:root {
  color-scheme: light dark;
  --ui-background: #f5f5f7;
  --ui-surface: #ffffff;
  --ui-material: rgba(250, 250, 252, 0.88);
  --ui-label: #1d1d1f;
  --ui-secondary-label: #5f5f64;
  --ui-tertiary-label: #737378;
  --ui-separator: rgba(60, 60, 67, 0.2);
  --ui-opaque-separator: #d2d2d7;
  --ui-fill: rgba(120, 120, 128, 0.12);
  --ui-fill-strong: rgba(120, 120, 128, 0.2);
  --ui-accent: #007aff;
  --ui-accent-pressed: #0066d6;
  --ui-selection: rgba(0, 122, 255, 0.1);
  --ui-shadow: rgba(0, 0, 0, 0.12);
  --ui-track: #c7c7cc;

  --ink: var(--ui-label);
  --muted: var(--ui-secondary-label);
  --paper: var(--ui-background);
  --card: var(--ui-surface);
  --line: var(--ui-separator);
  --player-red: var(--ui-accent);
}

html { font-size: 16px; }
body {
  color: var(--ui-label);
  background: var(--ui-background);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", "PingFang SC", sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}
button,
input,
select { color: var(--ui-label); }

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

/* App chrome */
.app-header {
  border-bottom-color: var(--ui-separator);
  background: var(--ui-material);
  box-shadow: 0 1px 0 rgba(255, 255, 255, 0.46);
  -webkit-backdrop-filter: saturate(180%) blur(22px);
  backdrop-filter: saturate(180%) blur(22px);
}
.app-header-inner {
  width: min(1120px, calc(100% - 48px));
  min-height: 64px;
  grid-template-columns: 1fr;
  justify-items: center;
}
.wordmark { gap: 10px; }
.wordmark-badge {
  width: 30px;
  height: 30px;
  border: 0;
  border-radius: 8px;
  background: linear-gradient(145deg, #45a4ff, var(--ui-accent));
  color: white;
  font-family: inherit;
  font-size: 0.625rem;
  font-weight: 750;
  letter-spacing: -0.01em;
  box-shadow: inset 0 0 0 0.5px rgba(255, 255, 255, 0.35), 0 1px 3px rgba(0, 84, 180, 0.24);
}
.wordmark-copy { font-family: inherit; font-size: 0.875rem; font-weight: 650; letter-spacing: -0.01em; }
.header-note { color: var(--ui-tertiary-label); font-family: inherit; font-size: 0.75rem; letter-spacing: 0; }
.top-tabs {
  align-self: center;
  justify-self: center;
  height: 34px;
  padding: 3px;
  gap: 2px;
  border: 0;
  border-radius: 10px;
  background: var(--ui-fill);
}
.top-tab {
  min-width: 96px;
  min-height: 28px;
  padding: 0 14px;
  gap: 7px;
  border: 0;
  border-radius: 8px;
  color: var(--ui-secondary-label);
  font-size: 0.8125rem;
  font-weight: 550;
  transition: background-color 140ms ease, color 140ms ease, box-shadow 140ms ease;
}
.top-tab:last-child { border: 0; }
.top-tab small {
  display: inline;
  min-width: 0;
  height: auto;
  padding: 0;
  border: 0;
  border-radius: 0;
  font-family: inherit;
  font-size: 0.6875rem;
  font-variant-numeric: tabular-nums;
  opacity: 0.7;
}
.top-tab[aria-selected="true"] {
  background: var(--ui-surface);
  color: var(--ui-label);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12), inset 0 0 0 0.5px rgba(0, 0, 0, 0.04);
}
.top-tab:hover:not([aria-selected="true"]) { background: var(--ui-fill); color: var(--ui-label); }
.top-tab:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--ui-accent) 65%, transparent);
  outline-offset: 2px;
}

