:root {
  --bf-color-text: #1a1a1a;
  --bf-color-muted: #5a5a5a;
  --bf-color-border: #e2e2e2;
  --bf-color-bg-alt: #f7f7f5;
  --bf-color-accent: #1a1a1a;
  --bf-space: 1rem;
  --bf-max-width: 64rem;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--bf-color-text);
  line-height: 1.5;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
}

.skip-link:focus {
  left: 0;
  background: #fff;
  padding: 0.5rem 1rem;
  z-index: 100;
}

.wrap {
  max-width: var(--bf-max-width);
  margin: 0 auto;
  padding: 0 var(--bf-space);
}

.site-header {
  border-bottom: 1px solid var(--bf-color-border);
}

.site-header-inner {
  padding: var(--bf-space) 0;
}

main:not(:has(.hero)) {
  display: block;
  max-width: var(--bf-max-width);
  margin: 0 auto;
  padding: calc(var(--bf-space) * 2) var(--bf-space);
}

.site-brand {
  font-size: 1.5rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--bf-color-text);
}

.hero {
  padding: calc(var(--bf-space) * 4) 0 calc(var(--bf-space) * 3);
  text-align: center;
}

.hero h1 {
  font-size: 2.5rem;
  margin: 0 0 var(--bf-space);
}

.hero-sub {
  max-width: 40rem;
  margin: 0 auto;
  color: var(--bf-color-muted);
  font-size: 1.1rem;
}

.tracks {
  padding: calc(var(--bf-space) * 2) 0;
  background: var(--bf-color-bg-alt);
}

.tracks-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: calc(var(--bf-space) * 1.5);
  padding-top: var(--bf-space);
  padding-bottom: var(--bf-space);
}

.track-card {
  background: #fff;
  border: 1px solid var(--bf-color-border);
  border-radius: 0.5rem;
  padding: calc(var(--bf-space) * 1.5);
}

.track-card h2 {
  margin-top: 0;
}

.btn {
  display: inline-block;
  padding: 0.6rem 1.2rem;
  border-radius: 0.3rem;
  text-decoration: none;
  font-weight: 600;
}

.btn-primary {
  background: var(--bf-color-accent);
  color: #fff;
}

.about {
  padding: calc(var(--bf-space) * 3) 0;
}

.feature-list {
  padding-left: 1.25rem;
}

.feature-list li {
  margin-bottom: 0.5rem;
}

.site-footer {
  border-top: 1px solid var(--bf-color-border);
  margin-top: calc(var(--bf-space) * 2);
  padding: var(--bf-space) 0;
  color: var(--bf-color-muted);
  text-align: center;
}

.text-danger {
  color: #b00020;
}

@media (max-width: 40rem) {
  .hero h1 {
    font-size: 2rem;
  }
}