* { box-sizing: border-box; }
body {
  margin: 0;
  color: #222;
  background: #f5f5f5;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.8;
  letter-spacing: 0;
}
a { color: #1f5dba; text-decoration: none; }
a:hover { color: #0b3f8a; text-decoration: underline; }
img { max-width: 100%; display: block; }
.wrap {
  width: min(980px, calc(100% - 28px));
  margin: 0 auto;
  background: #fff;
}
.site-header .wrap {
  padding: 14px 24px;
  border-bottom: 1px solid #ececec;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
}
.logo {
  display: inline-flex;
  align-items: center;
  flex: 0 0 auto;
}
.logo img { width: 190px; height: auto; }
.top-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 20px;
  font-size: 15px;
}
main.wrap { padding: 26px 34px 36px; }
.article h1 {
  margin: 0 0 18px;
  font-size: 32px;
  line-height: 1.25;
  font-weight: 700;
}
.article h2 {
  margin: 30px 0 12px;
  padding-top: 8px;
  font-size: 24px;
  line-height: 1.35;
  font-weight: 700;
}
.article h3 {
  margin: 22px 0 10px;
  font-size: 19px;
  line-height: 1.45;
}
.article p { margin: 10px 0; }
.article ul, .article ol { margin: 10px 0 14px 24px; padding: 0; }
.app-download {
  margin: 20px 0 28px;
  padding: 18px;
  border: 1px solid #e8e8e8;
  background: #fafafa;
}
.app-download h2 {
  margin: 0 0 14px;
  padding: 0;
  font-size: 22px;
}
.download-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}
.download-item {
  min-height: 148px;
  padding: 12px 8px;
  border: 1px solid #e3e3e3;
  background: #fff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  text-align: center;
  color: #222;
}
.download-item img {
  width: 68px;
  height: 68px;
  border-radius: 14px;
  object-fit: cover;
}
.download-item span { font-weight: 700; }
.download-item b {
  display: inline-block;
  color: #fff;
  background: #1f5dba;
  border-radius: 4px;
  padding: 3px 10px;
  font-size: 13px;
}
.article-img {
  width: min(550px, 100%);
  margin: 12px auto 16px;
  border-radius: 4px;
}
.site-footer.wrap {
  padding: 20px 24px 28px;
  text-align: center;
  border-top: 1px solid #ececec;
  font-size: 15px;
}
@media (max-width: 720px) {
  .wrap { width: 100%; }
  main.wrap { padding: 22px 16px 30px; }
  .site-header .wrap {
    padding-inline: 14px;
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }
  .logo img { width: 176px; }
  .article h1 { font-size: 27px; }
  .download-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .top-nav { gap: 12px; justify-content: flex-start; }
}