.page {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    background-color: var(--bg-base);
}

.main-content {
    flex: 1;
    display: flex;
    justify-content: center;
    width: 100%;
}

article.content {
    width: 100%;
}

.page-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 1.5rem 4rem 1.5rem;
}

.scroll-to-top-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--bg-panel);
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    cursor: pointer;
    box-shadow: 0 0 15px rgba(0, 243, 255, 0.2);
    /* 初期状態は非表示 */
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
}

    /* スクロールしてクラスが付与されたら表示 */
    .scroll-to-top-btn.show {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .scroll-to-top-btn:hover {
        transform: translateY(-4px);
        background-color: var(--primary-color);
        color: var(--bg-base);
        box-shadow: 0 0 25px rgba(0, 243, 255, 0.6);
    }