:root {
  color-scheme: dark;
  color: #f8fafc;
  background: #020617;
  --page: #020617;
  --panel: #0f172a;
  --panel-strong: #111827;
  --panel-soft: #02061799;
  --border: #1e293b;
  --text: #f8fafc;
  --muted: #cbd5e1;
  --dim: #94a3b8;
  --accent: #06b6d4;
  --accent-soft: #67e8f9;
  --button-text: #04131a;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

:root[data-theme="light"] {
  color-scheme: light;
  color: #0f172a;
  background: #eef2f7;
  --page: #eef2f7;
  --panel: #ffffff;
  --panel-strong: #f8fafc;
  --panel-soft: #ffffffcc;
  --border: #cbd5e1;
  --text: #0f172a;
  --muted: #334155;
  --dim: #64748b;
  --accent: #0891b2;
  --accent-soft: #0e7490;
  --button-text: #ecfeff;
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--page); }

.app-shell {
  display: grid;
  grid-template-columns: minmax(300px, 400px) minmax(0, 1fr);
  grid-template-rows: auto minmax(0, 1fr);
  gap: 20px;
  height: 100vh;
  padding: 20px;
  overflow: hidden;
}

.top-bar,
.control-card,
.viewer-card,
.export-dialog {
  border: 1px solid var(--border);
  border-radius: 28px;
  background: linear-gradient(145deg, var(--panel-strong), var(--panel));
  box-shadow: 0 24px 80px #0006;
}

.top-bar {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: 1fr auto auto;
  align-items: center;
  gap: 18px;
  padding: 16px 18px;
}

.eyebrow { margin: 0 0 8px; color: var(--accent-soft); font-size: .72rem; font-weight: 900; letter-spacing: .14em; text-transform: uppercase; }
h1, h2, h3 { margin: 0; color: var(--text); line-height: 1; }
h1 { font-size: clamp(1.6rem, 3vw, 2.4rem); letter-spacing: -.055em; }
h2 { font-size: 1.15rem; }
h3 { font-size: .95rem; }
p, li { color: var(--muted); line-height: 1.55; }
code { border: 1px solid var(--border); border-radius: 8px; background: var(--page); color: var(--accent-soft); padding: 2px 6px; }

.section-tabs { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
button { border: 0; border-radius: 999px; background: var(--accent); color: var(--button-text); cursor: pointer; font-weight: 900; padding: 12px 16px; }
.tab-button, .secondary-action, .theme-toggle, .back-button { background: #1e293b; color: #f8fafc; }
:root[data-theme="light"] .tab-button,
:root[data-theme="light"] .secondary-action,
:root[data-theme="light"] .theme-toggle,
:root[data-theme="light"] .back-button { background: #e2e8f0; color: #0f172a; }
.tab-button.is-active { background: var(--accent); color: var(--button-text); }
.theme-toggle { white-space: nowrap; }

.control-card { min-height: 0; overflow: auto; }
.customization-panel { display: grid; gap: 16px; padding: 20px; }
.panel-view { display: none; gap: 16px; }
.panel-view.is-active { display: grid; }
.customization-header { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.field-row { display: grid; grid-template-columns: 1fr auto; align-items: end; gap: 10px; }
.more-button { min-width: 74px; }

.customization-panel label,
.export-dialog label { display: grid; gap: 8px; color: var(--text); font-size: .9rem; font-weight: 900; }
.customization-panel input[type="text"],
.customization-panel select,
.export-dialog select {
  width: 100%; border: 1px solid #334155; border-radius: 12px; background: #0f172a; color: #f8fafc; font: inherit; padding: 10px 12px;
}
:root[data-theme="light"] .customization-panel input[type="text"],
:root[data-theme="light"] .customization-panel select,
:root[data-theme="light"] .export-dialog select { border-color: #cbd5e1; background: #fff; color: #0f172a; }
.customization-panel input[type="text"] { text-transform: uppercase; }
.customization-panel input[type="range"] { width: 100%; accent-color: var(--accent); }
.slider-label { display: flex; align-items: center; justify-content: space-between; gap: 12px; }
.slider-label output { min-width: 4ch; border: 1px solid #334155; border-radius: 999px; background: var(--page); color: var(--accent-soft); font-variant-numeric: tabular-nums; padding: 3px 8px; text-align: center; }
.prototype-note, .export-note { margin: 0; color: var(--dim); font-size: .86rem; }

