:root {
  --bg: #ffffff;
  --surface: #f4f4f5;
  --surface-2: #e4e4e7;
  --text: #18181b;
  --muted: #71717a;
  --border: #e4e4e7;
  --accent: #18181b;
  --accent-text: #ffffff;
  --radius: 10px;
  --shadow: 0 20px 50px rgba(0, 0, 0, .18);
  color-scheme: light;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111113;
    --surface: #1c1c1f;
    --surface-2: #2a2a2e;
    --text: #f4f4f5;
    --muted: #a1a1aa;
    --border: #2a2a2e;
    --accent: #f4f4f5;
    --accent-text: #111113;
    --shadow: 0 20px 50px rgba(0, 0, 0, .5);
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html, body { height: 100%; }

body {
  margin: 0;
  display: grid;
  grid-template-rows: auto 1fr auto;
  background: var(--bg);
  color: var(--text);
  font: 14px/1.4 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  flex: none;
}

/* ---------- Toolbar ---------- */

.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px 20px;
  flex-wrap: wrap;
  padding: 12px 20px;
  border-bottom: 1px solid var(--border);
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -.01em;
}

.brand-mark {
  display: inline-flex;
  width: 24px;
  height: 24px;
  border-radius: 6px;
  overflow: hidden;
}
.brand-mark i { flex: 1; }
.brand-mark i:nth-child(1) { background: #264653; }
.brand-mark i:nth-child(2) { background: #2a9d8f; }
.brand-mark i:nth-child(3) { background: #e9c46a; }
.brand-mark i:nth-child(4) { background: #e76f51; }

.controls {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.field {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--muted);
  font-size: 13px;
}

select {
  height: 36px;
  padding: 0 28px 0 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2371717a' stroke-width='2'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat right 8px center / 14px;
  color: var(--text);
  font: inherit;
  appearance: none;
  cursor: pointer;
}

.btn-group { display: flex; gap: 6px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  height: 36px;
  padding: 0 12px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
  font-weight: 500;
  cursor: pointer;
  transition: background .15s, transform .1s, opacity .15s;
}
.btn:hover { background: var(--surface-2); }
.btn:active { transform: scale(.97); }
.btn:disabled { opacity: .4; cursor: not-allowed; transform: none; }
.btn.icon { width: 36px; padding: 0; }
.btn.ghost { background: transparent; border-color: transparent; }
.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-text);
  padding: 0 18px;
}
.btn.primary:hover { opacity: .88; }

:focus-visible { outline: 2px solid #3b82f6; outline-offset: 2px; }

/* ---------- Palette ---------- */

.palette {
  display: flex;
  min-height: 0;
}

.swatch {
  --fg: #fff;
  position: relative;
  flex: 1 1 0;
  min-width: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  padding: 24px 8px 40px;
  background: var(--c);
  color: var(--fg);
  transition: background-color .35s ease, flex-grow .25s ease;
  animation: swatch-in .3s ease both;
}
.swatch.dragging { opacity: .5; }
.swatch.drop-target { box-shadow: inset 4px 0 0 var(--fg); }

@keyframes swatch-in {
  from { opacity: 0; transform: translateY(6px); }
}

.swatch-actions {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.swatch-btn {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: inherit;
  cursor: pointer;
  opacity: .75;
  transition: background .15s, opacity .15s;
}
.swatch-btn:hover { background: color-mix(in srgb, var(--fg) 14%, transparent); opacity: 1; }
.swatch-btn svg { width: 20px; height: 20px; }
.swatch-btn.drag { cursor: grab; }
.swatch-btn.edit { position: relative; overflow: hidden; }
.swatch-btn.edit input {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
  width: 100%;
  height: 100%;
  border: 0;
  padding: 0;
}

/* Desktop: hide secondary actions until hover; lock stays visible when locked */
@media (hover: hover) {
  .swatch .swatch-btn { opacity: 0; }
  .swatch:hover .swatch-btn,
  .swatch:focus-within .swatch-btn { opacity: .75; }
  .swatch:hover .swatch-btn:hover { opacity: 1; }
  .swatch.locked .swatch-btn.lock { opacity: 1; }
}

.swatch-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  max-width: 100%;
}

.code-btn {
  max-width: 100%;
  padding: 6px 10px;
  border: 0;
  border-radius: 8px;
  background: transparent;
  color: inherit;
  font: 600 clamp(14px, 1.8vw, 24px)/1.2 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  letter-spacing: .02em;
  cursor: copy;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.code-btn.small { font-size: clamp(11px, 1.1vw, 15px); }
.code-btn:hover { background: color-mix(in srgb, var(--fg) 14%, transparent); }

.meta {
  display: flex;
  gap: 6px;
  font-size: 12px;
  opacity: .8;
  white-space: nowrap;
}

.badge {
  padding: 1px 6px;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
}

/* ---------- Hint ---------- */

.hint {
  margin: 0;
  padding: 8px 16px;
  color: var(--muted);
  font-size: 12px;
  text-align: center;
  border-top: 1px solid var(--border);
}

kbd {
  padding: 1px 5px;
  border: 1px solid var(--border);
  border-bottom-width: 2px;
  border-radius: 4px;
  background: var(--surface);
  font: 11px ui-monospace, monospace;
}

