:root{--line:#e2e8f0;--gray:#64748b;--ink:#0f172a;--bad:#b91c1c;--pri:#2563eb}
body{font:15px/1.5 ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,sans-serif;color:var(--ink);margin:0;background:#f8fafc}
main{max-width:520px;margin:6vh auto;padding:0 1rem}
.card{background:#fff;border:1px solid var(--line);border-radius:10px;padding:1.4rem 1.6rem}
h1{font-size:1.25rem;margin:0 0 .3rem}
.sub{color:var(--gray);font-size:.9rem;margin:0 0 1rem}
label{display:block;font-size:.85rem;color:var(--gray);margin:.7rem 0 .2rem}
input{width:100%;box-sizing:border-box;font:inherit;padding:.55rem .65rem;border:1px solid var(--line);border-radius:7px}
button{font:inherit;width:100%;padding:.6rem;margin-top:1rem;border:0;border-radius:7px;background:var(--pri);color:#fff;cursor:pointer}
button.alt{background:#fff;color:var(--pri);border:1px solid var(--line)}
button:disabled{opacity:.6;cursor:not-allowed}
.err{display:none;margin-top:.9rem;padding:.6rem .8rem;border-radius:7px;background:#fef2f2;color:var(--bad);border:1px solid #fecaca}
.err.on{display:block}
.hint{color:var(--gray);font-size:.82rem}
.sep{display:flex;align-items:center;gap:.6rem;color:var(--gray);font-size:.8rem;margin:1rem 0}
.sep:before,.sep:after{content:"";flex:1;border-top:1px solid var(--line)}
a.link{display:block;padding:.8rem 1rem;border:1px solid var(--line);border-radius:8px;text-decoration:none;color:var(--ink);margin:.5rem 0;background:#fff}
a.link:hover{border-color:var(--pri)}
a.link small{display:block;color:var(--gray)}
.top{display:flex;justify-content:space-between;align-items:center;gap:1rem;margin-bottom:1rem}
.top button{width:auto;margin:0;padding:.4rem .8rem}
#gsi{display:flex;justify-content:center;min-height:44px}