.swatch-group, .placeholder-card, .dev-tools, .layout-calibration, .cube-export-calibration { display: grid; gap: 12px; border: 1px solid var(--border); border-radius: 18px; background: var(--panel-soft); padding: 14px; }
.swatch-row { display: flex; align-items: center; gap: 10px; width: 100%; border-radius: 14px; background: #1e293b; color: #f8fafc; text-align: left; }
label.swatch-row { display: flex; cursor: pointer; font-weight: 900; padding: 12px 16px; }
.swatch-row input[type="color"] { width: 44px; height: 32px; margin-left: auto; border: 0; border-radius: 8px; background: transparent; cursor: pointer; padding: 0; }
:root[data-theme="light"] .swatch-row { background: #e2e8f0; color: #0f172a; }
.swatch { width: 44px; height: 26px; border: 2px solid #ffffff66; border-radius: 8px; box-shadow: inset 0 0 0 1px #0004; }
.swatch.red { background: #e11d2e; }
.swatch.navy { background: #082f49; }
.swatch.white { background: #f8fafc; }
.dev-tools summary { color: var(--text); cursor: pointer; font-weight: 900; }
.dev-tools[open] summary { margin-bottom: 10px; }
.checkbox-control { display: flex !important; grid-template-columns: none; align-items: center; gap: 10px; }
.checkbox-control input { accent-color: var(--accent); }
.calibration-header { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.preset-groups, .preset-group { display: grid; gap: 8px; }
.preset-group p { margin: 0; font-size: .85rem; font-weight: 900; }
.preset-buttons { display: flex; flex-wrap: wrap; gap: 8px; }
.preset-buttons button { background: #1e293b; color: #e2e8f0; padding: 7px 10px; }
#calibrationReadout,
#cubeExportCalibrationReadout { width: 100%; min-height: 11rem; resize: vertical; border: 1px solid #334155; border-radius: 12px; background: #020617; color: #bae6fd; font: .85rem/1.45 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace; padding: 10px 12px; }

.viewer-card { display: grid; grid-template-rows: auto 1fr; min-height: 0; overflow: hidden; }
.viewer-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; border-bottom: 1px solid var(--border); padding: 18px 20px; }
.viewer-toolbar p { margin: 6px 0 0; font-size: .9rem; }
#viewer { min-height: 0; }
#viewer canvas { display: block; width: 100%; height: 100%; }

.modal-backdrop { position: fixed; inset: 0; z-index: 10; display: grid; place-items: center; background: #020617b8; padding: 20px; }
.modal-backdrop[hidden] { display: none; }
.export-dialog { display: grid; gap: 16px; width: min(480px, 100%); padding: 22px; }
.export-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }

