feat: Add demo card on demos page for first showcased demo

- add _data/demos.js data file
- add Nunjucks logic for dynamically injecting demo attributes into demo cards
- add style rules for demo cards

src/styles/demos.css

@@ -16,4 +16,96 @@ h1, h2 {
     text-align: center;
     margin-top: 200px;
     font-size: 2.5rem;
+    margin-top: 50px;
+}
+
+.demo-card {
+    box-shadow: var(--shadow-small);
+    transition: transform 0.3s ease, box-shadow 0.3s ease;
+}
+
+.demo-card:hover {
+    transform: translateY(-5px);
+    box-shadow: var(--shadow-medium);
+}
+
+.demo-title {
+    margin-top: 0;
+    font-size: 2rem;
+    color: var(--primary-color);
+    margin-bottom: var(--margin-small);
+}
+
+.demo-image {
+    width: 70%;
+    height: auto;
+    border-radius: 8px;
+    box-shadow: var(--shadow-small);
+    margin-bottom: var(--margin-medium);
+}
+
+.demo-description,
+.demo-problem,
+.demo-solution,
+.coming-soon {
+    line-height: 1.6;
+    margin-bottom: var(--margin-small);
+    font-size: 1.25rem;
+    text-align: center;
+}
+
+.demo-problem,
+.demo-solution {
+    font-weight: 500;
+}
+
+h3 {
+    font-weight: bold;
+    color: var(--primary-color);
+    font-size: 2rem;
+}
+
+.coming-soon {
+    font-weight: bold;
+    color: var(--secondary-color);
+    text-align: center;
+    font-style: italic;
+    margin-top: 10px;
+}
+
+.demo-link,
+.demo-repo {
+    display: inline-block;
+    padding: 8px 25px;
+    margin: 20px 10px;
+    background-color: var(--secondary-color);
+    color: var(--light-bg-color);
+    text-decoration: none;
+    font-weight: 600;
+    border-radius: 50px;
+    transition: background-color 0.3s ease, box-shadow 0.3s ease;
+}
+
+.demo-link:hover,
+.demo-repo:hover {
+    background-color: var(--primary-color);
+    box-shadow: 0 4px 8px rgba(46, 151, 190, 0.2);
+}
+
+/* Responsive tweaks */
+@media (max-width: 768px) {
+    h1 {
+        font-size: 2rem;
+    }
+
+    .demo-card {
+        padding: var(--padding-medium);
+    }
+
+    .demo-link,
+    .demo-repo {
+        display: block;
+        margin: 10px auto;
+        width: fit-content;
+    }
 }