:root{--bg:#1a1a2e;--shell:#16162a;--line:#2a2a4a;--ink:#e8e8f0;--muted:#8a8aaa;--accent:#4a9eff;--warning:#f5c542;}
*{box-sizing:border-box;}
body{margin:0;height:100vh;background:linear-gradient(160deg,#1e1e3a,#12121f);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",sans-serif;
  display:flex;align-items:center;justify-content:center;color:var(--ink);}
.login-card{width:360px;max-width:92vw;background:#1b1b30;border:1px solid var(--line);
  border-radius:16px;padding:32px 30px;box-shadow:0 12px 40px rgba(0,0,0,.4);}
.login-brand{font-size:22px;font-weight:780;letter-spacing:.05em;text-align:center;margin-bottom:22px;}
.brand-mark{display:inline-flex;width:34px;height:34px;background:#1e3a5f;color:#fff;border-radius:8px;
  align-items:center;justify-content:center;font-size:15px;margin-right:8px;vertical-align:middle;}
.login-tabs{display:flex;gap:6px;margin-bottom:20px;border-bottom:2px solid var(--line);}
.ltab{flex:1;border:none;background:none;padding:10px;font-size:15px;color:var(--muted);cursor:pointer;
  border-bottom:2px solid transparent;margin-bottom:-2px;font-family:inherit;}
.ltab.active{color:var(--accent);border-bottom-color:var(--accent);font-weight:640;}
.lfield{display:flex;flex-direction:column;gap:6px;font-size:13px;color:var(--muted);margin-bottom:16px;}
.lfield input{padding:11px 13px;border:1.5px solid var(--line);border-radius:9px;background:#12121f;
  color:var(--ink);font-size:14.5px;font-family:inherit;}
.lfield input:focus{outline:none;border-color:var(--accent);}
.login-btn{width:100%;border:none;background:var(--accent);color:#fff;font-size:15.5px;font-weight:640;
  padding:12px;border-radius:10px;cursor:pointer;margin-top:4px;}
.login-btn:hover{background:#3a8eef;}
.login-btn:disabled{opacity:.5;cursor:not-allowed;}
.login-err{color:#ff6b6b;font-size:13px;min-height:18px;margin-bottom:8px;}
.login-hint{text-align:center;color:var(--muted);font-size:12.5px;margin:16px 0 0;}