@media (max-width: 900px) {
  .app-shell { grid-template-columns: 1fr; height: auto; min-height: 100vh; overflow: visible; padding: 14px; }
  .top-bar { grid-template-columns: 1fr; }
  .section-tabs { justify-content: stretch; }
  .section-tabs button { flex: 1 1 42%; }
  .viewer-card { min-height: min(70vh, 560px); }
}
.swatch-text { display: grid; gap: 2px; min-width: 0; }
.swatch-text strong { color: inherit; font-size: .92rem; }
.swatch-text small { color: var(--dim); font-size: .78rem; font-weight: 800; }
.swatch-row input[type="color"] { position: absolute; opacity: 0; pointer-events: none; width: 1px; height: 1px; }
.color-picker-dialog { width: min(720px, 100%); max-height: min(86vh, 760px); overflow: auto; }
.color-picker-current { display: flex; align-items: center; gap: 12px; border: 1px solid var(--border); border-radius: 16px; background: var(--panel-soft); padding: 12px; }
.color-picker-current .swatch { width: 56px; height: 38px; flex: 0 0 auto; }
.color-picker-current strong { color: var(--text); }
.color-picker-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); gap: 10px; }
.swatch-category-heading { grid-column: 1 / -1; margin: 10px 0 0; color: var(--text); font-size: .95rem; }
.swatch-search-empty { grid-column: 1 / -1; }
.swatch-card { display: grid; grid-template-columns: auto 1fr; align-items: center; gap: 10px; border: 1px solid var(--border); border-radius: 16px; background: #1e293b; color: #f8fafc; padding: 10px; text-align: left; }
.swatch-card.is-selected { border-color: var(--accent); box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 50%, transparent); }
.swatch-card-chip { width: 38px; height: 32px; border: 2px solid #ffffff66; border-radius: 10px; box-shadow: inset 0 0 0 1px #0004; }
.swatch-card-text { display: grid; gap: 3px; min-width: 0; }
.swatch-card-text small { color: var(--dim); font-size: .78rem; }
.swatch-search-control input, .custom-hex-control input { width: 100%; border: 1px solid #334155; border-radius: 12px; background: #0f172a; color: #f8fafc; font: inherit; padding: 10px 12px; text-transform: uppercase; }
.custom-hex-error { min-height: 1.2em; color: #fca5a5; font-weight: 800; }
:root[data-theme="light"] .swatch-card { background: #e2e8f0; color: #0f172a; }
:root[data-theme="light"] .swatch-search-control input, :root[data-theme="light"] .custom-hex-control input { border-color: #cbd5e1; background: #fff; color: #0f172a; }

.color-picker-dialog {
  width: min(680px, calc(100vw - 32px));
  max-height: min(82vh, 720px);
  grid-template-rows: auto auto auto minmax(150px, 1fr) auto auto;
  overflow: hidden;
  padding: 18px;
}
.color-picker-current {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  padding: 10px;
}
.color-picker-current .swatch {
  width: 64px;
  height: 44px;
  border-radius: 14px;
}
.color-picker-current-text { min-width: 0; }
.color-picker-current-text .prototype-note { margin: 3px 0 0; }
.favorite-summary-button {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  padding: 0;
  border: 1px solid #facc1540;
  background: #0f172a;
  color: #f8fafc;
  font-size: 1.15rem;
}
.favorite-summary-button.is-active { color: #facc15; border-color: #facc15aa; background: #422006; }
.swatch-picker-tools { display: grid; gap: 10px; }
.filter-chip-row { display: flex; flex-wrap: wrap; gap: 7px; }
.filter-chip {
  border: 1px solid var(--border);
  background: #111827;
  color: var(--muted);
  padding: 7px 10px;
  font-size: .78rem;
}
.filter-chip.is-active {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 22%, #111827);
  color: var(--text);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--accent) 35%, transparent);
}
.color-picker-grid {
  grid-template-columns: repeat(auto-fill, minmax(40px, 1fr));
  align-content: start;
  gap: 8px;
  overflow: auto;
  min-height: 150px;
  padding: 2px 4px 8px 2px;
}
.swatch-category-heading {
  grid-column: 1 / -1;
  margin: 8px 0 0;
  color: var(--dim);
  font-size: .72rem;
  font-weight: 950;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.swatch-card {
  position: relative;
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  min-width: 42px;
  border: 1px solid #ffffff33;
  border-radius: 13px;
  background: #020617;
  padding: 3px;
  box-shadow: 0 10px 28px #0004;
}
.swatch-card:hover,
.swatch-card:focus-visible {
  transform: translateY(-1px);
  border-color: #ffffff99;
  outline: 2px solid color-mix(in srgb, var(--accent) 60%, transparent);
  outline-offset: 2px;
}
.swatch-card.is-selected {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent), 0 12px 32px #0007;
}
.swatch-card-chip {
  width: 100%;
  height: 100%;
  border: 1px solid #ffffff66;
  border-radius: 10px;
  background: var(--swatch-color);
  box-shadow: inset 0 0 0 1px #0005;
}
.swatch-favorite-mark {
  position: absolute;
  display: none;
  place-items: center;
  pointer-events: none;
}
.swatch-card.is-favorite .swatch-favorite-mark {
  display: grid;
  right: -4px;
  top: -7px;
  color: #facc15;
  font-size: .86rem;
}
.custom-hex-control {
  border-top: 1px solid var(--border);
  padding-top: 10px;
}
.color-picker-dialog .export-actions { position: sticky; bottom: 0; background: linear-gradient(180deg, transparent, var(--panel) 28%); padding-top: 8px; }
:root[data-theme="light"] .favorite-summary-button,
:root[data-theme="light"] .filter-chip,
:root[data-theme="light"] .swatch-card { background: #f8fafc; color: #0f172a; }