main { width: min(1120px, calc(100% - 48px)); }

/* Knowledge view, brought into the same platform-native system. */
.search-box {
  border-color: var(--ui-separator);
  border-radius: 12px;
  background: var(--ui-surface);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.03);
}
.search-box:focus-within {
  border-color: var(--ui-accent);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--ui-accent) 18%, transparent);
}
.filter-chip { min-height: 32px; border-color: var(--ui-separator); color: var(--ui-secondary-label); }
.filter-chip[aria-pressed="true"],
.filter-chip:hover { border-color: var(--ui-accent); background: var(--ui-accent); color: white; }
.feed-card,
.detail-article {
  border-color: var(--ui-separator);
  background: var(--ui-surface);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.07);
}
.feed-card { border-radius: 16px; }
.feed-card:hover { box-shadow: 0 14px 38px rgba(0, 0, 0, 0.11); }
.card-title,
.detail-hero h1,
.detail-section .lead { font-family: inherit; }
.card-cover,
.detail-hero { color: #1d1d1f; }
.card-tags span,
.detail-section blockquote,
.example-block { background: var(--ui-fill); }

/* Interview working surface */
.interview-view { padding-bottom: calc(126px + env(safe-area-inset-bottom)); }
.playlist-page-header {
  display: flex;
  min-height: 144px;
  align-items: flex-end;
  justify-content: space-between;
  gap: 48px;
  padding: 34px 0 26px;
  border-bottom: 1px solid var(--ui-separator);
}
.audio-eyebrow {
  display: block;
  color: var(--ui-accent);
  font-family: inherit;
  font-size: 0.75rem;
  font-weight: 650;
  letter-spacing: 0;
}
.audio-eyebrow::before { display: none; }
.playlist-title-block h1 {
  margin: 8px 0 7px;
  font-family: inherit;
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 750;
  line-height: 1.04;
  letter-spacing: -0.045em;
}
.playlist-title-block p {
  margin: 0;
  color: var(--ui-secondary-label);
  font-size: 0.875rem;
  line-height: 1.5;
}
.audio-stats {
  display: flex;
  min-width: 390px;
  justify-content: flex-end;
  margin: 0;
  border: 0;
}
.audio-stats div { min-width: 118px; padding: 0 20px; border-left: 1px solid var(--ui-separator); }
.audio-stats div:last-child { padding-right: 0; }
.audio-stats dt { color: var(--ui-secondary-label); font-size: 0.6875rem; letter-spacing: 0; }
.audio-stats dd {
  margin: 5px 0 0;
  color: var(--ui-label);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 650;
  font-variant-numeric: tabular-nums;
}

