:root {
  --bg: #ffffff;
  --fg: #111111;
  --muted: #666666;
  --nav-bg: #eeeeee;
  --btn-border: #cccccc;
  --border: #dddddd;
  --link: #0a66c2;
  --download-bg: #1a7a3a;
  --download-bg-hover: #156832;
  --download-fg: #ffffff;
  --download-shadow: rgba(26, 122, 58, 0.25);
}

[data-theme="dark"] {
  --bg: #0f1216;
  --fg: #e8e8e8;
  --muted: #a0a0a0;
  --nav-bg: #1b212a;
  --btn-border: #2a2f39;
  --border: #2a2f39;
  --link: #66aaff;
  --download-bg: #2d9a52;
  --download-bg-hover: #268a48;
  --download-fg: #ffffff;
  --download-shadow: rgba(45, 154, 82, 0.35);
}

html, body {
  background: var(--bg);
  color: var(--fg);
}

body {
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  margin: 0;
}

a { color: var(--link); }

nav {
  background: var(--nav-bg);
  padding: 10px 14px;
  display: flex;
  gap: 10px;
  align-items: center;
  justify-content: space-between;
}

.nav-left, .nav-right {
  display: flex;
  gap: 10px;
  align-items: center;
  flex-wrap: wrap;
}

nav a {
  text-decoration: none;
  color: var(--fg);
}

main {
  padding: 16px;
  max-width: 1000px;
  margin: 0 auto;
}

.btn {
  display: inline-block;
  padding: 7px 12px;
  border: 1px solid var(--btn-border);
  border-radius: 8px;
  text-decoration: none;
  background: transparent;
  color: var(--fg);
  cursor: pointer;
  font: inherit;
}

.muted { color: var(--muted); font-size: 14px; }

.toc a {
  text-decoration: none;
}

.toc h2 {
  margin: 0.4em 0;
}

.download-box {
  margin: 1.2em 0 1.6em;
  padding: 1.2em 1.4em;
  border: 1px solid var(--border);
  border-radius: 12px;
  text-align: center;
  background: color-mix(in srgb, var(--nav-bg) 70%, transparent);
}

.download-box .version {
  margin: 0 0 0.35em;
  font-size: 1.05em;
}

.download-btn {
  display: inline-block;
  margin: 0.6em 0 0.4em;
  padding: 18px 48px;
  font-size: 1.35rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--download-fg);
  background: var(--download-bg);
  border: none;
  border-radius: 12px;
  text-decoration: none;
  box-shadow: 0 6px 18px var(--download-shadow);
  transition: background 0.15s ease, transform 0.1s ease;
}

.download-btn:hover {
  background: var(--download-bg-hover);
  color: var(--download-fg);
  transform: translateY(-1px);
}

.download-btn:active {
  transform: translateY(0);
}

.download-btn.is-disabled {
  opacity: 0.55;
  pointer-events: none;
  box-shadow: none;
}

.download-meta {
  margin: 0.25em 0 0;
}

.news-date {
  font-weight: 600;
  margin-top: 0.9em;
  margin-bottom: 0.15em;
}

.news-date + p {
  margin-top: 0;
}