:root {
  --swatch-tile-bg: #172033;
  --swatch-tile-bg-hover: #202b42;
  --swatch-tile-border: #475569;
  --swatch-selected-ring: #22d3ee;
  --swatch-light-border: #334155;
  --swatch-dark-border: #cbd5e1;
  --swatch-check-bg: #020617d9;
}

.color-picker-current .swatch {
  border-color: var(--swatch-dark-border);
  box-shadow: inset 0 0 0 1px #0007, 0 0 0 1px #ffffff22, 0 12px 32px #0007;
}
.color-picker-current .swatch.is-light-color {
  border-color: var(--swatch-light-border);
  box-shadow: inset 0 0 0 1px #0003, 0 0 0 1px #ffffff33, 0 12px 32px #0005;
}

.swatch-card {
  background:
    linear-gradient(145deg, color-mix(in srgb, var(--swatch-tile-bg) 88%, #fff 12%), var(--swatch-tile-bg));
  border-color: var(--swatch-tile-border);
  padding: 5px;
  box-shadow: inset 0 1px 0 #ffffff14, 0 10px 28px #0006;
}
.swatch-card:hover,
.swatch-card:focus-visible {
  background:
    linear-gradient(145deg, color-mix(in srgb, var(--swatch-tile-bg-hover) 86%, #fff 14%), var(--swatch-tile-bg-hover));
  border-color: #94a3b8;
  transform: translateY(-1px);
  box-shadow: inset 0 1px 0 #ffffff1f, 0 14px 34px #0008;
}
.swatch-card:focus-visible {
  outline: 2px solid var(--swatch-selected-ring);
  outline-offset: 3px;
}
.swatch-card.is-selected {
  border-color: var(--swatch-selected-ring);
  box-shadow:
    0 0 0 2px var(--swatch-selected-ring),
    0 0 0 5px color-mix(in srgb, var(--swatch-selected-ring) 18%, transparent),
    inset 0 1px 0 #ffffff1f,
    0 16px 36px #0009;
}
.swatch-card-chip {
  border-width: 2px;
  border-color: var(--swatch-dark-border);
  border-radius: 9px;
  box-shadow: inset 0 0 0 1px #0008, 0 1px 4px #0009;
}
.swatch-card.is-light-color .swatch-card-chip {
  border-color: var(--swatch-light-border);
  box-shadow: inset 0 0 0 1px #fff7, 0 1px 5px #0006;
}
.swatch-card.is-favorite .swatch-favorite-mark {
  right: -3px;
  top: -6px;
  display: grid;
  width: 16px;
  height: 16px;
  border: 1px solid #02061799;
  border-radius: 999px;
  background: #facc15;
  color: #422006;
  font-size: .68rem;
  text-shadow: none;
  box-shadow: 0 2px 8px #0009;
}

