:root {
  --tc-ink: #16313b;
  --tc-muted: #4f6870;
  --tc-accent: #0e8b7f;
  --tc-accent-soft: #dff3ee;
  --tc-accent-strong: #0b5e59;
  --tc-bg: #f7f5ef;
  --tc-card: rgba(255, 255, 255, 0.86);
  --tc-line: #bfd7d1;
  --tc-dark: #10242c;
  --tc-warning: #b5651d;
  --tc-danger: #ab2f2f;
  --tc-success: #1f6d4a;
  --shadow: 0 18px 40px rgba(16, 36, 44, 0.08);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: "Aptos", "Segoe UI", "Helvetica Neue", sans-serif;
  color: var(--tc-ink);
  line-height: 1.45;
  background:
    radial-gradient(circle at top right, rgba(14, 139, 127, 0.08), transparent 24%),
    linear-gradient(180deg, #fbfaf6 0%, var(--tc-bg) 100%);
}

.hero {
  background:
    radial-gradient(circle at top left, rgba(126, 232, 209, 0.15), transparent 22%),
    radial-gradient(circle at bottom right, rgba(14, 139, 127, 0.28), transparent 28%),
    linear-gradient(145deg, #10242c 0%, #173b45 45%, #0f6f68 100%);
  color: #f6fbfa;
}

.hero__inner {
  width: min(1200px, calc(100% - 32px));
  margin: 0 auto;
  padding: 56px 0 48px;
  display: grid;
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
  gap: 28px;
  align-items: stretch;
}

.eyebrow {
  margin: 0 0 10px;
  text-transform: uppercase;
  letter-spacing: 0.14em;
  font-size: 0.8rem;
  opacity: 0.84;
}

.hero__copy {
  min-width: 0;
}

.hero h1 {
  margin: 0 0 18px;
  font-size: clamp(2rem, 4vw, 3.6rem);
  line-height: 1.05;
  font-family: "Aptos Display", "Aptos", "Segoe UI", "Helvetica Neue", sans-serif;
  letter-spacing: -0.03em;
  display: inline-block;
  padding-bottom: 0.18em;
  border-bottom: 5px solid rgba(246, 251, 250, 0.92);
}

.hero__lead {
  max-width: 42rem;
  margin: 0;
  font-size: 1.08rem;
  line-height: 1.6;
  color: rgba(246, 251, 250, 0.92);
}

.layout {
  width: min(1320px, calc(100% - 32px));
  margin: 0 auto;
  padding: 28px 0 40px;
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 24px;
}

h1,
h2,
h3 {
  font-family: "Aptos Display", "Aptos", "Segoe UI", "Helvetica Neue", sans-serif;
  letter-spacing: -0.02em;
}

.panel,
.module-card,
.question-card,
.callout,
.summary-card {
  background: var(--tc-card);
  border: 1px solid var(--tc-line);
  border-radius: 20px;
  box-shadow: var(--shadow);
}

.panel {
  padding: 18px;
}

.panel--sticky {
  position: sticky;
  top: 18px;
}

.hero__progress {
  background: rgba(246, 251, 250, 0.12);
  border-color: rgba(223, 243, 238, 0.24);
  color: #f6fbfa;
  backdrop-filter: blur(8px);
  width: 100%;
  min-width: 0;
  align-self: start;
  padding: 16px 16px 14px;
}

.hero__progress-head {
  margin-bottom: 12px;
}

.hero__progress-kicker {
  margin: 0 0 4px;
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(246, 251, 250, 0.72);
}

.hero__progress h2,
.panel.hero__progress h2 {
  margin: 0;
  color: #f6fbfa;
}

.panel h2,
.content h2,
.content h3 {
  margin-top: 0;
  color: var(--tc-ink);
}

.stats {
  display: grid;
  gap: 12px;
  margin-bottom: 16px;
}

.hero__progress .stats {
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 10px;
  margin-bottom: 12px;
}

.stat {
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(14, 139, 127, 0.08);
}

.hero__progress .stat {
  background: rgba(246, 251, 250, 0.1);
  padding: 10px 10px 9px;
}

.stat__label {
  display: block;
  font-size: 0.85rem;
  color: var(--tc-muted);
  margin-bottom: 4px;
}

.hero__progress .stat__label {
  color: rgba(246, 251, 250, 0.78);
}

.stat strong {
  font-size: 1.2rem;
}

.hero__progress .stat strong {
  color: #f6fbfa;
  font-size: 1.05rem;
}

.progress-bar {
  height: 10px;
  border-radius: 999px;
  background: rgba(16, 36, 44, 0.1);
  overflow: hidden;
  margin-bottom: 16px;
}

.hero__progress .progress-bar {
  background: rgba(246, 251, 250, 0.14);
  margin-bottom: 12px;
}

.progress-bar__fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--tc-accent) 0%, #34b5a2 100%);
  transition: width 180ms ease;
}

.button {
  appearance: none;
  border: 0;
  border-radius: 999px;
  padding: 10px 16px;
  font: inherit;
  cursor: pointer;
  transition: transform 120ms ease, background 120ms ease, color 120ms ease;
}

.button:hover {
  transform: translateY(-1px);
}

.button--ghost {
  width: 100%;
  color: var(--tc-accent-strong);
  background: rgba(14, 139, 127, 0.1);
}

