/* Page center karne ke liye */
body{
    margin: 0;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: Arial, sans-serif;
    background-image: url(OIP.jpeg);
    background-size: cover;
    background-repeat:no-repeat;
    background-position:center;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(4px);
  z-index: -1;
}

/* Calculator container */
#calculator{
    width: 400px;
    padding: 22px;
    border-radius: 18px;

    background: rgba(255,255,255,0.08);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);

    border: 1px solid rgba(255,255,255,0.2);

    box-shadow:
        0 25px 60px rgba(0,0,0,0.6),
        inset 0 1px 0 rgba(255,255,255,0.2);

    transition: transform .25s ease;
}

#calculator:hover{
    transform: translateY(-6px);
}

/* Display screen */
#display{
    width: 93%;
    height: 70px;
    padding: 12px;
    margin-bottom: 18px;
    overflow: hidden;
    white-space: nowrap;
    text-overflow: ellipsis;

    border-radius: 12px;
    border: none;
    outline: none;

    background: #0b0f14;
    color: #00ffc3;
    font-size: 30px;
    text-align: right;
    letter-spacing: 2px;
    font-weight: bold;

    box-shadow:
        inset 0 0 10px rgba(0,255,195,0.6),
        inset 0 0 25px rgba(0,255,195,0.2);

    text-shadow: 0 0 8px rgba(0,255,195,0.7);
}

/* Buttons grid */
.button-container{
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}
button{
    height: 65px;
    font-size: 25px;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    color: white;
    position: relative;
    overflow: hidden;

    box-shadow:
        0 6px 0 #1a252f,
        0 12px 20px rgba(0,0,0,0.5);

    transition: all .12s ease;
}

/* number buttons */
.button{
    background: linear-gradient(145deg,#3b5875,#2c3e50);
}

/* operator */
.button-grey{
    background: linear-gradient(145deg,#bdc3c7,#95a5a6);
    color: black;
}

/* clear */
.buttonC{
    background: linear-gradient(145deg,#ff7a7a,#e74c3c);
}

/* glossy shine */
button::after{
    content:"";
    position:absolute;
    top:3px;
    left:6px;
    right:6px;
    height:35%;
    border-radius:10px;
    background:linear-gradient(to bottom,
        rgba(255,255,255,0.35),
        rgba(255,255,255,0.05));
}

/* hover lift */
button:hover{
    transform: translateY(-2px);
}

/* press effect */
button:active{
    transform: translateY(6px);
    box-shadow:
        0 2px 0 #1a252f,
        0 4px 8px rgba(0,0,0,0.5);
}






/* Hover effect */
button:hover{
    opacity: 0.8;
}