.playlist-heading {
  display: grid;
  width: 100%;
  min-height: 52px;
  align-items: end;
  grid-template-columns: minmax(0, 1fr) 160px;
  margin: 24px 0 0;
  padding: 0 14px 10px;
  border-bottom: 1px solid var(--ui-opaque-separator);
}
.playlist-heading h2 { margin: 0; font-family: inherit; font-size: 1.25rem; font-weight: 700; letter-spacing: -0.02em; }
.playlist-column-labels {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 50px;
  gap: 14px;
  color: var(--ui-secondary-label);
  font-size: 0.6875rem;
}
.playlist-column-labels span:last-child { text-align: right; }
.audio-list {
  display: block;
  width: 100%;
  margin: 0;
  border-bottom: 1px solid var(--ui-separator);
}
.playlist-item {
  overflow: visible;
  border: 0;
  border-bottom: 1px solid var(--ui-separator);
  border-radius: 0;
  background: transparent;
  transition: background-color 120ms ease;
}
.playlist-item:last-child { border-bottom: 0; }
.playlist-item:nth-child(even) { background: color-mix(in srgb, var(--ui-fill) 38%, transparent); }
.playlist-item:hover { border-color: var(--ui-separator); background: var(--ui-fill); transform: none; }
.playlist-item.is-current { border-color: var(--ui-separator); background: var(--ui-selection); }
.track-button {
  display: grid;
  width: 100%;
  min-height: 66px;
  align-items: center;
  grid-template-columns: 34px minmax(0, 1fr) 160px;
  gap: 12px;
  padding: 8px 14px;
  border: 0;
  border-radius: 0;
  background: transparent;
  cursor: pointer;
  text-align: left;
}
.track-button:focus-visible {
  position: relative;
  z-index: 1;
  outline: 3px solid color-mix(in srgb, var(--ui-accent) 70%, transparent);
  outline-offset: -3px;
}
.track-play-icon {
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  border: 0;
  border-radius: 50%;
  color: var(--ui-secondary-label);
  font-size: 0.6875rem;
  font-variant-numeric: tabular-nums;
}
.playlist-item:hover .track-play-icon { color: var(--ui-label); }
.playlist-item.is-current .track-play-icon { background: var(--ui-accent); color: white; }
.playlist-item.is-playing .track-play-icon { box-shadow: 0 0 0 4px color-mix(in srgb, var(--ui-accent) 13%, transparent); }
.track-copy { display: block; min-width: 0; }
.track-copy small {
  display: block;
  margin-bottom: 3px;
  overflow: hidden;
  color: var(--ui-secondary-label);
  font-family: inherit;
  font-size: 0.6875rem;
  letter-spacing: 0;
  text-overflow: ellipsis;
  text-transform: none;
  white-space: nowrap;
}
.track-copy strong {
  display: block;
  overflow: hidden;
  color: var(--ui-label);
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.playlist-item.is-current .track-copy strong { color: var(--ui-accent); }
.track-copy > span {
  display: block;
  margin-top: 3px;
  overflow: hidden;
  color: var(--ui-secondary-label);
  font-size: 0.75rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.track-meta {
  display: grid;
  min-width: 0;
  align-items: center;
  grid-template-columns: minmax(0, 1fr) 50px;
  gap: 14px;
  justify-items: end;
  color: var(--ui-secondary-label);
}
.track-meta small,
.track-meta strong { font-family: inherit; font-size: 0.6875rem; font-weight: 450; font-variant-numeric: tabular-nums; }

.transcript-disclosure { border-top: 1px dashed var(--ui-separator); background: transparent; }
.transcript-disclosure > summary {
  display: flex;
  min-height: 40px;
  align-items: center;
  justify-content: space-between;
  padding: 8px 14px 8px 60px;
  color: var(--ui-accent);
  font-size: 0.75rem;
  font-weight: 550;
  letter-spacing: 0;
}
.transcript-disclosure > summary::after { color: var(--ui-accent); }
.transcript-disclosure > summary:focus-visible { outline: 3px solid color-mix(in srgb, var(--ui-accent) 70%, transparent); outline-offset: -3px; }
.transcript-body { max-width: 850px; padding: 5px 60px 30px; border-top: 0; }
.transcript-body h3 { margin: 20px 0 8px; color: var(--ui-label); font-size: 0.75rem; letter-spacing: 0; }
.transcript-body p { color: var(--ui-label); font-size: 0.9375rem; line-height: 1.75; }
.transcript-followup { border-top-color: var(--ui-separator); }

