body {
  font-family: "Kaisei Opti", serif;
  font-size: 60px;
  font-style: normal;
  background-color: #9bd2dc;
}

.hamburger-menu-button {
  position: fixed;
  top: 16px;
  right: 16px;
  width: 45px;
  height: 40px;
  background-color: transparent;
  border: none;
  z-index: 2;
}

.hamburger-menu-button span {
  position: absolute;
  left: 0;
  width: 100%;
  height: 4px;
  background-color: #fff;
  border-radius: 4px;
}

.hamburger-menu-button span {
  display: inline-block;
  transition: all 0.5s;
  box-sizing: border-box;
}
.hamburger-menu-button span:nth-of-type(1) {
  top: 0;
}
.hamburger-menu-button span:nth-of-type(2) {
  top: 18px;
}
.hamburger-menu-button span:nth-of-type(3) {
  bottom: 0;
}

.hamburger-menu-button.active span:nth-of-type(1) {
  -webkit-transform: translateY(20px) rotate(-45deg);
  transform: translateY(18px) rotate(-45deg);
  background-color: #252525;
}
.hamburger-menu-button.active span:nth-of-type(2) {
  opacity: 0;
}
.hamburger-menu-button.active span:nth-of-type(3) {
  -webkit-transform: translateY(-20px) rotate(45deg);
  transform: translateY(-18px) rotate(45deg);
  background-color: #252525;
}

.side-menu-panel {
  position: fixed;
  top: 0;
  right: 0;
  width: 300px;
  height: 100vh;
  background-color: rgba(255, 255, 255, 0.8);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.5s ease-out;
  z-index: 1;
}

.side-menu-panel.is-open {
  opacity: 1;
  pointer-events: auto;
}

.youtube-player-wrapper {
  position: relative;
  width: 260px;
  height: 260px;
}

.youtube-player-wrapper.is-hidden {
  display: none;
}

.youtube-player-cover {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(255, 255, 255, 0.95);
  display: none;
  pointer-events: none;
  z-index: 1;
}

.youtube-player-wrapper.is-covered .youtube-player-cover {
  display: block;
}