Made changes to CSS and merged together.

web/vue-app/src/assets/button-shared.css

@@ -0,0 +1,54 @@
+/* Base button style */
+.btn {
+  font-weight: 600;
+  border: none;
+  border-radius: 8px;
+  padding: 0.7rem 1.5rem;
+  font-size: 1.1rem;
+  cursor: pointer;
+  box-shadow: 0 2px 8px rgba(102, 126, 234, 0.08);
+  transition:
+    background 0.18s,
+    color 0.18s;
+  display: inline-block;
+}
+
+/* Primary button (e.g., Save, Confirm) */
+.btn-primary {
+  background: #667eea;
+  color: #fff;
+}
+.btn-primary:hover,
+.btn-primary:focus {
+  background: #5a67d8;
+}
+
+/* Secondary button (e.g., Cancel) */
+.btn-secondary {
+  background: #f3f3f3;
+  color: #666;
+}
+.btn-secondary:hover,
+.btn-secondary:focus {
+  background: #e2e8f0;
+}
+
+/* Danger button (e.g., Delete) */
+.btn-danger {
+  background: #ef4444;
+  color: #fff;
+}
+.btn-danger:hover,
+.btn-danger:focus {
+  background: #dc2626;
+}
+
+/* Green button (e.g., Confirm) */
+.btn-green {
+  background: #22c55e;
+  color: #fff;
+}
+.btn-green:hover,
+.btn-green:focus {
+  background: #16a34a;
+}