/* ============================================
   VN POWER - ARTICLE PAGE STYLES
   ============================================ */

/* ===== DROPDOWN MENU (Desktop) ===== */
.desktop-links .has-dropdown { position: relative; }
.desktop-links .has-dropdown > a {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
}
.desktop-links .has-dropdown > a i {
    font-size: 10px;
    transition: transform 0.3s;
}
.desktop-links .has-dropdown:hover > a i { transform: rotate(180deg); }

.dropdown-menu {
    position: absolute;
    top: calc(100% + 12px);
    right: 0;
    width: 380px;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.15);
    border: 1px solid #eef2f6;
    padding: 12px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    z-index: 100;
    max-height: 80vh;
    overflow-y: auto;
}
.desktop-links .has-dropdown:hover .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.dropdown-menu::before {
    content: '';
    position: absolute;
    top: -8px;
    right: 30px;
    width: 16px;
    height: 16px;
    background: #fff;
    border-top: 1px solid #eef2f6;
    border-left: 1px solid #eef2f6;
    transform: rotate(45deg);
}
.dropdown-menu a {
    display: flex !important;
    align-items: center;
    gap: 12px;
    padding: 12px 14px !important;
    border-radius: 10px;
    color: #1a1a2e !important;
    font-size: 14px !important;
    font-weight: 500 !important;
    transition: all 0.25s;
    line-height: 1.4;
}
.dropdown-menu a::after { display: none !important; }
.dropdown-menu a:hover {
    background: rgba(0, 184, 148, 0.08);
    color: #00b894 !important;
    transform: translateX(4px);
}
.dropdown-menu a.active {
    background: rgba(0, 184, 148, 0.12);
    color: #00b894 !important;
    font-weight: 600 !important;
}
.dropdown-icon {
    width: 32px;
    height: 32px;
    border-radius: 8px;
    background: rgba(0, 184, 148, 0.1);
    color: #00b894;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 13px;
}
.dropdown-menu a.active .dropdown-icon,
.dropdown-menu a:hover .dropdown-icon {
    background: #00b894;
    color: #fff;
}

/* ===== MOBILE SUBMENU ===== */
.mobile-news-toggle > a {
    display: flex !important;
    justify-content: space-between;
    align-items: center;
}
.mobile-news-toggle > a i {
    transition: transform 0.3s;
    font-size: 12px;
}
.mobile-news-toggle.open > a i { transform: rotate(180deg); }

.mobile-submenu {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease;
    padding-left: 16px;
    border-left: 2px solid rgba(0, 184, 148, 0.2);
    margin-left: 4px;
}
.mobile-news-toggle.open .mobile-submenu {
    max-height: 800px;
}
.mobile-submenu li {
    border-bottom: none !important;
}
.mobile-submenu a {
    font-size: 14px !important;
    padding: 10px 4px !important;
    color: rgba(255, 255, 255, 0.7) !important;
    line-height: 1.4;
}
.mobile-submenu a:hover { color: #00b894 !important; }

/* ============================================
   ARTICLE HERO
   ============================================ */
.article-hero {
    padding: 120px 0 60px;
    background: linear-gradient(160deg, #0a1628 0%, #1a2a4a 60%, #0d1f3c 100%);
    position: relative;
    overflow: hidden;
}
.article-hero::before {
    content: '';
    position: absolute;
    top: -30%; right: -10%;
    width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(0, 184, 148, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}
.article-hero-content {
    max-width: 900px;
    margin: 0 auto;
    position: relative;
    z-index: 2;
    text-align: center;
}

/* Breadcrumb */
.breadcrumb {
    margin-bottom: 32px;
}
.breadcrumb ol {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    list-style: none;
    font-size: 13px;
}
.breadcrumb li {
    color: rgba(255, 255, 255, 0.5);
    display: flex;
    align-items: center;
    gap: 8px;
}
.breadcrumb li:not(:last-child)::after {
    content: '/';
    color: rgba(255, 255, 255, 0.3);
}
.breadcrumb a {
    color: rgba(255, 255, 255, 0.7);
    transition: color 0.3s;
}
.breadcrumb a:hover { color: #00d2a0; }
.breadcrumb li[aria-current="page"] { color: rgba(255, 255, 255, 0.9); }

.article-category-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(0, 184, 148, 0.15);
    border: 1px solid rgba(0, 184, 148, 0.3);
    color: #00d2a0;
    font-size: 13px;
    font-weight: 600;
    padding: 8px 18px;
    border-radius: 50px;
    margin-bottom: 20px;
    text-transform: uppercase;
    letter-spacing: 1px;
}
.article-title {
    font-size: clamp(26px, 4vw, 42px);
    font-weight: 800;
    line-height: 1.25;
    color: #fff;
    margin-bottom: 24px;
    letter-spacing: -0.5px;
}
.article-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 24px;
    justify-content: center;
    margin-bottom: 28px;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.65);
}
.article-meta .meta-item {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}
.article-meta i { color: #00d2a0; }