.hero__progress .button--ghost {
  color: #f6fbfa;
  background: rgba(246, 251, 250, 0.12);
  padding: 9px 14px;
}

.hero__progress .button--ghost:hover {
  background: rgba(246, 251, 250, 0.18);
}

.module-nav {
  display: grid;
  gap: 10px;
}

.module-nav__button {
  width: 100%;
  text-align: left;
  padding: 14px 14px 12px;
  border: 1px solid var(--tc-line);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.82);
  color: var(--tc-ink);
  cursor: pointer;
}

.module-nav__button:hover {
  border-color: var(--tc-accent);
}

.module-nav__button.is-active {
  background: var(--tc-accent-soft);
  border-color: var(--tc-accent);
}

.module-nav__top {
  display: flex;
  justify-content: space-between;
  gap: 10px;
  align-items: center;
  margin-bottom: 8px;
}

.module-nav__title {
  font-weight: 700;
}

.module-nav__meta {
  font-size: 0.85rem;
  color: var(--tc-muted);
}

.module-nav__badge {
  flex: 0 0 auto;
  padding: 4px 8px;
  border-radius: 999px;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--tc-accent-strong);
  background: rgba(14, 139, 127, 0.1);
}

.content {
  min-width: 0;
}

.module-card {
  padding: 28px;
  margin-bottom: 18px;
}

.module-card__header {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 12px;
}

.module-card__actions {
  display: grid;
  gap: 10px;
  justify-items: end;
  flex: 0 0 auto;
}

.module-card__header h2 {
  margin-bottom: 8px;
}

.module-card__summary {
  margin: 0;
  color: var(--tc-muted);
  line-height: 1.55;
}

.module-card__tag {
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--tc-accent-soft);
  color: var(--tc-accent-strong);
  font-weight: 700;
  font-size: 0.85rem;
}

.button--module-reset {
  width: auto;
  min-width: 150px;
}

.two-column {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 18px;
}

.callout {
  padding: 18px;
}

.callout h3 {
  margin-bottom: 10px;
}

.callout ul {
  margin: 0;
  padding-left: 18px;
  line-height: 1.5;
}

.question-list {
  display: grid;
  gap: 16px;
}

.question-card {
  padding: 20px;
}

.question-card__top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  align-items: flex-start;
  margin-bottom: 12px;
}

.question-card__label {
  display: inline-block;
  margin-bottom: 8px;
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--tc-accent-strong);
  background: rgba(14, 139, 127, 0.12);
  border-radius: 999px;
  padding: 4px 10px;
}

.question-card__status {
  flex: 0 0 auto;
  border-radius: 999px;
  padding: 6px 10px;
  font-size: 0.8rem;
  font-weight: 700;
  background: rgba(16, 36, 44, 0.08);
  color: var(--tc-muted);
}

.question-card__status.is-correct {
  background: rgba(31, 109, 74, 0.12);
  color: var(--tc-success);
}

.question-card__status.is-wrong {
  background: rgba(171, 47, 47, 0.12);
  color: var(--tc-danger);
}

.question-card p {
  margin-top: 0;
  line-height: 1.5;
}

.options {
  display: grid;
  gap: 10px;
}

.option {
  width: 100%;
  text-align: left;
  border: 1px solid var(--tc-line);
  background: rgba(255, 255, 255, 0.88);
  border-radius: 14px;
  padding: 12px 14px;
  font: inherit;
  color: var(--tc-ink);
  cursor: pointer;
}

.option:hover {
  border-color: var(--tc-accent);
}

.option:disabled {
  cursor: not-allowed;
  opacity: 1;
}

.option:disabled:hover {
  border-color: var(--tc-line);
}

.option.is-selected {
  border-color: var(--tc-dark);
}

.option.is-correct {
  border-color: var(--tc-success);
  background: rgba(31, 109, 74, 0.08);
}

.option.is-wrong {
  border-color: var(--tc-danger);
  background: rgba(171, 47, 47, 0.08);
}

.feedback {
  margin-top: 12px;
  padding: 12px 14px;
  border-radius: 14px;
  background: rgba(16, 36, 44, 0.05);
  line-height: 1.5;
}

.feedback.is-correct {
  background: rgba(31, 109, 74, 0.08);
}

.feedback.is-wrong {
  background: rgba(171, 47, 47, 0.08);
}

.summary-card {
  padding: 18px 20px;
  margin-top: 18px;
}

.summary-card strong {
  color: var(--tc-accent-strong);
}

.button:disabled {
  cursor: not-allowed;
  opacity: 0.55;
  transform: none;
}

.button:disabled:hover {
  transform: none;
}

@media (max-width: 860px) {
  .hero__inner,
  .layout {
    grid-template-columns: 1fr;
  }

  .panel--sticky {
    position: static;
  }

  .two-column {
    grid-template-columns: 1fr;
  }

  .hero__progress {
    max-width: 520px;
  }

  .hero__progress .stats {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .hero__inner,
  .layout {
    width: min(100% - 20px, 100%);
  }

  .hero__inner {
    padding: 42px 0 36px;
  }

  .module-card,
  .question-card,
  .panel,
  .callout,
  .summary-card {
    padding: 16px;
  }

  .module-card__header,
  .question-card__top {
    flex-direction: column;
  }

  .hero h1 {
    font-size: clamp(2rem, 9vw, 2.8rem);
  }
}