body {
    margin: 0;
    padding: 0;
    width: 100vw;
    font-family: "Helvetica Neue",
        Arial,
        "Hiragino Kaku Gothic ProN",
        "Hiragino Sans",
        Meiryo,
        sans-serif;
    color: rgb(0, 1, 24);
    background-color: rgba(255, 255, 255, 0.6);
}

p, h1, h2, h3, h4, h5, h6, ul, li, dl, dt, dd, a, ul{
    margin: 0;
    padding: 0;
}

a {
    text-decoration: none;
    cursor: pointer;
    color: inherit;
}

ul {
    list-style: none;
}

li {
    text-indent: 1em;
}

button, a, .btn {
  cursor: pointer;
}

button:hover, a:hover, .btn:hover,
button:active, a:active, .btn:active {
  opacity: 0.8;
  transform: scale(1.2);
}

/* logo */
header {
    height: 80px;
    position: fixed;
    top: 0;
    bottom: auto;
    left: 0;
    right: 0;
    z-index: 2;
    background: linear-gradient(25deg, rgba(255, 255, 255, 0.8), rgb(114, 37, 158));
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    height: 100%;
    text-align: left;
    display: flex;
    align-items: center;
}
.logo img {
    height: 90%;
    object-fit: contain;
}

nav {
    color: white;
    padding-right: 16px;
    flex-shrink: 0;
}

.circle-btn {
    display: inline-block;
    width: 60px;
    height: 60px;
}

.circle-btn img {
    width: 100%;
    height: 100%;
}

/* .circle-btn:active {
    opacity: 0.6;
} */

/* main */
main {
    width: 100%;
    margin: 80px auto 0;
    max-width: 800px;
    text-align: center;
}

article {
    position: relative;
    text-align: left;
    font-size: small;
    padding-left: 36px;

}
article::before {
    content: 'New!';
    position: absolute;
    top: 0;
    left: 0;
    transform: rotate(-10deg);
    color: orange;
    font-weight: bold;
    text-decoration: underline;

}

/* aspect: 800*564 */
.top-img {
    width: 100%;
    max-width: 700px;
    max-height: calc(700px * (564 / 800));
    margin: 0 auto;
    position: relative;
    /* background: #000; */
    overflow: hidden;
  }

  .top-img > img {
    width: 90%;
    object-fit: contain;
  }

  #prev-btn, #next-btn {
    background-image: url('./arrow-l.png');
    background-size: contain;
    background-repeat: no-repeat;
    width: calc(14vmin * (159 / 279));
    height: 14vmin;
    position: absolute;
    top: 50%;
    left: 10px;
    z-index: 2;
    transform: translateY(-50%);
  }
  #next-btn {
    background-image: url('./arrow-r.png');
    position: absolute;
    left: auto;
    right: 10px;
  }

    #next-btn span {
        display: none;
        position: absolute;
        right: 100%;
        top: 50%;
        transform: translateY(-50%);
        width: 50vw;
        font-size: 5vmin;
        text-align: right;
        padding-right: 0.5em;
        color: ivory;
        font-weight: bold;
        /* text-shadow: 1px 1px 0 red, -1px 1px 0 red, 1px -1px 0 red, -1px -1px 0 red, 5px 5px 0 red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red, 0 0 0.1em red; */
        text-shadow: 1px 1px 0 #6f00ff, -1px 1px 0 #6f00ff, 1px -1px 0 #6f00ff, -1px -1px 0 #6f00ff, 5px 5px 0 #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff, 0 0 0.1em #6f00ff;
    }

    #next-btn.animation {
        animation: flicker 1.2s infinite;
        animation-timing-function: step-end;
      }
      @keyframes flicker {
        0% {
          opacity: 1;
        }
        60% {
          opacity: 0.4;
        }
    }

    #next-btn.animation span {
        display: block;
    }


  .game-panel-container {
    width: 74%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 13%;
    display: flex;
    z-index: 1;
    transition: transform 0.3s;
  }

  .game-panel-container .panel {
    width: 100%;
    height: 100%;
    flex-shrink: 0;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  .panel .panel-content {
    width: 100%;
    height:100%;
    max-height: 80%;
    /* max-width: 100%;
    max-height: 100%; */
    border-radius: 8px;
  }

  .panel .panel-content.with-shadow {
    border:6px solid rgba(227, 227, 227, 0.9);
    background: rgba(227, 227, 227);
    box-shadow: 0 0 2px white, 0 0 2px white, 0 0 2px white, 0 0 2px white, 0 0 2px white, 0 0 4px white;
  }

.caution {
    max-width: 80%;
    margin: 4px auto;
    text-align: left;
    line-height: 1.2em;
}
.caution.head {
    text-align: center;
}
.caution img {
    height: 90%;
    vertical-align: bottom;
    object-fit: contain;
}
.caution.browser-list {
    padding: 5px 10px;
    border: 1px solid #000;
    text-align: left;
}
.caution-yellow {
    color: #ff9500;
    font-weight: bold;
    line-height: 1.4em;
}

