#main-navbar {
    color: #000000;
    transition: color 0.3s ease;
}

.burger-btn {
    width: 36px;
    height: 36px;
    position: relative;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 60;
    /* ボタンのみメニューの上に配置 */
}

.burger-btn span {
    display: block;
    position: absolute;
    width: 30px;
    height: 2px;
    background-color: currentColor;
    /* 通常時は黒色 */
    border-radius: 2px;
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1),
        top 0.3s cubic-bezier(0.16, 1, 0.3, 1),
        opacity 0.25s ease,
        background-color 0.3s ease;
}

/* 通常時: 均等な3本線 (黒色) */
.burger-btn span:nth-child(1) {
    top: 8px;
}

.burger-btn span:nth-child(2) {
    top: 17px;
}

.burger-btn span:nth-child(3) {
    top: 26px;
}

/* メニュー開時: 中央の線を消し、青色(#1e95d4)の「×」に変形 */
.burger-btn.is-open span:nth-child(1) {
    top: 17px;
    transform: rotate(45deg);
    background-color: #1e95d4 !important;
}

.burger-btn.is-open span:nth-child(2) {
    opacity: 0;
}

.burger-btn.is-open span:nth-child(3) {
    top: 17px;
    transform: rotate(-45deg);
    background-color: #1e95d4 !important;
}

/* フルスクリーンメニュー表示制御 (z-index: 50) */
#mobile-menu {
    opacity: 0;
    visibility: hidden;
    transform: scale(0.98);
    transition: opacity 0.35s ease, visibility 0.35s ease, transform 0.35s ease;
}

#mobile-menu.is-active {
    opacity: 1;
    visibility: visible;
    transform: scale(1);
}