/* theme-1 — UI dựa trên web-1 (Bootstrap 5, navy + amber) */
:root {
    --color-primary: #1e3a8a;
    --color-accent: #d97706;
    --color-accent-2: #fbbf24;
    --color-dark: #0f172a;
    --color-light: #f8fafc;
}
body { overflow-x: hidden; font-family: 'Segoe UI', system-ui, -apple-system, sans-serif; }
.text-white-75 { color: rgba(255, 255, 255, .8); }
.text-white-50 { color: rgba(255, 255, 255, .65); }
.bg-glass { background: rgba(255, 255, 255, .06); backdrop-filter: blur(12px); }
.bg-cta { background: var(--color-primary); }

/* ===== Header ===== */
.header-official {
    background: rgba(15, 23, 42, 0.95);
    backdrop-filter: blur(20px);
    border-bottom: 2px solid var(--color-accent);
    padding: 0.5rem 0;
}
.header-official .navbar-brand img { max-height: 44px; }
.header-official .nav-link {
    color: #cbd5e1 !important;
    font-weight: 500;
    margin: 0 0.75rem;
    transition: color 0.2s;
}
.header-official .nav-link:hover { color: #fff !important; }
.header-official .nav-link.active { color: var(--color-accent-2) !important; font-weight: 600; }
.header-official .btn-register {
    background-color: var(--color-accent);
    border: none;
    color: #0f172a !important;
    font-weight: 600;
    border-radius: 4px;
    padding: 0.5rem 1.8rem;
    text-decoration: none;
    transition: 0.3s;
}
.header-official .btn-register:hover { background-color: #b45309; }
.header-official .btn-login {
    color: #cbd5e1;
    border: 1px solid #334155;
    border-radius: 4px;
    padding: 0.5rem 1.4rem;
    font-weight: 500;
    text-decoration: none;
    transition: 0.3s;
}
.header-official .btn-login:hover { color: #fff; border-color: #cbd5e1; }

/* ===== Breadcrumb ===== */
.breadcrumb-nav { background: #f8fafc; border-bottom: 1px solid #e2e8f0; }

/* ===== Hero ===== */
.hero-section {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a8a 100%);
    min-height: 72vh;
}
.hero-section .hero-accent { color: var(--color-accent-2); }
.hero-section .hero-img {
    max-height: 420px;
    border: 2px solid rgba(255, 255, 255, 0.1);
}

/* ===== Stats bar ===== */
.stats-bar .stat-num { color: var(--color-accent-2); }

/* ===== Category header (trang danh sách) ===== */
.category-header {
    background: linear-gradient(105deg, #f8fafc 0%, #ffffff 100%);
    border-bottom: 1px solid #eef2f9;
}
.hot-tag {
    background: #fef3e8;
    color: #e67e22;
    border-radius: 40px;
    padding: 0.25rem 0.9rem;
    font-size: 0.75rem;
    font-weight: 500;
}
.stat-box { background: #f1f5f9; border-radius: 1rem; transition: 0.2s; }

/* ===== Card bài viết ===== */
.card-list {
    transition: all 0.3s cubic-bezier(0.2, 0, 0, 1);
    border: none;
    border-radius: 1.25rem;
    background: #fff;
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.02), 0 1px 2px rgba(0, 0, 0, 0.02);
}
.card-list:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 28px -12px rgba(0, 0, 0, 0.1);
}
.card-list .ratio img { object-fit: cover; border-radius: 1.25rem 1.25rem 0 0; }
.list-badge-date {
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(4px);
    color: #fff;
    font-size: 0.7rem;
    border-radius: 30px;
    padding: 0.2rem 0.7rem;
}
@media (max-width: 768px) {
    .card-list .ratio { border-radius: 1rem 1rem 0 0; }
}

/* ===== Trang chi tiết ===== */
.badge-category {
    background: var(--color-primary);
    color: #fff;
    border-radius: 30px;
    padding: 0.3rem 1rem;
    font-size: 0.75rem;
    text-decoration: none;
}
.badge-category:hover { background: #16306f; color: #fff; }
.content-box { line-height: 1.9; }
.content-box img { max-width: 100%; height: auto; }

/* ===== Sidebar ===== */
.sticky-sidebar { position: sticky; top: 90px; }
.sidebar-card { border: none; border-radius: 1rem; overflow: hidden; }
.sidebar-card.bg-primary { background: var(--color-primary) !important; }

/* ===== Panel / feature box ===== */
.feature-box { border: 1px solid #e2e8f0; border-radius: 0; }
.icon-card { background: #fff; }

/* ===== Form liên hệ / đăng nhập ===== */
.theme1-form .form-control {
    border-radius: 0;
    border: 1px solid #e2e8f0;
    padding: 0.75rem 1rem;
}
.theme1-form .form-control:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 0.2rem rgba(30, 58, 138, 0.1);
}
.auth-card { background: #fff; border-radius: 1rem; box-shadow: 0 10px 30px rgba(15, 23, 42, 0.08); }
.btn-accent {
    background-color: var(--color-accent);
    border: none;
    color: #0f172a;
    font-weight: 600;
}
.btn-accent:hover { background-color: #b45309; color: #0f172a; }

/* ===== Footer ===== */
.footer-official {
    background: #060e1a;
    border-top: 4px solid var(--color-accent);
    color: #94a3b8;
}
.footer-official h6 { color: #f1f5f9; font-weight: 600; text-transform: uppercase; letter-spacing: 1px; }
.footer-official a { color: #94a3b8; text-decoration: none; }
.footer-official a:hover { color: var(--color-accent-2); }

/* ===== Back to top ===== */
#back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: #fff;
    border: none;
    display: none;
    z-index: 1000;
    cursor: pointer;
    box-shadow: 0 4px 12px rgba(0, 0, 0, .15);
}