.back {
    color:#166534;
    display:block;
    font-weight:bold;
    margin-top:16px;
    text-align:center;
    text-decoration:none;
}

body {
    align-items:center;
    background:linear-gradient(135deg,#06130d,#0b2418);
    display:flex;
    font-family:Arial, sans-serif;
    justify-content:center;
    margin:0;
    min-height:100vh;
}

button {
    background:linear-gradient(135deg,#166534,#22c55e);
    border:none;
    border-radius:14px;
    color:white;
    cursor:pointer;
    font-weight:bold;
    padding:14px;
    width:100%;
}

.error {
    background:#fee2e2;
    border-radius:10px;
    color:#991b1b;
    font-weight:bold;
    margin-bottom:18px;
    padding:12px;
}

.form {
    padding:28px;
}

.header {
    background:linear-gradient(135deg,#0b2418,#166534);
    color:white;
    padding:28px;
}

input {
    border:1px solid #dbe8df;
    border-radius:12px;
    box-sizing:border-box;
    margin-bottom:18px;
    padding:14px;
    width:100%;
}

label {
    display:block;
    font-weight:bold;
    margin-bottom:8px;
}

.login-card {
    background:#f6fbf8;
    border-radius:26px;
    box-shadow:0 25px 70px rgba(0,0,0,.35);
    overflow:hidden;
    width:420px;
}