:root {
  --bg: #ffffff;
  --surface: #f7f8fa;
  --text: #14161a;
  --muted: #626a75;
  --border: #e2e5ea;
  --accent: #0066ff;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, monospace;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #131519;
    --surface: #1a1d22;
    --text: #e7eaee;
    --muted: #9aa2ad;
    --border: #2a2e35;
    --accent: #4d9bff;
  }
}

*, *::before, *::after { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* 只隐藏「另一种语言」，不去还原 display——见 index.html 里的同段说明。 */
html[lang="zh-Hans"] [data-lang="en"] { display: none; }
html[lang="en"] [data-lang="zh"] { display: none; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code { font-family: var(--mono); font-size: .9em; }

.wrap { max-width: 720px; margin: 0 auto; padding: 0 24px; }

nav {
  border-bottom: 1px solid var(--border);
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(16px);
}
nav .wrap { display: flex; align-items: center; gap: 16px; height: 56px; max-width: 960px; }
.brand { display: flex; align-items: center; gap: 9px; font-weight: 600; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand img { width: 24px; height: 24px; border-radius: 6px; }
nav .spacer { flex: 1; }
.langbtn {
  font: inherit; font-size: 13px; cursor: pointer;
  background: var(--surface); color: var(--muted);
  border: 1px solid var(--border); border-radius: 7px; padding: 4px 10px;
}
.langbtn:hover { color: var(--text); }

main { padding: 56px 0 80px; }
h1 { font-size: 32px; letter-spacing: -.025em; margin: 0 0 8px; line-height: 1.25; }
.updated { color: var(--muted); font-size: 14px; margin: 0 0 40px; }
h2 { font-size: 19px; margin: 36px 0 12px; letter-spacing: -.015em; }
p, li { color: var(--text); }
p { margin: 0 0 14px; }
ul { padding-left: 22px; margin: 0 0 14px; }
li { margin-bottom: 7px; }

.note {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 10px; padding: 16px 18px; margin: 0 0 32px;
  font-size: 14.5px; color: var(--muted);
}

.release { border-top: 1px solid var(--border); padding: 28px 0; }
.release:first-of-type { border-top: 0; padding-top: 0; }
.release h2 { margin-top: 0; display: flex; align-items: baseline; gap: 12px; }
.release .date { font-size: 14px; font-weight: 400; color: var(--muted); }

footer { border-top: 1px solid var(--border); padding: 32px 0 56px; font-size: 14px; color: var(--muted); }
footer a { color: var(--muted); }
footer .links { display: flex; gap: 20px; flex-wrap: wrap; margin-bottom: 14px; }