body {
    background: linear-gradient(135deg, #ff0066, #ffdd00, #00ff99, #00aaff, #a400ff);
    background-size: 400% 400%;
    animation: gradient 15s ease infinite;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    font-family: Arial, sans-serif;
    margin: 0;
}

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

.calculator {
    max-width: 400px;
    width: 100%;
    background-color: #ffffff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    padding: 30px;
    border-radius: 20px;
    text-align: center;
}

h3 {
    padding-bottom: 20px;
    margin: auto;
    font-weight: 300;
    color: #333333;
}

.button-85 {
    padding: 0.6em 2em;
    border: none;
    outline: none;
    color: #ffffff;
    background: #007bff;
    cursor: pointer;
    position: relative;
    z-index: 0;
    border-radius: 10px;
    user-select: none;
    margin: 10px;
    transition: background-color 0.3s ease;
}

.button-85:hover {
    background-color: #0056b3;
}

.button-85:active {
    background-color: #003f7f;
}

.button-85:before,
.button-85:after {
    content: "";
    position: absolute;
    width: calc(100% + 4px);
    height: calc(100% + 4px);
    border-radius: 10px;
    z-index: -1;
}

.button-85:before {
    top: -2px;
    left: -2px;
    background: linear-gradient(45deg, #ff0000, #ff7300, #fffb00, #48ff00, #00ffd5, #002bff, #7a00ff, #ff00c8, #ff0000);
    background-size: 400%;
    filter: blur(5px);
    animation: glowing-button-85 20s linear infinite;
}

@keyframes glowing-button-85 {
    0% {
        background-position: 0 0;
    }
    50% {
        background-position: 400% 0;
    }
    100% {
        background-position: 0 0;
    }
}

.button-85:after {
    background: #222222;
    top: 0;
    left: 0;
}

.form-group {
    text-align: left;
    margin-bottom: 20px;
}

.form-control {
    border-radius: 10px;
}