.article-lead {
    font-size: 17px;
    line-height: 1.8;
    color: rgba(255, 255, 255, 0.8);
    text-align: left;
    padding: 24px 28px;
    background: rgba(255, 255, 255, 0.05);
    border-left: 4px solid #00b894;
    border-radius: 12px;
    backdrop-filter: blur(10px);
}

/* ============================================
   ARTICLE LAYOUT
   ============================================ */
.article-layout {
    padding: 60px 0 80px;
    background: #fff;
}
.article-grid {
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 50px;
    align-items: start;
}

/* ===== SIDEBAR ===== */
.article-sidebar {
    position: sticky;
    top: 90px;
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.toc-card {
    background: #f8fafc;
    border: 1px solid #eef2f6;
    border-radius: 16px;
    overflow: hidden;
}
.toc-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 20px;
    background: linear-gradient(135deg, #0a1628, #1a2a4a);
    color: #fff;
}
.toc-header h3 {
    font-size: 15px;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 10px;
}
.toc-header h3 i { color: #00d2a0; }
.toc-toggle {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: #fff;
    width: 28px; height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    transition: all 0.3s;
}
.toc-toggle:hover { background: rgba(255, 255, 255, 0.2); }
.toc-card.collapsed .toc-toggle i { transform: rotate(180deg); }
.toc-card.collapsed .toc-body { max-height: 0; padding: 0 20px; }

.toc-body {
    max-height: 600px;
    overflow: hidden;
    transition: all 0.4s ease;
    padding: 12px 20px;
}
.toc-body ol { list-style: none; }
.toc-body li { margin: 0; }
.toc-body a {
    display: block;
    padding: 10px 0;
    font-size: 14px;
    color: #555;
    line-height: 1.5;
    border-bottom: 1px solid #eef2f6;
    transition: all 0.3s;
    position: relative;
}
.toc-body li:last-child a { border-bottom: none; }
.toc-body a:hover,
.toc-body a.active {
    color: #00b894;
    padding-left: 8px;
}
.toc-body a.active { font-weight: 600; }
.toc-body a.active::before {
    content: '';
    position: absolute;
    left: -20px;
    top: 0;
    bottom: 0;
    width: 3px;
    background: #00b894;
}
.toc-num {
    color: #00b894;
    font-weight: 700;
    margin-right: 6px;
}

/* Sidebar CTA */
.sidebar-cta {
    background: linear-gradient(135deg, #0a1628, #1a2a4a);
    border-radius: 16px;
    padding: 28px 24px;
    text-align: center;
    color: #fff;
    position: relative;
    overflow: hidden;
}
.sidebar-cta::before {
    content: '';
    position: absolute;
    top: -50%; right: -50%;
    width: 200px; height: 200px;
    background: radial-gradient(circle, rgba(0, 184, 148, 0.15) 0%, transparent 70%);
    border-radius: 50%;
}
.sidebar-cta-icon {
    width: 56px; height: 56px;
    border-radius: 50%;
    background: rgba(0, 184, 148, 0.15);
    color: #00d2a0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin: 0 auto 16px;
    position: relative;
    z-index: 1;
}
.sidebar-cta h4 {
    font-size: 17px;
    font-weight: 700;
    margin-bottom: 10px;
    position: relative;
    z-index: 1;
}
.sidebar-cta p {
    font-size: 13px;
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 20px;
    line-height: 1.6;
    position: relative;
    z-index: 1;
}
.btn-sm {
    padding: 10px 22px;
    font-size: 13px;
    position: relative;
    z-index: 1;
}

/* ============================================
   ARTICLE CONTENT
   ============================================ */
.article-content {
    max-width: 100%;
    min-width: 0;
}

/* Share bar */
.share-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 14px 20px;
    background: #f8fafc;
    border-radius: 12px;
    margin-bottom: 32px;
    border: 1px solid #eef2f6;
    flex-wrap: wrap;
}
.share-label {
    font-size: 13px;
    font-weight: 600;
    color: #666;
    margin-right: 6px;
}
.share-btn {
    width: 36px; height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 14px;
    transition: all 0.3s;
}
.share-btn:hover { transform: translateY(-3px) scale(1.1); }
.share-facebook { background: #1877f2; }
.share-twitter { background: #1da1f2; }
.share-linkedin { background: #0a66c2; }
.share-copy { background: #64748b; }
.share-copy.copied { background: #00b894; }

/* Article body */
.article-body {
    font-size: 16px;
    line-height: 1.85;
    color: #334155;
}
.article-body > p {
    margin-bottom: 20px;
    text-align: justify;
}
.article-body strong { color: #1a1a2e; font-weight: 600; }
.article-body em { color: #00b894; font-style: italic; }

