:root{
    --concept-color: rgb(255, 255, 0);
    --sub-color: rgb(255, 255, 128);
    --text-color: white;
}

a{
    text-decoration: none;
    color: var(--text-color);
}

li{
    list-style: none;
}

ul{
    padding-left: 0;
}

html{
    font-family: 'Noto Sans JP', sans-serif;
}

.pop{  
    font-family: 'Poppins', sans-serif;
}

.container{
    width: 90%;
    max-width: 1120px;
    margin: 0 auto;
    position: relative;
}

.flex{
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    align-items: center;
}
@media only screen and (max-width: 768px) {
    .flex{
        flex-direction: column;
    }
}

body{
    background-color: rgb(0, 0, 16);
}

/*ヘッダ*/
header{
    padding: 27px 0;
}
.logo{ /*クラスを指定するときは.*/
    font-size: 24px;
    font-weight: 700;
    letter-spacing: -0.04em;
}
.logo span{
    color: var(--concept-color);
}
.header_menu li{
    margin-left: 40px;
}
.header_menu li a{
    color: gray;
    transition: .3s;
}
.header_menu li a:hover{
    color: var(--text-color);
    transition: .3s;
}

@media only screen and (max-width: 768px) {
    header .container{
        justify-content: center;
    }
    .header_menu li{
        margin: 20px 16px 0;
    }
}

/*メイン*/
#hero{ /* idを指定するときは＃ */
    background-image: url(../images/hero.png);
    background-position: center;
    background-size: cover;
    height: 540px;
    border-radius: 30px;
    display: flex;
    align-items: center;
    margin-bottom: 90px;
    overflow: hidden;
}
#hero::before {
    content: '';
    width: 100%;
    height: 100%;
    background-color: black;
    position: absolute;
    opacity: 0.3;
    z-index: 1;
}
.hero_inner{
    z-index: 2;
    color: var(--text-color);
    width: 100%;
    text-align: center;
}
.hero_inner p {
    font-size: 20px;
    font-weight: 500;
    margin-bottom: 16px;
}
.hero_inner h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 16px;
}

@media only screen and (max-width: 768px) {
    #hero{
        height: 460px;
    }
    .hero_inner p {
        font-size: 15px;
    }
    .hero_inner h1 {
        font-size: 17px;
    }
}

/* About */
#about{
    margin-bottom: 120px;
    color: var(--text-color);
}
.title{
    font-size: 25px;
    font-weight: 500;
    color: var(--sub-color);
    margin-bottom: 10px;
}
#about h3{
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 60px;
}
.column-2{
    width: 52%;
}
.column-3{
    width: 42%;
}
.text{
    line-height: 2;
}
.about-img{
    background-image: url(../images/Riddle.png);
    background-position: center;
    background-size: cover;
    height: 360px;
    border-radius: 20px;
}
.heading{
    font-family: 'Dancing Script', cursive;
    font-size: 100px;
    font-weight: 700;
    color: var(--concept-color);
    opacity: 0.4;
    position: absolute;
    top: 0;
    right: 0;
    transform: translateY(-30%);
    z-index: -1;
}
.heading_left{
    font-family: 'Dancing Script', cursive;
    font-size: 100px;
    font-weight: 700;
    color: var(--concept-color);
    opacity: 0.4;
    position: absolute;
    top: 0;
    left: 0;
    transform: translateY(-30%);
    z-index: -1;
}

@media only screen and (max-width: 768px){
    #about h3{
        font-size: 24px;
        line-height: 1.5;
    }
    .column-2{
        width: 100%;
    }
    .text{
        font-size: 15px;
        line-height: 1.7;
    }
    .about-img{
        margin-top: 30px;
    }
    .heading{
        font-size: 80px;
    }
    .heading_left{
        font-size: 80px;
    }
}

/* Worlds */
#worlds{
    margin-bottom: 120px;
    color: var(--text-color);
}
.caution{
    font-size: 15px;
    line-height: 2;
    margin-bottom: 40px;
    color: red;
}
.worlds_inner{
    margin-bottom: 40px;
    position: relative;
}
.column-40{
    width: 40%;
}
.column-55{
    width: 55%;
}
#worlds img{
    border-radius: 30px;
}
#worlds h3{
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 24px;
}
.detail{
    text-align: right;
}
.worlds_inner .detail a{
    color: gray;
    transition: .3s;
}
.worlds_inner .detail a:hover{
    color: var(--text-color);
    transition: .3s;
}

@media only screen and (max-width: 768px){
    .column-40{
        width: 100%;
    }
    .column-55{
        width: 100%;
    }
    #worlds img{
        margin-top: 40px;
    }
    #worlds h3{
        font-size: 17px;
    }
    .order1{
        order: 1;
    }
    .order2{
        order: 2;
    }
    .order3{
        order: 3;
    }
    .order4{
        order: 4;
    }
    .order5{
        order: 5;
    }
    .order6{
        order: 6;
    }
    .order7{
        order: 7;
    }
    .order8{
        order: 8;
    }
    .order9{
        order: 9;
    }
    .order10{
        order: 10;
    }
    .order11{
        order: 11;
    }
    .order12{
        order: 12;
    }
    .order13{
        order: 13;
    }
    .order14{
        order: 14;
    }
    .order15{
        order: 15;
    }
    .order16{
        order: 16;
    }
    .order17{
        order: 17;
    }
    .order18{
        order: 18;
    }
    .order19{
        order: 17;
    }
    .order20{
        order: 18;
    }
}

/* Contact */
#contact{
    margin-bottom: 120px;
    color: var(--text-color);
}
#contact dl{
    max-width: 900px;
    margin-left: auto;
}
#contact dt{
    width: 30%;
    padding: 20px 0;
    font-weight: 500;
    border-bottom: solid 1px var(--concept-color);
}
#contact dd{
    width: 65%;
    padding: 20px 0;
    border-bottom: solid 1px var(--concept-color);
}

@media only screen and (max-width: 768px){
    #contact dl{
        font-size: 13px;
    }
    #contact dd{
        width: 55%;
    }
}
/* footer */
footer{
    text-align: center;
    margin: 90px 0;
}