/* ===== Foundation ===== */
:root {
  --bg: #000000;
  --bg-elevated: #1c1c1e;
  --bg-grouped: #2c2c2e;
  --bg-hover: #38383a;
  --fill-accent: #af52de;
  --fill-accent-hover: #c77deb;
  --fill-pink: #ff2d55;
  --text-primary: #ffffff;
  --text-secondary: rgba(255,255,255,0.55);
  --text-tertiary: rgba(255,255,255,0.25);
  --separator: rgba(255,255,255,0.08);
  --vibrancy: rgba(28,28,30,0.72);
  --radius-xs: 6px;
  --radius-sm: 10px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --sidebar-w: 240px;
  --timing: cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

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

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  min-height: 100dvh;
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ===== Layout ===== */
.app {
  display: flex;
  height: 100dvh;
}

/* ===== Sidebar ===== */
.sidebar {
  width: var(--sidebar-w);
  background: var(--vibrancy);
  backdrop-filter: blur(40px) saturate(180%);
  -webkit-backdrop-filter: blur(40px) saturate(180%);
  border-right: 1px solid var(--separator);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  padding: 20px 12px;
  user-select: none;
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 8px;
  margin-bottom: 24px;
}

.sidebar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.sidebar-title {
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--text-secondary);
}

.connection-badge {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.conn-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--text-tertiary);
  transition: all 0.4s var(--timing);
}

.conn-dot.connected {
  background: #30d158;
  box-shadow: 0 0 6px rgba(48,209,88,0.5);
}

.conn-dot.disconnected {
  background: #ff453a;
}

.sidebar-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  font-size: 14px;
  font-weight: 500;
  font-family: inherit;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.15s var(--timing);
  text-align: left;
  width: 100%;
}

.nav-item:hover {
  background: rgba(255,255,255,0.06);
  color: var(--text-primary);
}

.nav-item.active {
  background: rgba(255,255,255,0.1);
  color: var(--text-primary);
}

.nav-item svg {
  flex-shrink: 0;
  opacity: 0.7;
}

.nav-item.active svg {
  opacity: 1;
  color: var(--fill-accent);
}

/* ===== Main ===== */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

.main-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 24px 32px 16px;
  flex-shrink: 0;
  gap: 16px;
}

.header-left {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-title {
  font-size: 28px;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.track-count {
  font-size: 14px;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ===== Search ===== */
.search-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-grouped);
  border-radius: var(--radius-sm);
  padding: 8px 14px;
  border: 1px solid transparent;
  transition: all 0.2s var(--timing);
}

.search-wrap:focus-within {
  border-color: var(--fill-accent);
  background: var(--bg-elevated);
}

.search-icon {
  color: var(--text-tertiary);
  flex-shrink: 0;
}

.search-input {
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  width: 160px;
}

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

/* ===== Connection Text ===== */
.conn-text {
  font-size: 10px;
  color: var(--text-tertiary);
  white-space: nowrap;
}

.btn-add {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: none;
  background: var(--fill-accent);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s var(--timing);
  box-shadow: 0 2px 8px rgba(175,82,222,0.3);
}

.btn-add:hover {
  transform: scale(1.08);
  background: var(--fill-accent-hover);
  box-shadow: 0 4px 16px rgba(175,82,222,0.4);
}

.btn-add:active { transform: scale(0.95); }

/* ===== Upload Sheet ===== */
.upload-sheet {
  margin: 0 32px 16px;
  animation: slideDown 0.35s var(--timing);
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-12px); }
  to { opacity: 1; transform: translateY(0); }
}

.upload-zone {
  border: 1.5px dashed rgba(255,255,255,0.15);
  border-radius: var(--radius-md);
  padding: 32px;
  text-align: center;
  cursor: pointer;
  transition: all 0.25s var(--timing);
  background: rgba(255,255,255,0.02);
}

.upload-zone:hover,
.upload-zone.drag-over {
  border-color: var(--fill-accent);
  background: rgba(175,82,222,0.06);
}

.upload-icon-wrap {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: rgba(175,82,222,0.12);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
  color: var(--fill-accent);
}

