:root {
  --pine: #1b4332;
  --leaf: #2d6a4f;
  --mint: #d8f3dc;
  --wash: #f6fff8;
  --ink: #081c15;
  --line: #95d5b2;
  --alert: #6b2d12;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  min-height: 100vh;
  display: grid;
  grid-template-columns: 240px 1fr;
  grid-template-rows: auto 1fr auto;
  color: var(--ink);
  background: var(--wash);
  font: 15px/1.65 "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.rail {
  grid-row: 1 / span 3;
  background: var(--pine);
  color: #e8f5e9;
  padding: 22px 16px;
}
.rail .logo {
  display: flex;
  gap: 8px;
  align-items: center;
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  margin-bottom: 28px;
}
.rail nav a {
  display: block;
  color: #cde7d6;
  text-decoration: none;
  padding: 10px 8px;
  border-left: 3px solid transparent;
}
.rail nav a.is-current { background: #163528; border-left-color: #95d5b2; color: #fff; }
.workbench { padding: 0; }
.masthead {
  background: var(--mint);
  padding: 28px 36px 22px;
  border-bottom: 1px dashed var(--leaf);
}
.masthead h1 { margin: 0 0 10px; font-size: 28px; letter-spacing: 0.02em; }
.spec-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.spec-actions a {
  background: var(--pine);
  color: #fff;
  text-decoration: none;
  padding: 8px 12px;
  font-size: 14px;
}
.spec-actions a.primary { background: #40916c; }
.work {
  padding: 24px 36px 48px;
  max-width: 860px;
}
.spec-list { margin: 0 0 28px; padding: 0; }
.spec-list > div { margin-bottom: 26px; }
.spec-list h2 {
  margin: 0 0 8px;
  font-size: 19px;
  color: var(--pine);
  border-bottom: 1px solid var(--line);
  padding-bottom: 4px;
}
dl.facts { margin: 0; }
dl.facts dt { font-weight: 700; margin-top: 8px; }
dl.facts dd { margin: 4px 0 0 16px; }
table.diff { width: 100%; border-collapse: collapse; }
table.diff th, table.diff td { border: 1px solid #b7e4c7; padding: 7px 8px; text-align: left; }
table.diff th { background: #d8f3dc; }
.alert {
  background: #fff3e6;
  border: 1px solid #e07a3d;
  color: var(--alert);
  padding: 12px 14px;
  margin: 18px 0;
}
.colophon {
  grid-column: 2;
  background: #081c15;
  color: #cde7d6;
  padding: 18px 36px 24px;
  font-size: 13px;
}
.colophon p { margin: 0 0 8px; }
.hint { color: #3a5a40; font-size: 13px; }

@media (max-width: 800px) {
  body { grid-template-columns: 1fr; }
  .rail { grid-row: auto; }
  .colophon { grid-column: 1; }
}