:root {
  color-scheme: light;
  --ink: #20242a;
  --muted: #5b6573;
  --paper: #f4f6f1;
  --surface: #ffffff;
  --soft: #e8ede4;
  --line: #d2d9cf;
  --accent: #2f6b52;
  --accent-dark: #224d3d;
  --red: #b95745;
  --blue: #315f86;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Arial, Helvetica, sans-serif;
  line-height: 1.55;
}

a {
  color: inherit;
}

.site-header {
  background: #1f2a27;
  color: #fff;
}

nav {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 18px 0;
  display: flex;
  justify-content: flex-end;
  gap: 22px;
  font-size: 0.95rem;
}

nav a,
.site-footer a {
  text-decoration: none;
  font-weight: 700;
}

.hero {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 82px 0 96px;
}

.kicker,
.label {
  margin: 0 0 10px;
  color: var(--red);
  font-size: 0.78rem;
  font-weight: 800;
  text-transform: uppercase;
}

.site-header .kicker {
  color: #ffb29f;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  max-width: 900px;
  margin-bottom: 18px;
  font-size: clamp(3rem, 7vw, 6.2rem);
  line-height: 1.02;
}

h2 {
  margin-bottom: 14px;
  font-size: clamp(2rem, 4vw, 3.2rem);
  line-height: 1.08;
}

h3 {
  margin-bottom: 10px;
  font-size: 1.18rem;
}

p,
li,
td {
  color: var(--muted);
}

.hero p {
  max-width: 820px;
  color: rgba(255, 255, 255, 0.84);
  font-size: 1.18rem;
}

main {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
}

.section,
.case-section {
  padding: 72px 0;
  border-bottom: 1px solid var(--line);
}

.section-heading {
  max-width: 820px;
  margin-bottom: 28px;
}

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

.overview-grid article,
.thinking-block,
.stat-card,
.score-card,
.task-table,
.video-compare article {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.overview-grid article,
.thinking-block,
.stat-card,
.score-card,
.task-table {
  padding: 24px;
}

.overview-stats {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 12px;
  margin-top: 18px;
}

.overview-stats span {
  padding: 16px;
  background: var(--soft);
  border-radius: 8px;
  color: var(--muted);
}

strong {
  color: var(--ink);
}

.case-header {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 230px;
  gap: 28px;
  align-items: end;
  margin-bottom: 24px;
}

.case-header > div:first-child {
  max-width: 820px;
}

.score-card span {
  display: block;
  color: var(--muted);
  font-weight: 700;
}

.score-card strong {
  display: block;
  margin: 8px 0;
  color: var(--accent);
  font-size: 3.2rem;
  line-height: 1;
}

.score-card p {
  margin-bottom: 0;
}

.thinking-block {
  margin-bottom: 24px;
}

.thinking-block ol {
  max-width: 920px;
}

.stat-grid {
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin-bottom: 24px;
}

.stat-card span {
  display: block;
  min-height: 42px;
  color: var(--muted);
  font-weight: 700;
}

.stat-card strong {
  display: block;
  margin-top: 12px;
  color: var(--accent);
  font-size: 2rem;
  line-height: 1;
}

ol,
ul {
  margin-bottom: 0;
  padding-left: 22px;
}

li + li {
  margin-top: 10px;
}

table {
  width: 100%;
  border-collapse: collapse;
}

th,
td {
  padding: 12px 8px;
  border-bottom: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th {
  color: var(--ink);
  font-size: 0.82rem;
  text-transform: uppercase;
}

td:last-child {
  color: var(--blue);
  font-weight: 800;
}

.task-table {
  margin-bottom: 24px;
}

.task-table table {
  margin-top: 8px;
}

.video-compare {
  grid-template-columns: repeat(2, minmax(0, 1fr));
  align-items: start;
}

.video-copy {
  padding: 22px 22px 10px;
}

.video-copy p:last-child {
  margin-bottom: 0;
}

video {
  width: 100%;
  display: block;
  background: #0d1117;
  border-top: 1px solid var(--line);
}

.site-footer {
  width: min(1180px, calc(100% - 32px));
  margin: 0 auto;
  padding: 30px 0 42px;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  color: var(--accent-dark);
}

@media (max-width: 900px) {
  nav {
    justify-content: flex-start;
  }

  .overview-grid,
  .overview-stats,
  .stat-grid,
  .case-header,
  .video-compare {
    grid-template-columns: 1fr;
  }

  .score-card {
    width: min(100%, 340px);
  }
}

@media (max-width: 640px) {
  .hero {
    padding: 54px 0 64px;
  }

  .section,
  .case-section {
    padding: 52px 0;
  }

  nav {
    overflow-x: auto;
    white-space: nowrap;
  }
}