Cap Web CSS

style.css

*, *:before, *:after {
    box-sizing:  border-box;
}

html {
    width: 100%;
    height: 100%;
    font-family: -apple-system, system-ui, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu;
    color: white;
    background-color: hsl(210, 27%, 13%);
}

body {
    width: 100%;
    min-height: 100%;
    margin: 0;
    padding: 15px;
    display: flex;
    flex-direction: column;
}

h1 {
    z-index: 2;
    margin: 0;
    text-transform: uppercase;
    font-weight: bold;
    color: white;
    font-size: 24px;
    text-align: center;
    margin-bottom: 15px;
}

form {
    display: contents;
    width: 100%;
    position: relative;
    padding: 65px 20px 20px;
}

form > * {
    border: 0;
    display: inline-block;
    vertical-align: text-top;
    margin-bottom: 15px;
    width: 100%;
}

select {
    margin-right: 10px; 
}

select,
input[type="text"] {
    height: 35px;
    border-radius: 3px;
    padding: 0 10px;
    background: #fff;
    min-width: 130px;
}

input[type="submit"] {
    padding: 20px 48px 20px 20px;
    background-image: url("data:image/svg+xml;base64,PHN2ZyB3aWR0aD0nMjAwJyBoZWlnaHQ9JzIwMCcgZmlsbD0iI0ZGRkZGRiIgeG1sbnM9Imh0dHA6Ly93d3cudzMub3JnLzIwMDAvc3ZnIiB4bWxuczp4bGluaz0iaHR0cDovL3d3dy53My5vcmcvMTk5OS94bGluayIgdmVyc2lvbj0iMS4xIiB4PSIwcHgiIHk9IjBweCIgdmlld0JveD0iMCAwIDEwMCAxMDAiIGVuYWJsZS1iYWNrZ3JvdW5kPSJuZXcgMCAwIDEwMCAxMDAiIHhtbDpzcGFjZT0icHJlc2VydmUiPjxwYXRoIGZpbGw9IiNGRkZGRkYiIGQ9Ik03OC4xMjUsODkuMzc1TDUyLjk5OCw3NS4wMTdsLTkuMTE3LDguNzMzTDM4Ljc1LDY2Ljg3NUw3OC4xMjUsMjcuNUwyOS44NjIsNTkuNjc1TDUsNDQuMzc1bDkwLTMzLjc1ICBMNzguMTI1LDg5LjM3NXoiLz48L3N2Zz4="),
                      linear-gradient(-15deg, hsl(210, 100%, 35%), hsl(165, 100%, 65%));
    background-repeat: no-repeat;
    background-size: 30px, 100%;
    background-position: calc(50% + 48px), center;
    border-radius: 3px;
    text-transform: uppercase;
    font-size: 22px;
    color: white;
}

input[type="submit"]:hover {
    cursor: pointer;
    background-image: url("data:image/svg+xml;base64,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"),
                      linear-gradient(-15deg, hsl(210, 100%, 40%), hsl(165, 100%, 70%));
}

iframe {
    flex-grow: 1;
    width: auto;
    border: 15px solid black;
    background: black;
    margin: 0 -15px -15px;
}

@media only screen and (min-width: 640px) {
    body {
        display: grid;
        grid-gap: 15px;
        grid-template-columns: 1fr 1fr 1fr 1fr 1fr 1fr;
        grid-template-rows: auto auto 1fr;
    }

    h1 {
        grid-column-start: 1;
        grid-column-end: 4;
        text-align: left;
        margin-bottom: 0;
    }

    form > * {
        margin-bottom: 0;
    }

    select {
        grid-column-start: 1;
    }

    input[type="text"] {
        grid-column-start: 2;
    }

    input[type="submit"] {
        grid-column-start: 4;
        grid-column-end: 7;
        grid-row-start: 1;
        grid-row-end: 3;
        justify-self: end;
        margin: -15px;
        width: auto;
        border-radius: 0;
        padding: 20px 85px 20px 60px;
        font-size: 24px;
        background-position: calc(50% + 53px), center;
    }

    iframe {
        grid-column-start: 1;
        grid-column-end: 7;
        justify-self: stretch;
        align-self: stretch;
        width: auto;
        height: auto;
    }
}