/* ===== body ===== */
body {
    background: #fff;
    color: #333;
    display: block;
    padding: 0;
    margin: 0;
}

/* ===== header ===== */
.header {
    width: 100%;
    box-sizing: border-box;
    justify-content: flex-start;
}

.header nav {
    margin-left: auto;
}

.header h1 {
    color: #fff;
    margin-bottom: 0;
}

/* ===== page-wrapper ===== */
.page-wrapper {
    display: flex;
    flex-direction: column;
}

/* ===== main ===== */
main {
    display: block;
    width: 100%;
}

/* ===== game-description ===== */
.game-description {
    padding: 24px 16px 8px;
}

.game-description h2 {
    font-size: 1.2rem;
    margin-bottom: 16px;
    padding-left: 8px;
    border-left: 4px solid #555;
}

.game-description-inner {
    display: grid;
    grid-template-columns: 1fr;
    gap: 12px;
}

.game-description article {
    background: #f5f5f5;
    border-radius: 8px;
    padding: 14px 16px;
}

.game-description h3 {
    font-size: 1rem;
    margin-bottom: 8px;
    color: #444;
}

.game-description p,
.game-description ul {
    font-size: 0.95rem;
    line-height: 1.7;
    color: #555;
}

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

/* ===== acknowledgement ===== */
.acknowledgement {
    margin: 16px;
    padding: 16px;
    background: #f5f5f5;
    border-radius: 8px;
    font-size: 0.95rem;
    color: #555;
    line-height: 1.7;
}

.acknowledgement h2 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    padding-left: 8px;
    border-left: 4px solid #555;
    color: #333;
}

/* ===== PC（1024px以上） ===== */
@media (min-width: 1024px) {
    .page-wrapper {
        flex-direction: row;
        align-items: flex-start;
    }

    main {
        flex: 1;
        min-width: 0;
        max-width: 600px;
        margin: 0 auto;
    }

    .right-column {
        flex-basis: 280px;
        flex-shrink: 0;
        align-self: flex-start;
    }
}