/* 使用教程页 — 依赖 styles.css 提供的设计变量与纸张底色 */
.doc {
  max-width: 720px;
  margin: 0 auto;
  padding: clamp(24px, 5vw, 56px) clamp(20px, 4vw, 48px) 96px;
}

.doc-back { margin: 0 0 8px; }
.doc-back a {
  color: var(--muted);
  font-size: 13px;
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  padding-bottom: 1px;
}
.doc-back a:hover { color: var(--ink); border-color: var(--ink); }
.doc-back a:focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }

.doc h1 { font-size: clamp(26px, 4vw, 34px); margin: 14px 0 6px; letter-spacing: .06em; }
.doc-sub { color: var(--muted); font-size: 13px; margin: 0 0 8px; letter-spacing: .12em; }

.doc h2 {
  font-size: 19px;
  margin: 40px 0 10px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  letter-spacing: .04em;
}
.doc h3 { font-size: 15px; margin: 22px 0 4px; color: var(--muted-strong); }
.doc p, .doc li { font-size: 14px; line-height: 1.9; }
.doc p { margin: 8px 0; }
.doc ol, .doc ul { margin: 8px 0; padding-left: 24px; }
.doc li { margin: 4px 0; }

.doc code {
  font-family: "SF Mono", Menlo, Consolas, "Courier New", monospace;
  font-size: 12.5px;
  background: var(--surface-muted);
  padding: 1px 5px;
}
.doc pre {
  background: var(--surface-muted);
  border: 1px solid var(--line);
  margin: 10px 0;
  padding: 14px 16px;
  overflow-x: auto;
}
.doc pre code { background: none; padding: 0; line-height: 1.8; }

.doc-note {
  color: var(--muted);
  border-left: 2px solid var(--seal);
  padding-left: 12px;
  margin-top: 18px;
}

@media (prefers-reduced-motion: no-preference) {
  .doc-back a { transition: color .15s ease, border-color .15s ease; }
}