/* ===== 经济学人风格 个人研究站点 ===== */
:root {
  --red: #E3120B;
  --red-dark: #B00B05;
  --ink: #1a1a1a;
  --gray-1: #4a4a4a;
  --gray-2: #8a8a8a;
  --gray-3: #d4d4d4;
  --gray-4: #f5f5f5;
  --yellow: #F4C430;
  --blue: #1E5AA8;
  --bg: #ffffff;
  --serif: Georgia, "Times New Roman", "Songti SC", "SimSun", serif;
  --sans: "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: var(--serif);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.7;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--ink); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--red); }

/* ===== 顶部导航 ===== */
.topbar {
  border-top: 5px solid var(--red);
  border-bottom: 2px solid var(--ink);
  background: var(--bg);
  position: sticky; top: 0; z-index: 100;
}
.topbar-inner {
  max-width: 1100px; margin: 0 auto; padding: 14px 32px;
  display: flex; align-items: center; justify-content: space-between;
}
.brand {
  font-family: var(--serif);
  font-size: 22px; font-weight: bold; letter-spacing: -0.3px;
}
.brand .brand-red { color: var(--red); }
.nav-links { display: flex; gap: 28px; }
.nav-links a {
  font-family: var(--sans);
  font-size: 13px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 1px;
  color: var(--gray-1);
}
.nav-links a:hover, .nav-links a.active { color: var(--red); }

/* ===== 主容器 ===== */
.container { max-width: 1100px; margin: 0 auto; padding: 0 32px; }

/* ===== Hero区 ===== */
.hero {
  padding: 60px 0 48px;
  border-bottom: 1px solid var(--gray-3);
  margin-bottom: 48px;
}
.hero-eyebrow {
  font-family: var(--sans);
  font-size: 12px; color: var(--red); font-weight: bold;
  letter-spacing: 3px; text-transform: uppercase; margin-bottom: 12px;
}
.hero h1 {
  font-family: var(--serif);
  font-size: 42px; font-weight: bold; line-height: 1.15;
  letter-spacing: -0.5px; margin-bottom: 16px; max-width: 700px;
}
.hero-sub {
  font-family: var(--serif);
  font-size: 19px; color: var(--gray-1); font-style: italic;
  line-height: 1.5; max-width: 640px;
}
.hero-meta {
  display: flex; gap: 24px; margin-top: 24px;
  font-size: 13px; color: var(--gray-2);
  font-family: var(--sans);
}

/* ===== 分类卡片区 ===== */
.section { margin-bottom: 56px; }
.section-header {
  display: flex; align-items: baseline; gap: 12px;
  margin-bottom: 24px; padding-bottom: 10px;
  border-bottom: 2px solid var(--ink);
}
.section-num {
  font-family: var(--serif);
  font-size: 28px; font-weight: bold; color: var(--red);
  font-style: italic; line-height: 1;
}
.section-title {
  font-family: var(--serif);
  font-size: 24px; font-weight: bold;
}
.section-count {
  font-family: var(--sans);
  font-size: 12px; color: var(--gray-2); margin-left: auto;
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}
.card {
  border: 1px solid var(--gray-3);
  border-top: 3px solid var(--ink);
  padding: 24px;
  background: var(--bg);
  transition: border-top-color 0.2s, box-shadow 0.2s;
  cursor: pointer;
  display: flex; flex-direction: column;
}
.card:hover {
  border-top-color: var(--red);
  box-shadow: 0 4px 16px rgba(0,0,0,0.08);
}
.card-tag {
  font-family: var(--sans);
  font-size: 11px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 1.5px;
  color: var(--red); margin-bottom: 10px;
}
.card h3 {
  font-family: var(--serif);
  font-size: 19px; font-weight: bold; line-height: 1.3;
  margin-bottom: 8px;
}
.card-sub {
  font-family: var(--serif);
  font-size: 14px; color: var(--gray-1); font-style: italic;
  line-height: 1.5; margin-bottom: 14px; flex-grow: 1;
}
.card-meta {
  display: flex; justify-content: space-between;
  font-family: var(--sans);
  font-size: 12px; color: var(--gray-2);
  border-top: 1px solid var(--gray-3); padding-top: 12px;
}
.card-status {
  display: inline-block; padding: 2px 8px;
  font-size: 11px; font-weight: 600; border-radius: 2px;
}
.status-published { background: rgba(45,125,74,0.12); color: #2D7D4A; }
.status-draft { background: rgba(244,196,48,0.18); color: #8a6d00; }

/* ===== 文章内容页（iframe内嵌报告） ===== */
.article-page { padding: 40px 0 60px; }
.article-header {
  border-bottom: 2px solid var(--ink);
  padding-bottom: 20px; margin-bottom: 32px;
}
.article-header .kicker {
  font-size: 11px; color: var(--red); font-weight: bold;
  letter-spacing: 3px; text-transform: uppercase; margin-bottom: 8px;
}
.article-header h1 {
  font-family: var(--serif);
  font-size: 34px; font-weight: bold; line-height: 1.2;
  margin-bottom: 10px;
}
.article-header .subtitle {
  font-size: 16px; color: var(--gray-1); font-style: italic; line-height: 1.5;
}
.article-header .meta {
  font-family: var(--sans);
  font-size: 12px; color: var(--gray-2); margin-top: 14px;
  border-top: 1px solid var(--gray-3); padding-top: 10px;
  display: flex; gap: 20px; flex-wrap: wrap;
}
.back-link {
  font-family: var(--sans);
  font-size: 13px; color: var(--gray-1); margin-bottom: 24px;
  display: inline-block;
}
.back-link:hover { color: var(--red); }

/* ===== About区 ===== */
.about-block {
  background: var(--gray-4);
  border-left: 4px solid var(--red);
  padding: 28px 32px; margin: 48px 0;
}
.about-block h3 {
  font-family: var(--serif);
  font-size: 18px; font-weight: bold; margin-bottom: 12px;
}
.about-block p {
  font-size: 15px; color: var(--gray-1); line-height: 1.8; margin-bottom: 10px;
}

/* ===== 页脚 ===== */
.footer {
  border-top: 2px solid var(--ink);
  padding: 32px 0; margin-top: 60px;
  font-family: var(--sans);
  font-size: 12px; color: var(--gray-2);
}
.footer-inner {
  max-width: 1100px; margin: 0 auto; padding: 0 32px;
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 16px;
}
.footer .brand { font-family: var(--serif); font-size: 14px; color: var(--ink); }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
  .hero h1 { font-size: 30px; }
  .container, .topbar-inner, .footer-inner { padding: 0 18px; }
  .nav-links { gap: 16px; }
  .nav-links a { font-size: 11px; }
  .card-grid { grid-template-columns: 1fr; }
  .article-header h1 { font-size: 26px; }
}