/* ---------- Dialogs ---------- */

.dialog {
  width: min(560px, calc(100vw - 32px));
  max-height: calc(100vh - 64px);
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: var(--bg);
  color: var(--text);
  box-shadow: var(--shadow);
}
.dialog::backdrop { background: rgba(0, 0, 0, .45); backdrop-filter: blur(2px); }

.dialog-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px 6px 20px;
}
.dialog-head h2 { margin: 0; font-size: 16px; }

.tabs {
  display: flex;
  gap: 4px;
  padding: 6px 20px;
  overflow-x: auto;
}
.tabs button {
  padding: 6px 12px;
  border: 0;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-weight: 500;
  cursor: pointer;
}
.tabs button[aria-selected="true"] { background: var(--surface-2); color: var(--text); }

.code {
  display: block;
  width: calc(100% - 40px);
  height: 220px;
  margin: 8px 20px;
  padding: 12px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--text);
  font: 13px/1.5 ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  resize: vertical;
}

.dialog-actions {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 8px;
  padding: 8px 20px 20px;
}

.library {
  list-style: none;
  margin: 0;
  padding: 6px 20px 20px;
  display: grid;
  gap: 10px;
}

.library-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.library-strip {
  flex: 1;
  display: flex;
  height: 48px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  cursor: pointer;
  transition: transform .15s;
}
.library-strip:hover { transform: translateY(-1px); }
.library-strip span { flex: 1; }

.empty {
  margin: 0;
  padding: 8px 20px 24px;
  color: var(--muted);
}

/* ---------- Source image thumbnail ---------- */

.source {
  position: fixed;
  left: 16px;
  bottom: 48px;
  z-index: 5;
  margin: 0;
  padding: 4px;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--bg);
  box-shadow: var(--shadow);
  animation: swatch-in .25s ease both;
}
.source img {
  display: block;
  max-width: 160px;
  max-height: 120px;
  border-radius: 8px;
}
.source figcaption {
  display: flex;
  flex-direction: column;
  gap: 1px;
  max-width: 160px;
  padding: 6px 4px 2px;
  font-size: 12px;
  color: var(--muted);
}
.source figcaption strong {
  color: var(--text);
  font-size: 13px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.song-form {
  display: flex;
  gap: 8px;
  padding: 8px 20px 4px;
}
.song-form input {
  flex: 1;
  min-width: 0;
  height: 36px;
  padding: 0 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--surface);
  color: var(--text);
  font: inherit;
}
.song-status { min-height: 1.4em; margin: 6px 20px 0; font-weight: 500; }
.song-status.error { color: #dc2626; }
.song-note { margin: 4px 20px 20px; color: var(--muted); font-size: 12px; }

.source-close {
  position: absolute;
  top: -10px;
  right: -10px;
  display: grid;
  place-items: center;
  width: 26px;
  height: 26px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
}
.source-close svg { width: 14px; height: 14px; }

@media (max-width: 720px) {
  .source { bottom: 16px; }
  .source img { max-width: 96px; max-height: 72px; }
  .source figcaption { max-width: 96px; }
  .song-form { flex-direction: column; }
}

/* ---------- Image drop overlay ---------- */

.drop-overlay {
  position: fixed;
  inset: 12px;
  z-index: 20;
  display: grid;
  place-items: center;
  border: 3px dashed var(--accent);
  border-radius: 16px;
  background: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(3px);
  pointer-events: none;
}
.drop-overlay p { margin: 0; font-size: 20px; font-weight: 600; }

/* ---------- Toast ---------- */

.toast {
  position: fixed;
  left: 50%;
  bottom: 48px;
  z-index: 10;
  padding: 10px 16px;
  border-radius: 999px;
  background: var(--accent);
  color: var(--accent-text);
  font-weight: 500;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transform: translate(-50%, 10px);
  transition: opacity .2s, transform .2s;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

/* ---------- Small screens: stack swatches as rows ---------- */

@media (max-width: 720px) {
  .toolbar { padding: 10px 16px; }
  .controls { width: 100%; }
  .btn-group .btn span { display: none; }
  .btn-group .btn { width: 36px; padding: 0; }
  #generate { flex: 1; }

  .palette { flex-direction: column; }
  .swatch {
    flex-direction: row-reverse;
    justify-content: space-between;
    align-items: center;
    padding: 8px 8px 8px 16px;
    min-height: 64px;
  }
  .swatch.drop-target { box-shadow: inset 0 4px 0 var(--fg); }
  .swatch-actions { flex-direction: row; }
  .swatch-btn { width: 36px; height: 36px; }
  .swatch-btn.drag { display: none; }
  .swatch-info { display: flex; flex-direction: column; align-items: flex-start; gap: 2px; min-width: 0; }
  .code-btn { padding: 2px 4px; margin-left: -4px; font-size: 16px; }
  .code-btn.small { font-size: 13px; }
  .hint { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation: none !important; transition: none !important; }
}