.upload-label {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
}

.upload-link {
  color: var(--fill-accent);
  font-weight: 500;
  cursor: pointer;
}

.upload-link:hover { text-decoration: underline; }

.upload-bar {
  margin-top: 12px;
  height: 3px;
  background: var(--bg-grouped);
  border-radius: 2px;
  overflow: hidden;
  position: relative;
}

.upload-bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--fill-accent), var(--fill-pink));
  border-radius: 2px;
  transition: width 0.3s var(--timing);
}

.upload-bar-text {
  display: block;
  text-align: center;
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 8px;
}

/* ===== Content Panels ===== */
.content-panel {
  display: none;
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0 32px 32px;
  scrollbar-width: thin;
  scrollbar-color: rgba(255,255,255,0.1) transparent;
}

.content-panel::-webkit-scrollbar { width: 6px; }
.content-panel::-webkit-scrollbar-thumb {
  background: rgba(255,255,255,0.1);
  border-radius: 3px;
}

.content-panel.active { display: flex; flex-direction: column; }

/* ===== Track Table ===== */
.track-table {
  display: flex;
  flex-direction: column;
}

.track-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  transition: background 0.15s var(--timing);
  cursor: default;
}

.track-row:hover { background: rgba(255,255,255,0.04); }

.track-num {
  width: 24px;
  text-align: center;
  font-size: 14px;
  font-weight: 400;
  color: var(--text-tertiary);
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

.track-row:hover .track-num { color: var(--text-secondary); }

.track-thumb {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-xs);
  overflow: hidden;
  flex-shrink: 0;
  background: var(--bg-grouped);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.track-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.track-thumb-placeholder {
  color: var(--text-tertiary);
  font-size: 18px;
}

.track-meta {
  flex: 1;
  min-width: 0;
}

.track-name {
  font-size: 15px;
  font-weight: 500;
  line-height: 1.3;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.track-sub {
  font-size: 13px;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-top: 1px;
}

.track-album {
  flex: 0 0 160px;
  font-size: 13px;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.track-remove {
  opacity: 0;
  width: 30px;
  height: 30px;
  border: none;
  border-radius: 50%;
  background: transparent;
  color: var(--text-tertiary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s;
  flex-shrink: 0;
}

.track-row:hover .track-remove { opacity: 1; }
.track-remove:hover { color: #ff453a; background: rgba(255,69,58,0.12); }

/* ===== Playlist Grid ===== */
.playlist-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 20px;
}

.playlist-card {
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  padding: 16px;
  cursor: pointer;
  transition: all 0.2s var(--timing);
  position: relative;
  border: 1px solid transparent;
}

.playlist-card:hover {
  background: var(--bg-grouped);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
  border-color: var(--separator);
}

.playlist-card-art {
  width: 100%;
  aspect-ratio: 1;
  background: linear-gradient(135deg, rgba(175,82,222,0.2), rgba(255,45,85,0.15));
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  color: var(--fill-accent);
}

.playlist-card-name {
  font-size: 14px;
  font-weight: 600;
  margin-bottom: 2px;
}

.playlist-card-count {
  font-size: 12px;
  color: var(--text-secondary);
}

.playlist-card-remove {
  position: absolute;
  top: 8px;
  right: 8px;
  opacity: 0;
  width: 26px;
  height: 26px;
  border: none;
  border-radius: 50%;
  background: rgba(0,0,0,0.6);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 14px;
  transition: opacity 0.15s;
}

.playlist-card:hover .playlist-card-remove { opacity: 1; }
.playlist-card-remove:hover { color: #ff453a; }

/* ===== FAB ===== */
.fab {
  position: absolute;
  bottom: 24px;
  right: 32px;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: none;
  background: var(--fill-accent);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(175,82,222,0.4);
  transition: all 0.2s var(--timing);
  z-index: 10;
}

.fab:hover { transform: scale(1.08); box-shadow: 0 6px 28px rgba(175,82,222,0.5); }
.fab:active { transform: scale(0.94); }

