/* Set 2: dark sidebar dashboard, teal accent, two-column workspace */
:root {
  --bg: #0e1116;
  --panel: #161b22;
  --edge: #30363d;
  --text: #e6edf3;
  --dim: #8b949e;
  --teal: #2dd4bf;
  --teal-dim: #134e4a;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { min-height: 100%; }
body {
  font-family: ui-sans-serif, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  display: grid;
  grid-template-columns: 240px 1fr;
  font-size: 15px;
  line-height: 1.7;
}
.sidebar {
  background: #0a0d12;
  border-right: 1px solid var(--edge);
  padding: 22px 16px;
  position: sticky;
  top: 0;
  height: 100vh;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 0.04em;
  margin-bottom: 28px;
  color: var(--teal);
}
nav { display: flex; flex-direction: column; gap: 6px; }
nav a {
  color: var(--dim);
  text-decoration: none;
  padding: 10px 12px;
  border-radius: 8px;
  border: 1px solid transparent;
}
nav a.active,
nav a:hover {
  color: var(--text);
  background: var(--panel);
  border-color: var(--edge);
}
nav a.active { box-shadow: inset 3px 0 0 var(--teal); }
.main { padding: 28px 32px 48px; max-width: 1080px; }
.hero {
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 20px;
  margin-bottom: 24px;
}
.hero-copy {
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: 12px;
  padding: 24px;
}
.hero h1 { font-size: 26px; line-height: 1.35; margin-bottom: 12px; }
.hero .lead { color: var(--dim); margin-bottom: 18px; }
.hero-aside {
  background: linear-gradient(180deg, #134e4a, #0e1116);
  border: 1px solid #115e59;
  border-radius: 12px;
  padding: 20px;
}
.hero-aside li { margin: 8px 0 8px 1.1em; color: #99f6e4; }
.btn-dl {
  display: inline-block;
  background: var(--teal);
  color: #042f2e;
  text-decoration: none;
  font-weight: 700;
  padding: 12px 18px;
  border-radius: 8px;
}
.btn-dl:hover { filter: brightness(1.08); }
.btn-sub {
  display: inline-block;
  margin-left: 10px;
  color: var(--teal);
  text-decoration: none;
  border: 1px solid var(--teal);
  padding: 11px 14px;
  border-radius: 8px;
}
.grid2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}
section {
  background: var(--panel);
  border: 1px solid var(--edge);
  border-radius: 12px;
  padding: 20px 22px;
  margin-bottom: 16px;
}
h2 { font-size: 18px; margin-bottom: 10px; color: var(--teal); }
p { margin-bottom: 10px; }
ul, ol { margin: 0 0 10px 1.2em; }
.faq-item {
  background: #0e1116;
  border: 1px solid var(--edge);
  border-radius: 8px;
  padding: 12px 14px;
  margin-bottom: 10px;
}
.faq-item h3 { font-size: 15px; margin-bottom: 6px; }
footer {
  grid-column: 1 / -1;
  background: #05070a;
  color: var(--dim);
  padding: 22px 28px 32px;
  font-size: 13px;
  border-top: 1px solid var(--edge);
}
footer nav {
  flex-direction: row;
  gap: 16px;
  margin-bottom: 12px;
}
footer nav a { padding: 0; box-shadow: none; background: none; border: 0; }
.note { color: #6e7681; }
@media (max-width: 900px) {
  body { grid-template-columns: 1fr; }
  .sidebar { position: relative; height: auto; }
  nav { flex-direction: row; flex-wrap: wrap; }
  .hero, .grid2 { grid-template-columns: 1fr; }
}