* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Roboto', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background: #111;
    position: relative;
    overflow: hidden;
}

.background {
    position: absolute;
    z-index: -2;
}

.circle {
    position: absolute;
    border-radius: 50%;
    opacity: 0.4;
    animation: float 30s ease-in-out infinite;
}

.c1 {
    width: 200px;
    height: 200px;
    background-color: rgba(255, 255, 255, 0.1);
    top: 10%;
    left: 20%;
    animation-duration: 40s;
}

.c2 {
    width: 250px;
    height: 250px;
    background-color: rgba(255, 255, 255, 0.15);
    top: 60%;
    left: 70%;
    animation-duration: 50s;
}

.c3 {
    width: 150px;
    height: 150px;
    background-color: rgba(255, 255, 255, 0.2);
    top: 50%;
    left: 10%;
    animation-duration: 60s;
}


.calculator-container {
    background: #202d4c;
    padding: 40px;
    border-radius: 30px;
    width: 600px;
    height: 700px;
    max-width: 100%;
    box-shadow: 0px 5px 10px rgba(0, 0, 0, 0.3);
    position: relative;
    z-index: 1;
    animation: pulse 2s ease-in-out infinite;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

@keyframes pulse {
    0% {
        box-shadow: 0 0 5px #00f1ff, 0 0 15px #00f1ff, 0 0 30px #00f1ff;
    }
    50% {
        box-shadow: 0 0 10px #00f1ff, 0 0 30px #00f1ff, 0 0 40px #00f1ff;
    }
    100% {
        box-shadow: 0 0 5px #00f1ff, 0 0 15px #00f1ff, 0 0 30px #00f1ff;
    }
}

.calculator-title {
    font-size: 2.5rem;
    color: #00f1ff;
    text-align: center;
    margin-bottom: 20px;
}

.screen {
    background-color: #ffffff;
    padding: 20px;
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: inset 0px 4px 10px rgba(0, 0, 0, 0.1);
}

#display {
    width: 100%;
    height: 70px;
    border: none;
    background-color: #f9f9f9;
    text-align: right;
    font-size: 2.8rem;
    color: #333;
    border-radius: 10px;
    padding: 10px;
    box-shadow: inset 0 3px 10px rgba(0, 0, 0, 0.1);
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 15px;
}

.button {
    background-color: #ffffff;
    border: none;
    padding: 20px;
    font-size: 1.8rem;
    color: #333;
    border-radius: 15px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0px 5px 15px rgba(0, 0, 0, 0.1);
}

.button:hover {
    background-color: #c1e0e0;
    transform: translateY(-4px);
    box-shadow: 0 0 10px #00f1ff, 0 0 20px #00f1ff, 0 0 30px #00f1ff;
}

.button:active {
    background-color: #a0b8b8;
    box-shadow: none;
    transform: translateY(2px);
}

.operator {
    background-color: #fdb813;
    color: #333;
}

.operator:hover {
    background-color: #f9a100;
    box-shadow: 0 0 10px #f9a100, 0 0 20px #f9a100;
}

.equal {
    background-color: #009688;
    color: white;
}

.equal:hover {
    background-color: #00796b;
    box-shadow: 0 0 10px #009688, 0 0 20px #009688;
}

.clear {
    background-color: #e53935;
    color: white;
}

.clear:hover {
    background-color: #d32f2f;
    box-shadow: 0 0 10px #e53935, 0 0 20px #e53935;
}

.button:disabled {
    background-color: #ccc;
    color: #888;
}

.footer-text {
    text-align: center;
    color: #f7f3f9;
    font-size: 1.2rem;
    margin-top: 10px;
}