.c-heading{
    color: #333;
    font-size: 280%;
    margin-bottom: 20px;
}
.c-subheading{
    background: none;
    border: none;
    color: #333;
    font-size: 180%;
    margin-bottom: 10px;
    text-indent: -0.5em;
}

.c-catch{
    text-align: center;
    font-weight: bold;
    text-decoration: underline;
}
.c-btn{
    transition: all 0.3s;
}
.c-btn:hover{
    opacity: 0.7;
}
.l-flex{
    display: flex;
    align-items: center;
}
section{
    margin-bottom: 50px;
    padding: 0;
}
.briefing-box{
    margin-bottom: 30px;
}

.briefing p,.briefing ul .briefing-aside ul, .c-text, .c-list{
    font-size: 160%;
    margin-left: 0;
}
.briefing li, .briefing-aside li{
    background: none;
    padding-left: 0;
}
#p-briefing p:last-child, #p-briefing ul:last-child, #p-briefing li:last-child, .briefing-box:last-child{
    margin-bottom: 0;
}

/*-------------------------------*/
.briefing-fv{
    padding: 30px 0 0;
}
.briefing-fv img{
    width: 100%;
}
.briefing-fv-main{
    max-width: 800px;
    margin: 0 auto;
}
.briefing-fv-columns{
    display: flex;
    justify-content: space-between;
    margin-bottom: 30px;
}
.briefing-fv-col{
    width: 48.5%;
}
.briefing-fv-bottom{
    max-width: 700px;
    margin: 0 auto 20px;
}
.briefing-fv-btn{
    margin-top: 30px;
}

.briefing-intro u{
    display: block;
    text-align: center;
    margin-bottom: 15px;
}
.briefing-recommend li{
    text-decoration: underline;
    list-style: none;
    position: relative;
    padding-left: 20px;
}
.briefing-recommend li:before{
    position: absolute;
    left: 0;
    top: 0.3em;
    content: "";
    display: block;
    width: 0.6em;
    height: 0.3em;
    border-left: 3px solid #555;
    border-bottom: 3px solid #555;
    transform: rotate(-45deg);
}
.briefing-detail{
    border: 1px solid #ddd;
    border-radius: 6px;
    padding: 30px 50px;
    overflow: hidden;
}
.briefing-detail img{
    width: 100%;
}

.briefing-detail-img{
    flex-shrink: 0;
    width: 80px;
    margin-right: 30px;
}

.briefing-aside{
    padding: 50px 0;
    background: #C4DCF2;
    margin-bottom: 50px;
}
.briefing-aside li{
    padding-left: 0.8em;
    position: relative;
}
.briefing-aside li:before{
    width: 0.3em;
    height: 0.3em;
    border-radius: 50%;
    background: #333;
    content: '';
    display: inline-block;
    vertical-align: middle;
    margin-right: 0.5em;
    position: absolute;
    left: 0;
    top: 0.5em;
}
.briefing-info{
    margin-bottom: 30px;
}
.briefing-organizer{
    background: #fff;
    border-radius: 6px;
    padding: 20px;
}
.briefing-bottom{
    padding-bottom: 60px;
}
.briefing-bottom-btn img{
    width: 100%;
}
.briefing-fv-btn{
    width: 90%;
    margin: 0 auto;
}
.briefing-bottom-btn{
    width: 90%;
    margin: 0 auto;
}

@media screen and (max-width: 640px) {
section{
    margin-bottom: 7vw;
    padding: 0;
}
.briefing-fv{
    padding-top: 15px;
}
.briefing-fv-columns{
    display: block;
    margin: 0 auto 5vw;
}
.briefing-fv-col{
    margin: 0 auto 5vw;
    width: 70%;
}
.briefing-fv-bottom{
    width: 80%;
    margin: 0 auto 5vw;
}
.briefing-fv-btn , .briefing-bottom-btn{
    width: 75%;
    margin: 0 auto;
}
.briefing p,.briefing ul .briefing-aside ul, .c-text, .c-list{
    font-size: min(3.2vw, 14px);
}
.c-heading{
    font-size: min(3.7vw, 20px);
    margin-bottom: 2vw;
}
.c-subheading{
    font-size: min(3.4vw, 15px);
    margin-bottom: 1.5vw;
}
.briefing-intro u span{
    display: block;
}

.briefing-recommend li {
    padding-left: 15px;
}
.briefing-recommend li:before {
    border-width: 2px;
}
.briefing-detail {
    padding: 15px;
}
.briefing-detail-img {
    width: 50px;
    margin-right: 15px;
}
.briefing-aside{
    padding: 7vw 0;
    margin-bottom: 7vw;
}
.briefing-organizer{
    border-radius: 4px;
    padding: 15px;
}
}