:root{
    --primary:#2f7cf6;
    --primary-d:#1f63d6;
    --bg:#f2f5fa;
    --card:#ffffff;
    --text:#1f2733;
    --muted:#8a94a6;
    --ok:#19b36b;
    --err:#e54545;
}
*{box-sizing:border-box;-webkit-tap-highlight-color:transparent}
body{margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"PingFang SC","Microsoft YaHei",sans-serif;background:var(--bg);color:var(--text)}
.app{max-width:480px;margin:0 auto;padding:16px 14px 40px;min-height:100vh}

.topbar{text-align:center;padding:18px 0 8px}
.logo{font-size:22px;font-weight:700}
.sub{color:var(--muted);font-size:13px;margin-top:4px}

.card{background:var(--card);border-radius:16px;padding:18px 16px;box-shadow:0 6px 20px rgba(31,39,51,.06);margin-top:14px}
.card-title{font-size:15px;margin:18px 0 10px;color:var(--text)}
.card-title:first-child{margin-top:0}

.field{display:block;margin-bottom:12px}
.field>span{display:block;font-size:12px;color:var(--muted);margin-bottom:6px}
.field input{width:100%;height:44px;border:1px solid #e2e7f0;border-radius:10px;padding:0 12px;font-size:15px;outline:none;background:#fbfcfe}
.field input:focus{border-color:var(--primary);background:#fff}

.divider{display:flex;align-items:center;color:var(--muted);font-size:12px;margin:6px 0 14px}
.divider::before,.divider::after{content:"";flex:1;height:1px;background:#e6eaf1}
.divider span{padding:0 10px}

.btn-primary{width:100%;height:48px;border:none;border-radius:12px;background:var(--primary);color:#fff;font-size:16px;font-weight:600;margin-top:6px;cursor:pointer}
.btn-primary:active{background:var(--primary-d)}
.btn-primary:disabled{opacity:.6}

.result{margin-top:14px;padding:12px 14px;border-radius:10px;font-size:14px;line-height:1.5}
.result.ok{background:#e8f8f0;color:#137a4d}
.result.err{background:#fdeaea;color:#b3271f}

.foot{text-align:center;color:var(--muted);font-size:12px;margin-top:22px}

/* 内容区居中模态弹窗广告 */
.ad-modal{position:fixed;inset:0;z-index:9999;display:flex;align-items:center;justify-content:center;padding:16px}
.ad-modal[hidden]{display:none}
.ad-backdrop{position:absolute;inset:0;background:rgba(15,23,42,.45);animation:fadeIn .25s ease}
.ad-dialog{position:relative;width:340px;max-width:92vw;max-height:86vh;overflow-y:auto;background:#fff;border-radius:16px;box-shadow:0 18px 50px rgba(0,0,0,.28);animation:popIn .3s ease}
.ad-dialog .ad-head{position:sticky;top:0;display:flex;justify-content:space-between;align-items:center;padding:12px 14px;background:linear-gradient(135deg,#2f7cf6,#6aa1ff);color:#fff;font-size:15px;font-weight:600}
.ad-dialog .ad-close{border:none;background:rgba(255,255,255,.25);color:#fff;width:26px;height:26px;border-radius:50%;cursor:pointer;font-size:16px;line-height:1}
.ad-dialog .ad-body{padding:16px}
.ad-dialog .ad-desc{font-size:13px;color:var(--muted);margin:8px 0}
.ad-dialog img{max-width:100%;border-radius:10px;display:block;margin:0 auto}
.ad-dialog .ad-qq-num{font-size:15px;font-weight:700;margin:8px 0;word-break:break-all}
.ad-dialog .ad-btn{display:block;text-align:center;margin-top:12px;padding:11px;border-radius:10px;background:var(--primary);color:#fff;text-decoration:none;font-size:14px;font-weight:600}
.ad-dialog .ad-rt{font-size:14px;line-height:1.6}
.ad-dialog .ad-rt img{max-width:100%;border-radius:8px;margin:8px auto}
.ad-dialog .ad-rt a{color:var(--primary)}

.hint.center{text-align:center;margin-top:16px}
.hint.center a{color:var(--primary);text-decoration:none}

@keyframes fadeIn{from{opacity:0}to{opacity:1}}
@keyframes popIn{from{opacity:0;transform:translateY(12px) scale(.96)}to{opacity:1;transform:none}}