:root {
  --bg: #fbfbfa;
  --fg: #1c1c1a;
  --muted: #6b6b66;
  --line: #e3e3df;
  --card: #ffffff;
  --accent: #b4531f;
  --radius: 6px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #131312;
    --fg: #e8e8e4;
    --muted: #96968f;
    --line: #2c2c29;
    --card: #1a1a18;
    --accent: #e8935c;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 16px/1.75 -apple-system, BlinkMacSystemFont, "PingFang SC",
        "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  font-feature-settings: "kern";
}

.wrap {
  max-width: 42rem;      /* 约 68 个字符行宽 */
  margin: 0 auto;
  padding: 0 1.25rem;
}

header {
  padding: 5rem 0 3.5rem;
  border-bottom: 1px solid var(--line);
}

.mark {
  font-size: 0.8125rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 1.25rem;
}

h1 {
  font-size: 1.9rem;
  line-height: 1.4;
  font-weight: 600;
  margin: 0 0 1rem;
  letter-spacing: -0.01em;
}

.lede {
  font-size: 1.0625rem;
  color: var(--muted);
  margin: 0;
  max-width: 34rem;
}

section {
  padding: 3.5rem 0;
  border-bottom: 1px solid var(--line);
}

section:last-of-type { border-bottom: 0; }

h2 {
  font-size: 1.1875rem;
  font-weight: 600;
  margin: 0 0 0.5rem;
  letter-spacing: -0.005em;
}

h3 {
  font-size: 0.9375rem;
  font-weight: 600;
  margin: 2rem 0 0.75rem;
  color: var(--muted);
}

p { margin: 0 0 1rem; max-width: 36rem; }

.note { color: var(--muted); font-size: 0.9375rem; }

a { color: var(--accent); text-underline-offset: 0.2em; }
a:focus-visible,
audio:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

/* 流程：真正有信息的图，不是装饰 */
.flow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: center;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
  font-size: 0.875rem;
}
.flow li {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.35rem 0.7rem;
  background: var(--card);
  white-space: nowrap;
}
.flow li[data-key] {
  border-color: var(--accent);
  color: var(--accent);
}
.flow .arrow {
  border: 0;
  background: none;
  color: var(--muted);
  padding: 0 0.1rem;
}

.track {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--card);
  padding: 1rem 1.1rem;
  margin: 0 0 0.75rem;
}
.track .name {
  font-weight: 600;
  font-size: 0.9375rem;
  margin: 0 0 0.15rem;
}
.track .meta {
  color: var(--muted);
  font-size: 0.8125rem;
  margin: 0 0 0.7rem;
}
audio { width: 100%; height: 2.25rem; display: block; }

.callout {
  border-left: 2px solid var(--accent);
  padding: 0.1rem 0 0.1rem 1rem;
  margin: 1.75rem 0;
}
.callout p:last-child { margin-bottom: 0; }

dl { margin: 1.5rem 0 0; }
dt { font-weight: 600; font-size: 0.9375rem; margin-top: 1.25rem; }
dd { margin: 0.2rem 0 0; color: var(--muted); font-size: 0.9375rem; }

footer {
  padding: 3rem 0 4rem;
  color: var(--muted);
  font-size: 0.8125rem;
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; scroll-behavior: auto !important; }
}

@media (max-width: 560px) {
  header { padding: 3.5rem 0 2.5rem; }
  h1 { font-size: 1.55rem; }
  section { padding: 2.5rem 0; }
}

/* 对比数据用表格，横向溢出时可滚动 */
.table-scroll { overflow-x: auto; margin: 1.5rem 0 0; }
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.875rem;
  min-width: 30rem;
}
th, td {
  text-align: left;
  vertical-align: top;
  padding: 0.7rem 0.85rem;
  border-bottom: 1px solid var(--line);
}
th {
  font-weight: 600;
  font-size: 0.8125rem;
  color: var(--muted);
  border-bottom-width: 2px;
}
td { line-height: 1.6; }
tr.self td { background: color-mix(in srgb, var(--accent) 7%, transparent); }
.dim { color: var(--muted); }
.yes { color: var(--accent); }
.no { color: var(--muted); }
.mark a { color: inherit; text-decoration: none; }
.mark a:hover { color: var(--accent); }
footer p { margin: 0 0 0.4rem; }