/* ── Reset ── */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

/* ── Back to Top ── */
.back-to-top {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 40px;
    height: 40px;
    background-color: #888;
    color: #fff;
    font-size: 1.4rem;
    text-align: center;
    line-height: 38px;
    border-radius: 4px;
    text-decoration: none;
    z-index: 999;
    transition: background 0.3s ease;
}

.back-to-top:hover {
    background-color: #555;
    color: #fff;
}