.article-body h2 {
    font-size: clamp(22px, 3vw, 28px);
    font-weight: 800;
    color: #1a1a2e;
    margin: 40px 0 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid #eef2f6;
    position: relative;
    scroll-margin-top: 90px;
}
.article-body h2::before {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 60px;
    height: 2px;
    background: linear-gradient(90deg, #00b894, #00d2a0);
}
.article-body h3 {
    font-size: clamp(18px, 2.5vw, 22px);
    font-weight: 700;
    color: #1D847C;
    margin: 32px 0 16px;
    scroll-margin-top: 90px;
}
.article-body h4 {
    font-size: 17px;
    font-weight: 700;
    color: #1a1a2e;
    margin: 24px 0 12px;
}

.article-body ul,
.article-body ol {
    margin: 0 0 20px 0;
    padding-left: 24px;
}
.article-body ul li {
    list-style: disc;
    margin-bottom: 8px;
    line-height: 1.7;
}
.article-body ol li {
    list-style: decimal;
    margin-bottom: 8px;
    line-height: 1.7;
}
.article-body li::marker { color: #00b894; font-weight: 600; }

.article-link {
    color: #0a5bd1;
    font-weight: 500;
    border-bottom: 1px dashed rgba(10, 91, 209, 0.4);
    transition: all 0.3s;
}
.article-link:hover {
    color: #00b894;
    border-bottom-color: #00b894;
}

/* Article figure */
.article-figure {
    margin: 28px 0;
    text-align: center;
}
.article-figure img {
    max-width: 100%;
    height: auto;
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
}
.article-figure figcaption {
    font-size: 13px;
    color: #94a3b8;
    margin-top: 12px;
    font-style: italic;
}

/* Callout */
.article-callout {
    display: flex;
    gap: 16px;
    padding: 20px 24px;
    background: linear-gradient(135deg, rgba(0, 184, 148, 0.08), rgba(0, 210, 160, 0.04));
    border-left: 4px solid #00b894;
    border-radius: 12px;
    margin: 28px 0;
}
.callout-icon {
    width: 40px; height: 40px;
    border-radius: 10px;
    background: #00b894;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    flex-shrink: 0;
}
.callout-content {
    font-size: 15px;
    line-height: 1.7;
    color: #334155;
}
.callout-content strong { color: #00b894; }

/* ESG Grid */
.esg-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin: 24px 0;
}
.esg-card {
    background: #f8fafc;
    border: 1px solid #eef2f6;
    border-radius: 14px;
    padding: 22px 18px;
    text-align: center;
    transition: all 0.3s;
}
.esg-card:hover {
    transform: translateY(-4px);
    border-color: #00b894;
    box-shadow: 0 10px 30px rgba(0, 184, 148, 0.08);
}
.esg-icon {
    width: 50px; height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: #fff;
    margin: 0 auto 14px;
}
.esg-e { background: linear-gradient(135deg, #00b894, #00a86b); }
.esg-s { background: linear-gradient(135deg, #3498db, #2980b9); }
.esg-g { background: linear-gradient(135deg, #9b59b6, #8e44ad); }
.esg-card h4 {
    font-size: 15px;
    font-weight: 700;
    color: #1a1a2e;
    margin: 0 0 8px !important;
}
.esg-card p {
    font-size: 13px;
    color: #64748b;
    line-height: 1.6;
    margin: 0;
}

/* Highlight box */
.article-highlight-box {
    background: #f8fafc;
    border: 1px solid #eef2f6;
    border-left: 4px solid #00b894;
    border-radius: 12px;
    padding: 20px 24px;
    margin: 20px 0;
}
.article-highlight-box h4 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 700;
    color: #00b894;
    margin: 0 0 10px !important;
}
.article-highlight-box h4 i { font-size: 16px; }
.article-highlight-box p {
    margin: 0;
    font-size: 15px;
    line-height: 1.75;
    color: #334155;
}

/* Timeline */
.process-timeline {
    position: relative;
    margin: 28px 0;
    padding-left: 0;
}
.timeline-item {
    display: flex;
    gap: 20px;
    margin-bottom: 24px;
    position: relative;
}
.timeline-item:not(:last-child)::before {
    content: '';
    position: absolute;
    left: 22px;
    top: 48px;
    bottom: -24px;
    width: 2px;
    background: linear-gradient(180deg, #00b894, rgba(0, 184, 148, 0.1));
}
.timeline-num {
    width: 46px; height: 46px;
    border-radius: 50%;
    background: linear-gradient(135deg, #00b894, #00a86b);
    color: #fff;
    font-size: 18px;
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: 0 6px 20px rgba(0, 184, 148, 0.3);
    z-index: 2;
}
.timeline-content {
    background: #f8fafc;
    border: 1px solid #eef2f6;
    border-radius: 12px;
    padding: 16px 20px;
    flex: 1;
}
.timeline-content h4 {
    font-size: 16px;
    font-weight: 700;
    color: #1a1a2e;
    margin: 0 0 6px !important;
}
.timeline-content p {
    margin: 0;
    font-size: 14px;
    line-height: 1.7;
    color: #64748b;
}

