* { box-sizing: border-box; margin: 0; padding: 0; }
html, body { min-height: 100%; }
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: #f6f7fb;
  color: #161823;
}
.header {
  position: relative;
  background: linear-gradient(160deg, #111 0%, #1b1b1b 55%, #25f4ee 140%);
  color: #fff;
  text-align: center;
  padding: 36px 20px 72px;
  overflow: hidden;
}
.logo {
  width: 92px;
  height: 92px;
  margin: 0 auto 12px;
  border-radius: 22px;
  background: #fff url("logo.png") center/cover no-repeat;
  box-shadow: 0 8px 24px rgba(0, 0, 0, .28);
}
.header h1 { font-size: 28px; letter-spacing: .5px; }
.header p { margin-top: 6px; font-size: 13px; opacity: .8; }
.wave {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 42px;
}
.panel { padding: 8px 22px 40px; max-width: 480px; margin: 0 auto; }
.btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  height: 54px;
  margin-top: 18px;
  border: 0;
  border-radius: 14px;
  background: #111;
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  cursor: pointer;
}
.btn svg { width: 22px; height: 22px; fill: currentColor; }
.btn small { display: block; font-size: 11px; font-weight: 500; opacity: .7; letter-spacing: .4px; }
.btn-android { background: #111; }
.help {
  display: block;
  margin: 12px auto 0;
  text-align: center;
  color: #fe2c55;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  background: none;
  border: 0;
}
.card {
  margin-top: 22px;
  background: #fff;
  border-radius: 16px;
  padding: 16px 18px;
  box-shadow: 0 6px 20px rgba(22, 24, 35, .06);
}
.card h3 { font-size: 15px; margin-bottom: 8px; }
.card div { font-size: 13px; line-height: 1.7; color: #555; }
.footer {
  text-align: center;
  color: #9a9aa3;
  font-size: 13px;
  padding: 8px 0 28px;
}
.desktop {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: #fff;
  text-align: center;
  padding: 40px 20px;
}
#qcode { width: 240px; height: 240px; margin: 0 auto 18px; }
#qcode img, #qcode canvas { width: 240px !important; height: 240px !important; }
.desktop h2 { color: #fe2c55; font-size: 22px; margin-bottom: 8px; }
.desktop h4 { font-weight: 500; color: #333; font-size: 15px; }
.mask {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .82);
  color: #fff;
  z-index: 20;
  padding: 28px 24px;
  text-align: right;
}
.mask b { display: block; text-align: left; margin-top: 80px; font-size: 18px; line-height: 1.6; }
.modal {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, .45);
  z-index: 30;
  overflow: auto;
}
.modal-content {
  background: #fff;
  margin: 24px auto 40px;
  width: min(520px, calc(100% - 28px));
  border-radius: 16px;
  padding: 18px 18px 28px;
}
.modal-content h2 { text-align: center; font-size: 22px; margin: 8px 0 16px; }
.modal-content p { font-size: 15px; line-height: 1.6; margin: 14px 0 6px; }
.close {
  float: right;
  cursor: pointer;
  font-size: 20px;
  color: #888;
}
.step {
  background: #f6f7fb;
  border-radius: 10px;
  padding: 10px 12px;
  color: #333;
  font-size: 14px;
}