MySQL query optimization. Added loading component.

components/common/Loading.module.css

@@ -0,0 +1,41 @@
+@keyframes blink {
+  0% {
+    opacity: 0.2;
+  }
+  20% {
+    opacity: 1;
+  }
+  100% {
+    opacity: 0.2;
+  }
+}
+
+.loading {
+  display: flex;
+  position: absolute;
+  top: 50%;
+  left: 50%;
+  transform: translate(-50%, -50%);
+  margin: 0;
+}
+
+.loading div {
+  width: 10px;
+  height: 10px;
+  border-radius: 100%;
+  background: var(--gray400);
+  animation: blink 1.4s infinite;
+  animation-fill-mode: both;
+}
+
+.loading div + div {
+  margin-left: 10px;
+}
+
+.loading div:nth-child(2) {
+  animation-delay: 0.2s;
+}
+
+.loading div:nth-child(3) {
+  animation-delay: 0.4s;
+}