:root {
  --bg: #0f1420;
  --bg-alt: #161d2e;
  --card: #1b2436;
  --card-hover: #212c42;
  --border: #2a3550;
  --text: #e8ecf5;
  --text-dim: #9aa5bd;
  --accent: #6c8cff;
  --accent-soft: rgba(108, 140, 255, 0.15);
  --radius: 14px;
  color-scheme: dark;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f4f6fb;
    --bg-alt: #eaeef7;
    --card: #ffffff;
    --card-hover: #f7f9ff;
    --border: #dde3f0;
    --text: #1c2333;
    --text-dim: #5b6478;
    --accent: #4a6bff;
    --accent-soft: rgba(74, 107, 255, 0.1);
    color-scheme: light;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  background: radial-gradient(circle at top, var(--bg-alt), var(--bg) 60%);
  color: var(--text);
  min-height: 100vh;
}

.site-header {
  text-align: center;
  padding: 3rem 1.5rem 1.5rem;
}
.site-header h1 {
  margin: 0 0 0.4rem;
  font-size: 2.2rem;
}
.subtitle {
  color: var(--text-dim);
  margin: 0;
}

#app {
  max-width: 1000px;
  margin: 0 auto;
  padding: 1rem 1.5rem 4rem;
}

.status { text-align: center; color: var(--text-dim); }

.category-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

details.category-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: background 0.15s ease, border-color 0.15s ease;
}
details.category-card[open] {
  border-color: var(--accent);
}

details.category-card > summary {
  list-style: none;
  cursor: pointer;
  padding: 1.1rem 1.4rem;
  display: flex;
  align-items: center;
  gap: 0.9rem;
  user-select: none;
}
details.category-card > summary::-webkit-details-marker { display: none; }

details.category-card > summary:hover {
  background: var(--card-hover);
}

.chevron {
  margin-left: auto;
  flex-shrink: 0;
  transition: transform 0.2s ease;
  color: var(--text-dim);
}
details.category-card[open] > summary .chevron {
  transform: rotate(90deg);
  color: var(--accent);
}

.card-title-wrap { display: flex; flex-direction: column; gap: 0.2rem; }
.card-title { font-size: 1.15rem; font-weight: 600; }
.card-desc { color: var(--text-dim); font-size: 0.92rem; }
.card-count {
  font-size: 0.78rem;
  color: var(--accent);
  background: var(--accent-soft);
  padding: 0.15rem 0.55rem;
  border-radius: 999px;
  white-space: nowrap;
}

.category-body {
  padding: 0 1.4rem 1.3rem;
  border-top: 1px solid var(--border);
}

.howto {
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 0.9rem 1rem;
  margin: 1rem 0 0.2rem;
  font-size: 0.9rem;
  white-space: pre-line;
  line-height: 1.5;
}
.howto strong { color: var(--accent); }

.subcategories {
  margin-top: 1rem;
  display: grid;
  gap: 0.7rem;
}
.subcategories > details.category-card {
  background: var(--bg-alt);
}

.file-list {
  list-style: none;
  margin: 1rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.55rem;
}

.file-row {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 0.7rem 0.9rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--bg-alt);
}

.file-name { font-weight: 500; flex: 1; min-width: 0; overflow-wrap: anywhere; }
.file-meta { color: var(--text-dim); font-size: 0.82rem; white-space: nowrap; }

.download-btn {
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.45rem 0.9rem;
  border-radius: 8px;
  white-space: nowrap;
  transition: opacity 0.15s ease;
}
.download-btn:hover { opacity: 0.85; }

.empty-note {
  color: var(--text-dim);
  font-size: 0.88rem;
  padding: 1rem 0 0;
}

.site-footer {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.82rem;
  padding: 2rem 1.5rem 3rem;
}
.site-footer .version {
  opacity: 0.5;
  margin-top: 0.4rem;
}

@media (max-width: 480px) {
  .file-row { flex-wrap: wrap; }
  .file-name { flex-basis: 100%; }
  .file-meta { order: 2; }
  .download-btn { order: 3; margin-left: auto; }
}