/* =============================================================
   blog.css — CSS chung cho tất cả bài viết blog 27BigGroup
   Import: <link rel="stylesheet" href="../blog/blog.css">
   (hoặc "blog.css" nếu file cùng thư mục blog/)
   ============================================================= */

/* ── Google Fonts ── */
@import url('https://fonts.googleapis.com/css2?family=Philosopher:ital,wght@0,400;0,700;1,400&family=Roboto:wght@300;400;500;700&display=swap');

/* ── Reset & Base ── */
:root {
  --primary: #ff5757;
  --primary-dk: #dc0101;
  --primary-lt: #fff0f0;
  --text: #222;
  --muted: #666;
  --light: #f8f4f0;
  --border: #ede8e0;
  --radius: 12px;
  --max-w: 760px;
}

*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Roboto', system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.75;
  color: var(--text);
  background: #fff;
}

a {
  color: var(--primary);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* ── Site Header ── */
.site-header {
  background: #fff;
  border-bottom: 1px solid var(--border);
  padding: 0 20px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.site-header-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 58px;
  gap: 16px;
}

.site-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.site-logo img {
  height: 30px;
  width: auto;
  max-width: 140px;
  display: block;
  object-fit: contain;
}

.footer-brand .site-logo {
  margin-bottom: 10px;
}

.footer-brand .site-logo img {
  height: 26px;
  max-width: 120px;
}

.header-nav {
  display: flex;
  gap: 20px;
  font-size: 14px;
}

.header-nav a {
  color: var(--muted);
  font-weight: 500;
}

.header-nav a:hover {
  color: var(--primary);
  text-decoration: none;
}

.header-cta {
  background: var(--primary);
  color: #fff !important;
  padding: 7px 16px;
  border-radius: 8px;
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
}

.header-cta:hover {
  background: var(--primary-dk);
  text-decoration: none !important;
}

/* ── Breadcrumb ── */
.breadcrumb-wrap {
  background: var(--light);
  border-bottom: 1px solid var(--border);
  padding: 10px 20px;
}

.breadcrumb {
  max-width: 1100px;
  margin: 0 auto;
  font-size: 13px;
  color: var(--muted);
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  align-items: center;
}

.breadcrumb a {
  color: var(--muted);
}

.breadcrumb a:hover {
  color: var(--primary);
}

.breadcrumb .sep {
  opacity: .4;
}

.breadcrumb .current {
  color: var(--text);
  font-weight: 500;
}

/* ── Article Layout ── */
.article-wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 36px 20px 60px;
  display: grid;
  grid-template-columns: 1fr 280px;
  gap: 48px;
  align-items: start;
}

/* ── Article Header ── */
.article-header {
  margin-bottom: 28px;
}

.article-category {
  display: inline-block;
  background: var(--primary-lt);
  color: var(--primary);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .5px;
  text-transform: uppercase;
  padding: 4px 10px;
  border-radius: 6px;
  margin-bottom: 14px;
}

.article-title {
  font-family: 'Philosopher', serif;
  font-size: clamp(26px, 5vw, 38px);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text);
  margin-bottom: 16px;
}

.article-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 13px;
  color: var(--muted);
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 24px;
}

.article-meta span {
  display: flex;
  align-items: center;
  gap: 5px;
}

.article-excerpt {
  font-size: 17px;
  color: var(--muted);
  line-height: 1.7;
  margin-bottom: 24px;
  font-style: italic;
}

/* ── Featured Image ── */
.featured-img {
  border-radius: var(--radius);
  overflow: hidden;
  margin-bottom: 32px;
  aspect-ratio: 16/9;
  background: var(--light);
}

.featured-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* ── Table of Contents ── */
.toc-box {
  background: var(--light);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 20px;
  margin-bottom: 32px;
}

.toc-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
  display: flex;
  align-items: center;
  gap: 6px;
}

.toc-list {
  list-style: none;
  counter-reset: toc;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.toc-list li {
  font-size: 14px;
  counter-increment: toc;
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.toc-list li::before {
  content: counter(toc) ".";
  color: var(--primary);
  font-weight: 700;
  font-size: 13px;
  flex-shrink: 0;
  min-width: 18px;
}

.toc-list a {
  color: var(--text);
  font-weight: 500;
}

.toc-list a:hover {
  color: var(--primary);
}

/* ── Article Body Typography ── */
.article-body {
  font-size: 16px;
  line-height: 1.82;
}