/* Persistent playback controls use a material layer above scrolling content. */
.now-playing {
  position: fixed;
  right: 0;
  bottom: 0;
  left: 0;
  z-index: 50;
  display: grid;
  width: 100%;
  min-height: 94px;
  margin: 0;
  padding: 10px max(24px, calc((100vw - 1120px) / 2)) calc(10px + env(safe-area-inset-bottom));
  overflow: visible;
  align-items: center;
  grid-template-columns: minmax(230px, 1fr) minmax(360px, 1.35fr) minmax(260px, 1fr);
  gap: clamp(22px, 4vw, 56px);
  border: 0;
  border-top: 1px solid var(--ui-separator);
  border-radius: 0;
  background: var(--ui-material);
  color: var(--ui-label);
  box-shadow: 0 -8px 30px var(--ui-shadow);
  -webkit-backdrop-filter: saturate(180%) blur(24px);
  backdrop-filter: saturate(180%) blur(24px);
}
.player-track-info { display: grid; min-width: 0; align-items: center; grid-template-columns: 42px minmax(0, 1fr); gap: 12px; }
.player-cover-number {
  display: grid;
  width: 42px;
  height: 42px;
  place-items: center;
  border: 0;
  border-radius: 9px;
  background: var(--ui-fill-strong);
  color: var(--ui-label);
  font-family: inherit;
  font-size: 0.75rem;
  font-weight: 650;
  line-height: 1;
  letter-spacing: 0;
  font-variant-numeric: tabular-nums;
}
.now-playing.is-playing .player-cover-number { animation: none; background: var(--ui-accent); color: white; }
.player-track-copy { min-width: 0; }
.player-cover-topic {
  display: block;
  overflow: hidden;
  color: var(--ui-secondary-label);
  font-family: inherit;
  font-size: 0.6875rem;
  letter-spacing: 0;
  text-overflow: ellipsis;
  text-transform: none;
  white-space: nowrap;
}
.player-track-copy strong {
  display: block;
  margin-top: 3px;
  overflow: hidden;
  color: var(--ui-label);
  font-size: 0.8125rem;
  font-weight: 600;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.player-track-copy p {
  margin: 2px 0 0;
  overflow: hidden;
  color: var(--ui-secondary-label);
  font-size: 0.6875rem;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.player-main { display: grid; min-width: 0; gap: 7px; }
.transport-controls { display: flex; align-items: center; justify-content: center; gap: 14px; }
.transport-controls button {
  display: grid;
  width: 32px;
  height: 32px;
  place-items: center;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--ui-label);
  cursor: pointer;
}
.transport-controls button:hover:not(:disabled) { background: var(--ui-fill); }
.transport-controls button:focus-visible { outline: 3px solid color-mix(in srgb, var(--ui-accent) 65%, transparent); outline-offset: 2px; }
.transport-controls button:disabled { cursor: default; opacity: 0.28; }
.transport-controls button svg { width: 18px; height: 18px; fill: currentColor; stroke: currentColor; stroke-linejoin: round; stroke-width: 1.2; }
.transport-controls .player-toggle {
  width: 40px;
  height: 40px;
  background: var(--ui-label);
  color: var(--ui-surface);
  box-shadow: none;
}
.transport-controls .player-toggle:hover:not(:disabled) { background: var(--ui-accent); color: white; }
.player-toggle .pause-glyph { display: none; }
.now-playing.is-playing .player-toggle .play-glyph { display: none; }
.now-playing.is-playing .player-toggle .pause-glyph { display: block; }
.player-progress-row {
  display: grid;
  align-items: center;
  grid-template-columns: 42px minmax(0, 1fr) 42px;
  gap: 8px;
  color: var(--ui-secondary-label);
  font-family: inherit;
  font-size: 0.6875rem;
  font-variant-numeric: tabular-nums;
}
.player-progress-row span:last-child { text-align: right; }
.player-progress-row input,
.volume-control input {
  width: 100%;
  height: 18px;
  margin: 0;
  padding: 0;
  appearance: none;
  background: transparent;
  cursor: pointer;
}
.player-progress-row input::-webkit-slider-runnable-track,
.volume-control input::-webkit-slider-runnable-track {
  height: 4px;
  border-radius: 999px;
  background: linear-gradient(to right, var(--ui-accent) 0 var(--range-progress, 0%), var(--ui-track) var(--range-progress, 0%) 100%);
}
.player-progress-row input::-moz-range-track,
.volume-control input::-moz-range-track { height: 4px; border: 0; border-radius: 999px; background: var(--ui-track); }
.player-progress-row input::-moz-range-progress,
.volume-control input::-moz-range-progress { height: 4px; border-radius: 999px; background: var(--ui-accent); }
.player-progress-row input::-webkit-slider-thumb,
.volume-control input::-webkit-slider-thumb {
  width: 12px;
  height: 12px;
  margin-top: -4px;
  appearance: none;
  border: 0;
  border-radius: 50%;
  background: var(--ui-surface);
  box-shadow: 0 0 0 0.5px rgba(0, 0, 0, 0.25), 0 1px 3px rgba(0, 0, 0, 0.24);
}
.player-progress-row input::-moz-range-thumb,
.volume-control input::-moz-range-thumb { width: 12px; height: 12px; border: 0; border-radius: 50%; background: var(--ui-surface); }
.player-progress-row input:focus-visible,
.volume-control input:focus-visible { outline: 3px solid color-mix(in srgb, var(--ui-accent) 60%, transparent); outline-offset: 2px; border-radius: 4px; }
.player-side { display: flex; min-width: 0; align-items: center; justify-content: flex-end; gap: 20px; }
.player-position { color: var(--ui-secondary-label); font-family: inherit; font-size: 0.6875rem; font-variant-numeric: tabular-nums; }
.player-options { display: flex; align-items: center; gap: 18px; }
.player-options label { display: flex; align-items: center; gap: 7px; color: var(--ui-secondary-label); font-size: 0.6875rem; letter-spacing: 0; }
.player-options select {
  min-height: 28px;
  padding: 3px 24px 3px 8px;
  border: 1px solid var(--ui-separator);
  border-radius: 7px;
  background-color: var(--ui-surface);
  color: var(--ui-label);
  font-size: 0.75rem;
}
.player-options select:focus-visible { outline: 3px solid color-mix(in srgb, var(--ui-accent) 60%, transparent); outline-offset: 2px; }
.volume-control svg { width: 17px; height: 17px; fill: none; stroke: currentColor; stroke-linecap: round; stroke-linejoin: round; stroke-width: 1.7; }
.volume-control input { width: 76px; }
#playlist-audio { display: none; }