/* Inline CTA */
.article-cta-inline {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 28px 32px;
    background: linear-gradient(135deg, #0a1628, #1a2a4a);
    border-radius: 16px;
    margin: 36px 0;
    color: #fff;
    flex-wrap: wrap;
}
.cta-inline-content h3 {
    font-size: 20px;
    font-weight: 700;
    color: #fff !important;
    margin: 0 0 6px !important;
}
.cta-inline-content p {
    font-size: 14px;
    color: rgba(255, 255, 255, 0.75);
    margin: 0;
    line-height: 1.6;
}

/* ============================================
   FAQ
   ============================================ */
.article-faq {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 2px solid #eef2f6;
}
.article-faq h2 {
    font-size: clamp(22px, 3vw, 28px);
    font-weight: 800;
    color: #1a1a2e;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}
.article-faq h2 i { color: #00b894; }

.faq-list { display: flex; flex-direction: column; gap: 12px; }
.faq-item {
    background: #fff;
    border: 1.5px solid #e2e8f0;
    border-radius: 14px;
    overflow: hidden;
    transition: all 0.3s;
}
.faq-item[open] {
    border-color: #00b894;
    background: rgba(0, 184, 148, 0.03);
    box-shadow: 0 8px 25px rgba(0, 184, 148, 0.08);
}
.faq-item summary {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    padding: 18px 22px;
    cursor: pointer;
    font-weight: 600;
    font-size: 15px;
    color: #1a1a2e;
    list-style: none;
    transition: all 0.3s;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary:hover { color: #00b894; }
.faq-icon {
    width: 28px; height: 28px;
    border-radius: 50%;
    background: rgba(0, 184, 148, 0.1);
    color: #00b894;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    flex-shrink: 0;
    transition: all 0.3s;
}
.faq-item[open] .faq-icon {
    background: #00b894;
    color: #fff;
    transform: rotate(45deg);
}
.faq-answer {
    padding: 0 22px 20px;
    font-size: 15px;
    line-height: 1.75;
    color: #475569;
}
.faq-answer p { margin: 0; }

/* ============================================
   ARTICLE TAGS
   ============================================ */
.article-tags {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 10px;
    margin-top: 40px;
    padding-top: 24px;
    border-top: 1px solid #eef2f6;
}
.tags-label {
    font-size: 14px;
    font-weight: 600;
    color: #666;
}
.tag-link {
    font-size: 13px;
    padding: 6px 14px;
    background: #f1f5f9;
    color: #475569;
    border-radius: 50px;
    transition: all 0.3s;
}
.tag-link:hover {
    background: #00b894;
    color: #fff;
    transform: translateY(-2px);
}

/* ============================================
   RELATED NEWS
   ============================================ */
.related-news {
    padding: 80px 0;
    background: #f8fafc;
}

/* ============================================
   ARTICLE CONTACT CTA
   ============================================ */
.article-contact-cta {
    padding: 100px 0;
    background: linear-gradient(135deg, #0a1628, #1a2a4a);
    position: relative;
    overflow: hidden;
}
.article-contact-cta::before {
    content: '';
    position: absolute;
    top: -50%; right: -20%;
    width: 600px; height: 600px;
    background: radial-gradient(circle, rgba(0, 184, 148, 0.08) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
    animation: pulse-glow 6s ease-in-out infinite;
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 1024px) {
    .dropdown-menu { width: 340px; }
    .article-grid { grid-template-columns: 260px 1fr; gap: 36px; }
}

@media (max-width: 900px) {
    .article-grid { grid-template-columns: 1fr; }
    .article-sidebar {
        position: static;
        order: -1;
    }
    .toc-card { margin-bottom: 8px; }
    .sidebar-cta { display: none; }
    .article-hero { padding: 100px 0 40px; }
    .esg-grid { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    /* Hide desktop dropdown on mobile */
    .dropdown-menu { display: none; }

    .article-hero { padding: 90px 0 40px; }
    .article-title { font-size: 24px; }
    .article-lead {
        font-size: 15px;
        padding: 18px 20px;
    }
    .article-meta { gap: 14px; font-size: 13px; }
    .breadcrumb ol { font-size: 12px; }

    .article-layout { padding: 40px 0 60px; }
    .article-body { font-size: 15px; }
    .article-body h2 { margin: 32px 0 16px; }
    .article-body h3 { margin: 24px 0 12px; }
    .article-body ul, .article-body ol { padding-left: 20px; }

    .share-bar { padding: 12px 14px; }
    .share-label { width: 100%; margin-bottom: 6px; }

    .article-cta-inline {
        flex-direction: column;
        text-align: center;
        padding: 24px 20px;
    }
    .article-cta-inline .btn-primary {
        width: 100%;
        justify-content: center;
    }

    .timeline-item { gap: 14px; }
    .timeline-item:not(:last-child)::before { left: 20px; }
    .timeline-num { width: 40px; height: 40px; font-size: 16px; }
    .timeline-content { padding: 14px 16px; }

    .faq-item summary { padding: 14px 16px; font-size: 14px; }
    .faq-answer { padding: 0 16px 16px; font-size: 14px; }

