/* yt2mp3 frontend v2.0 — presentation only; backend/API contracts remain unchanged. */
body[data-ui-version="2.0"] .shell {
  width:min(980px,calc(100% - 32px));
  padding:36px 0 48px;
}
body[data-ui-version="2.0"] .page-header {
  align-items:center;
}
body[data-ui-version="2.0"] h1 {
  font-size:clamp(2rem,5vw,3rem);
}
body[data-ui-version="2.0"] .lede {
  max-width:620px;
  margin:.4rem 0 0;
}
body[data-ui-version="2.0"] .source-card {
  margin-top:22px;
}
body[data-ui-version="2.0"] .v2-internal-stepper {
  display:none !important;
}
body[data-ui-version="2.0"] .analysis-settings {
  margin-top:14px;
  border-top:1px solid var(--line);
}
body[data-ui-version="2.0"] .analysis-settings > summary {
  display:flex;
  min-height:44px;
  padding:12px 2px 0;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  color:var(--muted);
  cursor:pointer;
  list-style:none;
}
body[data-ui-version="2.0"] .analysis-settings > summary::-webkit-details-marker {
  display:none;
}
body[data-ui-version="2.0"] .analysis-settings > summary span {
  color:var(--text);
  font-weight:700;
}
body[data-ui-version="2.0"] .analysis-settings > summary small {
  font-size:.8rem;
}
body[data-ui-version="2.0"] .analysis-settings .ai-key-option {
  margin-top:10px;
}
body[data-ui-version="2.0"] #result {
  display:grid;
  gap:0;
  margin-top:22px;
}
body[data-ui-version="2.0"] #result.hidden {
  display:none;
}
body[data-ui-version="2.0"] .song-head {
  padding-bottom:22px;
  border-bottom:1px solid var(--line);
}
body[data-ui-version="2.0"] .song-details {
  min-width:0;
}
body[data-ui-version="2.0"] .v2-song-actions {
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  margin-top:12px;
}
body[data-ui-version="2.0"] .v2-song-actions button {
  min-height:38px;
  padding:0 14px;
}
body[data-ui-version="2.0"] [data-phase-content].v2-stage-visible {
  display:block !important;
}
body[data-ui-version="2.0"] .transpose-panel,
body[data-ui-version="2.0"] .stems-panel,
body[data-ui-version="2.0"] .melody-panel,
body[data-ui-version="2.0"] .v2-locked-stage {
  margin-top:0;
  padding:26px 0;
  border-bottom:1px solid var(--line);
}
body[data-ui-version="2.0"] .melody-panel,
body[data-ui-version="2.0"] .v2-locked-stage:last-child {
  border-bottom:0;
}
body[data-ui-version="2.0"] .v2-stage-kicker {
  display:flex;
  margin:0 0 5px;
  align-items:center;
  gap:7px;
  color:var(--accent);
  font-size:.83rem;
  font-weight:800;
  letter-spacing:.02em;
}
body[data-ui-version="2.0"] .v2-stage-number {
  display:grid;
  width:24px;
  height:24px;
  place-items:center;
  background:color-mix(in srgb,var(--accent) 15%,#10141d);
  border:1px solid color-mix(in srgb,var(--accent) 55%,var(--line));
  border-radius:50%;
  color:var(--accent);
  font-size:.76rem;
}
body[data-ui-version="2.0"] .panel-heading h3 {
  font-size:1.28rem;
}
body[data-ui-version="2.0"] .key-summary {
  grid-template-columns:repeat(4,minmax(0,1fr));
  margin-top:18px;
}
body[data-ui-version="2.0"] .key-summary > div {
  min-height:82px;
}
body[data-ui-version="2.0"] .key-summary div:first-child {
  background:color-mix(in srgb,var(--accent) 9%,#10141d);
  border-color:color-mix(in srgb,var(--accent) 40%,var(--line));
}
body[data-ui-version="2.0"] .shift-grid {
  margin-top:22px;
}
body[data-ui-version="2.0"] .shift-option {
  grid-template-rows:auto 62px;
}
body[data-ui-version="2.0"] .shift-label {
  min-height:30px;
  align-items:center;
}
body[data-ui-version="2.0"] .shift-button {
  min-height:62px;
  flex-direction:column;
  gap:1px;
}
body[data-ui-version="2.0"] .shift-button-label {
  display:block;
  color:var(--muted);
  font-size:.76rem;
  font-weight:700;
}
body[data-ui-version="2.0"] .shift-button.is-selected .shift-button-label {