.article-body h2 {
  font-family: 'Philosopher', serif;
  font-size: clamp(20px, 3.5vw, 26px);
  font-weight: 700;
  color: var(--text);
  margin: 40px 0 14px;
  padding-top: 8px;
  border-top: 3px solid var(--primary);
  padding-top: 14px;
}

.article-body h3 {
  font-family: 'Philosopher', serif;
  font-size: clamp(17px, 2.5vw, 20px);
  font-weight: 700;
  color: var(--text);
  margin: 28px 0 10px;
}

.article-body p {
  margin-bottom: 18px;
}

.article-body ul,
.article-body ol {
  padding-left: 22px;
  margin-bottom: 18px;
}

.article-body li {
  margin-bottom: 7px;
}

.article-body strong {
  font-weight: 700;
  color: var(--text);
}

.article-body blockquote {
  border-left: 4px solid var(--primary);
  background: var(--primary-lt);
  padding: 14px 18px;
  margin: 24px 0;
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--muted);
}

/* ── Figures & Image Placeholders ── */
.article-figure {
  margin: 28px 0;
  border-radius: var(--radius);
  overflow: hidden;
}

.article-figure img {
  width: 100%;
  border-radius: var(--radius);
  display: block;
}

.article-figure figcaption {
  font-size: 13px;
  color: var(--muted);
  text-align: center;
  padding: 8px 12px;
  font-style: italic;
}

/* Placeholder hiện khi chưa có ảnh */
.img-ph {
  background: #f5ede7;
  border: 2px dashed #e0c0b0;
  border-radius: var(--radius);
  min-height: 200px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 24px 20px;
  color: #b08070;
  text-align: center;
}

.img-ph-icon {
  font-size: 36px;
  opacity: .55;
}

.img-ph-name {
  font-size: 13px;
  font-weight: 700;
  color: #c08070;
}

.img-ph-hint {
  font-size: 12px;
  color: #c0a090;
}

.img-ph code {
  background: rgba(0, 0, 0, .06);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 12px;
}

/* ── Tip / Callout Boxes ── */
.tip-box {
  background: #fffbf0;
  border: 1px solid #f5d98e;
  border-left: 4px solid #f0b429;
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 14px 18px;
  margin: 24px 0;
  font-size: 15px;
}

.tip-box strong {
  color: #8b6000;
  display: block;
  margin-bottom: 4px;
}

.note-box {
  background: var(--primary-lt);
  border: 1px solid #fcc;
  border-left: 4px solid var(--primary);
  border-radius: 0 var(--radius) var(--radius) 0;
  padding: 14px 18px;
  margin: 24px 0;
  font-size: 15px;
}

/* ── CTA Box ── */
.cta-box {
  background: linear-gradient(135deg, #fff0f0 0%, #fde8e8 100%);
  border: 1px solid #fcc;
  border-radius: 16px;
  padding: 28px 24px;
  margin: 40px 0;
  text-align: center;
}

.cta-box h3 {
  font-family: 'Philosopher', serif;
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 10px;
}

.cta-box p {
  font-size: 15px;
  color: var(--muted);
  margin-bottom: 18px;
}

.cta-btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 15px;
  padding: 12px 28px;
  border-radius: 10px;
  transition: background .15s;
}

.cta-btn:hover {
  background: var(--primary-dk);
  text-decoration: none;
}

/* ── Related Articles ── */
.related-section {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
}

.related-title {
  font-family: 'Philosopher', serif;
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 18px;
}

.related-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.related-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow .15s, transform .15s;
}

.related-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, .1);
  transform: translateY(-2px);
  text-decoration: none;
}

.related-card-img {
  aspect-ratio: 16/9;
  background: var(--light);
  overflow: hidden;
}

.related-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.related-card-body {
  padding: 12px 14px;
}

.related-card-cat {
  font-size: 11px;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.related-card-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text);
  line-height: 1.4;
}

/* ── Sidebar ── */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.sidebar-box {
  background: var(--light);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
}

.sidebar-box-title {
  font-size: 14px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--primary);
}

.sidebar-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.sidebar-links a {
  font-size: 14px;
  color: var(--text);
  display: flex;
  gap: 7px;
  align-items: flex-start;
  line-height: 1.4;
}

.sidebar-links a:hover {
  color: var(--primary);
}

.sidebar-links .s-num {
  font-size: 11px;
  font-weight: 700;
  color: var(--primary);
  background: var(--primary-lt);
  border-radius: 4px;
  padding: 1px 5px;
  flex-shrink: 0;
  margin-top: 2px;
}

