[Add] Day calendar

+import React, { useContext } from "react";
+import GridItem from "./GridItem.js";
+
+import { CalendarStateContext } from "../pages/Calendar";
+import "../styles/Day.css";
+
+const Day = () => {
+  const { state } = useContext(CalendarStateContext);
+  return (
+    <div className="Day">
+      <GridItem targetDate={new Date(state.date)} />
+    </div>
+  );
+};
+
+export default Day;

@@ -102,6 +102,7 @@ button:disabled {
   border-radius: 3px;
   cursor: pointer;
   position: relative;
+  flex-flow: wrap;
 }
 
 .ScheduleItem > span {
@@ -128,6 +129,11 @@ button:disabled {
   padding: 0;
 }
 
+.s_substr {
+  width: 100%;
+  font-weight: bold;
+}
+
 [popup] {
   position: absolute;
   z-index: 1000;

+.GridItem[scope="day"] {
+  flex-basis: 100px;
+  padding: 5px;
+}
+
+.GridItem[scope="day"] > span {
+  display: none;
+}
+
+.GridItem[scope="day"] > .ScheduleItem {
+  margin: 3px 0 3px 0;
+}
+
+.GridItem[scope="day"] > .ScheduleItem > span {
+  line-height: 30px;
+  margin: 5px 5px 5px 5px;
+  font-size: large;
+}
+
+.GridItem[scope="day"] > .ScheduleItem > img {
+  width: 30px;
+  height: 30px;
+  margin: 5px;
+}