  color:var(--accent);
}
body[data-ui-version="2.0"] .v2-bitrate-details {
  margin-top:16px;
  border:1px solid var(--accent);
  border-radius:12px;
  background:#10141d;
  box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 45%,transparent);
}
body[data-ui-version="2.0"] .v2-bitrate-details > summary {
  display:flex;
  min-height:48px;
  padding:11px 14px;
  align-items:center;
  justify-content:space-between;
  gap:14px;
  cursor:pointer;
  list-style:none;
}
body[data-ui-version="2.0"] .v2-bitrate-details > summary::-webkit-details-marker {
  display:none;
}
body[data-ui-version="2.0"] .v2-bitrate-details > summary span {
  color:var(--muted);
}
body[data-ui-version="2.0"] .v2-bitrate-details > summary strong {
  font-size:.9rem;
}
body[data-ui-version="2.0"] .v2-bitrate-details .bitrate-picker {
  margin:0;
  padding:0 14px 14px;
}
body[data-ui-version="2.0"] .v2-bitrate-details .bitrate-picker legend {
  position:absolute;
  width:1px;
  height:1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
}

body[data-ui-version="2.0"] .bitrate-option:hover {
  border-color:var(--accent);
}
body[data-ui-version="2.0"] .bitrate-option:has(input:checked) {
  background:#10141d;
  border-color:var(--accent);
  box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 45%,transparent);
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) {
  display:grid !important;
  grid-template-columns:minmax(0,1fr) 168px;
  column-gap:12px;
  align-items:start;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-stage-kicker,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .panel-heading,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-transpose-status-anchor,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .key-summary,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .muted,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .shift-grid,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-output-heading,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .downloads,
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-status-frame {
  grid-column:1 / -1;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .ai-key-summary {
  grid-column:1;
  min-width:0;
  align-self:center;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details {
  position:relative;
  grid-column:2;
  margin-top:14px;
  align-self:start;
  background:transparent;
  border:0;
  border-radius:10px;
  box-shadow:none;
  z-index:4;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details > summary {
  display:flex;
  width:168px;
  height:48px;
  min-height:48px;
  padding:0 14px;
  align-items:center;
  justify-content:center;
  flex-direction:row;
  gap:6px;
  background:#222a37;
  border:1px solid var(--accent);
  border-radius:10px;
  box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 45%,transparent);
  color:var(--text);
  font-weight:800;
  text-align:center;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details > summary span {
  position:absolute;
  width:1px;
  height:1px;
  margin:-1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
  white-space:nowrap;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details > summary strong {
  font-size:.9rem;
  line-height:1.2;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details[open] > summary {
  border-color:var(--accent);
  box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 45%,transparent);
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details .bitrate-picker {
  position:absolute;
  top:calc(100% + 8px);
  right:0;
  width:280px;
  margin:0;
  padding:10px;
  background:#10141d;
  border:1px solid var(--line);
  border-radius:12px;
  box-shadow:0 14px 32px #0008;
