feat: scroll top button

public/styles.css

@@ -635,6 +635,49 @@ body {
     }
 }
 
+/* Scroll to Top Button */
+.scroll-to-top-btn {
+    position: fixed;
+    bottom: 2rem;
+    right: 2rem;
+    width: 50px;
+    height: 50px;
+    border-radius: 50%;
+    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
+    color: white;
+    border: none;
+    cursor: pointer;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
+    transition: all 0.3s ease;
+    opacity: 0;
+    visibility: hidden;
+    transform: translateY(20px);
+    z-index: 999;
+}
+
+.scroll-to-top-btn.show {
+    opacity: 1;
+    visibility: visible;
+    transform: translateY(0);
+}
+
+.scroll-to-top-btn:hover {
+    transform: translateY(-3px);
+    box-shadow: 0 6px 16px rgba(99, 102, 241, 0.5);
+}
+
+.scroll-to-top-btn:active {
+    transform: translateY(-1px);
+}
+
+.scroll-to-top-btn svg {
+    width: 24px;
+    height: 24px;
+}
+
 @media (max-width: 400px) {
     .header-right {
         flex-direction: column;
@@ -649,5 +692,12 @@ body {
         width: 100%;
         justify-content: flex-start;
     }
+
+    .scroll-to-top-btn {
+        bottom: 1.5rem;
+        right: 1.5rem;
+        width: 45px;
+        height: 45px;
+    }
 }