body {
    margin: 0;
    min-height: 100vh;
    display: grid;
    place-items: center;
    background: linear-gradient(135deg, #e9eef2, #d6dee5);
    color: #1f2933;
    font-family: "Segoe UI", Tahoma, sans-serif;
}

h1 {
    margin-bottom: 0.5rem;
}

h4 {
    margin: 0;
    line-height: 1.4;
}

.err {
    background: #ffffff;
    border: 1px solid #cdd5df;
    border-radius: 10px;
    padding: 1rem 1.25rem;
}