:root {
  --bg: #eef3f8;
  --bg-soft: #f7f9fc;
  --surface: rgba(255, 255, 255, 0.93);
  --surface-soft: #f5f8fc;
  --text: #152033;
  --muted: #425063;
  --muted-2: #5f6b7a;
  --border: rgba(21, 32, 51, 0.08);
  --shadow: 0 18px 52px rgba(25, 42, 70, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "SF Pro Text", "Suisse Int'l", "Inter", "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(161, 196, 255, 0.26), transparent 28%),
    linear-gradient(180deg, var(--bg-soft) 0%, var(--bg) 100%);
  line-height: 1.65;
}

a {
  color: inherit;
  text-underline-offset: 3px;
}

.seo-shell {
  width: min(100%, 960px);
  margin: 0 auto;
  padding: 72px 24px 96px;
}

.seo-hero,
.card {
  padding: 28px 30px;
  border: 1px solid var(--border);
  border-radius: 24px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.seo-hero h1 {
  margin: 0 0 18px;
  font-size: clamp(2.4rem, 5vw, 4.25rem);
  line-height: 1.04;
  letter-spacing: -0.04em;
}

.eyebrow {
  margin: 0 0 12px;
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted-2);
}

.lede,
.seo-hero p {
  max-width: 780px;
  color: var(--muted);
  font-size: 1.08rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 16px;
}

.subcard {
  padding: 20px;
  border-radius: 18px;
  background: var(--surface-soft);
  border: 1px solid var(--border);
}

.guide-card {
  text-decoration: none;
}

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

@media (max-width: 720px) {
  .seo-shell {
    padding: 32px 16px 64px;
  }

  .seo-hero,
  .card {
    padding: 22px 20px;
    border-radius: 20px;
  }

  .seo-hero h1 {
    font-size: 2.4rem;
  }
}