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

:root {
  --bg: #1a1a1a;
  --bg-panel: #222;
  --bg-card: #2a2a2a;
  --bg-card-hover: #333;
  --bg-input: #2a2a2a;
  --text: #e8e4df;
  --text-dim: #999;
  --accent: #c44d3f;
  --accent-dim: rgba(196, 77, 63, 0.15);
  --accent-bright: #e8614f;
  --warning: #e0a030;
  --danger: #ff6b4a;
  --success: #5a9a5a;
  --border: #3a3a3a;
  --font-body: 'Space Grotesk', system-ui, sans-serif;
  --font-mono: 'Space Mono', 'Courier New', monospace;
  --radius: 6px;
}

html { font-size: 15px; }
body {
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* === HEADER === */
.header {
  padding: 12px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-panel);
}
.header-top {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}
.logo {
  font-family: var(--font-mono);
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.5px;
}
.playlist-controls {
  display: flex;
  align-items: center;
  gap: 6px;
}
.playlist-controls select {
  min-width: 160px;
}
.playlist-controls button {
  width: 32px;
  height: 32px;
  font-size: 1.1rem;
  line-height: 1;
}
.header-config {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-top: 10px;
  flex-wrap: wrap;
}
.config-group {
  display: flex;
  align-items: center;
  gap: 6px;
}
.config-group label {
  font-size: 0.8rem;
  color: var(--text-dim);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}
.config-group input[type="number"] {
  width: 64px;
}
.config-status {
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--text-dim);
}
.config-status .sep { margin: 0 6px; }
.config-unit {
  font-size: 0.75rem;
  color: var(--text-dim);
}

/* === SHARED FORM ELEMENTS === */
input, select, button {
  font-family: var(--font-body);
  font-size: 0.85rem;
  padding: 6px 10px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-input);
  color: var(--text);
  outline: none;
  transition: border-color 0.15s;
}
input:focus, select:focus {
  border-color: var(--accent);
}
button {
  cursor: pointer;
  background: var(--bg-card);
  border-color: var(--border);
  transition: background 0.15s, border-color 0.15s;
}
button:hover {
  background: var(--bg-card-hover);
  border-color: var(--accent);
}

/* === TEMPO CURVE === */
.curve-container {
  padding: 0 16px;
  background: var(--bg-panel);
  border-bottom: 1px solid var(--border);
}
#tempo-curve {
  width: 100%;
  height: 130px;
  display: block;
}

/* === PANELS === */
.panels {
  display: flex;
  flex: 1;
  min-height: 0;
}
.panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
}
.library-panel {
  width: 40%;
  border-right: 1px solid var(--border);
  background: var(--bg);
}
.playlist-panel {
  width: 60%;
  background: var(--bg);
}
.panel-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  background: var(--bg-panel);
}
.panel-header h2 {
  font-size: 0.9rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--text-dim);
}
.btn-toggle {
  display: none;
  width: 28px;
  height: 28px;
  font-size: 0.7rem;
  padding: 0;
}
.export-buttons {
  display: flex;
  gap: 6px;
}
.export-buttons button {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 4px 10px;
}

/* === LIBRARY === */
.library-filters {
  display: flex;
  gap: 6px;
  padding: 10px 14px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.library-filters input[type="search"] {
  flex: 1;
  min-width: 120px;
}
.library-filters select {
  min-width: 80px;
}
.song-list {
  flex: 1;
  overflow-y: auto;
  padding: 6px;
}
.song-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  margin-bottom: 4px;
  border-radius: var(--radius);
  background: var(--bg-card);
  cursor: grab;
  transition: background 0.15s;
  user-select: none;
}
.song-card:hover {
  background: var(--bg-card-hover);
}
.song-card.dragging {
  opacity: 0.4;
}
.song-info {
  flex: 1;
  min-width: 0;
}
.song-artist-title {
  font-size: 0.85rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.song-meta {
  display: flex;
  gap: 10px;
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-top: 2px;
}
.song-bpm {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--accent);
}
.song-add {
  width: 28px;
  height: 28px;
  font-size: 1.1rem;
  padding: 0;
  flex-shrink: 0;
  line-height: 1;
  color: var(--accent);
  border-color: transparent;
  background: transparent;
}
.song-add:hover {
  background: var(--accent-dim);
  border-color: var(--accent);
}

