body {
    background: #f8f9fa;
}
.card {
    box-shadow: 0 2px 8px rgba(0,0,0,0.07);
    border-radius: 1rem;
}
input[type="text"]#passwordResult {
    font-size: 1.5rem;
    letter-spacing: 0.1em;
    background: #f4f4f4;
    border: none;
    border-radius: .25rem 0 0 .25rem;
}
#copyBtn, #refreshBtn {
    font-size: 1.3rem;
}
#copyBtn:focus, #refreshBtn:focus {
    outline: none;
    box-shadow: 0 0 0 0.2rem #007bff33;
}
.custom-range {
    width: 100%;
}
.custom-control-label {
    cursor: pointer;
}
.btn-primary {
    background: #d32f2f;
    border: none;
}
.btn-primary:hover {
    background: #b71c1c;
}