.sidebar-cta-box {
  background: var(--primary);
  color: #fff;
  border-radius: var(--radius);
  padding: 20px 18px;
  text-align: center;
}

.sidebar-cta-box h4 {
  font-family: 'Philosopher', serif;
  font-size: 17px;
  margin-bottom: 8px;
}

.sidebar-cta-box p {
  font-size: 13px;
  opacity: .85;
  margin-bottom: 14px;
}

.sidebar-cta-btn {
  display: inline-block;
  background: #fff;
  color: var(--primary);
  font-weight: 700;
  font-size: 13px;
  padding: 9px 18px;
  border-radius: 8px;
}

.sidebar-cta-btn:hover {
  text-decoration: none;
  opacity: .9;
}

/* ── Blog Index ── */
.blog-hero {
  background: linear-gradient(135deg, var(--primary-lt) 0%, #fff8f5 100%);
  padding: 48px 20px;
  text-align: center;
}

.blog-hero h1 {
  font-family: 'Philosopher', serif;
  font-size: clamp(28px, 5vw, 42px);
  font-weight: 700;
  color: var(--text);
  margin-bottom: 12px;
}

.blog-hero p {
  font-size: 17px;
  color: var(--muted);
  max-width: 560px;
  margin: 0 auto;
}

.blog-index-wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 40px 20px 60px;
}

.blog-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 30px;
}

.filter-btn {
  padding: 7px 16px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  border: 1.5px solid var(--border);
  background: #fff;
  color: var(--muted);
  cursor: pointer;
  transition: all .15s;
}

.filter-btn.active,
.filter-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-lt);
}

.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 24px;
}

.blog-card {
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  background: #fff;
  transition: box-shadow .2s, transform .2s;
  display: flex;
  flex-direction: column;
}

.blog-card:hover {
  box-shadow: 0 6px 24px rgba(0, 0, 0, .1);
  transform: translateY(-3px);
  text-decoration: none;
}

.blog-card-img {
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--light);
  position: relative;
}

.blog-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform .3s;
}

.blog-card:hover .blog-card-img img {
  transform: scale(1.04);
}

.blog-card-img-ph {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 40px;
  opacity: .3;
}

.blog-card-body {
  padding: 16px 18px 20px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.blog-card-cat {
  font-size: 11px;
  font-weight: 700;
  color: var(--primary);
  text-transform: uppercase;
  letter-spacing: .4px;
  margin-bottom: 8px;
}

.blog-card-title {
  font-family: 'Philosopher', serif;
  font-size: 18px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.4;
  margin-bottom: 10px;
  flex: 1;
}

.blog-card-excerpt {
  font-size: 14px;
  color: var(--muted);
  line-height: 1.6;
  margin-bottom: 14px;
}

.blog-card-meta {
  font-size: 12px;
  color: var(--muted);
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}

.blog-card-meta span {
  display: flex;
  align-items: center;
  gap: 4px;
}

/* ── Footer ── */
.site-footer {
  background: #1a1a1a;
  color: rgba(255, 255, 255, .7);
  padding: 40px 20px;
}

.site-footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 32px;
}

.footer-brand .site-logo {
  color: #fff;
  width: 50%;
  margin: 0 auto;
  margin-bottom: 10px;
}

.footer-brand p {
  font-size: 13px;
  line-height: 1.7;
  opacity: .7;
  text-align: center;
}

.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  color: #fff;
  margin-bottom: 12px;
  letter-spacing: .4px;
  text-transform: uppercase;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.footer-col ul li a {
  font-size: 13px;
  color: rgba(255, 255, 255, .6);
}

.footer-col ul li a:hover {
  color: #fff;
  text-decoration: none;
}

.footer-bottom {
  max-width: 1100px;
  margin: 28px auto 0;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, .1);
  font-size: 13px;
  text-align: center;
  opacity: .5;
}

/* ── Responsive ── */
@media (max-width: 900px) {
  .article-wrap {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .sidebar {
    display: none;
  }

  /* Ẩn sidebar trên mobile, chỉ hiện bài viết */
  .site-footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  .article-wrap {
    padding: 20px 16px 40px;
  }

  .header-nav {
    display: none;
  }

  .site-footer-inner {
    grid-template-columns: 1fr;
  }

  .blog-grid {
    grid-template-columns: 1fr;
  }

  .related-grid {
    grid-template-columns: 1fr;
  }
}