.customization-page {
  min-height: 100vh;
  background:
    radial-gradient(circle at 88% 3%, color-mix(in srgb, var(--lime) 26%, transparent), transparent 25%),
    var(--canvas);
}

.customization-topbar {
  display: flex;
  min-height: 72px;
  align-items: center;
  justify-content: space-between;
  padding: 0 4vw;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.customization-topbar .brand {
  color: var(--ink);
}

.customization-topbar nav {
  display: flex;
  gap: 8px;
}

.customization-topbar nav a {
  padding: 8px 11px;
  color: var(--muted);
  font-size: 10px;
  font-weight: 750;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 7px;
}

.customization-topbar nav a:hover {
  color: var(--green-dark);
  background: var(--paper);
}

.customization-shell {
  width: min(1180px, 92vw);
  margin: 0 auto;
  padding: 52px 0 76px;
}

.customization-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(280px, 0.75fr);
  gap: 8vw;
  align-items: end;
  margin-bottom: 36px;
}

.customization-hero h1 {
  margin: 8px 0 0;
  font-family: var(--display);
  font-size: clamp(42px, 5.6vw, 76px);
  font-weight: 450;
  letter-spacing: -0.055em;
  line-height: 0.96;
}

.customization-hero > p {
  margin: 0 0 5px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.75;
}

.customization-layout {
  display: grid;
  grid-template-columns: minmax(360px, 0.9fr) minmax(390px, 1.1fr);
  gap: 20px;
  align-items: start;
}

.customization-controls {
  display: grid;
  gap: 14px;
}

.customization-panel,
.customization-preview {
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.customization-panel {
  margin: 0;
  padding: 22px;
}

.customization-panel-heading {
  display: flex;
  align-items: center;
  gap: 11px;
  margin-bottom: 18px;
}

.customization-panel-heading > span {
  display: grid;
  width: 32px;
  height: 32px;
  flex: 0 0 auto;
  place-items: center;
  color: var(--nav);
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 850;
  background: var(--lime);
  border-radius: 50%;
}

.customization-panel-heading p,
.customization-panel-heading h2 {
  margin: 0;
}

.customization-panel-heading h2 {
  font-size: 17px;
  line-height: 1.25;
}

.color-control-row,
.range-heading,
.customization-actions,
.preview-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.color-field {
  display: flex;
  align-items: center;
  gap: 11px;
  color: var(--muted);
  font-size: 10px;
  font-weight: 750;
}

.color-field input {
  width: 54px;
  height: 40px;
  padding: 3px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: 7px;
  cursor: pointer;
}

#themeColorValue,
#brightnessValue {
  color: var(--green-dark);
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 800;
}

.color-presets {
  display: flex;
  gap: 10px;
  margin-top: 16px;
}

.color-presets button {
  width: 30px;
  height: 30px;
  padding: 0;
  background: var(--preset-color);
  border: 3px solid var(--paper);
  border-radius: 50%;
  box-shadow: 0 0 0 1px var(--line);
  cursor: pointer;
}

.color-presets button.selected {
  box-shadow: 0 0 0 2px var(--ink);
}

.range-heading {
  color: var(--muted);
  font-size: 9px;
  font-weight: 700;
}

#brightness {
  width: 100%;
  margin: 13px 0 5px;
  accent-color: var(--green);
}

.control-help {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 9px;
  line-height: 1.55;
}

.explanation-panel {
  display: grid;
  gap: 9px;
  border: 1px solid var(--line);
}

.explanation-panel .customization-panel-heading {
  margin-bottom: 8px;
}

.explanation-choice {
  display: grid;
  grid-template-columns: 18px 1fr;
  gap: 10px;
  align-items: start;
  padding: 12px;
  background: var(--canvas);
  border: 1px solid var(--line);
  border-radius: 8px;
  cursor: pointer;
}

.explanation-choice:has(input:checked) {
  background: var(--green-soft);
  border-color: var(--green);
}

