feat(styles): remove cream-section alias, add button-center utility, make h3 font-size fluid

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

www/src/styles/layout.css

@@ -9,11 +9,11 @@ img { display: block; height: auto; max-width: 100%; }
 .section-tint, .page-header { background: var(--color-tint); }
 .section-heading { margin-bottom: var(--space-lg); max-width: 700px; }
 .split { align-items: center; display: flex; gap: var(--space-lg); justify-content: space-between; }
+.button-center { margin-block: 2.5rem; margin-inline-start: 50%; translate: -50%; }
 .card-grid { display: grid; gap: var(--space-lg); grid-template-columns: repeat(3, minmax(0, 1fr)); }
 .skip-link { background: white; left: 1rem; padding: .75rem; position: fixed; top: -10rem; z-index: 100; }
 .skip-link:focus { top: 1rem; }
 .page-header { padding-block: var(--space-xl); text-align: center; }
 .feature-grid { align-items: center; display: grid; gap: clamp(2rem, 6vw, 5rem); grid-template-columns: 1fr 1fr; }
-.cream-section { background: var(--color-tint); }
 @media (max-width: 850px) { .card-grid { grid-template-columns: 1fr; } .split { align-items: flex-start; flex-direction: column; } }
 @media (max-width: 760px) { .feature-grid { grid-template-columns: 1fr; } }

www/src/styles/typography.css

@@ -7,7 +7,7 @@ h1, h2, h3 { color: var(--color-primary); font-family: var(--font-heading); line
 .no-balance { text-wrap: auto; }
 h1 { font-size: clamp(2.5rem, 5vw, 3rem); line-height: 1.12; margin: 0 0 var(--space-md); }
 h2 { font-size: clamp(2rem, 4vw, 2.4rem); line-height: 1.25; }
-h3 { font-size: 1.5rem; }
+h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
 a { color: var(--color-primary); }
 .eyebrow { color: var(--color-secondary); font-size: .8rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; }
 .lede, .hero-copy { color: var(--color-muted); font-size: 1.25rem; }