    .esg-card { padding: 18px 16px; }

    .related-news { padding: 60px 0; }
    .article-contact-cta { padding: 60px 0 100px; }
}

@media (max-width: 480px) {
    .article-title { font-size: 21px; }
    .article-lead { font-size: 14px; padding: 16px; }
    .article-body { font-size: 14px; }
    .article-body h2 { font-size: 20px; }
    .article-body h3 { font-size: 17px; }
    .article-meta { gap: 10px; font-size: 12px; }
    .article-meta .meta-item { gap: 5px; }
    .toc-header h3 { font-size: 14px; }
    .toc-body a { font-size: 13px; padding: 8px 0; }
}

/* ============================================
   REDUCED MOTION
   ============================================ */
@media (prefers-reduced-motion: reduce) {
    .article-contact-cta::before { animation: none; }
}

/* ============================================
   FORMULA BOX (Công thức toán học)
   ============================================ */
.formula-box {
    background: linear-gradient(135deg, #0a1628, #1a2a4a);
    border-radius: 16px;
    padding: 28px 24px;
    margin: 24px 0;
    color: #fff;
    text-align: center;
    position: relative;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(10, 22, 40, 0.15);
}
.formula-box::before {
    content: '';
    position: absolute;
    top: -50%; right: -30%;
    width: 300px; height: 300px;
    background: radial-gradient(circle, rgba(0, 184, 148, 0.15) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}
.formula-label {
    display: inline-block;
    background: rgba(0, 184, 148, 0.2);
    color: #00d2a0;
    font-size: 11px;
    font-weight: 700;
    letter-spacing: 1.5px;
    text-transform: uppercase;
    padding: 5px 14px;
    border-radius: 50px;
    margin-bottom: 16px;
    position: relative;
    z-index: 1;
}
.formula-equation {
    font-size: clamp(20px, 3vw, 28px);
    font-weight: 800;
    font-family: 'Cambria Math', 'Times New Roman', Georgia, serif;
    color: #fff;
    letter-spacing: 1px;
    padding: 12px 0;
    position: relative;
    z-index: 1;
}
.formula-equation-sm {
    font-size: clamp(16px, 2.2vw, 20px);
    line-height: 1.5;
    letter-spacing: 0.5px;
}
.formula-equation sub {
    font-size: 0.6em;
    vertical-align: sub;
}
.formula-box-green {
    background: linear-gradient(135deg, #00b894, #00a86b);
}
.formula-box-green::before {
    background: radial-gradient(circle, rgba(255, 255, 255, 0.15) 0%, transparent 70%);
}
.formula-box-green .formula-label {
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
}
.formula-vars {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 8px 24px;
    margin-top: 16px;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.15);
    text-align: left;
    font-size: 14px;
    color: rgba(255, 255, 255, 0.9);
    font-family: 'Inter', sans-serif;
    font-weight: 400;
    letter-spacing: 0;
    position: relative;
    z-index: 1;
}
.formula-vars strong {
    color: #00d2a0;
}

/* ============================================
   EXAMPLE BOX (Ví dụ minh họa)
   ============================================ */
.example-box {
    background: rgba(0, 184, 148, 0.05);
    border: 1.5px dashed rgba(0, 184, 148, 0.4);
    border-radius: 14px;
    padding: 22px 24px;
    margin: 20px 0;
}
.example-box h4 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 700;
    color: #00b894;
    margin: 0 0 14px !important;
}
.example-box h4 i {
    font-size: 18px;
    width: 32px; height: 32px;
    background: #00b894;
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}
.example-box ul {
    margin: 0;
    padding-left: 24px;
}
.example-box li {
    margin-bottom: 6px;
    font-size: 15px;
    color: #334155;
}

/* ============================================
   COMPARE GRID (So sánh 2 cột)
   ============================================ */
.compare-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 28px 0;
}
.compare-card {
    border-radius: 16px;
    padding: 24px 22px;
    position: relative;
    overflow: hidden;
    transition: all 0.3s;
}
.compare-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.08);
}
.compare-card-blue {
    background: linear-gradient(135deg, #eff6ff, #dbeafe);
    border: 1.5px solid #bfdbfe;
}
.compare-card-green {
    background: linear-gradient(135deg, #ecfdf5, #d1fae5);
    border: 1.5px solid #a7f3d0;
}
.compare-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
    padding-bottom: 14px;
    border-bottom: 2px solid rgba(0, 0, 0, 0.05);
}
.compare-header i {
    font-size: 20px;
    width: 42px; height: 42px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}
.compare-card-blue .compare-header i {
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
    color: #fff;
}
.compare-card-green .compare-header i {
    background: linear-gradient(135deg, #10b981, #059669);
    color: #fff;
}
.compare-header h4 {
    font-size: 16px;
    font-weight: 700;
    color: #1a1a2e;
    margin: 0 !important;
    line-height: 1.3;
}
.compare-card ul {
    margin: 0;
    padding-left: 20px;
}
.compare-card li {
    margin-bottom: 8px;
    font-size: 14px;
    line-height: 1.6;
    color: #334155;
}
.compare-card li strong {
    color: #1a1a2e;
}
.compare-card-blue li::marker { color: #3b82f6; }
.compare-card-green li::marker { color: #10b981; }

