:root {
  color-scheme: light;
  --font-display: "Avenir Next", "Trebuchet MS", sans-serif;
  --font-body: "Nunito Sans", "Segoe UI", sans-serif;

  --bg-0: #f6f8ff;
  --bg-1: #f0f4ff;
  --bg-2: #e7f8f7;
  --surface: rgba(255, 255, 255, 0.7);
  --surface-strong: rgba(255, 255, 255, 0.9);
  --text-main: #12233f;
  --text-muted: #486184;
  --accent: #2168e5;
  --accent-strong: #0f4bb2;
  --accent-soft: rgba(33, 104, 229, 0.14);
  --border: rgba(255, 255, 255, 0.58);
  --danger: #8e1834;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 2.75rem;

  --step--1: 0.88rem;
  --step-0: 1rem;
  --step-1: 1.2rem;
  --step-2: 1.45rem;
  --step-3: 1.85rem;
  --step-4: 2.3rem;

  --radius-sm: 0.65rem;
  --radius-md: 1rem;
  --radius-lg: 1.4rem;
  --radius-xl: 1.8rem;

  --blur-soft: 16px;
  --shadow-sm: 0 10px 22px rgba(16, 30, 57, 0.08);
  --shadow-md: 0 16px 40px rgba(16, 30, 57, 0.12);

  --content-width: 920px;
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg-0: #0f1628;
    --bg-1: #15213a;
    --bg-2: #0f2a36;
    --surface: rgba(20, 29, 49, 0.66);
    --surface-strong: rgba(23, 34, 58, 0.86);
    --text-main: #ebf1ff;
    --text-muted: #b9caeb;
    --accent: #7ab5ff;
    --accent-strong: #9ac7ff;
    --accent-soft: rgba(121, 180, 255, 0.2);
    --border: rgba(255, 255, 255, 0.12);
    --danger: #ff869e;
    --shadow-sm: 0 10px 22px rgba(7, 11, 23, 0.45);
    --shadow-md: 0 16px 40px rgba(6, 9, 19, 0.55);
  }
}

:root[data-theme="light"] {
  color-scheme: light;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg-0: #0f1628;
  --bg-1: #15213a;
  --bg-2: #0f2a36;
  --surface: rgba(20, 29, 49, 0.66);
  --surface-strong: rgba(23, 34, 58, 0.86);
  --text-main: #ebf1ff;
  --text-muted: #b9caeb;
  --accent: #7ab5ff;
  --accent-strong: #9ac7ff;
  --accent-soft: rgba(121, 180, 255, 0.2);
  --border: rgba(255, 255, 255, 0.12);
  --danger: #ff869e;
  --shadow-sm: 0 10px 22px rgba(7, 11, 23, 0.45);
  --shadow-md: 0 16px 40px rgba(6, 9, 19, 0.55);
}

* {
  box-sizing: border-box;
}

html,
body {
  min-height: 100%;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--step-0);
  line-height: 1.5;
  color: var(--text-main);
  background:
    radial-gradient(circle at 7% 4%, var(--bg-1), transparent 45%),
    radial-gradient(circle at 92% 90%, var(--bg-2), transparent 38%),
    linear-gradient(155deg, var(--bg-0), #ffffff 68%);
  padding: var(--space-4);
}

[data-enhanced="true"] .pe-fallback {
  display: none;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: var(--space-2);
  background: var(--surface-strong);
  color: var(--text-main);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  left: var(--space-3);
  z-index: 100;
}

a {
  color: var(--accent-strong);
  text-underline-offset: 0.12em;
}

.app-header,
main,
.app-footer {
  width: min(100%, var(--content-width));
  margin-inline: auto;
}

.app-header {
  display: grid;
  gap: var(--space-3);
  align-items: center;
  grid-template-columns: 1fr;
  margin-bottom: var(--space-4);
}

.brand-wrap {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: inline-flex;
  text-decoration: none;
  color: var(--text-main);
  font-family: var(--font-display);
  font-size: var(--step-2);
  font-weight: 700;
  letter-spacing: 0.01em;
}

.top-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.top-nav a,
.top-nav .is-active {
  border-radius: 999px;
  padding: var(--space-2) var(--space-3);
  text-decoration: none;
  font-weight: 700;
  color: var(--text-main);
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

.top-nav .is-active {
  color: var(--accent-strong);
  border-color: color-mix(in srgb, var(--accent) 46%, transparent);
}

.header-controls {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.card {
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface);
  backdrop-filter: blur(var(--blur-soft));
  -webkit-backdrop-filter: blur(var(--blur-soft));
  box-shadow: var(--shadow-md);
  padding: var(--space-5);
}

