding: 8px 10px;
  border-radius: 7px;
  background: var(--blue-soft);
  color: var(--blue);
  font-weight: 900;
}

.plan-header p,
.plan-block p,
.week-table p {
  color: var(--muted);
  line-height: 1.52;
}

.plan-block,
.week-table article {
  margin-top: 16px;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
}

.plan-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.week-table {
  display: grid;
  gap: 10px;
}

.week-table strong {
  color: var(--blue);
}

.week-table span {
  color: var(--ink);
  font-weight: 900;
}

.validation-panel {
  display: grid;
  grid-template-columns: minmax(260px, 0.8fr) minmax(0, 1.2fr);
  gap: clamp(18px, 4vw, 34px);
  margin: 0 clamp(18px, 5vw, 58px) clamp(28px, 5vw, 58px);
  padding: clamp(18px, 4vw, 30px);
}

.validation-copy p {
  margin: 0 0 12px;
  color: var(--muted);
  line-height: 1.62;
}

.validation-copy a {
  color: var(--blue);
  font-weight: 900;
  text-decoration: underline;
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.sample-workflow {
  grid-template-columns: minmax(0, 1fr) minmax(320px, 430px);
}

@media (max-width: 980px) {
  .lesson-hero,
  .lesson-workflow,
  .validation-panel,
  .sample-workflow {
    grid-template-columns: 1fr;
  }

  .lesson-hero {
    min-height: auto;
  }

  .field-pair,
  .field-pair.thirds,
  .plan-grid,
  .day-card {
    grid-template-columns: 1fr;
  }

  .day-card .wide {
    grid-column: auto;
  }
}

@media (max-width: 640px) {
  .lesson-topbar {
    align-items: flex-start;
    flex-direction: column;
  }

  .lesson-topbar nav {
    justify-content: flex-start;
  }

  .hero-actions,
  .form-actions {
    flex-direction: column;
  }

  button,
  .lesson-button {
    width: 100%;
  }

  .lesson-workflow,
  .validation-panel {
    padding-inline: 14px;
    margin-inline: 14px;
  }

  h1 {
    font-size: clamp(2.45rem, 18vw, 4rem);
  }
}

@media print {
  .lesson-topbar,
  .lesson-panel,
  .validation-panel,
  .lesson-hero {
    display: none;
  }

  body {
    background: #fff;
  }

  .lesson-workflow,
  .lesson-sheet {
    display: block;
    padding: 0;
    border: 0;
    box-shadow: none;
  }
}