body {
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: linear-gradient(to right, #3a0ca3, #7209b7, #f72585);
    overflow: hidden;
    font-family: 'Arial', sans-serif;
}

#calculator {
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid #ffffff1a;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    border-radius: 30px;
    max-width: 350px;
    overflow: hidden;
    padding: 20px;
    position: relative;
}

#display {
    width: 95%;
    padding: 10px;
    font-family: 'Orbitron', monospace;
    font-size: 2rem;
    letter-spacing: 0.4rem;
    text-align: right;
    background-color: rgba(0, 0, 50, 0.7);
    color: #ff00ff;
    border-radius: 15px;
    margin-bottom: 20px;
    box-shadow: inset 0 0 10px #ff00ff;
}

#keys {
    display: grid;
    grid-template-columns: repeat(4, 2fr);
    gap: 10px;
}

button {
    width: 100%;
    height: 80px;
    border-radius: 50% 20% / 30% 50%;
    border: none;
    background: rgba(255, 255, 255, 0.1);
    color: #ffffff;
    font-size: 2rem;
    font-weight: bold;
    cursor: pointer;
    position: relative;
    transition: transform 0.3s ease, background 0.3s ease;
    animation: squishy 5s infinite ease-in-out alternate;
}

@keyframes squishy {
    0% { transform: scale(1) rotate(0deg); }
    50% { transform: scale(1.02) rotate(1deg); }
    100% { transform: scale(0.98) rotate(-1deg); }
}

button:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1) rotate(2deg);
    animation: bounce 0.5s ease-out;
}

@keyframes bounce {
    0%   { transform: translateY(0); }
    30%  { transform: translateY(-10px); }
    50%  { transform: translateY(5px); }
    100% { transform: translateY(0); }
}

button:active {
    transform: scale(0.9) rotate(-2deg);
    background-color: #9d4edd;
}

.operator-btn {
    background-color: #f72585;
    color: #ffffff;
    border: 2px solid #ffb3e6;
}

.operator-btn:hover,
.operator-btn:active {
    background-color: #d63384;
    color: #ffe6fa;
}

button:hover::after {
    content: '';
    position: absolute;
    top: -60px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 60px;
    background-image: url('https://raw.githubusercontent.com/PokeAPI/sprites/master/sprites/pokemon/39.png'); /* Jigglypuff for fun */
    background-size: cover;
    animation: floatUp 1s ease-out forwards, spinny 1s linear;
    pointer-events: none;
}

@keyframes floatUp {
    0% {
        opacity: 0;
        transform: translateX(-50%) translateY(10px);
    }
    100% {
        opacity: 1;
        transform: translateX(-50%) translateY(-60px);
    }
}

@keyframes spinny {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}