:root {
  --bg: #0d1117;
  --bg2: #161b22;
  --bg3: #21262d;
  --border: #30363d;
  --text: #e6edf3;
  --muted: #8b949e;
  --blue: #58a6ff;
  --green: #3fb950;
  --yellow: #e3b341;
  --red: #f78166;
  --easy: #58a6ff;
  --medium: #e3b341;
  --hard: #f78166;
}

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-size: 14px;
  line-height: 1.5;
}

/* ── Header ──────────────────────────────────────────────────────── */
header {
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  gap: 16px;
}

h1 { font-size: 18px; font-weight: 600; }
h1 .dim { color: var(--muted); font-weight: 400; }
.header-sub { font-size: 12px; color: var(--muted); margin-top: 2px; }

.header-links { display: flex; gap: 16px; flex-shrink: 0; }
.header-links a {
  color: var(--blue);
  text-decoration: none;
  font-size: 13px;
  white-space: nowrap;
}
.header-links a:hover { text-decoration: underline; }

.banner {
  padding: 8px 24px;
  background: var(--bg2);
  border-top: 1px solid var(--border);
  font-size: 12px;
  color: var(--muted);
}

/* ── Controls ────────────────────────────────────────────────────── */
.controls { padding: 16px 24px 0; }

.tabs { display: flex; gap: 4px; }
.tab {
  background: none;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 5px 14px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 13px;
  transition: all 0.15s;
}
.tab:hover { border-color: var(--blue); color: var(--text); }
.tab.active { background: var(--blue); border-color: var(--blue); color: #0d1117; font-weight: 600; }
.tab .count { opacity: 0.7; font-size: 11px; }

/* ── Grid ────────────────────────────────────────────────────────── */
.grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 16px;
  padding: 20px 24px;
}

.card {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  transition: border-color 0.2s, transform 0.15s;
  animation: fadeIn 0.3s ease both;
}
.card:hover { border-color: var(--blue); transform: translateY(-2px); }
.card.hidden { display: none; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

.card-thumb { width: 100%; aspect-ratio: 4/3; object-fit: cover; display: block; }

.card-body { padding: 10px 12px; }
.card-row { display: flex; align-items: center; justify-content: space-between; }
.card-id { font-size: 11px; color: var(--muted); }
.badge {
  font-size: 10px;
  font-weight: 600;
  padding: 2px 7px;
  border-radius: 10px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.badge-easy   { background: rgba(88,166,255,0.15); color: var(--easy); }
.badge-medium { background: rgba(227,179,65,0.15);  color: var(--medium); }
.badge-hard   { background: rgba(247,129,102,0.15); color: var(--hard); }

.card-source { font-size: 11px; color: var(--muted); margin-top: 4px; }
.card-mean { font-size: 13px; font-weight: 600; color: var(--text); margin-top: 2px; }

/* ── Detail Panel ────────────────────────────────────────────────── */
.detail-panel {
  margin: 0 24px 32px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  animation: slideUp 0.25s ease;
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(16px); }
  to   { opacity: 1; transform: translateY(0); }
}

.detail-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
  background: var(--bg3);
}

.close-btn {
  background: none;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 4px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
  transition: all 0.15s;
}
.close-btn:hover { border-color: var(--red); color: var(--red); }

.detail-meta { font-size: 13px; color: var(--muted); }
.detail-meta strong { color: var(--text); }

.detail-body {
  display: flex;
  gap: 0;
  min-height: 400px;
}

.reference-col {
  width: 260px;
  flex-shrink: 0;
  padding: 16px;
  border-right: 1px solid var(--border);
}

.section-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 10px;
}
.section-label .small { font-size: 10px; text-transform: none; letter-spacing: 0; font-weight: 400; }

.reference-img { width: 100%; border-radius: 4px; border: 1px solid var(--border); }

.variants-col { flex: 1; padding: 16px; min-width: 0; }

/* ── Variant Strip ───────────────────────────────────────────────── */
.variant-strip {
  display: flex;
  gap: 10px;
  overflow-x: auto;
  padding-bottom: 10px;
  margin-bottom: 16px;
  scrollbar-width: thin;
  scrollbar-color: var(--border) transparent;
}

.variant-thumb {
  flex-shrink: 0;
  width: 130px;
  cursor: pointer;
  border-radius: 6px;
  border: 2px solid var(--border);
  overflow: hidden;
  transition: border-color 0.15s;
}
.variant-thumb:hover { border-color: var(--blue); }
.variant-thumb.active { border-color: var(--blue); }

.variant-thumb img { width: 100%; display: block; }
.variant-thumb-label {
  padding: 5px 7px;
  text-align: center;
  background: var(--bg3);
}
.variant-name { font-size: 10px; color: var(--muted); }
.variant-score {
  font-size: 13px;
  font-weight: 700;
  display: block;
}

/* ── Reward Bar Chart ────────────────────────────────────────────── */
.reward-panel {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  margin-bottom: 12px;
}

.reward-title {
  font-size: 12px;
  color: var(--muted);
  margin-bottom: 12px;
  display: flex;
  align-items: baseline;
  gap: 10px;
}
.reward-total {
  font-size: 22px;
  font-weight: 700;
  color: var(--text);
}

.bar-row {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 7px;
}
.bar-label {
  width: 90px;
  font-size: 11px;
  color: var(--muted);
  text-align: right;
  flex-shrink: 0;
}
.bar-track {
  flex: 1;
  height: 10px;
  background: var(--bg);
  border-radius: 5px;
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  border-radius: 5px;
  width: 0;
  transition: width 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}
.bar-value {
  width: 38px;
  font-size: 11px;
  color: var(--muted);
  text-align: right;
  flex-shrink: 0;
}
.bar-weight {
  width: 28px;
  font-size: 10px;
  color: var(--border);
  flex-shrink: 0;
}

/* ── Code View ───────────────────────────────────────────────────── */
.code-toggle {
  background: none;
  border: 1px solid var(--border);
  color: var(--muted);
  padding: 5px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 12px;
  transition: all 0.15s;
  width: 100%;
  text-align: left;
}
.code-toggle:hover { border-color: var(--blue); color: var(--text); }

.code-view {
  margin-top: 8px;
  padding: 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  font-family: "SFMono-Regular", Consolas, monospace;
  font-size: 11px;
  line-height: 1.6;
  overflow: auto;
  max-height: 320px;
  white-space: pre;
  color: var(--muted);
}

/* ── Utilities ───────────────────────────────────────────────────── */
.dim { color: var(--muted); }