* { box-sizing: border-box; }

:root {
  --blue: #0066cc;
  --ink: #1d1d1f;
  --muted: #6e6e73;
  --canvas: #f5f5f7;
  --surface: #fff;
  --hairline: #d2d2d7;
}

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--canvas);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI", sans-serif;
  line-height: 1.72;
}

a { color: var(--blue); text-decoration: none; }
a:hover { text-decoration: underline; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid rgba(210, 210, 215, 0.82);
  background: rgba(245, 245, 247, 0.86);
  backdrop-filter: blur(18px);
}

.nav {
  width: min(100%, 1040px);
  height: 64px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  color: var(--ink);
  font-weight: 800;
}

.nav-links,
.footer-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px;
  font-size: 14px;
  font-weight: 650;
}

.page {
  width: min(100%, 920px);
  margin: 0 auto;
  padding: 42px 20px 72px;
}

.hero-copy {
  padding: 34px 0 18px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 700;
}

h1 {
  max-width: 820px;
  margin: 0;
  font-size: clamp(34px, 5vw, 58px);
  line-height: 1.04;
  letter-spacing: 0;
}

.lead {
  max-width: 760px;
  margin: 18px 0 0;
  color: #3a3a3c;
  font-size: 18px;
}

.content-card {
  margin-top: 22px;
  padding: 30px;
  border: 1px solid rgba(210, 210, 215, 0.72);
  border-radius: 24px;
  background: var(--surface);
}

h2 {
  margin: 28px 0 10px;
  font-size: 26px;
  line-height: 1.22;
}

h3 {
  margin: 22px 0 8px;
  font-size: 20px;
  line-height: 1.25;
}

p, li { color: #3a3a3c; }

ul, ol {
  padding-left: 22px;
}

.link-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin-top: 18px;
}

.link-grid a,
.button-link {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 14px;
  border: 1px solid var(--hairline);
  border-radius: 999px;
  background: #fff;
  font-weight: 700;
}

.button-link.primary {
  border-color: var(--blue);
  background: var(--blue);
  color: #fff;
}

.source-list {
  font-size: 14px;
}

.ad-area {
  margin-top: 46px;
  padding-top: 24px;
  border-top: 1px solid var(--hairline);
}

.ad-label {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
}

.ad-slot {
  width: min(100%, 728px);
  min-height: 100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.ad-slot .adsbygoogle {
  display: block;
  width: 728px;
  max-width: 100%;
  min-height: 90px;
}

.site-footer {
  border-top: 1px solid var(--hairline);
  padding: 26px 20px 34px;
  color: var(--muted);
  text-align: center;
  font-size: 13px;
}

.footer-links {
  justify-content: center;
  margin-bottom: 10px;
}

@media (max-width: 640px) {
  .nav {
    height: auto;
    padding: 14px;
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }

  .page { padding-top: 24px; }
  .content-card { padding: 22px; border-radius: 20px; }
  .link-grid { grid-template-columns: 1fr; }
  .ad-slot, .ad-slot .adsbygoogle { width: 320px; min-height: 100px; }
}