:root {
  color-scheme: light;
  --ink: #182026;
  --muted: #596873;
  --rule: #d7e0e5;
  --panel: #f4f8fa;
  --accent: #1f6f8b;
  --accent-dark: #174f63;
}
body {
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
  color: var(--ink);
  background: #ffffff;
}
.site-masthead {
  background: linear-gradient(rgba(248, 251, 252, 0.92), rgba(248, 251, 252, 0.92)), url("cog.png") 0 0 / 25px 25px repeat;
  border-bottom: 1px solid var(--rule);
}

.site-masthead-inner {
  align-items: center;
  display: flex;
  gap: 28px;
  justify-content: space-between;
  margin: 0 auto;
  max-width: 1220px;
  min-height: 112px;
  padding: 22px 32px;
}

.brand-lockup {
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.logo {
  display: inline-flex;
  line-height: 0;
}

.logo img {
  display: block;
  height: auto;
  width: clamp(154px, 16vw, 218px);
}

.logo-sub {
  color: var(--accent-dark);
  font-size: 1.02rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.site-nav {
  margin-top: 0;
  align-items: center;
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  justify-content: flex-end;
}

.site-nav a,
.site-nav button {
  color: var(--ink);
  font: inherit;
}

.site-nav a {
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a.active {
  color: var(--accent-dark);
}

.site-nav a.active {
  font-weight: 700;
}

.site-nav button {
  background: transparent;
  border: 0;
  cursor: pointer;
  padding: 0;
}

.course-link {
  background: var(--accent);
  border-radius: 999px;
  color: #fff !important;
  font-weight: 700;
  padding: 12px 18px;
}

@media (max-width: 720px) {
  .site-masthead-inner {
    align-items: flex-start;
    flex-direction: column;
  }

  .site-nav {
    justify-content: flex-start;
    gap: 12px;
  }
}
main, footer {
  max-width: 1040px;
  margin: 0 auto;
  padding: 24px;
}
header:not(.site-masthead) {
  max-width: 1040px;
  margin: 0 auto;
  padding: 24px;
  border-bottom: 1px solid var(--rule);
}
.site-title {
  margin: 0;
  font-size: 28px;
  font-weight: 700;
}
nav {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 14px;
}
a {
  color: var(--accent-dark);
}
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-top: 24px;
}
.card {
  border: 1px solid var(--rule);
  border-radius: 8px;
  padding: 16px;
  background: var(--panel);
}
.card h2, .card h3 {
  margin-top: 0;
}
footer {
  border-top: 1px solid var(--rule);
  color: var(--muted);
  font-size: 14px;
}