:root {
  --bg: #0d1117;
  --bg-card: #161b22;
  --bg-hover: #1c2129;
  --border: #30363d;
  --text: #e6edf3;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --accent-hover: #79c0ff;
  --tag-bg: #1f2937;
  --tag-text: #9ca3af;
  --search-bg: #0d1117;
  --overlay: rgba(0, 0, 0, 0.7);
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f8fa;
    --bg-card: #ffffff;
    --bg-hover: #f3f4f6;
    --border: #d0d7de;
    --text: #1f2328;
    --text-muted: #656d76;
    --accent: #0969da;
    --accent-hover: #0550ae;
    --tag-bg: #eef1f5;
    --tag-text: #57606a;
    --search-bg: #ffffff;
    --overlay: rgba(0, 0, 0, 0.5);
  }
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
}

/* Header */
.header {
  padding: 2rem 1.5rem 1rem;
  max-width: 1200px;
  margin: 0 auto;
}

.header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.header p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* Search and filters */
.controls {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--bg);
  padding: 1rem 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  border-bottom: 1px solid var(--border);
}

.search-input {
  width: 100%;
  padding: 0.6rem 1rem;
  font-size: 0.95rem;
  background: var(--search-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  outline: none;
  transition: border-color 0.15s;
}

.search-input:focus {
  border-color: var(--accent);
}

.search-input::placeholder {
  color: var(--text-muted);
}

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

.tag-filter {
  padding: 0.25rem 0.65rem;
  font-size: 0.8rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border: 1px solid transparent;
  border-radius: 999px;
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}

.tag-filter:hover {
  border-color: var(--border);
}

.tag-filter.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

.tool-count {
  font-size: 0.85rem;
  color: var(--text-muted);
  padding-top: 0.25rem;
}

/* Category sections */
.category-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1.5rem;
}

.category-section h2 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1rem;
  color: var(--text-muted);
  text-transform: lowercase;
}

.category-section.hidden {
  display: none;
}

/* Card grid */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 0.75rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 1rem 1.15rem;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.card:hover {
  background: var(--bg-hover);
  border-color: var(--accent);
}

.card.hidden {
  display: none;
}

.card-name {
  font-size: 0.95rem;
  font-weight: 600;
}

.card-desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.3rem;
  margin-top: auto;
  padding-top: 0.3rem;
}

.card-tag {
  font-size: 0.7rem;
  padding: 0.15rem 0.5rem;
  background: var(--tag-bg);
  color: var(--tag-text);
  border-radius: 999px;
}

/* Tool viewer overlay */
.viewer {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 100;
  background: var(--overlay);
}

.viewer.open {
  display: flex;
  flex-direction: column;
}

.viewer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.6rem 1rem;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  min-height: 48px;
}

.viewer-title {
  font-size: 0.95rem;
  font-weight: 600;
}

.viewer-actions {
  display: flex;
  gap: 0.5rem;
  align-items: center;
}

.viewer-btn {
  padding: 0.35rem 0.75rem;
  font-size: 0.85rem;
  background: var(--tag-bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.15s;
}

.viewer-btn:hover {
  background: var(--bg-hover);
}

.viewer-back {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
  font-weight: 600;
}

.viewer-back:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
}

.viewer-frame {
  flex: 1;
  border: none;
  background: #fff;
  width: 100%;
}

/* Footer */
.footer {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

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

.footer a:hover {
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 600px) {
  .header { padding: 1.5rem 1rem 0.75rem; }
  .header h1 { font-size: 1.4rem; }
  .controls { padding: 0.75rem 1rem; }
  .category-section { padding: 1rem; }
  .grid { grid-template-columns: 1fr; }
}