App.css

.app {
  display: flex;
  width: 100%;
  flex-direction: column;
  align-items: center;
}

.header {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 80px;
  background: #fff;
  box-shadow: 1px 4px 16px rgba(0, 0, 0, 0.15);
  display: flex;
  align-items: center;
  justify-content: flex-end;
  padding: 0 16px;
}

/* Update .container CSS */
.container {
  display: flex;
  flex-direction: column;
  margin-top: 48px;
  width: 540px;
  height: 540px;
  background: white;
  border-radius: 6px;
  box-shadow: 1px 1px 4px 0 rgba(0, 0, 0, 0.15);
}