* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    overflow-x: hidden;
    overflow-y: hidden;
    height: 100vh;
    width: 100vw;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(45deg, #000000, rgb(62, 59, 59));
    font-family: Arial, sans-serif;
}
header {
    background-color: #313030;
    color: #fff; /* White text color */
    text-align: left; 
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;

}

header img {
    width: 30px;
    height: 30px;
    margin-right: 10px;
}

.calculator {
    border: 2px solid #ffffff;
    border-radius: 15px;
    padding: 20px;
    background-color: transparent;
    box-shadow: 0px 3px 15px rgba(113, 115, 119, 0.5);
}
input {
    width: calc(100% - 20px);
    height: 4rem;
    background-color: transparent;
    border-radius: 20px;
    color: white;
    box-shadow: 0px 3px 15px rgba(84, 84, 84, 0.1);
    border: none;
    font-size: 2rem;
    text-align: right;
    margin: 10px;
    padding: 10px;
    outline: none;
}
input::placeholder {
    color: white;
    opacity: 0.6;
}
input:hover {
    background-color: rgba(67, 66, 66, 0.3);
    transform: scale(1);
}
button {
    height: 4rem;
    width: 4rem;
    border-radius: 50%;
    cursor: pointer;
    font-size: 1.5rem;
    font-weight: bold;
    background-color: rgba(255, 255, 255, 0.1);
    color: white;
    border: none;
    box-shadow: 0px 5px 25px rgba(84, 84, 84, 0.3);
    transition: background-color 0.3s ease, transform 0.2s ease;
}
button:hover {
    background-color: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}
.btn {
    display: flex;
    justify-content: space-around;
    margin: 1em 0;
}
.equal-btn {
    background-color: rgb(225, 156, 52);
}
.calculator::before,
.calculator::after {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    width: 100%;
    background: linear-gradient(90deg, rgba(255, 255, 255, 0.05) 0%, transparent 50%, transparent 100%);
    z-index: -1;
    pointer-events: none;
}
.calculator::before {
    left: -50%;
}
.calculator::after {
    right: -50%;
}

@media only screen and (max-width: 600px) {
    .calculator {
        padding: 5px;
    }
    input {
        font-size: 1.2rem;
    }
    button {
        font-size: 1rem;
    }
}