  z-index:20;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details .bitrate-options {
  grid-template-columns:1fr;
  gap:8px;
}
body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details .bitrate-option {
  padding:9px 10px;
}
body[data-ui-version="2.0"] .v2-transpose-status-anchor:empty {
  display:none;
}
body[data-ui-version="2.0"] .v2-transpose-status-anchor .v2-status-frame {
  margin:12px 0 0;
}
body[data-ui-version="2.0"] .v2-output-heading {
  display:none !important;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel {
  min-height:58px;
  margin-top:18px;
  padding:12px;
  background:#0e1118;
  border:1px solid var(--line);
  border-radius:12px;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download][hidden] {
  display:none;
}
body[data-ui-version="2.0"] .v2-output-empty {
  margin:0;
  padding:8px 4px;
  color:var(--muted);
  font-size:.86rem;
}
body[data-ui-version="2.0"] .shift-button {
  position:relative;
}
body[data-ui-version="2.0"] .shift-button[data-v2-output-ready="true"]::after {
  position:absolute;
  top:5px;
  right:6px;
  display:grid;
  width:17px;
  height:17px;
  place-items:center;
  background:var(--accent);
  border-radius:50%;
  color:#07110e;
  content:"✓";
  font-size:.68rem;
  font-weight:900;
}
body[data-ui-version="2.0"] .stems-panel.v2-stage-visible {
  display:grid !important;
  grid-template-columns:minmax(0,1fr) 84px 168px;
  column-gap:12px;
}
body[data-ui-version="2.0"] .stems-panel > .v2-stage-kicker,
body[data-ui-version="2.0"] .stems-panel > [data-stems-content],
body[data-ui-version="2.0"] .stems-panel > .v2-status-frame {
  grid-column:1 / -1;
}
body[data-ui-version="2.0"] .stems-panel > .panel-heading {
  display:contents;
}
body[data-ui-version="2.0"] .stems-panel > .panel-heading > div {
  grid-column:1;
  grid-row:2;
  min-width:0;
}
body[data-ui-version="2.0"] .stems-panel > .panel-heading .muted {
  font-size:0;
}
body[data-ui-version="2.0"] .stems-panel > .panel-heading .muted::after {
  color:var(--muted);
  content:"額外處理一次，即可分別下載人聲與伴奏；下載會套用目前練唱 Key，系統分析仍使用原調。";
  font-size:.92rem;
}
body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note,
body[data-ui-version="2.0"] .stems-panel > .panel-heading .primary-action {
  width:168px;
  height:48px;
  min-height:48px;
  align-self:start;
}
body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note {
  grid-column:2;
  grid-row:2;
  display:grid;
  width:84px;
  margin:0;
  padding:4px 12px;
  align-content:center;
  row-gap:1px;
  overflow:hidden;
  background:#10141d;
  border:1px solid var(--line);
  border-radius:10px;
  color:transparent;
  font-size:0;
}
body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note::before {
  display:block;
  color:var(--muted);
  content:"練唱 Key";
  font-size:.76rem;
  line-height:1.05;
}
body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note strong {
  display:block;
  color:var(--text);
  font-size:.95rem;
  line-height:1.1;
}
body[data-ui-version="2.0"] .stems-panel > .panel-heading .primary-action {
  grid-column:3;
  grid-row:2;
}
body[data-ui-version="2.0"] .stems-panel .stem-downloads {
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:20px;
}
body[data-ui-version="2.0"] .stems-panel .stem-downloads button {
  width:100%;
  min-width:0;
  min-height:48px;
}
body[data-ui-version="2.0"] .v2-locked-stage {
  opacity:.78;
}
body[data-ui-version="2.0"] .v2-locked-stage .v2-lock-row {
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:18px;
}
body[data-ui-version="2.0"] .v2-locked-stage h3 {
  margin:0;
  font-size:1.28rem;
}
body[data-ui-version="2.0"] .v2-locked-stage p {
  margin:.35rem 0 0;
}
body[data-ui-version="2.0"] .v2-lock-badge {
  flex:0 0 auto;
  padding:5px 10px;
