/*last update：2022/11/08*/
:root {
  --main-text: #042159;
  --main-bg: #fff;
  --main-h1: #2c9c8e;
  --main-h2: #000;
  --link-color: #313131;
  font-family: 'M PLUS 1 Code', sans-serif
}

@media (prefers-color-scheme:dark) {
  :root {
    --main-text: #8899A6;
    --main-bg: #15202B;
    --main-h1: #33d64f;
    --main-h2: #FFF;
    --link-color: #FFF;
    --head-backcolor: #000
  }
}

a {
  text-decoration: none;
  color: #309fff
}

body {
  color: var(--main-text);
  background-color: var(--main-bg);
  transition: .0s;
  margin: 0;
  display: flex;
  flex-flow: column;
  min-height: 100vh
}

.center {
  text-align: center
}

header {
  font-family: 'Zen Kaku Gothic New', sans-serif;
  text-align: center;
  height: auto;
  width: 100%
}

header h1 {
  color: var(--main-h1)
}

header p {
  color: var(--main-text);
  margin: 0px 5px;
}

header ul {
  display: flex;
  justify-content: space-around;
  padding: 0
}

header li {
  list-style: none
}

header .a {
  text-decoration: none;
  color: #309fff
}

main {
  font-family: 'M PLUS 1 Code', sans-serif;
  font-size: 100%;
  height: auto;
  margin: 15px 20px 15px;
  flex: 1;
  background-color: var(--main-bg)
}

.post-title {
  color: #fff
}

main h2 {
  color: var(--main-h2);
  text-align: center;
  width: 100%
}

main a {
  color: #478bff
}

.about {
  color: var(--main-text);
  width: auto;
  height: auto
}

#q {
  color: #ffb357;
  width: 100%
}

#a {
  color: #66a1ff
}

.btn {
  padding: 10px 30px;
  background: orange;
  color: #fff;
  border-radius: 15px
}

.btn:hover {
  opacity: .7
}

summary {
  display: block
}

summary::-webkit-details-marker {
  display: none
}

.link-list {
  list-style-type: none;
  background-image: none;
  padding-left: 0;
  width: 80%;
  height: auto;
  text-align: center;
  margin: auto
}

footer {
  height: auto;
  margin: 0px 20px;
}

.button_line004 a {
  position: relative;
  display: flex;
  justify-content: space-around;
  align-items: center;
  margin: 0 auto;
  max-width: 200px;
  padding: 10px 25px;
  color: var(--link-color);
  transition: 0.3s ease-in-out;
  font-weight: 600
}

.button_line004 a:before,
.button_line004 a:after {
  content: '';
  width: 18px;
  height: 18px;
  border-color: #6bb6ff;
  box-sizing: border-box;
  border-style: solid;
  display: block;
  position: absolute;
  transition: all 0.3s ease-in-out
}

.button_line004 a:before {
  top: -6px;
  left: -6px;
  border-width: 2px 0 0 2px;
  z-index: 5
}

.button_line004 a:after {
  bottom: -6px;
  right: -6px;
  border-width: 0 2px 2px 0
}

.button_line004 a:hover:before,
.button_line004 a:hover:after {
  width: calc(100% + 12px);
  height: calc(100% + 12px);
  border-color: #6bb6ff
}

.button_line004 a:hover {
  color: #fff;
  background-color: #6bb6ff;
  border-color: #6bb6ff
}