feat: add foreign key constraints and metrics for blockchain node

apps/explorer-web/public/css/layout.css

@@ -6,6 +6,45 @@
   z-index: 1000;
 }
 
+@media (max-width: 600px) {
+  .page {
+    padding: 1.5rem 1rem 3rem;
+  }
+
+  .site-header__inner {
+    flex-direction: column;
+    align-items: flex-start;
+  }
+
+  .site-header__controls {
+    align-items: stretch;
+    gap: 0.5rem;
+  }
+
+  .site-header__nav {
+    gap: 0.5rem;
+  }
+
+  .site-header__nav a {
+    flex: 1 1 45%;
+    text-align: center;
+  }
+
+  .addresses__input-group,
+  .receipts__input-group {
+    flex-direction: column;
+  }
+
+  .toast-container {
+    left: 0;
+    right: 0;
+    top: auto;
+    bottom: 1rem;
+    width: min(90vw, 360px);
+    margin: 0 auto;
+  }
+}
+
 .site-header__inner {
   margin: 0 auto;
   max-width: 1200px;
@@ -80,6 +119,37 @@
   padding: 2rem 1.5rem 4rem;
 }
 
+.toast-container {
+  position: fixed;
+  top: 1.25rem;
+  right: 1.25rem;
+  display: grid;
+  gap: 0.75rem;
+  z-index: 1200;
+}
+
+.toast {
+  opacity: 0;
+  transform: translateY(-6px);
+  transition: opacity 150ms ease, transform 180ms ease;
+  border-radius: 0.75rem;
+  padding: 0.75rem 1rem;
+  font-size: 0.9rem;
+  min-width: 220px;
+}
+
+.toast--error {
+  background: rgba(255, 102, 102, 0.16);
+  border: 1px solid rgba(255, 102, 102, 0.35);
+  color: #ffd3d3;
+  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
+}
+
+.toast.is-visible {
+  opacity: 1;
+  transform: translateY(0px);
+}
+
 @media (max-width: 768px) {
   .site-header__inner {
     justify-content: space-between;