/* Task 23A visual fix: compact swatches must read as solid color chips, not UI tiles with stripes. */
.swatch-card {
  display: grid;
  grid-template-columns: none;
  grid-template-rows: none;
  place-items: center;
  width: 48px;
  height: 48px;
  min-width: 48px;
  padding: 4px;
  border: 1px solid var(--swatch-tile-border);
  border-radius: 14px;
  background: var(--swatch-tile-bg);
  box-shadow: inset 0 1px 0 #ffffff12, 0 10px 24px #0007;
  overflow: visible;
}
.swatch-card:hover,
.swatch-card:focus-visible {
  background: var(--swatch-tile-bg-hover);
  border-color: #94a3b8;
  transform: translateY(-1px);
  box-shadow: inset 0 1px 0 #ffffff20, 0 14px 30px #0009;
}
.swatch-card:focus-visible {
  outline: 2px solid var(--swatch-selected-ring);
  outline-offset: 3px;
}
.swatch-card-chip {
  display: block;
  width: 40px;
  height: 40px;
  border: 2px solid rgba(255, 255, 255, .72);
  border-radius: 11px;
  background-color: var(--swatch-color);
  background-image: none;
  opacity: 1;
  box-shadow: inset 0 0 0 1px #0008, 0 2px 6px #0008;
}
.swatch-card.is-light-color .swatch-card-chip {
  border-color: rgba(15, 23, 42, .78);
  box-shadow: inset 0 0 0 1px #fff8, 0 2px 6px #0006;
}
.swatch-card.is-selected {
  border-color: var(--swatch-selected-ring);
  box-shadow:
    0 0 0 2px var(--swatch-selected-ring),
    0 0 0 5px color-mix(in srgb, var(--swatch-selected-ring) 20%, transparent),
    inset 0 1px 0 #ffffff24,
    0 16px 34px #0009;
}
.swatch-card.is-favorite .swatch-favorite-mark {
  right: -4px;
  top: -5px;
  width: 16px;
  height: 16px;
}
.color-picker-current .swatch {
  background-image: none;
  opacity: 1;
  border: 2px solid rgba(255, 255, 255, .72);
}
.color-picker-current .swatch.is-light-color {
  border-color: rgba(15, 23, 42, .78);
}

/* Final compact swatch modal polish. */
.color-picker-dialog { gap: 12px; }
.color-picker-current { padding: 9px 10px; gap: 10px; }
.color-picker-current strong { font-size: .98rem; }
.color-picker-current-text .prototype-note { font-size: .82rem; line-height: 1.35; }
.swatch-picker-tools { gap: 7px; }
.filter-chip-row { gap: 6px; }
.filter-chip { padding: 6px 9px; }
.color-picker-grid { gap: 7px; padding-bottom: 6px; }
.swatch-category-heading { margin: 6px 0 0; }
.custom-hex-control { padding-top: 8px; }

/* Authentication is an outer access boundary; authorized users retain the existing app shell. */
[hidden] { display: none !important; }
.auth-boundary { min-height: 100vh; display: grid; place-items: center; padding: 24px; }
.auth-boundary[hidden] { display: none; }
.auth-card { width: min(100%, 420px); padding: 28px; border: 1px solid var(--border); border-radius: 18px; background: var(--panel); box-shadow: 0 24px 70px #0008; }
.auth-card h1 { margin: 4px 0 10px; }
.auth-form { display: grid; gap: 14px; margin-top: 22px; }
.auth-form label { display: grid; gap: 6px; }
.auth-actions { display: flex; gap: 10px; }
.link-action { padding: 4px 0; border: 0; background: none; color: inherit; text-align: left; text-decoration: underline; box-shadow: none; }
.generator-sign-out { position: fixed; z-index: 20; right: 18px; bottom: 18px; }