.site-footer { background: #fff; margin-top: 50px; border-top: 2px solid #d32f2f; font-family: 'Arial', sans-serif; }

/* 1. Tin tức được quan tâm */
.interested-news h3 { color: #d32f2f; margin-top: 0; margin-bottom: 20px; font-size: 16px; }
.news-item { min-width: 180px; text-align: center; }
.news-item img { width: 100%; border-radius: 4px; }
.news-item a { text-decoration: none; color: #333; font-size: 14px; transition: color 0.3s; }
.news-item a:hover { color: #d32f2f; }

.slider-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }

.slider-btn { background-color: #f1f1f1; border: none; border-radius: 50%; width: 35px; height: 35px; font-size: 16px; color: #555; cursor: pointer; transition: background-color 0.3s, color 0.3s; margin-left: 10px; display: inline-flex; justify-content: center; align-items: center; }
.slider-btn:hover { background-color: #e0e0e0; color: #d32f2f; }

.horizontal-scroll { display: flex; overflow-x: auto; gap: 20px; padding-bottom: 10px; scroll-behavior: smooth; scrollbar-width: none; }
.horizontal-scroll::-webkit-scrollbar { display: none; }

/* 2. Thông tin tòa soạn */
.footer-info-section { padding: 40px 0; }
.footer-grid { display: flex; justify-content: space-between; gap: 30px; font-size: 14px; color: #444; line-height: 1.8; }
.footer-col-1 { flex: 2; }
.footer-col-2 { flex: 1.5; }
.footer-col-3 { flex: 1.5; }

.footer-logo { color: #d32f2f; font-size: 24px; margin-top: 0; margin-bottom: 15px; }
.footer-col-1 p { margin: 2px 0; }
.footer-col-2 ul { list-style: none; padding: 0; margin: 0; }
.footer-col-2 li { margin-bottom: 8px; }
.footer-col-2 a { text-decoration: none; color: #444; transition: color 0.3s; }
.footer-col-2 a:hover { color: #d32f2f; }

.app-links { display: flex; gap: 10px; margin-bottom: 20px; margin-top: 5px; }
.btn-app { background: #333; color: white; border: none; padding: 8px 15px; border-radius: 4px; cursor: pointer; font-weight: bold; }
.btn-app:hover { background: #555; }
.social-links a { text-decoration: none; color: #444; margin-right: 5px; }
.social-links a:hover { color: #d32f2f; }

/* 3. Bản quyền */
.footer-copyright { border-top: 1px solid #eee; padding: 20px 0; text-align: center; color: #888; font-size: 14px; background: #fafafa; }
.footer-copyright p { margin: 0; }

/* Nút Lên đầu trang */
#backToTop { position: fixed; bottom: 30px; right: 30px; width: 45px; height: 45px; background: #d32f2f; color: white; border: none; border-radius: 50%; cursor: pointer; display: none; box-shadow: 0 2px 5px rgba(0,0,0,0.2); font-size: 18px; font-weight: bold; z-index: 9999; }
#backToTop:hover { background: #b71c1c; }

/* =========================================
   RESPONSIVE FOOTER (DÀNH CHO ĐIỆN THOẠI)
   ========================================= */
@media (max-width: 768px) {
    .footer-grid { flex-direction: column; gap: 20px; }
    .footer-col-1, .footer-col-2, .footer-col-3 { flex: 1; width: 100%; }
    .footer-info-section { padding: 20px 0; }
    .app-links, .social-links { justify-content: flex-start; }
    #backToTop { bottom: 20px; right: 20px; width: 40px; height: 40px; font-size: 16px; }
    .footer-logo { font-size: 20px; margin-bottom: 10px; }
}
@media (min-width: 769px) and (max-width: 992px) {
    .footer-grid { flex-wrap: wrap; }
    .footer-col-1 { flex: 100%; margin-bottom: 20px; }
    .footer-col-2, .footer-col-3 { flex: 1; }
}