@media (max-width: 820px) {
  .interview-view { padding-bottom: calc(158px + env(safe-area-inset-bottom)); }
  .playlist-page-header { display: block; min-height: 0; padding: 28px 2px 22px; }
  .playlist-title-block h1 { font-size: 2.125rem; }
  .playlist-title-block p { max-width: 520px; margin-top: 8px; }
  .audio-stats { min-width: 0; justify-content: flex-start; margin-top: 22px; }
  .audio-stats div { min-width: 0; flex: 1; padding: 0 14px; }
  .audio-stats div:first-child { padding-left: 0; border-left: 0; }
  .playlist-heading { margin-top: 18px; }
  .now-playing {
    min-height: 138px;
    padding: 10px 16px calc(10px + env(safe-area-inset-bottom));
    grid-template-columns: minmax(0, 1fr) auto;
    grid-template-rows: auto auto;
    gap: 8px 16px;
  }
  .player-track-info { grid-column: 1; grid-row: 1; }
  .player-main { grid-column: 1 / -1; grid-row: 2; gap: 6px; }
  .player-side { grid-column: 2; grid-row: 1; }
  .player-position,
  .volume-control { display: none; }
  .transport-controls { gap: 18px; }
  .transport-controls button,
  .transport-controls .player-toggle { width: 44px; height: 44px; }
  .transcript-disclosure > summary { min-height: 44px; }
}

