studycase(CSS)

html, body, div, span, applet, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
a, abbr, acronym, address, big, cite, code,
del, dfn, em, img, ins, kbd, q, s, samp,
small, strike, strong, sub, sup, tt, var,
b, u, i, center,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, embed,
figure, figcaption, footer, header, hgroup,
menu, nav, output, ruby, section, summary,
time, mark, audio, video {
    margin: 0;
    padding: 0;
    border: 0;
    font-size: 100%;
    font: inherit;
    vertical-align: baseline;
}
/* HTML5 display-role reset for older browsers */
article, aside, details, figcaption, figure,
footer, header, hgroup, menu, nav, section {
    display: block;
}
body {
    line-height: 1;
}
ol, ul {
    list-style: none;
}
blockquote, q {
    quotes: none;
}
blockquote:before, blockquote:after,
q:before, q:after {
    content: '';
    content: none;
}
table {
    border-collapse: collapse;
    border-spacing: 0;
}

html {
    font-family: Arial, Helvetica, sans-serif;
    box-sizing: border-box;
}

body {
    background-color: #529ffa;
    display: flex;
    justify-content: center;
    min-height: 100vh;
}


.panel {
    background-color: white;
    border-radius: 10px;
    padding: 15px 25px;
    width: 100%;
    max-width: 960px;
    text-align: center;
    text-transform: uppercase;
    display: flex;
    flex-direction: row;

}

.pricing-plan {
    border-bottom: 1px solid #e1f1ff;
}

.pricing-plan:last-child {
    border-bottom: none;
}

.pricing-img {
    margin-bottom: 25px;
    max-width: 100%;
}

img {
    height: 300px;
}

.pricing-header {
    color: #888;
    font-weight: 600;
    letter-spacing: 1px;
}

.pricing-features {
    margin: 50px 0px 25px;
    color: #015ff9;
}

.pricing-features-item {
    font-weight: 600;
    font-size: 12px;
    letter-spacing: 1px;
    line-height: 1.5;
    padding: 25px 0;
    border-top: 1px solid #e1f1ff;
}

.pricing-features-item:last-child {
    border-bottom: 1px solid #e1f1ff;
}

.prising-price {
    font-size: 32px;
    color: #016ff9;
    display: block;
    font-weight: 700;
}

.pricing-button {
    border: 1px solid #9dd1ff;
    padding: 15px 35px;
    border-radius: 10px;
    display: inline-block;
    margin: 25px 0;
    text-decoration: none;
    color: #348efe;
}

.pricing-button:hover,
.pricing-button:focus {
    background-color: #e1f1ff;
}

.pricing-button.is-fetured {
    background-color: #48aaff ;
    color: white;
}

.pricing-button.is-fetured:hover,
.pricing-button.is-fetured:focus {
    background-color: #269aff;
    color: white;

}

@media (min-width: 900px){
    .panel  {
        flex-direction: row;
    }
}