style.css

* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: "Rubik", sans-serif;
    }
    body {
    height: 100vh;
    background: rgb(245, 239, 66);
    }
    .container {
    width: 70vw;
    max-width: 37.5em;
    background-color: #f6f9fa;
    padding: 3em 1em;
    position: absolute;
    transform: translate(-50%, -50%);
    top: 50%;
    left: 50%;
    border-radius: 2rem;
    }
    .heading{
    background: rgb(18, 128, 207);
    color: white;
    margin: -48px -16px 50px -16px;
    font-size: 23px;
    padding: 5px;
    text-align: center;
    }
    .inp-wrapper {
    display: flex;
    justify-content: space-around;
    gap: 1.2em;
    }
    label {
    color: #0f1e32;
    display: block;
    font-weight: 600;
    }
    input[type="date"] {
    font-size: 16px;
    padding: 1em;
    color: #242831;
    border: 2px solid rgb(7, 108, 147);
    outline: none;
    border-radius: 0.2em;
    margin-top: 0.6em;
    }
    ::-webkit-calendar-picker-indicator {
    background-color: #7eceee;
    padding: 0.2em;
    cursor: pointer;
    border-radius: 0.1em;
    }
    button {
    display: block;
    background-color: #1a78db;
    color: #ffffff;
    font-size: 18px;
    margin: 2.2em auto 2em auto;
    border: none;
    padding: 0.7em 2em;
    border-radius: 0.3em;
    font-weight: 500;
    }
    
    #output {
    background-color: rgba(255, 255, 255, 0.15);
    text-align: center;
    padding: 1em;
    margin: 0px 30px 0px 30px;
    color: #0a49c7;
    font-size: 1.2em;
    letter-spacing: 0.05em;
    box-shadow: 0 0 20px rgba(0,139,253,0.45);
    }
    #output span {
    color: #18f08b;
    font-size: 1.4em;
    font-weight: 600;
    }
    .inp-wrapper {
      flex-direction: column;
    }
    .date-wrapper {
      display: flex;
      align-items: center;
      flex-direction: column;
    }