@media (max-width: 640px) {
  .app-header-inner { width: calc(100% - 24px); min-height: 64px; grid-template-columns: 1fr; }
  .top-tabs { justify-self: center; height: 50px; padding: 3px; border: 0; }
  .top-tab { min-width: 84px; min-height: 44px; padding: 0 12px; border: 0; }
  main { width: calc(100% - 32px); }
  .playlist-page-header { padding-top: 24px; }
  .playlist-title-block h1 { font-size: 2rem; }
  .playlist-title-block p { font-size: 0.8125rem; }
  .audio-stats div { padding: 0 10px; }
  .audio-stats dt { font-size: 0.6875rem; }
  .audio-stats dd { font-size: 0.75rem; }
  .playlist-heading { min-height: 48px; grid-template-columns: minmax(0, 1fr) 64px; padding-right: 8px; padding-left: 8px; }
  .playlist-heading h2 { font-size: 1.125rem; }
  .playlist-column-labels { display: block; text-align: right; }
  .playlist-column-labels span:first-child { display: none; }
  .track-button { min-height: 64px; grid-template-columns: 30px minmax(0, 1fr) 54px; gap: 8px; padding: 8px; }
  .track-play-icon { width: 28px; height: 28px; }
  .track-copy strong { font-size: 0.875rem; }
  .track-copy > span { display: none; }
  .track-meta { display: block; text-align: right; }
  .track-meta small { display: none; }
  .track-meta strong { font-size: 0.6875rem; }
  .audio-list .transcript-disclosure > summary { padding-right: 8px; padding-left: 46px; }
  .audio-list .transcript-body { padding-right: 8px; padding-left: 46px; }
  .transcript-body p { font-size: 0.9375rem; }
  .player-track-info { grid-template-columns: 38px minmax(0, 1fr); gap: 10px; }
  .player-cover-number { width: 38px; height: 38px; border-radius: 8px; }
  .player-track-copy p { display: none; }
  .control-label { display: none; }
  .player-options select { min-height: 44px; }
  .player-progress-row input { height: 28px; }
}

@media (prefers-color-scheme: dark) {
  :root {
    --ui-background: #000000;
    --ui-surface: #242426;
    --ui-material: rgba(28, 28, 30, 0.9);
    --ui-label: #f5f5f7;
    --ui-secondary-label: #c7c7cc;
    --ui-tertiary-label: #a1a1a6;
    --ui-separator: rgba(84, 84, 88, 0.68);
    --ui-opaque-separator: #38383a;
    --ui-fill: rgba(120, 120, 128, 0.2);
    --ui-fill-strong: rgba(120, 120, 128, 0.3);
    --ui-accent: #0a84ff;
    --ui-accent-pressed: #409cff;
    --ui-selection: rgba(10, 132, 255, 0.2);
    --ui-shadow: rgba(0, 0, 0, 0.45);
    --ui-track: #48484a;
  }
  .app-header { box-shadow: 0 1px 0 rgba(255, 255, 255, 0.04); }
  .top-tab[aria-selected="true"] { box-shadow: 0 1px 4px rgba(0, 0, 0, 0.36), inset 0 0 0 0.5px rgba(255, 255, 255, 0.08); }
  .playlist-item:nth-child(even) { background: rgba(255, 255, 255, 0.025); }
  .feed-card,
  .detail-article { box-shadow: 0 8px 28px rgba(0, 0, 0, 0.34); }
  .player-progress-row input::-webkit-slider-thumb,
  .volume-control input::-webkit-slider-thumb { box-shadow: 0 0 0 0.5px rgba(255, 255, 255, 0.18), 0 1px 4px rgba(0, 0, 0, 0.6); }
}

@media (prefers-contrast: more) {
  :root { --ui-separator: currentColor; --ui-selection: color-mix(in srgb, var(--ui-accent) 25%, transparent); }
  .top-tab,
  .filter-chip,
  .track-button,
  .transport-controls button,
  .player-options select { font-weight: 650; }
}

@media (prefers-reduced-transparency: reduce) {
  .app-header,
  .now-playing {
    background: var(--ui-surface);
    -webkit-backdrop-filter: none;
    backdrop-filter: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .playlist-item,
  .top-tab { transition: none; }
}