:root {
  color-scheme: light dark;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.5;
  font-size: 16px;
  background: #f6f7fb;
  color: #1f252f;
}

body {
  margin: 0;
  padding: 2rem;
  display: flex;
  justify-content: center;
  background: linear-gradient(180deg, #f6f7fb 0%, #eef1f7 100%);
}

main {
  width: min(960px, 100%);
  display: grid;
  gap: 1.5rem;
}

header h1 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 2.8rem);
}

header p {
  margin-top: 0.5rem;
  color: #4a5568;
}

.card {
  background: rgba(255, 255, 255, 0.9);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 18px 35px rgba(31, 37, 47, 0.08);
  backdrop-filter: blur(12px);
}

.card h2 {
  margin-top: 0;
  font-size: 1.3rem;
}

.connection-form {
  display: grid;
  gap: 1rem;
  align-items: end;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.field {
  display: grid;
  gap: 0.4rem;
  font-size: 0.9rem;
  color: #4a5568;
}

.field select,
.field input[type="search"] {
  padding: 0.55rem 0.75rem;
  border-radius: 10px;
  border: 1px solid rgba(31, 37, 47, 0.12);
  background: rgba(255, 255, 255, 0.8);
  font-size: 1rem;
}

button {
  cursor: pointer;
  border-radius: 12px;
  border: none;
  font-weight: 600;
  padding: 0.65rem 1.3rem;
  background: linear-gradient(135deg, #1e5adb 0%, #4c8dff 100%);
  box-shadow: 0 6px 18px rgba(30, 90, 219, 0.28);
  color: white;
  transition: filter 0.2s ease, transform 0.2s ease;
}

button:hover:not(:disabled) {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

button:disabled {
  cursor: not-allowed;
  background: #a0aec0;
}

.secondary {
  background: rgba(255, 255, 255, 0.3);
  border: 1px solid rgba(31, 37, 47, 0.18);
  color: #1f252f;
}

.status {
  margin-top: 1rem;
  font-size: 0.94rem;
  color: #2d3748;
}

.file-actions {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  align-items: end;
  margin-bottom: 1rem;
}

.library {
  border: none;
  padding: 0;
  background: transparent;
}

.upload-label {
  display: grid;
  gap: 0.5rem;
  font-size: 0.9rem;
  color: #4a5568;
}

.upload-label input {
  padding: 0.75rem;
  border: 1px dashed rgba(31, 37, 47, 0.3);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.7);
}

.selected-file {
  padding: 0.75rem 1rem;
  background: rgba(31, 37, 47, 0.05);
  border-radius: 12px;
  color: #1f252f;
  margin-bottom: 1rem;
}

.playback-actions {
  display: flex;
  gap: 0.85rem;
  flex-wrap: wrap;
}

.playback-actions button {
  min-width: 4.5rem;
}

.rating-row {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  margin-top: 1.25rem;
}

.rating-control {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  color: #4a5568;
}

.rating-control span {
  font-weight: 600;
}

.rating-stars {
  display: inline-flex;
  gap: 0.25rem;
}

.rating-stars .star {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  border: none;
  background: rgba(30, 90, 219, 0.08);
  color: #1e5adb;
  font-size: 1.1rem;
  display: grid;
  place-items: center;
  cursor: pointer;
}

.rating-stars .star.active {
  background: #1e5adb;
  color: #fff;
}

.favorite-btn {
  white-space: nowrap;
}

.favorite-btn.active {
  background: #fbbf24;
  border: 1px solid rgba(31, 37, 47, 0.15);
  color: #1f252f;
}

.tiny {
  padding: 0.35rem 0.75rem;
  font-size: 0.85rem;
}

.library-layout {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.library-tree-section,
.library-results-section {
  display: grid;
  gap: 0.9rem;
}

.library-tree-section {
  width: 100%;
}

.library-tree-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.library-tree {
  border: 1px solid rgba(31, 37, 47, 0.12);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.6);
  padding: 0.9rem;
  max-height: 420px;
  overflow: auto;
}

.tree-node {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  border-radius: 10px;
  padding: 0.25rem 0.4rem;
  margin: 0.1rem 0;
  flex-wrap: wrap;
}

.tree-branch {
  margin: 0;
}

.tree-node.file .tree-label {
  font-weight: 500;
}

.tree-node.file {
  align-items: flex-start;
}

.tree-node.folder {
  font-weight: 600;
  align-items: center;
}

.tree-node .tree-label {
  border: none;
  background: none;
  text-align: left;
  flex: 1;
  cursor: pointer;
  font-size: 0.95rem;
  color: inherit;
  padding: 0.25rem 0.15rem;
  border-radius: 8px;
}

.tree-node .tree-label:hover,
.tree-node .tree-label:focus-visible {
  background: rgba(30, 90, 219, 0.12);
  outline: none;
}

.tree-node.active {
  background: rgba(30, 90, 219, 0.16);
}

.tree-toggle {
  width: 1.6rem;
  height: 1.6rem;
  border-radius: 50%;
  border: none;
  background: rgba(31, 37, 47, 0.08);
  color: inherit;
  display: grid;
  place-items: center;
  cursor: pointer;
}

.tree-toggle:hover {
  background: rgba(30, 90, 219, 0.18);
}

.tree-children {
  margin-left: 1.5rem;
  border-left: 1px dashed rgba(31, 37, 47, 0.2);
  padding-left: 0.75rem;
}

