@charset "UTF-8";

header {
    display: flex;
    align-items: center;
    background-color: black;
    color: white;
    padding: 10px 20px;
}

header picture {
    margin-right: 10px;
}

header h1 {
    flex: 1;
    font-size: 18px;
    font-family: 'Arial', sans-serif;
}

header nav {
    margin-left: auto;
}

header a {
    color: white;
    text-decoration: none;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

.center-column {
    padding: 0;
}

@media (min-width: 768px) {
    .center-column {
        padding: 0 20px;
    }
}

/* square-app-createlink.css の固定幅を上書き */
.center-column h2,
.center-column ul,
.center-column p {
    width: auto;
    max-width: 100%;
}

/* iframeサイズ（square-app-createlink.cssのデフォルトを上書き） */
#box {
    width: 98vw;
    height: 98vw;
    max-width: 620px;
    max-height: 620px;
    margin: 10px auto 0;
}

@media (min-width: 768px) {
    #box {
        width: 620px;
        height: 700px;
        max-height: none;
    }
}

@media (min-width: 1024px) {
    #box {
        width: 860px;
        height: 440px;
    }
}

/* ── 説明セクション (marble-solitaire 準拠) ── */
.game-description {
    margin: 30px auto 0;
    padding: 0 20px 20px;
    max-width: 900px;
    color: #222;
    text-align: left;
}

@media (min-width: 1024px) {
    .game-description {
        max-width: 640px;
    }
}

.game-description h2 {
    text-align: center;
    font-size: 1.4rem;
    font-weight: 700;
    color: #1a3a5c;
    margin: 0 0 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #3a7bd5;
    letter-spacing: 0.05em;
}

.game-description-inner {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.game-description article {
    background: #f5f5f5;
    border-radius: 8px;
    padding: 16px 20px;
}

.game-description h3 {
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 10px;
    border-left: 4px solid #555;
    padding-left: 8px;
    text-align: left;
}

.game-description p,
.game-description ul {
    line-height: 1.7;
    font-size: 1.0rem;
}

.game-description ul {
    padding-left: 1.4em;
}

.acknowledgement {
    background: #f5f5f5;
    margin: 15px auto;
    padding: 16px 20px;
    max-width: 900px;
    text-align: left;
    line-height: 1.7;
}

@media (min-width: 1024px) {
    .acknowledgement {
        max-width: 640px;
    }
}

.acknowledgement h2 {
    font-size: 1.2rem;
    font-weight: 700;
    margin: 0 0 10px;
}

.acknowledgement .share-wrap {
    text-align: center;
    margin-top: 12px;
}

.btn-x-share {
    display: inline-block;
    background: #000;
    color: #fff;
    text-decoration: none;
    padding: 8px 20px;
    border-radius: 4px;
    font-size: 0.95rem;
}

.btn-x-share:hover {
    background: #333;
}

footer {
    background-color: black;
    color: white;
    text-align: center;
    padding: 16px 0;
}

footer p {
    margin: 6px 0;
}

footer a {
    color: white;
}

/* タブレット(768px〜1023px)では関連リンクを下に配置 */
@media (min-width: 768px) and (max-width: 1023px) {
    .right-column {
        flex-basis: 100%;
    }
}

/* デスクトップ(1024px〜)では関連リンクを右端に配置 */
@media (min-width: 1024px) {
    .container {
        max-width: none;
        padding-right: 0;
    }

    .right-column {
        flex-basis: 260px;
        flex-shrink: 0;
        position: sticky;
        top: 0;
        max-height: 100vh;
        overflow-y: auto;
        align-self: flex-start;
    }
}