:root {
  color-scheme: light;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: #262b34;
  background: #f6f7f9;
  font-synthesis: none;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; min-height: 100vh; display: flex; flex-direction: column; }
a { color: inherit; text-decoration: none; }
a:focus-visible { outline: 3px solid #ee4b60; outline-offset: 4px; }
.site-header { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 12px; padding: 18px max(24px, calc((100% - 1080px) / 2)); background: #fff; border-bottom: 1px solid #e9ecf1; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-size: 17px; font-weight: 600; }
.brand-mark { display: grid; place-items: center; width: 32px; height: 32px; border-radius: 9px; background: #ee4b60; color: #fff; }
.back-link { padding: 10px 0; font-size: 13px; color: #737b89; }
.back-link:hover, .below-link:hover { color: #ee4b60; }
.page { width: min(100%, 760px); flex: 1; margin: 0 auto; padding: 28px 28px 40px; }
.page-nav { display: flex; justify-content: center; gap: 6px; width: fit-content; max-width: 100%; margin: 0 auto 32px; padding: 5px; border: 1px solid #e9ecf1; border-radius: 13px; background: #fff; }
.page-nav a { padding: 11px 20px; border-radius: 9px; color: #737b89; font-size: 14px; text-align: center; }
.page-nav a[aria-current="page"] { background: #ee4b60; color: #fff; }
.intro { margin-bottom: 28px; text-align: center; }
.eyebrow { margin: 0 0 12px; color: #ee4b60; font-size: 12px; font-weight: 600; letter-spacing: 3px; }
h1 { margin: 0 0 12px; font-size: clamp(25px, 4vw, 32px); line-height: 1.4; font-weight: 600; }
.subtitle { margin: 0; font-size: 14px; color: #737b89; line-height: 1.8; }
.group-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.group-card { --platform: #1476cc; --platform-bg: #edf6ff; padding: 27px 24px 22px; text-align: center; border: 1px solid #e9ecf1; border-radius: 18px; background: #fff; box-shadow: 0 6px 24px #26334a05; }
.wechat { --platform: #138153; --platform-bg: #eaf8f1; }
h2 { display: flex; align-items: center; justify-content: center; gap: 8px; margin: 0 0 8px; font-size: 19px; font-weight: 600; }
.platform-dot { width: 8px; height: 8px; background: var(--platform); border-radius: 50%; }
.scan-hint { margin: 0 0 22px; color: #737b89; font-size: 13px; }
.qr-area { display: grid; place-items: center; width: min(100%, 220px); aspect-ratio: 1; margin: 0 auto 20px; }
.qr-placeholder { display: flex; align-items: center; justify-content: center; flex-direction: column; gap: 14px; width: 100%; height: 100%; border: 1px dashed #d9dfe7; border-radius: 12px; background: #f8f9fb; color: #737b89; font-size: 13px; }
.qr-symbol { font-size: 54px; line-height: 1; color: #a4adbb; }
.qr-image { display: block; width: 100%; height: 100%; object-fit: contain; background: #fff; }
.save-button { display: block; width: 100%; padding: 13px 10px; border-radius: 10px; color: var(--platform); background: var(--platform-bg); text-align: center; font-size: 14px; line-height: 1.5; font-weight: 500; }
.save-button:hover { filter: brightness(.96); }
.pending-note { margin: 0; padding: 13px 0; font-size: 13px; color: #737b89; }
.usage-note { margin: 24px 0; color: #737b89; font-size: 13px; line-height: 1.9; text-align: center; }
.contact-link { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 10px; padding: 19px 22px; border: 1px solid #e9ecf1; border-radius: 13px; background: #fff; font-size: 14px; }
.contact-link span { color: #737b89; }
.contact-link strong { color: #ee4b60; font-weight: 500; }
.contact-link:hover { border-color: #ee4b60; }
.contact-group { --platform: #c92e44; --platform-bg: #fff0f2; }
.contact-grid .qr-area { width: min(100%, 260px); aspect-ratio: 3 / 4; }
.contact-image-link { display: block; }
.contact-image { display: block; width: 100%; height: 100%; object-fit: contain; }
.friend-card { max-width: 430px; margin: 0 auto; }
.friend-card .qr-area { width: min(100%, 280px); }
.below-link { display: block; width: fit-content; margin: 26px auto 0; color: #737b89; font-size: 13px; padding: 10px; }
.site-footer { padding: 23px 16px; border-top: 1px solid #e9ecf1; color: #737b89; font-size: 12px; text-align: center; }
@media (max-width: 560px) {
  .site-header { padding: 14px 18px; }
  .brand { font-size: 15px; }
  .back-link { font-size: 12px; }
  .page { padding: 22px 18px 32px; }
  .page-nav { margin-bottom: 26px; }
  .page-nav a { padding: 11px 15px; font-size: 13px; }
  .group-grid { grid-template-columns: 1fr; gap: 18px; }
  .group-card { padding: 25px 24px 20px; }
  .qr-area { width: min(100%, 230px); }
}