body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #1a1a1a;
    color: white;
    font-family: Arial, sans-serif;
    overflow: hidden;
    transition: background-color 1s;
}
.container {
    text-align: center;
}
input {
    padding: 10px;
    font-size: 16px;
    margin-top: 10px;
    border: 2px solid white;
    transition: border-color 0.3s, transform 0.1s;
}
button {
    padding: 10px;
    font-size: 16px;
    cursor: pointer;
    margin-top: 10px;
}
.hidden {
    display: none;
}
.wrong {
    border-color: red !important;
    animation: shake 0.3s;
}
@keyframes shake {
    0% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    50% { transform: translateX(5px); }
    75% { transform: translateX(-5px); }
    100% { transform: translateX(0); }
}
.success {
    animation: glow 1s infinite alternate;
    border-color: limegreen !important;
}
@keyframes glow {
    from { box-shadow: 0 0 10px limegreen; }
    to { box-shadow: 0 0 20px limegreen; }
}
#fireworks {
    position: absolute;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: url('https://media.giphy.com/media/3oEjI6SIIHBdRxXI40/giphy.gif') center/cover no-repeat;
}