/* ===== "Việt Nam Sử Ký" — Chuyên đề Lịch sử & Triết học Mác – Lênin =====
   Phong cách BÁO GIẤY (tòa soạn): tờ báo nền giấy đặt trên nền đỏ-sẫm của site.
   Dùng chung cho trang nhất (index.html) và các bài viết (bai/<slug>/index.html). */

:root {
  --paper: #f7f2e7;
  --paper-edge: #e8dcc4;
  --ink: #1c1714;
  --ink-soft: #4a423b;
  --muted: #6f655b;
  --red: #b01622;
  --red-deep: #7a0d12;
  --gold: #b8860b;
  --rule: #1c1714;
  --line: #d8ccb4;
  /* Times New Roman — hỗ trợ tiếng Việt đầy đủ trên Windows, tránh lỗi dấu. */
  --display: "Times New Roman", Times, serif;
  --serif: "Times New Roman", Times, serif;
  
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: var(--serif);
  background: linear-gradient(rgba(70, 8, 10, 0.86), rgba(40, 4, 6, 0.92)),
    url("https://hypeddit-gates-prod.s3.amazonaws.com/nt1v81_coverartmanual")
      center top / cover no-repeat fixed,
    #2a0608;
  background-size: cover;
  padding: clamp(12px, 3vw, 40px) 12px;
}

/* ===== Tờ báo (sheet) ===== */
.paper {
  max-width: 1120px;
  margin: 0 auto;
  background: var(--paper);
  border: 1px solid var(--paper-edge);
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.55);
  padding: clamp(18px, 3.5vw, 48px);
}

/* ===== Măng-sét (masthead) ===== */
.masthead {
  text-align: center;
  border-bottom: 3px double var(--rule);
  padding-bottom: 14px;
}

.masthead-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--muted);
  border-bottom: 1px solid var(--line);
  padding-bottom: 8px;
  margin-bottom: 14px;
}

.masthead-top a {
  color: var(--red-deep);
  text-decoration: none;
  font-weight: bold;
}

.masthead-top a:hover {
  text-decoration: underline;
}

.masthead-brand {
  font-size: 13px;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--red-deep);
  margin: 0 0 4px;
}

.masthead-title {
  font-family: var(--display);
  font-size: clamp(30px, 6vw, 58px);
  line-height: 1.04;
  margin: 4px 0 8px;
  font-weight: 900;
  letter-spacing: -0.5px;
}

.masthead-sub {
  font-style: italic;
  color: var(--ink-soft);
  margin: 0 auto;
  max-width: 720px;
  font-size: clamp(14px, 2vw, 17px);
}

/* ===== Nhãn chuyên mục / kicker ===== */
.kicker {
  display: inline-block;
  font-family: var(--serif);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 1.2px;
  text-transform: uppercase;
  color: var(--red-deep);
  margin-bottom: 6px;
}

.section-bar {
  display: flex;
  align-items: center;
  gap: 14px;
  margin: 34px 0 18px;
}

.section-bar span {
  font-family: var(--serif);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--red-deep);
  white-space: nowrap;
}

.section-bar::before,
.section-bar::after {
  content: "";
  height: 2px;
  background: var(--rule);
  flex: 1;
}

/* ===== Trang nhất: khu vực tin chính ===== */
.lead-grid {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 0;
  margin-top: 22px;
}

.feature {
  padding-right: 28px;
  border-right: 1px solid var(--line);
}

.feature-img {
  width: 100%;
  height: clamp(220px, 38vw, 420px);
  object-fit: cover;
  filter: grayscale(15%) contrast(1.03);
  border: 1px solid var(--paper-edge);
  margin-bottom: 14px;
  display: block;
}

.feature-title {
  font-family: var(--display);
  font-size: clamp(26px, 4vw, 42px);
  line-height: 1.1;
  font-weight: 900;
  margin: 6px 0 12px;
}

.feature-title a {
  color: var(--ink);
  text-decoration: none;
}

.feature-title a:hover {
  color: var(--red-deep);
}

.feature-sapo {
  font-size: clamp(15px, 1.8vw, 18px);
  line-height: 1.7;
  color: var(--ink-soft);
  margin: 0 0 12px;
}

.sidebar {
  padding-left: 28px;
  display: flex;
  flex-direction: column;
}

.side-item {
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.side-item:first-child {
  padding-top: 0;
}

.side-item:last-child {
  border-bottom: 0;
}

.side-title {
  font-family: var(--display);
  font-size: clamp(17px, 2vw, 21px);
  line-height: 1.22;
  font-weight: 700;
  margin: 4px 0 6px;
}

.side-title a {
  color: var(--ink);
  text-decoration: none;
}

.side-title a:hover {
  color: var(--red-deep);
}

.side-sapo {
  font-size: 14px;
  line-height: 1.6;
  color: var(--muted);
  margin: 0;
}

/* ===== Lưới tin (các bài còn lại) — kiểu cột báo ===== */
.news-grid {
  column-count: 3;
  column-gap: 28px;
  column-rule: 1px solid var(--line);
}