/* ============================================
   STEPS BOX (Các bước tính toán)
   ============================================ */
.steps-box {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin: 24px 0;
}
.step-item {
    background: #fff;
    border: 1.5px solid #e2e8f0;
    border-radius: 14px;
    padding: 20px 22px 20px 24px;
    position: relative;
    transition: all 0.3s;
}
.step-item:hover {
    border-color: #00b894;
    box-shadow: 0 10px 30px rgba(0, 184, 148, 0.08);
    transform: translateX(4px);
}
.step-item::before {
    content: '';
    position: absolute;
    left: 0; top: 20px; bottom: 20px;
    width: 4px;
    background: linear-gradient(180deg, #00b894, #00d2a0);
    border-radius: 0 4px 4px 0;
}
.step-badge {
    display: inline-block;
    background: linear-gradient(135deg, #00b894, #00a86b);
    color: #fff;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    padding: 5px 14px;
    border-radius: 50px;
    margin-bottom: 12px;
    box-shadow: 0 4px 12px rgba(0, 184, 148, 0.25);
}
.step-item h4 {
    font-size: 16px;
    font-weight: 700;
    color: #1a1a2e;
    margin: 0 0 8px !important;
}
.step-item p {
    margin: 0;
    font-size: 14px;
    line-height: 1.7;
    color: #475569;
}

/* ============================================
   CALLOUT WARNING
   ============================================ */
.article-callout-warning {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.06), rgba(220, 38, 38, 0.03));
    border-left-color: #ef4444;
}
.article-callout-warning .callout-icon {
    background: #ef4444;
}

/* ============================================
   RESPONSIVE cho các component mới
   ============================================ */
@media (max-width: 768px) {
    .formula-box {
        padding: 22px 18px;
    }
    .formula-equation {
        padding: 8px 0;
    }
    .formula-vars {
        grid-template-columns: 1fr;
        gap: 6px;
        font-size: 13px;
    }
    .compare-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    .compare-card {
        padding: 20px 18px;
    }
    .step-item {
        padding: 18px 18px 18px 20px;
    }
    .example-box {
        padding: 18px 20px;
    }
}

/* ============================================
   COMPARE CARD - Variants (Red, Orange)
   ============================================ */
.compare-card-red {
    background: linear-gradient(135deg, #fef2f2, #fee2e2);
    border: 1.5px solid #fecaca;
}
.compare-card-red .compare-header i {
    background: linear-gradient(135deg, #ef4444, #dc2626);
    color: #fff;
}
.compare-card-red li::marker { color: #ef4444; }

.compare-card-orange {
    background: linear-gradient(135deg, #fff7ed, #ffedd5);
    border: 1.5px solid #fed7aa;
}
.compare-card-orange .compare-header i {
    background: linear-gradient(135deg, #f97316, #ea580c);
    color: #fff;
}
.compare-card-orange li::marker { color: #f97316; }

/* ============================================
   REGION CARDS (3 miền)
   ============================================ */
.region-cards {
    display: grid;
    grid-template-columns: 1fr;
    gap: 20px;
    margin: 28px 0;
}

.region-card {
    background: #fff;
    border-radius: 18px;
    overflow: hidden;
    border: 1.5px solid #e2e8f0;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}
.region-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.08);
}

/* Region Header */
.region-header {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 22px 24px;
    color: #fff;
    position: relative;
    overflow: hidden;
}
.region-header::before {
    content: '';
    position: absolute;
    top: -50%; right: -20%;
    width: 200px; height: 200px;
    background: radial-gradient(circle, rgba(255,255,255,0.15) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}
.region-south .region-header {
    background: linear-gradient(135deg, #f59e0b, #ea580c);
}
.region-central .region-header {
    background: linear-gradient(135deg, #f97316, #dc2626);
}
.region-north .region-header {
    background: linear-gradient(135deg, #3b82f6, #1d4ed8);
}

.region-icon {
    width: 56px; height: 56px;
    border-radius: 14px;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
    flex-shrink: 0;
    position: relative;
    z-index: 1;
}
.region-title {
    flex: 1;
    position: relative;
    z-index: 1;
}
.region-title h3 {
    font-size: 20px;
    font-weight: 800;
    margin: 0 0 6px !important;
    color: #fff !important;
    line-height: 1.2;
}
.region-rating {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 13px;
    flex-wrap: wrap;
}
.rating-stars {
    color: #fde047;
    letter-spacing: 2px;
    font-size: 15px;
}
.rating-label {
    background: rgba(255, 255, 255, 0.2);
    padding: 3px 10px;
    border-radius: 50px;
    font-weight: 500;
    backdrop-filter: blur(4px);
}

