:root{--primary:#1677ff;--bg:#f7f8fa;--text:#111;--muted:#8a8a8a;--border:#eee;--maxw:640px}
html{font-size:clamp(14px,4vw,18px)}
*{box-sizing:border-box}
body{margin:0;min-height:100dvh;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,Helvetica,Arial,sans-serif;background:var(--bg);color:var(--text);padding-bottom:calc(env(safe-area-inset-bottom,0) + .5rem)}
.page-header{position:sticky;top:0;background:#fff;border-bottom:1px solid var(--border);padding:calc(env(safe-area-inset-top,0) + .5rem) 1rem .5rem}
.title{font-size:1.125rem;font-weight:600}
.container{padding:1rem;max-width:var(--maxw);margin:0 auto}
.merchant{display:flex;align-items:center;background:#fff;border-radius:.75rem;padding:1rem;gap:.75rem}
.avatar{width:2.5rem;height:2.5rem;border-radius:.5rem;background:#e8f2ff;display:flex;align-items:center;justify-content:center;font-size:1.25rem}
.avatar.large{width:4rem;height:4rem;font-size:2rem;margin:0 auto}
.info .name{font-size:1rem;font-weight:600}
.info .desc{color:var(--muted);font-size:.8125rem;margin-top:.125rem}
.amount{margin-top:.75rem;background:#fff;border-radius:.75rem;padding:1rem}
.currency{font-size:1.125rem;color:var(--muted)}
.amount-input{width:100%;font-size:2.25rem;border:none;outline:none;padding:.375rem 0;margin:.375rem 0}
.quick-row{display:flex;gap:.5rem;margin:.625rem 0 .25rem}
.chip{flex:1;padding:.5rem 0;border:1px solid var(--border);border-radius:9999px;background:#fff}
.row{display:flex;justify-content:space-between;align-items:center;padding:.75rem 0;border-top:1px solid var(--border);font-size:.875rem}
.row.total span:last-child{color:var(--text);font-weight:600}
.muted{color:var(--muted)}
.action{margin-top:1rem}
.primary{display:block;width:100%;padding:.875rem 0;background:var(--primary);color:#fff;border:none;border-radius:.625rem;text-align:center;text-decoration:none;margin-bottom:env(safe-area-inset-bottom,0)}
.secondary{display:block;width:100%;padding:.75rem 0;background:#fff;border:1px solid var(--border);color:var(--text);border-radius:.625rem;text-align:center;text-decoration:none}
.block{margin-top:.625rem}
.tip{margin-top:.625rem;color:var(--muted);font-size:.75rem;text-align:center}
.about-card{background:#fff;border-radius:.75rem;padding:1rem;text-align:center}
.about-card .name{font-size:1.125rem;font-weight:600;margin-top:.5rem}
.about-card .desc{color:var(--muted);font-size:.875rem;margin-top:.25rem}
.list{list-style:none;margin:1rem 0 0;padding:0;border-top:1px solid var(--border)}
.list li{display:flex;justify-content:space-between;padding:.75rem 0;border-bottom:1px solid var(--border);font-size:.875rem}
.center{display:flex;flex-direction:column;align-items:center;gap:.625rem}
.success-icon{width:5.25rem;height:5.25rem;border-radius:50%;background:#e8f7e8;color:#10b981;display:flex;align-items:center;justify-content:center;font-size:3rem;margin-top:1.25rem}
.success-text{font-size:1.125rem;font-weight:600}

@media (max-width:340px){
  .amount-input{font-size:2rem}
  .chip{padding:.4rem 0}
}

@media (orientation:landscape) and (max-height:420px){
  .amount-input{font-size:1.75rem}
}