:root {
  --go-blue: #00add8;
  --go-blue-dark: #007d9c;
  --navy: #0b2533;
  --ink: #13303d;
  --paper: #f7fbfd;
  --card: #ffffff;
  --accent: #ffd84d;
  --radius: 16px;
  --maxw: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
}

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

a { color: var(--go-blue-dark); }

/* hero */
.hero {
  background: radial-gradient(1200px 500px at 80% -10%, #d8f4fd 0%, transparent 60%),
              linear-gradient(160deg, #ffffff 0%, #e9f7fc 100%);
  border-bottom: 4px solid var(--go-blue);
  padding: 56px 0 40px;
}
.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 40px;
  align-items: center;
}
.eyebrow {
  text-transform: uppercase;
  letter-spacing: .14em;
  font-weight: 700;
  color: var(--go-blue-dark);
  margin: 0 0 8px;
  font-size: .85rem;
}
h1 {
  font-size: clamp(2.4rem, 6vw, 4rem);
  line-height: 1.02;
  margin: 0 0 16px;
  color: var(--navy);
  letter-spacing: -0.5px;
}
.tagline { font-size: 1.25rem; margin: 0 0 28px; max-width: 32ch; }
.hero-art img {
  width: 100%;
  height: auto;
  filter: drop-shadow(0 18px 30px rgba(0, 125, 156, .25));
}

/* buttons */
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; }
.btn {
  display: inline-block;
  padding: 13px 22px;
  border-radius: 999px;
  font-weight: 700;
  text-decoration: none;
  transition: transform .08s ease, box-shadow .2s ease;
}
.btn:active { transform: translateY(1px); }
.btn-primary {
  background: var(--go-blue);
  color: #fff;
  box-shadow: 0 8px 18px rgba(0, 173, 216, .35);
}
.btn-primary:hover { background: var(--go-blue-dark); }
.btn-ghost {
  background: #fff;
  color: var(--go-blue-dark);
  border: 2px solid var(--go-blue);
}
.btn-ghost:hover { background: #eef9fd; }

/* sections */
.section { padding: 56px 0; }
.section h2 {
  font-size: clamp(1.6rem, 3.5vw, 2.2rem);
  color: var(--navy);
  margin: 0 0 20px;
}
.lead { font-size: 1.1rem; max-width: 70ch; }
.section h3 {
  color: var(--navy);
  font-size: 1.2rem;
  margin: 26px 0 8px;
}

/* cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-top: 8px;
}
.card {
  background: var(--card);
  border: 1px solid #d9edf4;
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: 0 6px 16px rgba(11, 37, 51, .05);
}
.card-num {
  display: inline-block;
  font-weight: 800;
  color: var(--go-blue);
  font-size: .9rem;
  letter-spacing: .1em;
}
.card h3 { margin: 6px 0 6px; color: var(--navy); font-size: 1.15rem; }
.card p { margin: 0; color: #3d5765; }
.card-covers {
  margin-top: 14px !important;
  padding-top: 12px;
  border-top: 1px dashed #cfe6ef;
}
.card-covers span {
  display: inline-block;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: .08em;
  font-size: .72rem;
  color: var(--go-blue);
}
.card-covers-list {
  margin: 6px 0 0;
  padding-left: 18px;
  font-size: .85rem;
  color: #5a7280;
  line-height: 1.45;
}
.card-covers-list li { margin: 2px 0; }
.card-covers-list code { font-size: .82em; }

/* code */
code {
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  background: #e7f4f9;
  color: var(--go-blue-dark);
  padding: 2px 6px;
  border-radius: 6px;
  font-size: .95em;
}
pre {
  background: var(--navy);
  color: #eafaff;
  padding: 18px 20px;
  border-radius: 12px;
  overflow-x: auto;
  box-shadow: 0 10px 24px rgba(11, 37, 51, .18);
}
pre code { background: none; color: inherit; padding: 0; }
.note { font-size: 1.05rem; font-weight: 600; color: var(--go-blue-dark); }

/* footer */
.footer {
  background: var(--navy);
  color: #cfe7f0;
  padding: 32px 0;
  margin-top: 24px;
}
.footer a { color: #7fd6ee; }
.footer .muted { color: #7f9aab; margin: 6px 0 0; }

@media (max-width: 820px) {
  .hero-grid { grid-template-columns: 1fr; }
  .hero-art { order: -1; }
}