:root{--navy:#003399;--navy-dark:#002666;--gold:#c8a45c;}
*{box-sizing:border-box;}
html,body{margin:0;height:100%;}
body{font-family:"Microsoft YaHei","PingFang SC","Hiragino Sans GB","Noto Sans CJK SC",sans-serif;
  background:linear-gradient(180deg,#eef2f8,#dfe7f2);color:#222;display:flex;align-items:center;justify-content:center;min-height:100vh;padding:16px;}
.gate-card{background:#fff;border:1px solid #e3ddcf;border-radius:14px;box-shadow:0 10px 40px rgba(0,40,120,.18);
  max-width:420px;width:100%;padding:30px 28px;text-align:center;}
.gate-card h1{color:var(--navy);font-size:21px;line-height:1.5;margin:0 0 10px;font-weight:700;}
.gate-sub{color:#555;margin:0 0 22px;font-size:14px;}
#gate-form{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;}
#pw{flex:1 1 200px;min-width:0;padding:12px 14px;border:1px solid #c7c7c7;border-radius:8px;font-size:16px;outline:none;}
#pw:focus{border-color:var(--navy);}
button{background:linear-gradient(180deg,var(--navy),var(--navy-dark));color:#fff;border:0;border-radius:8px;
  padding:12px 22px;font-size:16px;cursor:pointer;letter-spacing:2px;}
button:hover{opacity:.92;}
button:disabled{opacity:.6;cursor:default;}
.gate-msg{color:#c0392b;min-height:20px;font-size:14px;margin:14px 0 0;}
.gate-foot{color:#999;font-size:12px;margin:18px 0 0;line-height:1.6;}
@media(max-width:480px){#pw{flex:1 1 100%;}button{flex:1 1 100%;}}