.explanation-choice input {
  margin: 3px 0 0;
  accent-color: var(--green);
}

.explanation-choice strong,
.explanation-choice small {
  display: block;
}

.explanation-choice strong {
  font-size: 11px;
}

.explanation-choice small {
  margin-top: 2px;
  color: var(--muted);
  font-size: 9px;
  line-height: 1.45;
}

.customization-actions {
  margin-top: 3px;
}

.customization-actions .button {
  flex: 1;
}

.customization-status {
  min-height: 19px;
  margin: 0;
  color: var(--muted);
  font-size: 9px;
  text-align: center;
}

.customization-preview {
  position: sticky;
  top: 18px;
  padding: 20px;
}

.preview-window {
  overflow: hidden;
  background: var(--canvas);
  border: 1px solid var(--line);
  border-radius: 10px;
}

.preview-window-bar {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 11px 13px;
  color: color-mix(in srgb, white 68%, var(--nav));
  background: var(--nav);
}

.preview-window-bar span {
  width: 8px;
  height: 8px;
  background: var(--lime);
  border-radius: 50%;
}

.preview-window-bar span:nth-child(2) { opacity: 0.67; }
.preview-window-bar span:nth-child(3) { opacity: 0.38; }

.preview-window-bar strong {
  margin-left: 6px;
  font-size: 9px;
}

.preview-window-body {
  min-height: 450px;
  padding: clamp(28px, 5vw, 50px);
}

.preview-window-body h2 {
  max-width: 420px;
  margin: 8px 0 16px;
  font-family: var(--display);
  font-size: clamp(30px, 4vw, 46px);
  font-weight: 500;
  letter-spacing: -0.04em;
  line-height: 1.03;
}

.preview-window-body > p:not(.section-kicker) {
  color: var(--muted);
  font-size: 11px;
}

.preview-code {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 10px;
  margin: 24px 0 12px;
  padding: 14px;
  color: #dce7e0;
  background: var(--nav);
  border-radius: 7px;
}

.preview-code span {
  color: var(--nav-muted);
  font-family: var(--mono);
  font-size: 9px;
}

.preview-code code {
  overflow-wrap: anywhere;
  font-size: 10px;
}

.preview-detail {
  margin-bottom: 20px;
  padding: 13px;
  background: var(--green-soft);
  border-left: 3px solid var(--green);
}

.preview-detail strong {
  font-size: 10px;
}

.preview-detail p {
  margin: 3px 0 0;
  color: var(--muted);
  font-size: 9px;
}

.preview-summary {
  justify-content: flex-start;
  margin-top: 16px;
  padding: 2px 3px;
}

.preview-swatch {
  width: 34px;
  height: 34px;
  background: var(--green);
  border: 5px solid var(--green-soft);
  border-radius: 50%;
}

.preview-summary strong,
.preview-summary p {
  display: block;
  margin: 0;
}

.preview-summary strong { font-size: 10px; }
.preview-summary p { color: var(--muted); font-size: 9px; }

html[data-explanation-level="concise"] .customization-preview .preview-extra,
html[data-explanation-level="concise"] .customization-preview .preview-detail {
  display: none;
}

html[data-explanation-level="balanced"] .customization-preview .preview-detail {
  display: none;
}

@media (max-width: 820px) {
  .customization-layout,
  .customization-hero {
    grid-template-columns: 1fr;
  }

  .customization-preview {
    position: static;
    grid-row: 1;
  }
}

@media (max-width: 560px) {
  .customization-topbar {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
    padding: 16px 5vw;
  }

  .customization-topbar nav {
    width: 100%;
    overflow-x: auto;
  }

  .customization-shell { padding-top: 36px; }
  .customization-hero h1 { font-size: 43px; }
  .customization-actions { align-items: stretch; flex-direction: column-reverse; }
  .customization-actions .button { width: 100%; }
  .preview-window-body { min-height: 390px; padding: 30px 22px; }
}