/* Region Stats */
.region-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    padding: 20px 24px;
    background: #f8fafc;
    border-bottom: 1px solid #eef2f6;
}
.region-stat {
    text-align: center;
}
.stat-value {
    font-size: 24px;
    font-weight: 800;
    color: #00b894;
    line-height: 1.2;
    font-variant-numeric: tabular-nums;
}
.stat-unit {
    font-size: 12px;
    color: #64748b;
    font-weight: 500;
    margin-top: 2px;
}

/* Region Features */
.region-features {
    list-style: none;
    padding: 20px 24px !important;
    margin: 0 !important;
}
.region-features li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 8px 0;
    font-size: 14px;
    line-height: 1.6;
    color: #334155;
    border-bottom: 1px dashed #eef2f6;
}
.region-features li:last-child { border-bottom: none; }
.region-features li i {
    color: #00b894;
    font-size: 12px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: rgba(0, 184, 148, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    margin-top: 3px;
}

/* Region Highlight */
.region-highlight {
    margin: 0 24px 24px;
    padding: 16px 18px;
    background: linear-gradient(135deg, #fef3c7, #fde68a);
    border-radius: 12px;
    border-left: 4px solid #f59e0b;
    position: relative;
}
.region-highlight i {
    position: absolute;
    top: -10px; right: 16px;
    width: 34px; height: 34px;
    border-radius: 50%;
    background: #f59e0b;
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.4);
}
.region-highlight strong {
    display: block;
    color: #92400e;
    font-size: 14px;
    margin-bottom: 4px;
}
.region-highlight p {
    margin: 0;
    font-size: 13px;
    color: #78350f;
    line-height: 1.5;
}
.region-highlight p strong {
    display: inline;
    color: #78350f;
    font-size: 13px;
    margin: 0;
}

.region-highlight-yellow {
    background: linear-gradient(135deg, #fef9c3, #fef08a);
    border-left-color: #eab308;
}
.region-highlight-yellow i { background: #eab308; box-shadow: 0 4px 12px rgba(234, 179, 8, 0.4); }
.region-highlight-yellow strong { color: #854d0e; }
.region-highlight-yellow p { color: #713f12; }
.region-highlight-yellow p strong { color: #713f12; }

.region-highlight-blue {
    background: linear-gradient(135deg, #dbeafe, #bfdbfe);
    border-left-color: #3b82f6;
}
.region-highlight-blue i { background: #3b82f6; box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4); }
.region-highlight-blue strong { color: #1e40af; }
.region-highlight-blue p { color: #1e3a8a; }
.region-highlight-blue p strong { color: #1e3a8a; }

/* ============================================
   RESPONSIVE cho Region Cards
   ============================================ */
@media (max-width: 768px) {
    .region-header {
        padding: 18px 20px;
        gap: 12px;
    }
    .region-icon {
        width: 48px; height: 48px;
        font-size: 22px;
    }
    .region-title h3 {
        font-size: 17px;
    }
    .rating-stars { font-size: 13px; }
    .rating-label { font-size: 12px; padding: 2px 8px; }
    
    .region-stats {
        padding: 16px 20px;
    }
    .stat-value { font-size: 20px; }
    .stat-unit { font-size: 11px; }
    
    .region-features {
        padding: 16px 20px !important;
    }
    .region-features li {
        font-size: 13px;
        padding: 6px 0;
    }
    
    .region-highlight {
        margin: 0 20px 20px;
        padding: 14px 16px;
    }
    .region-highlight i {
        width: 30px; height: 30px;
        font-size: 12px;
        top: -8px; right: 12px;
    }
}

/* ============================================
   RESPONSIVE cho Region Cards
   ============================================ */
@media (max-width: 768px) {
    .region-header {
        padding: 18px 20px;
        gap: 12px;
    }
    .region-icon {
        width: 48px; height: 48px;
        font-size: 22px;
    }
    .region-title h3 {
        font-size: 17px;
    }
    .rating-stars { font-size: 13px; }
    .rating-label { font-size: 12px; padding: 2px 8px; }
    
    .region-stats {
        padding: 16px 20px;
    }
    .stat-value { font-size: 20px; }
    .stat-unit { font-size: 11px; }
    
    .region-features {
        padding: 16px 20px !important;
    }
    .region-features li {
        font-size: 13px;
        padding: 6px 0;
    }
    
    .region-highlight {
        margin: 0 20px 20px;
        padding: 14px 16px;
    }
    .region-highlight i {
        width: 30px; height: 30px;
        font-size: 12px;
        top: -8px; right: 12px;
    }
}

/* ============================================
   RISK GRID (4 rủi ro)
   ============================================ */
.risk-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin: 24px 0;
}
.risk-card {
    background: #fff;
    border: 1.5px solid #fee2e2;
    border-radius: 14px;
    padding: 20px 20px;
    position: relative;
    transition: all 0.3s;
}
.risk-card:hover {
    border-color: #ef4444;
    box-shadow: 0 10px 30px rgba(239, 68, 68, 0.1);
    transform: translateY(-3px);
}
.risk-icon {
    width: 38px; height: 38px;
    border-radius: 10px;
    background: linear-gradient(135deg, #ef4444, #dc2626);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    margin-bottom: 12px;
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}
.risk-card h4 {
    font-size: 15px;
    font-weight: 700;
    color: #1a1a2e;
    margin: 0 0 8px !important;
}
.risk-card p {
    margin: 0;
    font-size: 13.5px;
    line-height: 1.6;
    color: #64748b;
}
.risk-card p strong { color: #ef4444; }