.tree-node .results-meta {
  margin-left: auto;
  font-size: 0.82rem;
}

.tree-info {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.tree-meta {
  font-size: 0.75rem;
  color: #5f6f85;
  display: flex;
  gap: 0.5rem;
  align-items: center;
  max-width: 100%;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  min-width: 0;
}

.tree-meta span {
  min-width: 0;
}

.tree-meta-rating {
  color: #f6ad55;
}

.tree-item-actions {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  flex-wrap: wrap;
  justify-content: flex-end;
  margin-left: auto;
}

.tree-action-button {
  padding: 0.35rem 0.55rem;
  border-radius: 6px;
  border: 1px solid rgba(30, 90, 219, 0.3);
  background: rgba(30, 90, 219, 0.12);
  color: #1e3260;
  font-size: 0.78rem;
  font-weight: 600;
  line-height: 1;
  box-shadow: none;
  min-width: 2rem;
  transition: background 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

.tree-action-button:hover,
.tree-action-button:focus-visible {
  background: rgba(30, 90, 219, 0.22);
  outline: none;
  transform: none;
  filter: none;
}

.tree-action-button.active {
  background: #1e5adb;
  border-color: #1e5adb;
  color: #fff;
}

.tree-rating {
  display: inline-flex;
  gap: 0.1rem;
  align-items: center;
  padding-right: 0.1rem;
}

.tree-rating-star {
  width: 1.35rem;
  height: 1.35rem;
  border-radius: 50%;
  border: none;
  background: transparent;
  box-shadow: none;
  color: #b7c3d6;
  font-size: 0.9rem;
  line-height: 1;
  padding: 0;
  cursor: pointer;
}

.tree-rating-star.active {
  color: #f6ad55;
}

.tree-rating-star:hover,
.tree-rating-star:focus-visible {
  color: #fbd38d;
  background: rgba(251, 211, 141, 0.22);
  outline: none;
  transform: none;
  filter: none;
}

.tree-checkbox {
  display: grid;
  place-items: center;
}

.tree-checkbox input {
  width: 1.05rem;
  height: 1.05rem;
}

.results-list,
.favorites-list,
.playlist-list,
.playlist-detail {
  border: 1px solid rgba(31, 37, 47, 0.12);
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.6);
  min-height: 120px;
  padding: 0.75rem;
}

.results-list .empty,
.favorites-list .empty,
.playlist-list .empty,
.playlist-detail .empty {
  color: #4a5568;
  text-align: center;
  padding: 1rem;
}

.result-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.result-item .tree-checkbox {
  margin-right: 0.25rem;
}

.result-item .result-button {
  flex: 1;
}

.result-item .results-meta {
  margin-left: auto;
}

.favorites-list ul,
.results-list ul,
.playlist-list ul,
.playlist-detail ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.favorites-list button,
.results-list button,
.playlist-list button {
  width: 100%;
  text-align: left;
  padding: 0.55rem 0.6rem;
  border-radius: 8px;
  border: 1px solid rgba(31, 37, 47, 0.12);
  background: linear-gradient(140deg, rgba(255, 255, 255, 0.95), rgba(231, 239, 255, 0.95));
  box-shadow: 0 4px 12px rgba(31, 37, 47, 0.08);
  color: #111;
  cursor: pointer;
}

.favorites-list button:hover,
.results-list button:hover,
.playlist-list button:hover {
  background: rgba(30, 90, 219, 0.1);
}

.favorites-list button.active,
.results-list button.active,
.playlist-list button.active {
  background: rgba(30, 90, 219, 0.16);
}

.playlist-controls {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  align-items: end;
  margin-bottom: 1rem;
}

.playlist-buttons {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.favorites-controls,
.playlist-playback-controls {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 0.75rem;
}

.playlist-layout {
  display: grid;
  gap: 1rem;
  grid-template-columns: minmax(220px, 0.7fr) minmax(260px, 1fr);
}

.playlist-detail-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

.playlist-detail ul li {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.45rem 0.3rem;
  border-radius: 8px;
}

.playlist-detail ul li:nth-child(odd) {
  background: rgba(31, 37, 47, 0.05);
}

.playlist-detail .playlist-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
}

.playlist-detail .playlist-actions button {
  flex-shrink: 0;
}

.playlist-entry {
  flex: 1;
  text-align: left;
  border: none;
  background: none;
  padding: 0.5rem 0.45rem;
  border-radius: 8px;
  cursor: pointer;
  color: inherit;
}

.playlist-entry.active {
  background: rgba(30, 90, 219, 0.16);
}

.playlist-entry:hover {
  background: rgba(30, 90, 219, 0.1);
}

.results-meta {
  font-size: 0.85rem;
  color: #4a5568;
}

.help ul {
  margin: 0;
  padding-left: 1.2rem;
  color: #4a5568;
}

.help li + li {
  margin-top: 0.5rem;
}

@media (max-width: 720px) {
  body {
    padding: 1.5rem;
  }

  main {
    gap: 1rem;
  }

  .card {
    padding: 1.25rem;
  }

  .playlist-layout {
    grid-template-columns: 1fr;
  }

  .rating-row {
    flex-direction: column;
    align-items: flex-start;
  }

  .tree-item-actions {
    width: 100%;
    margin-left: 0;
    justify-content: flex-start;
  }
}