body {
    font-family: Arial, Helvetica, sans-serif;
    background:#f4f6f8;
    margin:0;
}
.nav {
    background:#2c3e50;
    padding:10px 16px;
}
.nav a {
    color:#ecf0f1;
    margin-right:12px;
    text-decoration:none;
    font-weight:600;
}
.container {
    max-width:1000px;
    margin:20px auto;
    background:#fff;
    padding:18px;
    border-radius:8px;
    box-shadow:0 2px 6px rgba(0,0,0,0.06);
}
.login-box {
    width:360px;
    margin:80px auto;
    background:#fff;
    padding:22px;
    border-radius:8px;
    box-shadow:0 2px 8px rgba(0,0,0,0.08);
    text-align:center;
}
input[type=text], input[type=password], input[type=date], input[type=number] {
    width:95%;
    padding:8px 10px;
    margin:6px 0;
    border:1px solid #ccd0d5;
    border-radius:4px;
}
button {
    padding:10px 16px;
    border:none;
    border-radius:6px;
    background:#27ae60;
    color:white;
    cursor:pointer;
    font-weight:600;
}
.error { color: #c0392b; }
.card { background:#ecf0f1; padding:12px; margin:12px 0; border-radius:6px; }
.card.big { text-align:center; }
.saldo { font-size:36px; color:#16a085; font-weight:800; margin:8px 0; }
table { width:100%; border-collapse:collapse; margin-top:12px; }
table th, table td { padding:8px 10px; border:1px solid #e1e4e8; text-align:left; }
.btn { padding:6px 8px; text-decoration:none; border-radius:4px; background:#2980b9; color:#fff; margin-right:6px; font-size:0.9em; }
.btn.del { background:#c0392b; }
.link { display:inline-block; margin-top:8px; text-decoration:none; color:#2980b9; font-weight:600; }