/* ===== Empty State ===== */
.empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 64px 20px;
  text-align: center;
  flex: 1;
}

.empty-icon { color: var(--text-tertiary); margin-bottom: 16px; }
.empty-title { font-size: 17px; font-weight: 600; margin-bottom: 4px; }
.empty-sub { font-size: 14px; color: var(--text-secondary); }

/* ===== Modal ===== */
.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.6);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: flex-end;
  justify-content: center;
  z-index: 500;
  animation: fadeIn 0.2s var(--timing);
}

.modal-backdrop[hidden] {
  display: none !important;
}

@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

.modal-sheet {
  background: var(--bg-elevated);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
  width: 100%;
  max-width: 520px;
  max-height: 80dvh;
  padding: 12px 28px 28px;
  display: flex;
  flex-direction: column;
  animation: sheetUp 0.35s var(--timing);
}

@keyframes sheetUp {
  from { transform: translateY(100%); }
  to { transform: translateY(0); }
}

.modal-handle {
  width: 36px;
  height: 5px;
  background: rgba(255,255,255,0.15);
  border-radius: 3px;
  margin: 0 auto 20px;
}

.modal-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 20px;
  text-align: center;
}

.modal-input {
  width: 100%;
  padding: 14px 16px;
  background: var(--bg-grouped);
  border: 1px solid var(--separator);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 16px;
  font-family: inherit;
  margin-bottom: 16px;
  transition: border-color 0.2s;
}

.modal-input:focus { outline: none; border-color: var(--fill-accent); }
.modal-input::placeholder { color: var(--text-tertiary); }

.modal-tracks {
  max-height: 40dvh;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 2px;
  margin-bottom: 20px;
}

.modal-track-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: background 0.15s;
}

.modal-track-item:hover { background: rgba(255,255,255,0.04); }

.modal-track-item input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 22px;
  height: 22px;
  border: 2px solid rgba(255,255,255,0.2);
  border-radius: 6px;
  flex-shrink: 0;
  position: relative;
  cursor: pointer;
  transition: all 0.15s;
}

.modal-track-item input[type="checkbox"]:checked {
  background: var(--fill-accent);
  border-color: var(--fill-accent);
}

.modal-track-item input[type="checkbox"]:checked::after {
  content: "✓";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: white;
  font-size: 13px;
  font-weight: 700;
}

.modal-track-label {
  font-size: 14px;
  font-weight: 500;
}

.modal-track-sub {
  font-size: 12px;
  color: var(--text-secondary);
}

.modal-actions {
  display: flex;
  gap: 10px;
}

.btn-flat {
  flex: 1;
  padding: 14px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--bg-grouped);
  color: var(--text-secondary);
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-flat:hover { background: var(--bg-hover); color: var(--text-primary); }

.btn-filled {
  flex: 1;
  padding: 14px;
  border: none;
  border-radius: var(--radius-sm);
  background: var(--fill-accent);
  color: white;
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-filled:hover { background: var(--fill-accent-hover); }

/* ===== Mobile: 768px以下に統合（後方の@media 768pxセクション参照） ===== */

/* ===== Scrollbar ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255,255,255,0.1); border-radius: 3px; }

/* ===== Toast ===== */
.toast-container {
  position: fixed;
  top: 24px;
  right: 24px;
  z-index: 1000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  color: white;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  opacity: 0;
  transform: translateX(24px);
  transition: all 0.3s var(--timing);
  pointer-events: auto;
  max-width: 340px;
}

.toast.show {
  opacity: 1;
  transform: translateX(0);
}

.toast-info {
  background: rgba(44,44,46,0.9);
  border: 1px solid var(--separator);
}

.toast-success {
  background: rgba(48,209,88,0.15);
  border: 1px solid rgba(48,209,88,0.3);
  color: #30d158;
}

.toast-error {
  background: rgba(255,69,58,0.15);
  border: 1px solid rgba(255,69,58,0.3);
  color: #ff453a;
}

/* ===== Confirm Dialog ===== */
.confirm-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 600;
  opacity: 0;
  transition: opacity 0.2s var(--timing);
}

