*{box-sizing:border-box}
body{margin:0;min-height:100vh;display:flex;align-items:center;justify-content:center;font-family:system-ui,sans-serif;background:linear-gradient(135deg,#0f1b2d,#0b5fff);color:#0f1b2d}
.panel{background:#fff;border-radius:14px;padding:2rem;width:min(380px,92vw);box-shadow:0 10px 40px rgba(0,0,0,.3)}
h1{margin:0 0 .2rem;font-size:1.5rem}
.sub{margin:0 0 1.2rem;color:#667}
label{display:block;font-size:.85rem;margin-bottom:.8rem}
input{display:block;width:100%;margin-top:.25rem;padding:.65rem;border:1px solid #ccd;border-radius:8px;font:inherit}
button{width:100%;padding:.7rem;border:0;border-radius:8px;background:#0b5fff;color:#fff;font:inherit;font-weight:600;cursor:pointer}
#error{color:#c22;min-height:1.2em;margin:.2rem 0 .6rem;font-size:.9rem}
.back{text-align:center;margin:1rem 0 0;font-size:.85rem}
.back a{color:#0b5fff}