Add site landing page

site/decodal-site/src/style.css

@@ -458,6 +458,99 @@ button:disabled {
   white-space: nowrap;
 }
 
+.frontpage {
+  max-width: 1120px;
+  margin: 0 auto;
+}
+
+.hero {
+  padding: 5rem 0 4rem;
+}
+
+.eyebrow {
+  color: var(--muted);
+  font-size: 0.9rem;
+  font-weight: 700;
+  letter-spacing: 0.08em;
+  margin: 0 0 1rem;
+  text-transform: uppercase;
+}
+
+.hero h1 {
+  font-size: clamp(2.4rem, 6vw, 5rem);
+  line-height: 0.95;
+  letter-spacing: -0.06em;
+  margin: 0;
+  max-width: 950px;
+}
+
+.hero-copy {
+  color: var(--muted);
+  font-size: 1.2rem;
+  line-height: 1.7;
+  max-width: 760px;
+  margin: 1.5rem 0 0;
+}
+
+.hero-actions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 0.9rem;
+  margin-top: 2rem;
+}
+
+.button {
+  border-radius: 999px;
+  font-weight: 700;
+  padding: 0.8rem 1.15rem;
+  text-decoration: none;
+}
+
+.button.primary {
+  background: var(--link);
+  color: #ffffff;
+}
+
+.button.secondary {
+  border: 1px solid var(--border);
+  color: var(--text);
+}
+
+.home-grid {
+  display: grid;
+  gap: 1rem;
+  grid-template-columns: repeat(3, minmax(0, 1fr));
+  margin-bottom: 1.5rem;
+}
+
+.home-card,
+.home-example {
+  background: var(--surface);
+  border: 1px solid var(--border);
+  border-radius: 18px;
+  padding: 1.4rem;
+}
+
+.home-card h2,
+.home-example h2 {
+  margin-top: 0;
+}
+
+.home-card p:last-child,
+.home-example p:last-child {
+  margin-bottom: 0;
+}
+
+.home-example {
+  display: grid;
+  gap: 1.5rem;
+  grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
+}
+
+.home-example pre {
+  margin: 0;
+}
+
 @media (max-width: 900px) {
   .layout {
     grid-template-columns: 1fr;
@@ -467,7 +560,12 @@ button:disabled {
     border-right: 0;
     max-height: 260px;
   }
-  .playground-shell {
+  .playground-shell,
+  .home-grid,
+  .home-example {
     grid-template-columns: 1fr;
   }
+  .hero {
+    padding-top: 3rem;
+  }
 }