  border:1px solid var(--line);
  border-radius:999px;
  color:var(--muted);
  font-size:.78rem;
  font-weight:700;
}
body[data-ui-version="2.0"] .v2-status-frame {
  margin-top:14px;
}
body[data-ui-version="2.0"] .v2-status-frame[hidden] {
  display:none;
}
body[data-ui-version="2.0"] .v2-status-frame .status {
  margin-top:0;
}
body[data-ui-version="2.0"] .stems-panel > .v2-status-frame .status.success {
  display:flex;
  min-height:64px;
  padding:12px 16px;
  align-items:center;
}
body[data-ui-version="2.0"] .v2-friendly-status {
  display:flex;
  padding:16px;
  align-items:center;
  gap:14px;
  background:#10141d;
  border:1px solid var(--line);
  border-radius:12px;
}
body[data-ui-version="2.0"] .v2-friendly-status > span:last-child {
  display:grid;
}
body[data-ui-version="2.0"] .v2-friendly-status small {
  color:var(--muted);
}
body[data-ui-version="2.0"] .v2-technical-details {
  margin-top:8px;
  color:var(--muted);
  font-size:.84rem;
}
body[data-ui-version="2.0"] .v2-technical-details > summary {
  cursor:pointer;
}
body[data-ui-version="2.0"] .v2-technical-details .status {
  margin-top:8px;
}
body[data-ui-version="2.0"] .source-card.v2-has-result {
  padding:18px 20px;
}
body[data-ui-version="2.0"] .source-card.v2-has-result .notice {
  display:none;
}
body[data-ui-version="2.0"] .source-card.v2-has-result .analysis-settings:not([open]) {
  margin-top:8px;
}

@media (max-width:640px) {
  body[data-ui-version="2.0"] .shell {
    padding:24px 0 36px;
  }
  body[data-ui-version="2.0"] .page-header {
    padding-right:72px;
  }
  body[data-ui-version="2.0"] h1 {
    font-size:2rem;
  }
  body[data-ui-version="2.0"] .lede {
    font-size:.92rem;
  }
  body[data-ui-version="2.0"] .key-summary {
    grid-template-columns:1fr 1fr;
  }
  body[data-ui-version="2.0"] .shift-grid {
    grid-auto-columns:minmax(72px,1fr);
  }
  body[data-ui-version="2.0"] .v2-lock-row {
    align-items:flex-start;
  }
  body[data-ui-version="2.0"] .v2-locked-stage .v2-lock-row {
    display:grid;
  }
  body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) {
    grid-template-columns:minmax(0,1fr);
    row-gap:12px;
  }
  body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .ai-key-summary,
  body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details {
    grid-column:1;
  }
  body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details {
    width:100%;
    margin-top:0;
  }
  body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details > summary {
    width:100%;
  }
  body[data-ui-version="2.0"] .transpose-panel.v2-stage-visible:has(.ai-key-summary) > .v2-bitrate-details .bitrate-picker {
    width:min(280px,100%);
  }
  body[data-ui-version="2.0"] .stems-panel.v2-stage-visible {
    grid-template-columns:minmax(0,1fr);
    row-gap:12px;
  }
  body[data-ui-version="2.0"] .stems-panel > .panel-heading > div,
  body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note,
  body[data-ui-version="2.0"] .stems-panel > .panel-heading .primary-action,
  body[data-ui-version="2.0"] .stems-panel > [data-stems-content],
  body[data-ui-version="2.0"] .stems-panel > .v2-status-frame {
    grid-column:1;
  }
  body[data-ui-version="2.0"] .stems-panel > .panel-heading > div {
    grid-row:2;
  }
  body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note {
    grid-row:3;
  }
  body[data-ui-version="2.0"] .stems-panel > .panel-heading .primary-action {
    grid-row:4;
  }
  body[data-ui-version="2.0"] .stems-panel > .v2-output-key-note,
  body[data-ui-version="2.0"] .stems-panel > .panel-heading .primary-action {
    width:100%;
  }
  body[data-ui-version="2.0"] .stems-panel .stem-downloads {
    grid-template-columns:minmax(0,1fr);
    gap:10px;
  }
