:root { color-scheme: light dark; --fg: #18181b; --muted: #6b7280; --line: #d8dce3; }
@media (prefers-color-scheme: dark) { :root { --fg: #e6e8ec; --muted: #9aa1ab; --line: #2a2f38; } }
* { box-sizing: border-box; }
body {
  margin: 0;
  padding: 0 24px 64px;
  color: var(--fg);
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  line-height: 1.7;
}
.wrap { max-width: 760px; margin: 0 auto; }
.back { display: inline-block; margin: 28px 0 8px; color: var(--muted); font-size: 14px; text-decoration: none; }
.back:hover { color: var(--fg); }
h1 { font-size: 26px; font-weight: 650; margin: 8px 0 4px; line-height: 1.3; }
.meta { color: var(--muted); font-size: 13px; margin: 0 0 18px; }
.tabs { display: flex; gap: 4px; margin: 0 0 18px; border-bottom: 1px solid var(--line); }
.tabs button {
  appearance: none;
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  margin-bottom: -1px;
  padding: 7px 12px;
  color: var(--muted);
  font: inherit;
  font-size: 14px;
  cursor: pointer;
}
.tabs button[aria-selected="true"] { color: var(--fg); border-bottom-color: var(--fg); font-weight: 600; }
.tabs button:focus-visible { outline: 2px solid #3b82f6; outline-offset: 2px; border-radius: 4px; }
iframe { width: 100%; min-height: 70vh; border: 0; display: block; }
.cards { display: grid; gap: 14px; margin: 22px 0 0; }
.card { display: block; padding: 16px 18px; border: 1px solid var(--line); border-radius: 10px; text-decoration: none; color: inherit; }
.card:hover { border-color: var(--muted); }
.card h2 { font-size: 17px; font-weight: 620; margin: 0 0 4px; }
.card p { margin: 0; color: var(--muted); font-size: 13px; }
footer { margin-top: 40px; color: var(--muted); font-size: 12px; }