/* ============================================
   CRITERIA BOX (3 tiêu chí đánh số)
   ============================================ */
.criteria-box {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    background: linear-gradient(135deg, #f0fdf4, #dcfce7);
    border-left: 5px solid #00b894;
    border-radius: 16px;
    padding: 24px 26px;
    margin: 28px 0 20px;
    position: relative;
    overflow: hidden;
}
.criteria-box::before {
    content: '';
    position: absolute;
    top: -50%; right: -20%;
    width: 200px; height: 200px;
    background: radial-gradient(circle, rgba(0, 184, 148, 0.1) 0%, transparent 70%);
    border-radius: 50%;
    pointer-events: none;
}
.criteria-number {
    font-size: 48px;
    font-weight: 900;
    color: #00b894;
    line-height: 1;
    flex-shrink: 0;
    opacity: 0.4;
    position: relative;
    z-index: 1;
    font-family: 'Inter', sans-serif;
    letter-spacing: -2px;
}
.criteria-content {
    flex: 1;
    position: relative;
    z-index: 1;
}
.criteria-content h3 {
    font-size: 18px !important;
    font-weight: 800 !important;
    color: #065f46 !important;
    margin: 0 0 10px !important;
    line-height: 1.3;
}
.criteria-content p {
    margin: 0;
    font-size: 14.5px;
    line-height: 1.7;
    color: #334155;
}
.criteria-content p strong {
    color: #00b894;
}

/* ============================================
   DECISION GRID (Tự làm hay thuê thợ)
   ============================================ */
.decision-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin: 28px 0;
}
.decision-card {
    background: #fff;
    border-radius: 16px;
    overflow: hidden;
    border: 1.5px solid #e2e8f0;
    transition: all 0.3s;
}
.decision-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 15px 40px rgba(0, 0, 0, 0.08);
}
.decision-header {
    padding: 20px 22px 16px;
    position: relative;
}
.decision-yes .decision-header {
    background: linear-gradient(135deg, #10b981, #059669);
    color: #fff;
}
.decision-no .decision-header {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: #fff;
}
.decision-icon {
    width: 44px; height: 44px;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    margin-bottom: 12px;
}
.decision-header h4 {
    font-size: 17px;
    font-weight: 800;
    margin: 0 0 8px !important;
    color: #fff !important;
    line-height: 1.3;
}
.decision-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.25);
    color: #fff;
    font-size: 11.5px;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
    padding: 4px 12px;
    border-radius: 50px;
    backdrop-filter: blur(4px);
}
.decision-card ul {
    list-style: none;
    padding: 18px 22px !important;
    margin: 0 !important;
}
.decision-card ul li {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 8px 0;
    font-size: 14px;
    line-height: 1.6;
    color: #334155;
    border-bottom: 1px dashed #eef2f6;
}
.decision-card ul li:last-child { border-bottom: none; }
.decision-card ul li::before {
    content: '•';
    color: #00b894;
    font-weight: 900;
    font-size: 18px;
    line-height: 1;
    flex-shrink: 0;
}
.decision-no ul li::before {
    color: #f59e0b;
}
.decision-note {
    margin: 0 22px 22px;
    padding: 14px 16px;
    background: rgba(0, 184, 148, 0.08);
    border-left: 3px solid #00b894;
    border-radius: 8px;
    font-size: 13.5px;
    line-height: 1.6;
    color: #334155;
}
.decision-note strong {
    color: #00b894;
}
.decision-note-warning {
    background: rgba(245, 158, 11, 0.08);
    border-left-color: #f59e0b;
}
.decision-note-warning strong {
    color: #d97706;
}

/* ============================================
   RESPONSIVE cho các component mới
   ============================================ */
@media (max-width: 768px) {
    .risk-grid,
    .decision-grid {
        grid-template-columns: 1fr;
        gap: 14px;
    }
    .criteria-box {
        flex-direction: column;
        gap: 8px;
        padding: 20px 20px;
    }
    .criteria-number {
        font-size: 36px;
    }
    .criteria-content h3 {
        font-size: 16px !important;
    }
    .criteria-content p {
        font-size: 14px;
    }
    .risk-card {
        padding: 18px 16px;
    }
    .decision-header {
        padding: 18px 18px 14px;
    }
    .decision-header h4 { font-size: 16px; }
    .decision-card ul {
        padding: 16px 18px !important;
    }
    .decision-card ul li { font-size: 13.5px; }
    .decision-note {
        margin: 0 18px 18px;
        padding: 12px 14px;
        font-size: 13px;
    }
}