.surface-grid {
  display: grid;
  gap: var(--space-4);
}

.stack-sm {
  display: grid;
  gap: var(--space-2);
}

.stack-md {
  display: grid;
  gap: var(--space-4);
}

h1,
h2,
h3 {
  font-family: var(--font-display);
  line-height: 1.2;
  margin: 0;
}

h1 {
  font-size: clamp(1.7rem, 2.2vw + 1rem, var(--step-4));
}

h2 {
  font-size: var(--step-3);
}

h3 {
  font-size: var(--step-2);
}

p {
  margin: 0;
  color: var(--text-muted);
}

.ui-button,
.ui-link-button,
.ui-toggle,
.ui-select {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 42px;
  padding: 0.6rem 1rem;
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, var(--accent) 30%, transparent);
  background: var(--accent-soft);
  color: var(--text-main);
  font: inherit;
  font-weight: 700;
  text-decoration: none;
  cursor: pointer;
}

.ui-button:hover,
.ui-link-button:hover,
.ui-toggle:hover,
.ui-select:hover {
  background: color-mix(in srgb, var(--accent-soft) 72%, var(--surface) 28%);
}

.ui-button:focus-visible,
.ui-link-button:focus-visible,
.ui-toggle:focus-visible,
.ui-select:focus-visible,
.radio-item:focus-within,
a:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 2px;
}

.ui-button.primary {
  background: var(--accent);
  color: #fff;
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
}

.ui-button[disabled] {
  opacity: 0.6;
  cursor: not-allowed;
}

.ui-select {
  min-width: 110px;
  appearance: none;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

.row-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  border-radius: 999px;
  padding: 0.35rem 0.7rem;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: var(--step--1);
  font-weight: 700;
}

.quiet {
  color: var(--text-muted);
  font-size: var(--step--1);
}

.quiz-list {
  display: grid;
  gap: var(--space-3);
}

.quiz-list article {
  display: grid;
  gap: var(--space-3);
}

.question-title {
  font-size: var(--step-2);
}

.question-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.progress-wrap {
  display: grid;
  gap: var(--space-1);
}

.progress-bar {
  width: 100%;
  height: 10px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--surface-strong) 75%, var(--bg-1) 25%);
  overflow: hidden;
}

.progress-fill {
  display: block;
  height: 100%;
  border-radius: inherit;
  background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 55%, #9cd2ff));
  transition: width 180ms ease;
}

.radio-list {
  display: grid;
  gap: var(--space-2);
}

.radio-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface-strong);
  padding: var(--space-3);
  cursor: pointer;
}

.radio-item input {
  margin-top: 0.23rem;
}

.radio-item.selected {
  border-color: color-mix(in srgb, var(--accent) 40%, transparent);
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent-soft) 70%, transparent);
}

.slider-wrap {
  display: grid;
  gap: var(--space-2);
}

.slider-input {
  width: 100%;
}

.result-grid {
  display: grid;
  gap: var(--space-3);
}

.result-card-preview {
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  background: var(--surface-strong);
  padding: var(--space-4);
  display: grid;
  gap: var(--space-2);
}

.axis-bars {
  display: grid;
  gap: var(--space-2);
}

.axis-row {
  display: grid;
  gap: var(--space-1);
}

.axis-row span {
  font-size: var(--step--1);
  color: var(--text-muted);
}

.field-inline {
  display: flex;
  gap: var(--space-2);
  align-items: center;
  flex-wrap: wrap;
}

code.inline {
  padding: 0.1rem 0.35rem;
  border-radius: 0.4rem;
  background: color-mix(in srgb, var(--surface-strong) 75%, var(--bg-1) 25%);
}

.error-box {
  border-radius: var(--radius-md);
  border: 1px solid color-mix(in srgb, var(--danger) 40%, transparent);
  background: color-mix(in srgb, var(--danger) 14%, transparent);
  padding: var(--space-3);
}

.error-box p,
.error-box li {
  color: color-mix(in srgb, var(--text-main) 80%, var(--danger) 20%);
}

.app-footer {
  margin-top: var(--space-5);
  padding-bottom: var(--space-4);
  color: var(--text-muted);
}

@media (min-width: 700px) {
  body {
    padding: var(--space-5);
  }

  .app-header {
    grid-template-columns: auto 1fr auto;
    gap: var(--space-4);
  }

  .top-nav {
    justify-content: center;
  }

  .header-controls {
    justify-content: flex-end;
  }

  .surface-grid.two {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}