  body[data-ui-version="2.0"] .bitrate-options {
    grid-template-columns:1fr;
  }
}

body[data-ui-version="2.0"] .downloads.v2-output-panel {
  grid-template-columns:repeat(3,minmax(0,1fr));
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download] {
  min-width:0;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download][data-bitrate="128"] {
  order:1;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download][data-bitrate="192"] {
  order:2;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download][data-bitrate="256"] {
  order:3;
}
body[data-ui-version="2.0"] .v2-output-empty {
  grid-column:1 / -1;
}
body[data-ui-version="2.0"] .stems-panel > .v2-status-frame .status.success {
  min-height:58px;
}

body[data-ui-version="2.0"] {
  --v2-output-row-height:64px;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel {
  height:var(--v2-output-row-height);
  min-height:var(--v2-output-row-height);
  align-items:center;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download] {
  display:flex;
  height:calc(var(--v2-output-row-height) - 26px);
  min-height:calc(var(--v2-output-row-height) - 26px);
  padding:0 12px;
  align-items:center;
  justify-content:center;
}
body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download]:disabled::before {
  display:inline-block;
  width:14px;
  height:14px;
  margin-right:8px;
  vertical-align:-2px;
  border:2px solid currentColor;
  border-right-color:transparent;
  border-radius:50%;
  content:"";
  animation:v2-download-spin .7s linear infinite;
}
@keyframes v2-download-spin {
  to { transform:rotate(360deg); }
}
body[data-ui-version="2.0"] .v2-transpose-status-anchor .v2-status-frame > .status.success,
body[data-ui-version="2.0"] .v2-transpose-status-anchor .v2-status-frame > .status:not(.processing-status):not(.error):not(:has(.progress-head)) {
  display:flex;
  height:var(--v2-output-row-height);
  min-height:var(--v2-output-row-height);
  padding:12px 16px;
  align-items:center;
}
body[data-ui-version="2.0"] .stems-panel > .v2-status-frame .status.success {
  min-height:var(--v2-output-row-height);
  border-color:var(--line);
  box-shadow:none;
}
@media (max-width:640px) {
  body[data-ui-version="2.0"] .downloads.v2-output-panel [data-download] {
    padding-inline:4px;
    font-size:clamp(.62rem,2.6vw,.9rem);
    line-height:1.2;
    white-space:nowrap;
  }
}

body[data-ui-version="2.0"] .stems-panel > .panel-heading .muted::after {
  content:"額外處理一次，即可分別下載人聲與伴奏。";
}


.source-unit-picker { margin-top: 1rem; border-top: 1px solid var(--line); padding-top: 1rem; }
.source-unit-heading { display: grid; gap: .25rem; margin-bottom: .7rem; }
.source-unit-heading small { color: var(--muted); }
.source-unit-list { display: grid; gap: .55rem; }
.source-unit-option { width: 100%; display: grid; grid-template-columns: 1rem minmax(0, 1fr) auto; gap: .75rem; align-items: center; text-align: left; padding: .8rem .9rem; border: 1px solid var(--line); border-radius: .8rem; background: var(--card); color: var(--text); }
.source-unit-option.is-selected { background: color-mix(in srgb, var(--accent) 9%, var(--card)); border-color: var(--accent); }
.source-unit-option:disabled { opacity: .5; cursor: not-allowed; }
.source-unit-choice { width: .8rem; height: .8rem; border-radius: 50%; border: 2px solid currentColor; }
.source-unit-option.is-selected .source-unit-choice { box-shadow: inset 0 0 0 2px var(--card); background: currentColor; }
.source-unit-copy { min-width: 0; display: grid; gap: .15rem; }
.source-unit-copy strong, .source-unit-copy small { overflow-wrap: anywhere; }
.source-unit-copy small, .source-unit-state { color: var(--muted); font-size: .82rem; }
.v2-song-actions { gap: .5rem; flex-wrap: wrap; }