:root {
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --bg: #fdfdfd;
  --accent: #2b5fb0;
  --border: #e4e4e4;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0 0 4rem;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
  color: var(--fg);
  background: var(--bg);
  line-height: 1.55;
}

header {
  width: 100%;
  height: 50px;
  background: #222;
  color: white;

  display: flex;
  align-items: center;

  padding: 0 1.25rem;
  margin: 0 0 2rem;
}

.header-content {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;

  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-title {
  font-size: 1.1rem;
  font-weight: 600;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.header-button {
  color: #ddd;
  padding: 0.35rem 0.7rem;
  border-radius: 5px;
  font-size: 0.85rem;
  text-decoration: none;
}

.header-button:hover {
  color: white;
  background: #333;
  text-decoration: none;
}

main {
  width: 100%;
  max-width: 900px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

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

a:hover {
  text-decoration: underline;
}

header a {
  color: white;
}

.home-link {
  font-size: 0.9rem;
  color: var(--muted);
}

.article-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: list-item flow;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.75rem;
  row-gap: 2.5rem;
}

.article-card {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  background: #fff;
}

.thumb-link {
  display: block;
  line-height: 0;
}

.thumbnail {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background: #eee;
}

.card-body {
  padding: 0.9rem 1rem 1.1rem;
}

.article-title {
  font-size: 1.05rem;
  font-weight: 600;
  display: flex;
  align-items: center;
}

.date {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 0.3rem;
}

.topic {
  font-size: 0.8rem;
  color: var(--accent);
  margin: 0.4rem 0 0.15rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.description {
  margin: 0.15rem 0 0.5rem;
  color: #333;
  font-size: 0.92rem;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.tag {
  font-size: 0.72rem;
  color: var(--muted);
  border: 1px solid var(--border);
  padding: 0.1rem 0.6rem;
}

.empty {
  color: var(--muted);
}

.icon {
  object-fit: cover;
  vertical-align: middle;
  margin-right: 0.5rem;
  flex-shrink: 0;
}

.icon-list {
  width: 1.15em;
  height: 1.15em;
}

.icon-header {
  width: 1.5rem;
  height: 1.5rem;
}

.thumbnail-banner {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border-radius: 10px;
  margin-bottom: 1.25rem;
  background: #eee;
}

article h1 {
  margin-bottom: 0.25rem;
  display: flex;
  align-items: center;
}

hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 1.5rem 0;
}

.txt-content {
  white-space: pre-wrap;
  word-wrap: break-word;
  background: #f6f6f6;
  padding: 1rem;
  font-size: 0.9rem;
}

.pdf-frame {
  width: 100%;
  height: 80vh;
  border: 1px solid var(--border);
}