.confirm-backdrop.show {
  opacity: 1;
}

.confirm-sheet {
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  padding: 24px;
  max-width: 340px;
  width: 90%;
  text-align: center;
}

.confirm-message {
  font-size: 15px;
  line-height: 1.5;
  margin-bottom: 20px;
  color: var(--text-primary);
}

.confirm-actions {
  display: flex;
  gap: 10px;
}

.btn-danger {
  flex: 1;
  padding: 14px;
  border: none;
  border-radius: var(--radius-sm);
  background: #ff453a;
  color: white;
  font-size: 15px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all 0.15s;
}

.btn-danger:hover {
  background: #ff6961;
}

/* ===== Inline Edit ===== */
.track-edit {
  background: none;
  border: none;
  color: var(--text-tertiary);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  opacity: 0;
  transition: all 0.15s;
}

.track-row:hover .track-edit {
  opacity: 1;
}

.track-edit:hover {
  color: var(--fill-accent);
  background: rgba(124,58,237,0.1);
}

.track-row.editing {
  background: rgba(124,58,237,0.08);
}

.edit-input {
  background: var(--bg-grouped);
  border: 1px solid var(--separator);
  border-radius: var(--radius-sm);
  padding: 4px 8px;
  color: var(--text-primary);
  font-size: 13px;
  font-family: inherit;
  outline: none;
  width: 100%;
  transition: border-color 0.15s;
}

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

.edit-title {
  font-weight: 500;
  margin-bottom: 4px;
}

/* ===== D&D ===== */
.drag-handle {
  color: var(--text-tertiary);
  cursor: grab;
  font-size: 18px;
  user-select: none;
  padding: 0 4px;
  line-height: 1;
}

.drag-handle:active {
  cursor: grabbing;
}

.modal-track-item.dragging {
  opacity: 0.4;
  background: rgba(124,58,237,0.1);
}

.modal-track-item.drag-above {
  border-top: 2px solid var(--fill-accent);
}

.modal-track-item[draggable="true"] {
  cursor: default;
}

/* ===== Sidebar Footer ===== */
.sidebar-footer {
  padding: 12px 16px;
  margin-top: auto;
  border-top: 1px solid var(--separator);
}

/* ===== Catalog Status ===== */
.catalog-status {
  font-size: 11px;
  font-weight: 500;
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  text-align: center;
}

.catalog-status.synced {
  color: #30d158;
  background: rgba(48,209,88,0.08);
}

.catalog-status.unsynced {
  color: var(--text-tertiary);
  background: rgba(255,255,255,0.04);
}

/* ===== Mobile Responsive ===== */
@media (max-width: 768px) {
  .app {
    flex-direction: column;
  }

  .sidebar {
    width: 100%;
    height: auto;
    flex-direction: row;
    padding: 6px 0 env(safe-area-inset-bottom, 8px);
    border-right: none;
    border-top: 1px solid var(--separator);
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 100;
  }

  .sidebar-header { display: none; }

  .sidebar-nav {
    display: flex;
    flex-direction: row;
    gap: 4px;
    width: 100%;
    justify-content: space-around;
  }

  .nav-item {
    flex: 1;
    flex-direction: column;
    gap: 3px;
    padding: 6px 12px;
    font-size: 11px;
    align-items: center;
    justify-content: center;
  }

  .main {
    padding-bottom: 72px;
    width: 100%;
  }

  .main-header {
    padding: 16px 20px 12px;
    flex-wrap: wrap;
    gap: 8px;
  }

  .page-title { font-size: 24px; }

  .header-actions {
    width: 100%;
  }

  .search-wrap {
    flex: 1;
  }

  .content-panel { padding: 0 20px 20px; }
  .upload-sheet { margin: 0 20px 12px; }
  .upload-zone { padding: 24px; }
  .track-album { display: none; }
  .fab { bottom: 84px; right: 20px; }

  .playlist-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .playlist-grid {
    grid-template-columns: 1fr;
  }

  .track-num { display: none; }
}