:root {
  --bg: #f7f7fb;
  --surface: #ffffff;
  --text: #1a1a2e;
  --text-muted: #5a5a72;
  --border: #e2e2ec;
  --accent: #5b5bf0;
  --accent-contrast: #ffffff;
  --radius: 10px;
}

[data-theme="dark"] {
  --bg: #14141f;
  --surface: #1e1e2e;
  --text: #eaeaf5;
  --text-muted: #a3a3b8;
  --border: #2c2c3d;
  --accent: #8080ff;
  --accent-contrast: #14141f;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background 0.2s ease, color 0.2s ease;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
}

.logo {
  font-size: 1.4rem;
  margin: 0;
}

.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 999px;
  width: 2.25rem;
  height: 2.25rem;
  cursor: pointer;
  font-size: 1rem;
}

.ad-slot {
  padding: 1rem 1.25rem 0;
  min-height: 0;
}

.controls {
  padding: 1.5rem 0 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

#search-input {
  padding: 0.6rem 0.9rem;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1rem;
}

.category-filters {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.category-filters button {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-muted);
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.85rem;
}

.category-filters button.active {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-contrast);
}

.trending-topics {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

.trending-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
}

.trend-chip {
  border: 1px solid var(--accent);
  background: color-mix(in srgb, var(--accent) 12%, transparent);
  color: var(--accent);
  padding: 0.3rem 0.75rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.8rem;
  font-weight: 600;
}

.trend-chip:hover {
  background: color-mix(in srgb, var(--accent) 25%, transparent);
}

.status-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.25rem 0 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.refresh-btn {
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  padding: 0.35rem 0.8rem;
  border-radius: 999px;
  cursor: pointer;
  font-size: 0.8rem;
}

.refresh-btn:disabled {
  opacity: 0.6;
  cursor: default;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
  padding: 0.5rem 0 2rem;
}

.news-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.card-image {
  aspect-ratio: 16 / 9;
  width: 100%;
  background: var(--border);
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.card-image.fallback {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.5rem;
  color: #fff;
}

.card-image.cat-industry.fallback {
  background: linear-gradient(135deg, #5b5bf0, #8080ff);
}

.card-image.cat-research.fallback {
  background: linear-gradient(135deg, #16a394, #4fd1c5);
}

.card-image.cat-papers.fallback {
  background: linear-gradient(135deg, #e08a3c, #f4b183);
}

.card-body {
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  flex: 1;
}

.news-card .meta {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.news-card .category-tag {
  background: color-mix(in srgb, var(--accent) 15%, transparent);
  color: var(--accent);
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  font-weight: 600;
}

.news-card h2 {
  margin: 0;
  font-size: 1.05rem;
}

.news-card p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.4;
}

.news-card a.source-link {
  margin-top: auto;
  color: var(--accent);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
}

.news-card a.source-link:hover {
  text-decoration: underline;
}

.empty-state {
  text-align: center;
  color: var(--text-muted);
  padding: 2rem 0;
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.25rem 0;
  color: var(--text-muted);
  font-size: 0.85rem;
}