:root {
  --bg0: #f0f2f5;
  --bg1: #ffffff;
  --text: #1a1d26;
  --muted: #6b7280;
  --blue: #2f6bff;
  --blue-deep: #1e4fd6;
  --gold: #e8c547;
  --gold-soft: #f3d978;
  --line: rgba(26, 29, 38, 0.1);
  --card-bg: #ffffff;
  --glow-blue: 0 12px 28px rgba(47, 107, 255, 0.18);
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body {
  color: var(--text);
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: linear-gradient(180deg, #ffffff 0%, #f3f4f6 55%, #eceff3 100%);
}
a { color: inherit; text-decoration: none; }

.subpage {
  width: min(720px, calc(100% - 40px));
  margin: 0 auto;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  padding: 28px 0 24px;
}
.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.logo { font-size: 28px; font-weight: 700; }
.btn-tutorial {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 40px;
  padding: 0 22px;
  border-radius: 999px;
  background: linear-gradient(180deg, #3d7aff, var(--blue-deep));
  box-shadow: var(--glow-blue);
  font-size: 14px;
  font-weight: 600;
}
.hero-block {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 40px 0;
}
h1 {
  margin: 0;
  font-size: clamp(32px, 6vw, 48px);
  font-weight: 750;
  letter-spacing: -0.03em;
}
.lead {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.8;
}
.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 20px;
  border-radius: 999px;
  font-size: 14px;
  font-weight: 600;
}
.btn-primary {
  background: linear-gradient(180deg, #3d7aff, var(--blue-deep));
  box-shadow: var(--glow-blue);
}
.btn-ghost {
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.78);
  color: var(--text);
}
.card-list { display: grid; gap: 12px; margin-top: 28px; }
.card {
  padding: 18px 20px;
  border-radius: 16px;
  border: 1px solid var(--line);
  background: var(--card-bg);
  box-shadow: 0 16px 36px rgba(23, 32, 51, 0.06);
}
.card h3 { margin: 0; font-size: 16px; }
.card p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
}
.version {
  margin: 22px 0 0;
  color: rgba(103, 116, 137, 0.92);
  font-size: 13px;
}
.foot {
  margin-top: auto;
  padding-top: 16px;
  text-align: center;
  color: rgba(103, 116, 137, 0.82);
  font-size: 13px;
}