*{
    box-sizing:border-box;
}
body{
    margin:0;
    font-family:Arial, sans-serif;
    background:#f4f4f4;
    min-height:100vh;
    display:flex;
    flex-direction:column;
}
.franja-superior,
.franja-inferior{
    height:10px;
    background:#8b0000;
    width:100%;
}
.banner{
    width:100%;
    background:#ffffff;
    text-align:center;
    padding:10px 0;
}
.banner img{
    max-width:100%;
    height:auto;
    display:block;
    margin:0 auto;
}
.contenedor{
    flex:1;
    display:flex;
    align-items:center;
    justify-content:center;
    padding:30px 20px;
}
.login-box{
    width:100%;
    max-width:420px;
    background:#fff;
    border-radius:16px;
    box-shadow:0 10px 28px rgba(0,0,0,.10);
    padding:30px 28px;
    text-align:center;
}
.titulo{
    font-size:20px;
    color:#8b0000;
    margin:0 0 8px 0;
    font-weight:bold;
}
.subtitulo{
    font-size:14px;
    color:#555;
    margin-bottom:24px;
    line-height:1.5;
}
.btn-google{
    display:flex;
    align-items:center;
    justify-content:center;
    gap:12px;
    width:100%;
    text-decoration:none;
    background:#fff;
    color:#333;
    border:1px solid #dcdcdc;
    border-radius:10px;
    padding:14px 16px;
    font-size:15px;
    font-weight:600;
    transition:.2s ease;
}
.btn-google:hover{
    box-shadow:0 4px 12px rgba(0,0,0,.08);
    transform:translateY(-1px);
}
.google-icon{
    width:20px;
    height:20px;
}
.mensaje-error{
    margin-top:18px;
    background:#ffe6e6;
    color:#9b0000;
    padding:12px;
    border-radius:10px;
    font-size:14px;
}
.nota{
    margin-top:20px;
    font-size:13px;
    color:#777;
    line-height:1.5;
}