:root{
  --bg:#f7f8fa;
  --card:#ffffff;
  --line:#e8ebf0;
  --text:#1f2328;
  --sub:#6b7280;
  --accent:#FF2442;
  --accent-weak:#fff1f2;
  --accent-soft:#fff7f7;
  --muted:#939aa3;
  --ok:#22c55e;
  --ok-weak:#ecfdf5;
  --ok-border:#bbf7d0;
  --ok-dark:#16a34a;
}
*{margin:0;padding:0;box-sizing:border-box;font-family:"PingFang SC","Helvetica Neue",Arial,sans-serif}
body{background:var(--bg);color:var(--text);line-height:1.6;padding:0 15px;max-width:500px;margin:0 auto}
.container{background:var(--card);border:1px solid var(--line);border-radius:14px;box-shadow:0 10px 24px rgba(31,35,40,.05);margin:15px 0 30px;overflow:hidden}
header{background:linear-gradient(180deg, #FF2442 0%, #ff5166 100%);position:relative;color:#fff;padding:26px 16px;text-align:center}
header::after{content:"";position:absolute;inset:auto 0 -1px 0;height:1px;background:linear-gradient(90deg,transparent,rgba(255,255,255,.45),transparent)}
h1{font-size:26px;font-weight:800;margin-bottom:8px;letter-spacing:.3px;color:#fff}
.subtitle{font-size:13.5px;color:#ffe5e9}
.breadcrumb{font-size:12px;color:var(--sub);padding:10px 15px;background:#fafafb;border-bottom:1px solid var(--line)}
.breadcrumb a{color:var(--accent);text-decoration:none}
.form-section{padding:18px 15px}
.input-group{margin-bottom:18px}
.input-group label{display:block;font-size:14px;margin-bottom:8px;font-weight:600;color:var(--text)}
.input-group input{width:100%;padding:12px 14px;border:1px solid var(--line);background:#fff;color:var(--text);border-radius:10px;font-size:15.5px;transition:border-color .25s, box-shadow .25s}
.input-group input::placeholder{color:#9aa3ad}
.input-group input:focus{border-color:var(--accent);outline:0;box-shadow:0 0 0 3px rgba(255,36,66,.12)}
.section-title{font-size:17px;font-weight:700;margin:14px 0 12px;color:var(--text)}
.amount-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:10px;margin-bottom:12px}
.amount-option{border:1px solid var(--line);border-radius:12px;padding:10px 8px;text-align:center;cursor:pointer;transition:all .2s;background:#fff}
.amount-option:hover{border-color:rgba(255,36,66,.5);box-shadow:0 4px 14px rgba(255,36,66,.08)}
.amount-option.selected{border-color:var(--accent);background:var(--accent-soft);position:relative;box-shadow:0 6px 18px rgba(255,36,66,.15)}
.amount-option.selected::after{content:"✓";position:absolute;top:-8px;right:-8px;background:var(--accent);color:#fff;width:20px;height:20px;border-radius:50%;font-size:12px;display:flex;align-items:center;justify-content:center}
.amount-coins-main{font-size:16px;font-weight:800;color:var(--accent);margin-bottom:2px;line-height:1.2}
.amount-bonus{font-size:12px;color:var(--ok-dark);font-weight:400;margin-bottom:2px;line-height:1.2}
.amount-price{font-size:12px;color:var(--sub);font-weight:700;line-height:1.2}
.coupon-tip{background:var(--ok-weak);border:1px dashed var(--ok-border);color:var(--ok-dark);padding:10px 12px;border-radius:10px;font-size:13px;margin:12px 0;display:flex;justify-content:space-between;align-items:center;gap:10px}
.coupon-tip b{color:#0a7a33}
.coupon-tip button{background:var(--ok);color:#fff;border:0;border-radius:10px;cursor:pointer}
.coupon-tip .btn-2line{display:flex;flex-direction:column;align-items:center;justify-content:center;min-width:60px;min-height:60px;padding:10px 12px;line-height:1}
.coupon-tip .btn-2line span{white-space:nowrap;letter-spacing:0;margin:0;padding:0;font-size:13px;font-weight:800;color:#fff}
.coupon-row{display:flex;align-items:center;justify-content:space-between;background:#fff;border:1px solid var(--line);padding:10px 12px;border-radius:10px;margin:10px 0}
.coupon-row .label{font-size:13px;color:var(--sub)}
.coupon-row .value{font-weight:800;color:#111}
.coupon-row .actions{display:flex;gap:8px}
.coupon-row .actions button{background:#fff;border:1px solid var(--line);color:var(--text);border-radius:8px;padding:6px 10px;font-size:12px;cursor:pointer}
.coupon-row .actions button.primary{background:var(--ok);border-color:var(--ok);color:#fff}
.payment-methods{display:flex;gap:12px;margin:12px 0}
.payment-method{flex:1;border:1px solid var(--line);border-radius:10px;padding:12px;text-align:center;cursor:pointer;transition:all .2s;background:#fff;color:var(--text)}
.payment-method.selected{border-color:var(--accent);background:var(--accent-soft);box-shadow:0 6px 18px rgba(255,36,66,.12)}
.payment-method img{width:30px;height:30px;margin-bottom:5px;filter:none}
.payment-method span{font-size:14px;display:block}
.total-amount{background:#fff;padding:12px;border-radius:12px;margin:12px 0;text-align:center;border:1px solid var(--line)}
.total-label{font-size:13px;color:var(--sub);margin-bottom:4px}
.total-price{font-size:22px;font-weight:900;color:#111}
.origin{font-size:12px;color:#9aa0a6;text-decoration:line-through;margin-left:8px}
.agreement{display:flex;align-items:center;margin:10px 0 16px;font-size:12.5px;color:var(--sub)}
.agreement input{margin-right:8px}
.agreement a{color:#b42335;text-decoration:none}
.recharge-btn{background:linear-gradient(135deg,var(--accent) 0%,#ff556c 100%);color:#fff;border:0;border-radius:12px;padding:14px;font-size:16px;font-weight:900;width:100%;cursor:pointer;box-shadow:0 10px 24px rgba(255,36,66,.25);transition:transform .08s ease}
.recharge-btn:active{transform:translateY(1px)}
footer{text-align:center;padding:20px 0;font-size:12px;color:#6b7280;border-top:1px solid var(--line);margin-top:20px}
.footer-links{margin-bottom:10px}
.footer-links a{color:#6b7280;text-decoration:none;margin:0 8px}
@media (max-width:420px){.amount-grid{grid-template-columns:repeat(2,1fr)}}
@media (max-width:360px){.amount-grid{grid-template-columns:1fr}}