/* Shared arena chrome — used by the dohyo, Docs, Dataset, and Ranking. */
header.arena-bar {
  height: 52px;
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  position: relative;
  z-index: 40;
  background: rgb(255, 149, 0);
  min-width: 0;
  max-width: 100%;
  overflow: hidden;
}
header.arena-bar .logo {
  flex: 0 0 auto;
  font-weight: 900;
  font-size: 18px;
  letter-spacing: -.045em;
  line-height: 1;
  color: #fff;
  text-decoration: none;
  text-indent: -.03em;
}
header.arena-bar .brand {
  margin: 0 auto;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  font-weight: 800;
  letter-spacing: .2px;
  font-size: 15px;
  color: #141414;
  text-decoration: none;
}
header.arena-bar .brand .on {
  font-weight: 500;
  color: rgba(20, 20, 20, .62);
  font-size: 12px;
  letter-spacing: .04em;
}
header.arena-bar .brand .host {
  font-weight: 700;
  color: #141414;
  font-size: 13px;
}
header.arena-bar .links {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 0 0 auto;
}
header.arena-bar .ic {
  width: 34px;
  height: 34px;
  border: 1px solid rgba(255, 255, 255, .45);
  background: rgba(255, 255, 255, .22);
  border-radius: 50%;
  color: #141414;
  font-size: 17px;
  display: grid;
  place-items: center;
  text-decoration: none;
  cursor: pointer;
}
header.arena-bar .ic:hover,
header.arena-bar .ic.on {
  border-color: #fff;
  background: rgba(255, 255, 255, .36);
}

/* Shared page footer — Docs, Dataset, Ranking. */
footer.arena-foot {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px 16px;
  padding: 10px 16px 12px;
  background: #0c0c10;
  border-top: 1px solid #2a2d33;
  color: #9ca3af;
  font: 13px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}
footer.arena-foot p { margin: 0; max-width: 42rem; }
footer.arena-foot a {
  color: #ff9500;
  font-weight: 700;
  text-decoration: none;
}
footer.arena-foot a:hover { text-decoration: underline; }
footer.arena-foot .soc {
  display: flex;
  align-items: center;
  gap: 8px;
}
footer.arena-foot .soc a {
  width: 34px;
  height: 34px;
  border: 1px solid #2a2d33;
  background: #12141a;
  border-radius: 50%;
  color: #f3f4f6;
  display: grid;
  place-items: center;
  text-decoration: none;
}
footer.arena-foot .soc a:hover {
  border-color: #ff9500;
  color: #ff9500;
  text-decoration: none;
}
footer.arena-foot .soc svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
  display: block;
}
@media (max-width: 520px) {
  header.arena-bar { gap: 8px; padding: 0 10px; }
  header.arena-bar .brand { font-size: 13px; }
  header.arena-bar .brand .on { display: none; }
}