body {
    font-family: sans-serif;
}

*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

.inner {
    max-width: 50em;
    margin-left: auto;
    margin-right: auto;
}

header {
    background-color: #eee;
    padding: 1em;

    .inner {
        display: flex;
        justify-content: space-between;
    }

    h1 {
        font-size: 1em;
    }

    nav ul {
        list-style: none;
        display: flex;
        gap: 1em;
    }
}

a {
    color: rgba(0, 0, 0, 1);
    text-decoration: underline;

    &:hover,
    &:focus {
        color: rgba(0, 0, 0, 0.6);
        text-decoration: double underline;
    }
}

#features {
    padding: 4em 1em;
    margin-top: 2em;
    margin-bottom: 2em;

    & h3 {
        font-size: 2.4em;
        line-height: 1.3;
        text-align: center;
        font-family: Georgia, 'Times New Roman', Times, serif;
        font-weight: normal;
        max-width: 18em;
        margin-left: auto;
        margin-right: auto;

        & i {
            font-weight: bold;
            letter-spacing: -0.02em;
        }
    }
}

#help {
    p {
        margin-top: 1em;
        margin-bottom: 1em;
    }
}

details {
    background-color: #f1f8f4;
    cursor: pointer;
    border-radius: 4px;
    position: relative;

    &.getting-started {
        background-color: #f3ede5;

        &[open] {
            background-color: #e4d7c6;
        }
    }
    
    &.billing-question {
        background-color: #e0e9f0;

        &[open] {
            background-color: #c5dbec;
        }
    }

    &[open] {
        background-color: #cfecdd;
    }

    &:before {
        content: "\00d7";
        position: absolute;
        top: 0.75em;
        left: 0.75em;
        font-size: 1.25em;
        line-height: 1;
        width: 1em;
        display: block;
        text-align: center;
        transform: rotate(45deg);
    }

    &[open] {
        &:before {
            transform: rotate(0deg);
            content: "\002D";
        }
    }

    & summary {
        list-style: none;
        padding: 1em;
        padding-left: 2.5em;

        &::-webkit-details-marker,
        &::marker {
            display: none; 
            content: "";
        }
    }

    & div {
        padding: 0 1em 1em 2.5em;
        
        & *:first-child {
            margin-top: 0;
        }

        & *:last-child {
            margin-bottom: 0;
        }
    }
}

details + details {
    margin-top: 1em;
}

footer {
    border-top: 1px solid #ccc;
    margin-top: 10em;
    padding-top: 1em;
    padding-bottom: 1em;
    text-align: center;

    p {
        margin: 0.5em 0;
        font-size: 90%;
        color: #666;
    }
}