html {
    height: 100%;
}

body {
    font: 400 12px/1.8 Open Sans, sans-serif;
}

.container {
    padding-left: 1rem;
    padding-right: 1rem;
    max-width: 1240px;
    margin-inline: auto;
}

.text-left{
    text-align: left;
}
.text-cener{
    text-align: center;
}
.text-right{
    text-align: right;
}

.top {
    margin-inline: auto;
    padding-top: 2rem;
    padding-bottom: 2rem;
    max-width: 1500px;
}

.top-image{
    max-width: 100%;
}

.w-full-vw {
    width: 100vw;
}

.period {
    width: 90%;
    position: relative;
    margin: 2em auto;
    padding: 0.8em 0.8em;
    border: solid 3px #95ccff;
    border-radius: 8px;
}
.period-title {
    position: absolute;
    display: inline-block;
    top: -13px;
    left: 10px;
    padding: 0 9px;
    line-height: 1;
    font-size: 19px;
    background: #FFF;
    color: #95ccff;
    font-weight: bold;
}
.period-content {
    text-align: center;
}

.greeting {
    margin-inline: auto;
}
.greeting-title {
    color: rgb(33, 127, 196);
    line-height: 2rem;
}
.greeting-content {
    padding-top: 1rem;
    padding-bottom: 1rem;
    line-height: 1.4rem;
}

@media screen and (min-width: 769px) {
    .period {
        width: 60%;
    }
    .period-title {
        font-size: 1.4rem;
    }
    .period-content {
        font-size: 1.2rem;
    }

    .greeting-title {
        font-size: 1.6rem;
    }

    .greeting {
        width: 80%;
    }
    .greeting-content {
        font-size: 1rem;
    }
    
    .mobile {
        display: none;
    }
}
@media screen and (max-width: 768px) {
    .period-title {
        font-size: 1.3rem;
    }
    .period-content {
        font-size: 1.0rem;
    }

    .greeting-title {
        font-size: 1.4rem;
    }

    .greeting-content {
        font-size: 0.85rem;
    }

    .pc {
        display: none;
    }
}

/* reset CSS */
html, body, div, span, object, iframe,
h1, h2, h3, h4, h5, h6, p, blockquote, pre,
abbr, address, cite, code,
del, dfn, em, img, ins, kbd, q, samp,
small, strong, sub, sup, var,
b, i,
dl, dt, dd, ol, ul, li,
fieldset, form, label, legend,
table, caption, tbody, tfoot, thead, tr, th, td,
article, aside, canvas, details, figcaption, figure, 
footer, header, hgroup, menu, nav, section, summary,
time, mark, audio, video {
    margin: 0;
    padding: 0;
    border: 0;
    outline: 0;
    font-size: 100%;
    vertical-align: baseline;
    background: transparent;
}