* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  text-decoration: none;
  color: black;
}

body {
  background: url(https://java.cse.ce.nihon-u.ac.jp/enshu5/common/gif/bgm.gif);
  -webkit-backdrop-filter: hue-rotate(210deg);
          backdrop-filter: hue-rotate(210deg);
}

main {
  padding: 10px;
}

.header {
  text-align: center;
}
.header h1 {
  font-size: 40px;
  line-height: 100px;
}

.menu {
  background: rgb(248, 248, 255);
  max-width: 1170px;
  margin: 0 auto;
  width: 100%;
  padding: 30px 10px 30px 10px;
  border-radius: 10px;
}
.menu > p {
  font-size: 20px;
  line-height: 40px;
}
.menu__form {
  background: white;
  margin-bottom: 10px;
  padding: 10px;
}
.menu__form input[type=text] {
  flex: 1;
  font-size: 20px;
  display: inline-block;
  line-height: 40px;
  border: none;
  background-color: rgb(238, 238, 255);
}
.menu__form__item {
  display: flex;
  margin: 4px;
}
.menu__form__item span {
  font-size: 20px;
  line-height: 40px;
}
.menu a {
  display: inline-block;
  background: rgb(238, 238, 255);
  border-left: 2px solid white;
  border-top: 2px solid white;
  border-right: 2px solid black;
  border-bottom: 2px solid black;
  padding: 8px;
  font-size: 20px;
}
.menu a:hover {
  background: rgb(218, 218, 232);
}
.menu a:active {
  background: rgb(192, 192, 204);
  border: none;
  border-left: 2px solid black;
  border-top: 2px solid black;
  border-right: 2px solid white;
  border-bottom: 2px solid white;
}
.menu__success {
  background: rgb(230, 249, 231);
  margin-bottom: 10px;
  padding: 10px;
  font-size: 20px;
}

.container {
  background: rgb(248, 248, 255);
  display: flex;
  max-width: 1170px;
  margin: 0 auto;
  width: 100%;
  padding: 30px 10px 30px 10px;
  flex-wrap: wrap;
}
.container__button {
  min-width: calc(33.3333333333% - 3px);
  text-align: center;
  font-size: 40px;
  line-height: 120px;
  background: rgb(238, 238, 255);
  border-left: 3px solid white;
  border-top: 3px solid white;
  border-right: 3px solid black;
  border-bottom: 3px solid black;
  margin: 3px 3px 3px 0;
  cursor: pointer;
}
.container__button:hover {
  background: rgb(218, 218, 232);
}
.container__button:active {
  background: rgb(192, 192, 204);
  border: none;
  border-left: 3px solid black;
  border-top: 3px solid black;
  border-right: 3px solid white;
  border-bottom: 3px solid white;
}

footer {
  padding: 0 10px;
}

.footer__pr {
  background: rgb(248, 248, 255);
  border-radius: 10px;
  display: flex;
  justify-content: center;
  padding: 10px;
  margin: 10px auto;
  max-width: 970px;
}
.footer__pr__icon {
  min-width: 200px;
  width: 200px;
  border-radius: 100px;
  border: 4px solid rgb(220, 220, 228);
  overflow: hidden;
}
.footer__pr__icon img {
  width: 100%;
}
.footer__pr__info {
  text-align: center;
}
.footer__pr__info__icons img {
  width: 40px;
}
.footer__link {
  background: #b0b0cb;
  padding: 30px 10px;
  margin: 0 -10px;
}
.footer__link a {
  display: inline-block;
  border-bottom: 1px solid black;
}
.footer__link a:hover {
  background: rgba(0, 0, 0, 0.2);
}
.footer__copyright {
  margin: 0 -10px;
  padding: 10px;
  background: #9999b1;
}

.amazon__btn {
  background: linear-gradient(to right, #00ffff, #9f9fff);
  width: 100% !important;
  animation: amazon__btn 5s linear infinite;
  font-size: 30px;
}
.amazon__btn:hover {
  background: linear-gradient(to right, #00e8e8, #0000e3);
}

@keyframes amazon__btn {
  0% {
    filter: hue-rotate(0);
  }
  50% {
    filter: hue-rotate(180deg);
  }
  100% {
    filter: hue-rotate(360deg);
  }
}
@media screen and (max-width: 767px) {
  .container__button {
    width: calc(50% - 3px);
  }
}
@media screen and (max-width: 467px) {
  .container__button {
    width: calc(100% - 3px);
    margin-right: 0;
  }
  .footer__pr {
    flex-wrap: wrap;
  }
  .footer__pr__info {
    width: 100%;
    padding-top: 10px;
  }
}/*# sourceMappingURL=style.css.map */