:root {
  --bg: #ffffff;
  --text: #0f1013;
  --muted: #4a4e57;
  --border: #e6e7eb;
  --accent: #0f1013;
  --btn-text: #ffffff;
  --max-width: 1180px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Space Grotesk", "Segoe UI", sans-serif;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

main {
  flex: 1;
}

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

img {
  max-width: 100%;
  display: block;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  gap: 24px;
  padding: 18px 0;
}

.brand {
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
  flex: 1;
  font-weight: 600;
  font-size: 14px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.nav-links a {
  padding: 8px 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.nav-links a:hover {
  color: #1b1d23;
}

.nav-links .active {
  border-color: var(--accent);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 600;
  padding: 10px 16px;
  border-radius: 999px;
  border: 1px solid transparent;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn.primary {
  background: var(--accent);
  color: var(--btn-text);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
}

.btn.primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 26px rgba(0, 0, 0, 0.12);
}

.section {
  padding: 120px 0 70px;
}

.narrow {
  max-width: 760px;
}

.intro h1 {
  font-size: 36px;
  letter-spacing: 0.08em;
  margin: 0 0 16px;
}

.intro p {
  margin: 0;
  color: var(--muted);
  font-size: 18px;
}

.hero {
  position: relative;
  height: 85vh;
  min-height: 540px;
  margin: 0;
  background: url("assets/meta-rider-hero.png") center/cover no-repeat;
  box-shadow: 0 18px 38px rgba(0, 0, 0, 0.18);
}

.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(6, 7, 9, 0.35) 0%, rgba(8, 9, 12, 0.08) 45%, rgba(8, 9, 12, 0.38) 100%);
  pointer-events: none;
}

.hero .sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.content-card h1,
.content-card h2,
.content-card h3 {
  margin: 0 0 12px;
}

.content-card h1 {
  font-size: 34px;
}

.content-card h2 {
  font-size: 22px;
}

.content-card p {
  margin: 0 0 14px;
  color: var(--muted);
}

.content-card {
  background: #f9f9fb;
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  box-shadow: 0 10px 28px rgba(0, 0, 0, 0.06);
}

.site-footer {
  background: #f4f4f7;
  border-top: 1px solid var(--border);
  padding: 48px 0;
  margin-top: 70px;
}

.footer-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  align-items: center;
  gap: 16px;
  text-align: center;
}

.footer-title {
  font-weight: 700;
  letter-spacing: 0.06em;
}

.footer-link {
  font-weight: 600;
}

@media (max-width: 900px) {
  .nav {
    flex-wrap: wrap;
    gap: 16px;
  }

  .nav-links {
    order: 3;
    width: 100%;
    justify-content: center;
  }

  .btn.primary {
    order: 2;
    width: calc(100% - 20px);
    margin: 8px auto 0;
    padding: 12px 18px;
  }

  .intro h1 {
    font-size: 30px;
  }
}

@media (max-width: 640px) {
  .section {
    padding: 80px 0 50px;
  }

  .intro h1 {
    font-size: 26px;
  }

  .intro p {
    font-size: 16px;
  }

  .hero {
    min-height: 420px;
  }

  .content-card {
    padding: 24px;
  }
}