function openKakao() {
    const kakaoUrl = document.querySelector('[data-kakao-url]')?.dataset.kakaoUrl || '#';
    if (kakaoUrl !== '#') {
        window.open(kakaoUrl, '_blank');
    } else {
        alert('카카오톡 채널 URL이 설정되지 않았습니다.');
    }
}

document.addEventListener('DOMContentLoaded', function() {
    // Sticky header shadow
    const navbar = document.querySelector('.navbar');
    window.addEventListener('scroll', function() {
        if (window.scrollY > 0) {
            navbar.style.boxShadow = '0 2px 8px rgba(0,0,0,0.1)';
        } else {
            navbar.style.boxShadow = '0 1px 3px rgba(0,0,0,0.1)';
        }
    });
});