body {
  font-family: 'Helvetica Neue', sans-serif;
  margin: 0;
  padding: 0;
  background: #fdfdfd;
  color: #222;
  line-height: 1.8;
}
header {
  background: #00274d;
  color: white;
  padding: 1.5em;
}
header h1 {
  margin: 0 0 0.5em 0;
  font-size: 1.6em;
}
nav ul {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1em;
}
nav ul li a {
  color: white;
  text-decoration: none;
}
main {
  padding: 2em;
  max-width: 960px;
  margin: auto;
}
.greeting p {
  text-align: justify;
}
.vr-image img, .banner img {
  display: block;
  margin: 2em auto;
  max-width: 100%;
  height: auto;
  border-radius: 4px;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}
footer {
  text-align: center;
  padding: 1em;
  background: #eee;
  font-size: 0.9em;
  margin-top: 2em;
}
ranking-tabs button {
  padding: 8px 16px;
  margin-right: 5px;
  border: none;
  background-color: #eee;
  cursor: pointer;
}
ranking-tabs button.active {
  background-color: #0077cc;
  color: white;
}
.ranking-tabs {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 1em;
}

.ranking-tabs button {
  padding: 8px 16px;
  border: none;
  background-color: #eee;
  cursor: pointer;
  font-size: 1em;
  border-radius: 5px;
  transition: background-color 0.2s;
}

.ranking-tabs button.active {
  background-color: #0077cc;
  color: white;
}

.ranking-tabs select {
  padding: 8px;
  font-size: 1em;
  border-radius: 5px;
  border: 1px solid #ccc;
}

/* 表の表示を見やすくする */
table.display {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1em;
}

table.display thead {
  background-color: #f5f5f5;
}

table.display th, table.display td {
  padding: 10px;
  border: 1px solid #ddd;
  text-align: left;
}

table.display td:nth-child(1) {
  width: 40px; /* 順位列を狭めに */
  text-align: center;
}

table.display td:nth-child(2) {
  width: 30%;
}

table.display td:nth-child(3),
table.display td:nth-child(4),
table.display td:nth-child(5) {
  width: auto;
}
.section-nav ul li {
  margin: 0.5em 0;
}

.section-nav a {
  text-decoration: none;
  color: #0077cc;
}

.section-nav a:hover {
  text-decoration: underline;
}
.section-nav {
  color: #222;
  margin-bottom: 2em;
}

.section-nav a {
  color: #0077cc;
  text-decoration: none;
}

.section-nav a:hover {
  text-decoration: underline;
}
#toc {
  background-color: #f0f8ff; /* 明るい青系背景 */
  padding: 1em 1.5em;
  border-left: 5px solid #0077cc;
  border-radius: 5px;
  margin-bottom: 2em;
}

#toc h2 {
  margin-top: 0;
  font-size: 1.2em;
  color: #00274d;
}

#toc ul {
  list-style: none;
  padding-left: 1em;
}

#toc ul li {
  margin: 0.4em 0;
}

#toc a {
  color: #0077cc;
  text-decoration: none;
}

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

.whats-new {
  margin-top: 2rem;
  padding: 1.25rem;
  border: 1px solid #ddd;
  border-radius: 4px;
  background-color: #fafafa;
}

.whats-new h1,
.whats-new h2 {
  font-size: 1.2rem;
  margin: 0 0 1rem 0;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid #eee;
}

.whats-new-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.whats-new-item + .whats-new-item {
  margin-top: 0.75rem;
  padding-top: 0.75rem;
  border-top: 1px dashed #ddd;
}

.whats-new-date {
  display: inline-block;
  min-width: 8em;
  font-size: 0.9rem;
  color: #666;
}

.whats-new-title {
  text-decoration: none;
}

.whats-new-title:hover,
.whats-new-title:focus {
  text-decoration: underline;
}

/* index.html 側の「一覧へ」リンク */
.whats-new-more {
  margin-top: 1rem;
  text-align: right;
  font-size: 0.95rem;
}

/* 読み込み中・エラーなど */
.whats-new-placeholder,
.whats-new-noscript,
.whats-new-error {
  color: #666;
  font-size: 0.95rem;
}