:root{
    --bg:#eef2f6;
    --card:#ffffff;
    --text:#111827;
    --muted:#64748b;
    --border:#dbe3ee;
    --danger-bg:#fee2e2;
    --danger:#991b1b;
    --btn:#111827;
    --btn-text:#ffffff;
}
*{box-sizing:border-box}
html,body{min-height:100%;margin:0}
body{
    font-family:Arial,sans-serif;
    background:var(--bg);
    color:var(--text);
    min-height:100vh;
    min-height:100dvh;
    display:flex;
    align-items:center;
    justify-content:center;
    padding:18px;
}
.st-gate-card{
    background:var(--card);
    border:1px solid var(--border);
    border-radius:28px;
    padding:24px;
    max-width:520px;
    width:100%;
    box-shadow:0 22px 60px rgba(15,23,42,.14);
    text-align:center;
}
.st-gate-logo{
    font-size:34px;
    font-weight:1000;
    margin-bottom:10px;
    letter-spacing:-.04em;
}
.st-gate-logo sup{font-size:13px}
.st-gate-msg{
    color:var(--muted);
    line-height:1.55;
    margin-bottom:18px;
    font-size:15px;
}
.st-gate-card input{
    width:100%;
    padding:15px 16px;
    border:1px solid var(--border);
    border-radius:18px;
    margin-bottom:10px;
    font-size:16px;
    background:#fff;
    color:var(--text);
}
.st-gate-card button{
    width:100%;
    border:0;
    border-radius:999px;
    background:var(--btn);
    color:var(--btn-text);
    padding:15px 16px;
    font-weight:1000;
    font-size:16px;
    min-height:50px;
}
.st-gate-error{
    background:var(--danger-bg);
    color:var(--danger);
    border-radius:16px;
    padding:12px;
    margin-bottom:12px;
    font-weight:900;
    font-size:14px;
}
.st-gate-admin{
    display:inline-block;
    margin-top:14px;
    color:var(--muted);
    font-size:13px;
    text-decoration:none;
    font-weight:800;
}
@media(min-width:720px){
    .st-gate-card{padding:30px}
}