/* ６段目 */
   .sixth-center-container {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 50vh;
    margin-top: 10%;
    }

.contact-btn {
    margin: auto;
    font-family: "dnp-shuei-nshogomincho-std";
    width: 450px;
    letter-spacing: 0.3em;
    font-size: 2em;
    color: white;
    text-decoration: none;
    background-image: url('../png/btn.png');
    background-size: cover;
    background-position: center;
    border-radius: 30px;
    border: none;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    cursor: pointer;
    text-align: center;
    overflow: hidden;
}

.contact-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg,
            rgba(255, 255, 255, 0) 0%,
            rgba(255, 255, 255, 0.3) 50%,
            rgba(255, 255, 255, 0) 100%);
    transition: left 0.5s ease;
}

.contact-btn:hover::before {
    left: 100%;
}

.contact-btn:hover {
    box-shadow: 0 6px 8px rgba(0, 0, 0, 0.15);
    transform: translateY(-2px);
}

.contact-btn:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}


@media (max-width: 768px) {
    .contact-btn {
        width: 100%;
        padding: 0.4em 2.5em;
        font-size: 1.3em;
    }
    .sixth-center-container {
        margin-top: 0;
        height: 30vh;
    }
}