:root {
  --primary: #4285F4;   /* tông màu chủ đạo theo yêu cầu */
  --primary-dark: #2b62c9;  
}

body { background:#f4f5f7; font-family: 'Segoe UI', Roboto, Arial, sans-serif; color:#222; }

/* ---------- Header ---------- */
.site-header { background:#fff; }
.top-bar { border-bottom:1px solid #eee; }
.site-logo { height:56px; width:auto; }
.site-title { line-height:1.2; }
.title-line1 { font-weight:500; font-size:1.25rem; color:var(--primary); text-transform:uppercase; }
.title-line2 { font-weight:700; font-size:1.25rem; color:var(--primary); text-transform:uppercase; }
.search-form { max-width:260px; }

.main-nav { background:var(--primary); text-transform: capitalize;}
.main-nav .nav-link { color:#fff !important; font-weight:600; padding:.75rem 1rem; }
.main-nav .nav-link:hover, .main-nav .nav-link:focus { background:var(--primary-dark); }
.main-nav .dropdown-menu { border:0; box-shadow:0 6px 16px rgba(0,0,0,.15); }
.main-nav .dropdown-item:hover { background:var(--primary); color:#fff; }

/* ---------- Slideshow ---------- */
.slideshow-img { height:380px; object-fit:cover; }
@media (max-width:768px){ .slideshow-img{ height:220px; } }

/* ---------- Article cards ---------- */
.section-title { border-left:4px solid var(--primary); padding-left:10px; margin:1rem 0 1.25rem; font-weight:700; }
.article-card { border:0; box-shadow:0 2px 8px rgba(0,0,0,.06); transition:.2s; }
.article-card:hover { box-shadow:0 6px 18px rgba(0,0,0,.12); }
.article-thumb { height:170px; object-fit:cover; }
.article-thumb-sm { height:110px; object-fit:cover; }
.article-thumb-lg { width:320px; object-fit:cover; }
.featured-article { display:flex; flex-direction:column; }
@media (min-width: 768px){ .featured-article{ flex-direction:row; } }
.card-title a, .article-title { color:#222; text-decoration:none; }
.card-title a:hover { color:var(--primary); }
table { width:100%; }
/* ---------- Sidebar ---------- */
.side-menu-card .card-header { background:var(--primary); color:#fff; font-weight:600; }
.side-menu-card a { color:#333; text-decoration:none; }
.side-menu-card a:hover { color:var(--primary); }
.sub-menu li { padding:2px 0; font-size:.9rem; }

/* ---------- Article detail ---------- */
.article-title { font-size:1.6rem; font-weight:700; }
.article-content { line-height:1.8; font-size:1.02rem; }
.article-content img { max-width:100%; height:auto; border-radius:6px; margin:.5rem 0; }
.article-content iframe.embed-video { width:100%; aspect-ratio:16/9; border:0; border-radius:6px; margin:.5rem 0; display:block; }
.article-content table { max-width:100%; }
.article-content a { color: var(--primary); }
.article-summary { color:#555; }

/* ---------- Footer ---------- */
.site-footer { background:var(--primary-dark); }
.footer-links a { color:#f0d9da; text-decoration:none; }
.footer-links a:hover { color:#fff; }
.footer-banner-img { height:80px; object-fit:contain; background:#fff; padding:6px; }

/* ---------- Admin ---------- */
.admin-sidebar { min-height:100vh; background:#1f2430; }
.admin-sidebar a { color:#c7cbd6; }
.admin-sidebar a.active, .admin-sidebar a:hover { color:#fff; background:#2c3242; }
.admin-thumb-preview { max-height:120px; }