.news-item {
  break-inside: avoid;
  padding-bottom: 18px;
  margin-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.news-img {
  width: 100%;
  height: 150px;
  object-fit: cover;
  filter: grayscale(15%) contrast(1.03);
  border: 1px solid var(--paper-edge);
  margin-bottom: 10px;
  display: block;
}

.news-title {
  font-family: var(--display);
  font-size: 20px;
  line-height: 1.22;
  font-weight: 700;
  margin: 4px 0 7px;
}

.news-title a {
  color: var(--ink);
  text-decoration: none;
}

.news-title a:hover {
  color: var(--red-deep);
}

.news-sapo {
  font-size: 14px;
  line-height: 1.62;
  color: var(--ink-soft);
  margin: 0 0 8px;
}

.readmore {
  font-family: var(--serif);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.5px;
  color: var(--red);
  text-transform: uppercase;
  text-decoration: none;
}

.readmore:hover {
  color: var(--red-deep);
}

/* ===== Trang bài viết ===== */
.article {
  margin-top: 24px;
}

.article-header {
  text-align: center;
  max-width: 820px;
  margin: 0 auto 22px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--line);
}

.article-title {
  font-family: var(--display);
  font-size: clamp(28px, 5vw, 50px);
  line-height: 1.08;
  font-weight: 900;
  margin: 8px 0 14px;
}

.article-sapo {
  font-size: clamp(16px, 2.2vw, 21px);
  line-height: 1.6;
  font-style: italic;
  color: var(--ink-soft);
  margin: 0 0 14px;
}

.article-meta {
  font-family: var(--serif);
  font-size: 12px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  color: var(--muted);
}

.article-hero {
  width: 100%;
  height: clamp(240px, 46vw, 500px);
  object-fit: cover;
  filter: grayscale(12%) contrast(1.03);
  border: 1px solid var(--paper-edge);
  margin: 0 0 6px;
  display: block;
}

.article-hero-cap {
  font-size: 12.5px;
  font-style: italic;
  color: var(--muted);
  text-align: center;
  margin: 0 0 24px;
}

/* Hộp nguyên lý triết học nổi bật */
.principle-box {
  margin: 0 auto 26px;
  max-width: 860px;
  padding: 18px 22px;
  background: #fffdf6;
  border: 1px solid var(--line);
  border-left: 5px solid var(--gold);
}

.principle-box .kicker {
  color: var(--red-deep);
}

.principle-box p {
  margin: 4px 0 0;
  font-size: clamp(17px, 2.4vw, 22px);
  font-weight: 700;
  line-height: 1.45;
  color: var(--red-deep);
}

/* Thân bài — 2 cột kiểu báo */
.article-body {
  max-width: 980px;
  margin: 0 auto;
  column-count: 2;
  column-gap: 36px;
  text-align: justify;
}

.article-body h2 {
  font-size: clamp(20px, 2.6vw, 26px);
  font-weight: 800;
  margin: 4px 0 10px;
  color: var(--red-deep);
  break-after: avoid;
}

.article-body h2:not(:first-child) {
  margin-top: 18px;
}

.article-body p {
  margin: 0 0 14px;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--ink);
}

/* Chữ cái đầu lớn (drop cap) cho đoạn mở đầu */
.article-body > p:first-of-type::first-letter {
  float: left;
  font-size: 64px;
  line-height: 0.78;
  font-weight: 900;
  padding: 6px 10px 0 0;
  color: var(--red-deep);
}

.article-body strong {
  color: var(--red-deep);
}

.pullquote {
  break-inside: avoid;
  margin: 6px 0 18px;
  padding: 12px 0 12px 18px;
  border-left: 4px solid var(--red);
  font-size: clamp(18px, 2.4vw, 23px);
  font-style: italic;
  line-height: 1.45;
  color: var(--red-deep);
}

.pullquote cite {
  display: block;
  margin-top: 8px;
  font-size: 14px;
  font-style: normal;
  font-weight: 700;
  color: var(--muted);
}

/* Điều hướng cuối bài */
.article-nav {
  max-width: 980px;
  margin: 30px auto 0;
  padding-top: 18px;
  border-top: 3px double var(--rule);
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
  font-family: var(--serif);
  font-size: 13px;
  font-weight: 700;
}

.article-nav a {
  color: var(--red-deep);
  text-decoration: none;
  max-width: 46%;
}

.article-nav a:hover {
  text-decoration: underline;
}

.article-nav .nav-home {
  color: var(--ink);
}

/* ===== Footer ===== */
.paper-footer {
  margin-top: 30px;
  padding-top: 14px;
  border-top: 3px double var(--rule);
  text-align: center;
  font-size: 12.5px;
  color: var(--muted);
  font-family: var(--serif);
  letter-spacing: 0.5px;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
  .lead-grid {
    grid-template-columns: 1fr;
  }
  .feature {
    padding-right: 0;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    padding-bottom: 18px;
    margin-bottom: 18px;
  }
  .sidebar {
    padding-left: 0;
  }
  .news-grid {
    column-count: 2;
  }
  .article-body {
    column-count: 1;
  }
}

@media (max-width: 560px) {
  .news-grid {
    column-count: 1;
  }
  .masthead-top {
    flex-direction: column;
    gap: 4px;
  }
}