/* === CUSTOM SONG FORM === */
.add-custom {
  padding: 8px 14px;
  border-top: 1px solid var(--border);
}
.add-custom button {
  width: 100%;
  font-size: 0.8rem;
  color: var(--text-dim);
}
.custom-form {
  padding: 10px 14px;
  border-top: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.custom-form.hidden { display: none; }
.custom-form input {
  width: 100%;
}
.custom-form-actions {
  display: flex;
  gap: 6px;
}
.custom-form-actions button {
  flex: 1;
}
#btn-save-custom {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

/* === PLAYLIST === */
.playlist-list {
  flex: 1;
  overflow-y: auto;
  padding: 6px;
}
.playlist-empty {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 200px;
  color: var(--text-dim);
  font-size: 0.9rem;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  margin: 10px;
}
.playlist-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  padding: 10px;
  margin-bottom: 4px;
  border-radius: var(--radius);
  background: var(--bg-card);
  cursor: grab;
  user-select: none;
  transition: background 0.15s;
  position: relative;
}
.playlist-item:hover {
  background: var(--bg-card-hover);
}
.playlist-item.dragging {
  opacity: 0.4;
}
.playlist-item.drop-above::before {
  content: '';
  position: absolute;
  top: -3px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}
.playlist-item.drop-below::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--accent);
  border-radius: 2px;
}
.playlist-list.drag-over-empty .playlist-empty {
  border-color: var(--accent);
  background: var(--accent-dim);
}
.pl-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--text-dim);
  min-width: 24px;
  text-align: right;
  padding-top: 2px;
}
.pl-info {
  flex: 1;
  min-width: 0;
}
.pl-artist-title {
  font-size: 0.85rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.pl-details {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  font-size: 0.75rem;
  color: var(--text-dim);
  margin-top: 4px;
  font-family: var(--font-mono);
}
.pl-native { color: var(--text-dim); }
.pl-target { color: var(--accent); font-weight: 700; }
.pl-adjust { font-weight: 700; }
.pl-adjust.ok { color: var(--success); }
.pl-adjust.warn { color: var(--warning); }
.pl-adjust.danger { color: var(--danger); }
.pl-time { color: var(--text-dim); }
.pl-controls {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex-shrink: 0;
}
.pl-controls button {
  width: 26px;
  height: 22px;
  font-size: 0.7rem;
  padding: 0;
  line-height: 1;
  border-color: transparent;
  background: transparent;
  color: var(--text-dim);
}
.pl-controls button:hover {
  background: var(--accent-dim);
  color: var(--text);
}
.pl-controls .btn-remove:hover {
  color: var(--danger);
}

/* === FOOTER === */
.footer {
  padding: 8px 16px;
  border-top: 1px solid var(--border);
  background: var(--bg-panel);
  font-size: 0.75rem;
  color: var(--text-dim);
  text-align: right;
}

/* === BPM EDIT === */
.bpm-editable {
  cursor: pointer;
  border-bottom: 1px dashed var(--text-dim);
}
.bpm-editable:hover {
  border-bottom-color: var(--accent);
}
.bpm-edit-input {
  width: 48px;
  font-family: var(--font-mono);
  font-size: inherit;
  padding: 1px 4px;
  text-align: center;
}

/* === SCROLLBAR === */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #555; }

/* === RESPONSIVE === */
@media (max-width: 768px) {
  .panels {
    flex-direction: column;
  }
  .library-panel, .playlist-panel {
    width: 100%;
  }
  .library-panel {
    border-right: none;
    border-bottom: 1px solid var(--border);
  }
  .library-panel .song-list {
    max-height: 40vh;
  }
  .library-panel.collapsed .song-list,
  .library-panel.collapsed .library-filters,
  .library-panel.collapsed .add-custom,
  .library-panel.collapsed .custom-form {
    display: none;
  }
  .btn-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  .library-panel.collapsed .btn-toggle {
    transform: rotate(-90deg);
  }
  .header-config {
    gap: 10px;
  }
  .config-status {
    margin-left: 0;
    width: 100%;
  }
}