* {
  box-sizing: border-box;
}

body {
  font-family: "Helvetica Neue", "Arial", sans-serif;
  background-color: #f6f6f6;
  color: #202122;
  margin: 0;
  padding: 0;
  display: flex;
  min-height: 100vh;
}

#sidebar {
  width: 220px;
  background-color: #f8f9fa;
  border-right: 1px solid #a2a9b1;
  padding: 20px 10px;
  position: sticky;
  top: 0;
  height: 100vh;
  flex-shrink: 0;
}

#logo {
  font-weight: bold;
  font-size: 20px;
  margin-bottom: 20px;
  text-align: center;
}

#sidebar h2 {
  font-size: 16px;
  margin-top: 0;
  border-bottom: 1px solid #a2a9b1;
  padding-bottom: 4px;
}

#sidebar ul {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

#sidebar li {
  margin: 8px 0;
}

#sidebar a {
  color: #0645ad;
  text-decoration: none;
  font-size: 14px;
}

#sidebar a:hover {
  text-decoration: underline;
}

#content-wrapper {
  display: flex;
  flex: 1;
  flex-direction: column;
  min-width: 0;
}

#content {
  max-width: 960px;
  width: 100%;
  margin: 0 auto;
  padding: 20px;
  background-color: #fff;
  border-left: 1px solid #a2a9b1;
  border-right: 1px solid #a2a9b1;
  flex: 1;
}

h1, h2, h3 {
  font-weight: bold;
  border-bottom: 1px solid #a2a9b1;
  margin-top: 24px;
  padding-bottom: 4px;
}

/* h1 {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
} */
 
h1 .fas {
  font-size: smaller;
}

p {
  line-height: 1.6;
  margin: 16px 0;
}

a {
  color: #0645ad;
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

.infobox {
  float: right;
  width: 250px;
  margin: 0 0 16px 16px;
  padding: 8px;
  background-color: #f8f9fa;
  border: 1px solid #a2a9b1;
  font-size: 90%;
}

.infobox th {
  background-color: #eaecf0;
  text-align: left;
  padding: 4px;
}

.infobox td {
  padding: 4px;
}

.toc {
  background-color: #f8f9fa;
  border: 1px solid #a2a9b1;
  padding: 10px;
  margin-bottom: 20px;
}

.toc ul {
  list-style: none;
  padding-left: 0;
}

.toc li {
  margin: 4px 0;
}

.note {
  font-size: smaller;
  vertical-align: super;
}

footer {
  font-size: 80%;
  color: #555;
  border-top: 1px solid #a2a9b1;
  padding-top: 10px;
  margin-top: 40px;
  text-align: center;
}

.dove {
  position: relative;
  margin: 0 auto;
  background: linear-gradient(-225deg, #7DE2FC 0%, #B9B6E5 100%);
  width: 300px;
  height: 300px; 
  -webkit-mask-image: url('../img/dove.png'); 
  mask-image: url('../img/dove.png'); 
  -webkit-mask-repeat: no-repeat;
  mask-repeat: no-repeat;
  -webkit-mask-size: contain;
  mask-size: contain;
  -webkit-mask-position: center;
  mask-position: center;
  overflow: hidden;
}

.dove::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: url('../img/clouds.png');
  background-repeat: repeat-x;
  background-size: auto 100%; /* 縦を維持して横を無限に */
  background-position: 0 0;
  mix-blend-mode: color-dodge;
  animation: cloud 180s linear infinite;
}

@keyframes cloud {
  0% {
    background-position: 0 0;
  }
  100% {
    background-position: 1920px 0; /* 左方向に流れる */
  }
}


/* レスポンシブ対応 */
@media (max-width: 1024px) {
  #sidebar {
    width: 180px;
  }

  #content {
    padding: 16px;
  }
}

@media (max-width: 768px) {
  body {
    flex-direction: column;
  }

  #sidebar {
    width: 100%;
    height: auto;
    position: relative;
    border-right: none;
    border-bottom: 1px solid #a2a9b1;
    padding: 10px;
  }

  #logo {
    font-size: 18px;
  }

  #content {
    border-left: none;
    border-right: none;
  }

  .infobox {
    float: none;
    width: 100%;
    margin: 16px 0;
  }
}

@media (max-width: 480px) {
  #sidebar h2, #sidebar a {
    font-size: 13px;
  }

  ul {
    padding-inline-start: 1rem;
  }

  #logo {
    margin: 0 auto;
    width: 50vw;
    font-size: 16px;
  }

  nav {
    margin-top: 1rem;
  }
  nav ul {
    display: flex;
    gap: 1rem;
    justify-content: center;
  }

  .toc {
    font-size: 90%;
  }

  #content {
    padding: 12px;
  }
}