.anchor {
    margin-top: -80px;
    padding-top: 80px;
}

.main-btn {
    display: flex;
    align-items: flex-end;
    justify-content: center;
    width: 300px;
    max-width: 80%;
    height: 60px;
    margin: 10px auto 5px;
    line-height: 30px;
    position: relative;
    cursor: pointer;
    color: #fff;
    border-radius: 50vh;
    font-size: 20px;
    text-shadow: 0 0 30px #bbbbbb;
}
.main-btn.start {
    background-image: url('./start-bg.png');
    background-size: cover;
}
.main-btn.tutorial, .main-btn.help {
    background-image: url('./inverted-start-bg.png');
    background-size: cover;
}
.main-btn:active {
    opacity: 0.6;
}

dl, dt, dd{
    width: 100%;
}
.dt-top-icon {
    width: 62px;
    height: 62px;
    position: absolute;
    top: 50%;
    left: 0;
    transform: translateY(-50%);
    border-radius: 50%;
}
.dt-top-icon.right {
    left: auto;
    right: 0;
}
.dt-top-icon img{
    height: 100%;
}

dd {
    display: none;
    background: linear-gradient(#fff, #fff 30%, #d1d0d0);
}

dd.appear, .detail.appear {
    display: block;
    animation: .5s fade-in;
}

@keyframes fade-in {
    0% {
    opacity: 0;
    transform: translateY(-5%);
    }
    100% {
    opacity: 1;
    transform: translateY(0);
    }
}

#howto p {
    width: 90%;
    margin: 10px auto 0;
    line-height: 1.2em;
    text-align: left;
}
.video-container{
    width: 100%;
    text-align: center;
}
video {
    width: 90%;
}
dd img {
    max-width: 90%;
    margin: 10px 0;
}

.qa {
    margin: 6px;
    padding: 6px 12px;
    text-align: left;
}

.qa h3 {
    padding: 14px 0;
    text-decoration: underline;
    font-size: 20px;
    line-height: 30px;
}

.question {
    cursor: pointer;
    position: relative;
    font-size: 14px;
    line-height: 18px;
}

.question::before {
    content: "";
    display: inline-block;
    width: 18px;
    height: 18px;
    box-sizing: border-box;
    border-left: 14px solid pink;
    border-top: 9px solid transparent;
    border-bottom: 9px solid transparent;
    vertical-align: bottom;
}

.detail {
    display: none;
    border: 1px solid rgba(43, 43, 43, 0.8);
    margin: 4px;
    padding: 10px;
    font-size: 0.9em;
    line-height: 1.8em;
    border-radius: 10px;
}

section + section {
    margin-top: 20px;
}

.detail ul {
    list-style-type: disc;
    list-style-position: inside;
}

li.number {
    list-style-type: decimal;
}

li.no-style {
    list-style-type: none;
}

footer {
    font-size: 0.7rem;
    margin-top: 100px;
    text-align: center;
}

.hidden {
    display: none;
}

/* ranking */
    .ranking-container {
        margin: 20px 0;
        color:rgb(54, 54, 54)
    }
    .ranking-container h2 {
        position: relative;
        width: 80%;
        margin: 5px auto;
        padding: 5px 30px;
        color: #fff;
        text-shadow: 2px 2px 0 #ff0000,
                    2px -2px 0 #bbbbbb,
                    -2px -2px 0 #bbbbbb,
                    -2px 2px 0 #bbbbbb;
        font-size: 32px;
    }
    .ranking-container h2::before {
        content: "";
        position: absolute;
        left: 0;
        top: 0;
        display: block;
        width: 100%;
        height: 100%;
        z-index: -1;
        background-image: linear-gradient(90deg, #ff49f9 0, #00eac3 50%, #ecf548 100%);
        -webkit-filter: blur(10px);
        filter: blur(5px);
    }
    .ranking {
        width: 100%;
    }
    .ranking li {
        display: flex;
        justify-content: center;
        align-items: flex-end;
        width: 100%;
    }
    .ranking li p {
        font-size: 16px;
        box-sizing: border-box;
        display: flex;
        justify-content: center;
        align-items: flex-end;
        text-indent: 0;
        border-bottom: 1px solid yellow;
    }
    .ranking-order {
        width: 10%;
        background: linear-gradient(#fff,rgb(253, 255, 108));
    }
    .ranking-name {
        width: 30%;
        background: linear-gradient(#fff,rgb(194, 244, 232));
        overflow-wrap: anywhere;
    }
    .ranking-score {
        width: 20%;
        background: linear-gradient(#fff,rgb(255, 159, 218));
    }
    .ranking-date {
        width: 30%;
        background: linear-gradient(#fff,rgb(209, 214, 248));
    }
    .ranking-container .notice {
        font-size: small;
    }


@media (min-aspect-ratio: 4/3) {
.top-img {
        width: 100%;
    }

    header {
    width: 100px;
    height: 100%;
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    right: auto;
    background: linear-gradient(315deg, rgba(255, 255, 255, 0.8), rgb(114, 37, 158));
    flex-direction: column;
    justify-content: flex-start;
    }

    .logo {
    width: 100%;
    height: 100px;
    }

    .logo img {
    width: 100%;
    margin: 0 auto;
    }

    nav {
    text-align: center;
    }

    .circle-btn + .circle-btn {
    margin-top: 10px;
    }

  .top-img > img {
    max-height: calc(100vh - 20px);
    object-fit: contain;
    }

    .flex {
    display: grid;
    grid-template-columns: 1fr 1fr;
    }

    .anchor {
    margin-top: 0;
    padding-top: 0;
    }

    main {
    margin: 0 auto;
    padding-left: 100px;
    width: calc(100% - 100px);
    }

    .main-btn {
    max-width: 90%;
    font-size: min(20px, 2.5vw);
    }

    footer {
    margin-left: 100px;
    }

}