/* Set 6: compact app chrome, red top bar, 4-col tiles, dense modules */
:root {
  --red: #c41e3a;
  --ink: #111111;
  --wash: #f2f2f7;
  --card: #ffffff;
  --line: #e5e5ea;
  --sub: #6e6e73;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--wash);
  color: var(--ink);
  font-size: 15px;
  line-height: 1.65;
  padding-top: 56px;
}
.appbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 56px;
  background: #111;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  z-index: 9;
}
.brand {
  font-weight: 700;
  font-size: 18px;
  display: flex;
  align-items: center;
  gap: 8px;
}
nav a {
  color: #d1d1d6;
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  margin-left: 14px;
  padding: 6px 10px;
  border-radius: 8px;
}
nav a.active {
  background: var(--red);
  color: #fff;
}
.sheet { max-width: 1040px; margin: 0 auto; padding: 16px 14px 48px; }
.hero {
  background: var(--card);
  border-radius: 16px;
  padding: 20px 20px 18px;
  box-shadow: 0 1px 0 var(--line);
  margin-bottom: 14px;
}
.hero h1 { font-size: 24px; margin-bottom: 8px; }
.chips { margin: 10px 0 14px; }
.chip {
  display: inline-block;
  background: #ffe5ea;
  color: var(--red);
  font-size: 12px;
  font-weight: 700;
  padding: 4px 10px;
  border-radius: 999px;
  margin: 0 6px 6px 0;
}
.btn-dl {
  display: inline-block;
  background: var(--red);
  color: #fff;
  text-decoration: none;
  font-weight: 700;
  padding: 11px 16px;
  border-radius: 12px;
}
.btn-sub {
  display: inline-block;
  margin-left: 8px;
  color: var(--red);
  text-decoration: none;
  font-weight: 700;
  padding: 11px 8px;
}
.tiles {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px;
  margin-bottom: 14px;
}
.tile {
  background: var(--card);
  border-radius: 14px;
  padding: 14px;
  min-height: 120px;
}
.tile svg { display: block; margin-bottom: 8px; }
.tile h2 { font-size: 15px; margin-bottom: 6px; }
.tile p { color: var(--sub); font-size: 13px; }
section {
  background: var(--card);
  border-radius: 14px;
  padding: 16px 18px 18px;
  margin-bottom: 12px;
}
h2 { font-size: 17px; margin-bottom: 8px; }
p { margin-bottom: 8px; }
ul, ol { margin: 0 0 8px 1.15em; }
.faq-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--line);
}
.faq-item:last-child { border-bottom: 0; }
.faq-item h3 { font-size: 15px; margin-bottom: 4px; }
footer {
  background: #111;
  color: #a1a1a6;
  padding: 20px 16px 32px;
  font-size: 12px;
  line-height: 1.75;
}
footer .foot-inner { max-width: 1040px; margin: 0 auto; }
footer nav a { color: #d1d1d6; margin-left: 0; margin-right: 12px; background: none; }
.note { color: #6e6e73; }
@media (max-width: 800px) {
  .tiles { grid-template-columns: 1fr 1fr; }
  nav a { margin-left: 4px; padding: 5px 8px; }
}