*{
    margin:0;
    padding:0;
    box-sizing:border-box;
    font-family:'Poppins',sans-serif;
}

body{
    background: linear-gradient(-45deg,#0f2027,#203a43,#2c5364,#1c1c1c);
    background-size:400% 400%;
    animation: gradient 10s ease infinite;
    height:100vh;
    display:flex;
    justify-content:center;
    align-items:center;
    color:white;
}

@keyframes gradient{
    0%{background-position:0% 50%}
    50%{background-position:100% 50%}
    100%{background-position:0% 50%}
}

/* CALCULATOR CARD */
.calculator{
    background:rgba(255,255,255,0.1);
    backdrop-filter:blur(15px);
    border-radius:25px;
    padding:30px;
    width:300px;
    box-shadow:0 20px 50px rgba(0,0,0,0.5);
}

.calculator h2{
    color:#00eaff;
    text-align:center;
    margin-bottom:20px;
}

/* DISPLAY */
.display{
    width:100%;
    height:50px;
    margin-bottom:20px;
    border-radius:15px;
    background:rgba(255,255,255,0.08);
    color:white;
    font-size:22px;
    text-align:right;
    padding:10px;
    overflow-x:auto;
}

/* BUTTONS */
.buttons{
    display:grid;
    grid-template-columns:repeat(4,1fr);
    gap:10px;
}

button{
    padding:20px;
    font-size:18px;
    border:none;
    border-radius:15px;
    cursor:pointer;
    background:rgba(0,234,255,0.2);
    color:white;
    transition:0.3s;
}

button:hover{
    background:linear-gradient(45deg,#00eaff,#00ffa2);
    transform:scale(1.05);
}

button.operator{
    background:rgba(255,165,0,0.3);
}

button.equals{
    background:#00ffa2;
    color:black;
    grid-column:span 2;
}