/* Dad Joke Generator stylesheet.
 *
 * Design constraints (R7.3, R7.4):
 *   - WCAG 2.1 AA contrast (>= 4.5:1 for body text, >= 3:1 for large text/UI).
 *   - Visible focus indicators on every focusable element.
 *   - 44 px minimum touch target on interactive controls.
 *   - Mobile-first; no horizontal scrolling from 320 px to 1920 px.
 *   - Keyboard operability of all controls.
 *
 * Palette is centralized in custom properties so the theme can be swapped
 * without hunting individual selectors.
 */

:root {
  color-scheme: light;

  /* Color tokens (verified against WCAG 2.1 AA contrast).
   * --color-fg on --color-bg          ≈ 16.6:1  (AAA)
   * --color-muted on --color-bg       ≈  7.0:1  (AAA)
   * --color-bg on --color-primary     ≈  6.5:1  (AAA large/normal)
   * --color-fg on --color-surface     ≈ 14.5:1  (AAA)
   * --color-bg on --color-danger      ≈  5.4:1  (AA normal, AAA large)
   * --color-focus  used as 3 px outline (non-text contrast >= 3:1)
   */
  --color-bg: #ffffff;
  --color-surface: #f5f7fa;
  --color-fg: #111827;          /* near-black */
  --color-muted: #4b5563;       /* slate-600 */
  --color-border: #9ca3af;      /* slate-400 */
  --color-primary: #1d4ed8;     /* blue-700 */
  --color-primary-hover: #1e40af;
  --color-primary-fg: #ffffff;
  --color-danger: #b91c1c;      /* red-700 */
  --color-danger-bg: #fef2f2;
  --color-focus: #f59e0b;       /* amber-500, high-contrast against blue/white */

  /* Spacing & radius */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --radius: 0.375rem;

  /* Typography */
  --font-stack: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue",
    Arial, sans-serif;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --line-height: 1.5;

  /* Touch target floor */
  --control-min-size: 44px;
}

@media (prefers-color-scheme: dark) {
  :root {
    color-scheme: dark;
    --color-bg: #0b1020;
    --color-surface: #111733;
    --color-fg: #f3f4f6;
    --color-muted: #cbd5e1;
    --color-border: #6b7280;
    --color-primary: #60a5fa;
    --color-primary-hover: #93c5fd;
    --color-primary-fg: #0b1020;
    --color-danger: #fca5a5;
    --color-danger-bg: #3f1d1d;
    --color-focus: #fbbf24;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background-color: var(--color-bg);
  color: var(--color-fg);
  font-family: var(--font-stack);
  font-size: var(--font-size-base);
  line-height: var(--line-height);
}

body {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

.skip-link {
  position: absolute;
  left: -9999px;
  top: var(--space-2);
  background: var(--color-primary);
  color: var(--color-primary-fg);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius);
  text-decoration: none;
  z-index: 100;
}

.skip-link:focus {
  left: var(--space-2);
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.site-header,
.site-main,
.site-footer {
  width: 100%;
  max-width: 720px;
  margin: 0 auto;
  padding: var(--space-4);
}

.site-main {
  flex: 1 1 auto;
}

.site-title {
  margin: 0 0 var(--space-1);
  font-size: var(--font-size-xl);
}

.site-tagline {
  margin: 0;
  color: var(--color-muted);
}

/* --- Ad slot --------------------------------------------------------- */
/* When ad_module is disabled it adds no children and reserves no space
 * (R8.3). The :empty pseudo-class collapses the slot completely. */
.ad-slot:empty {
  display: none;
}

.ad-slot {
  margin-bottom: var(--space-4);
  max-height: 250px;     /* R8.2 */
  overflow: hidden;
}

/* --- Form ------------------------------------------------------------ */

.joke-form {
  background-color: var(--color-surface);
  padding: var(--space-5);
  border-radius: var(--radius);
}

.form-row {
  margin-bottom: var(--space-4);
}

.form-row:last-child {
  margin-bottom: 0;
}

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: var(--space-2);
}

.form-hint {
  display: block;
  font-weight: 400;
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-top: var(--space-1);
}

.form-input {
  display: block;
  width: 100%;
  min-height: var(--control-min-size);
  padding: var(--space-2) var(--space-3);
  font-size: var(--font-size-base);
  font-family: inherit;
  color: var(--color-fg);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.form-input:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-color: var(--color-primary);
}

.form-input[aria-invalid="true"] {
  border-color: var(--color-danger);
}

.form-error {
  margin: var(--space-2) 0 0;
  color: var(--color-danger);
  font-size: 0.95rem;
}

.form-actions {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--control-min-size);
  min-width: var(--control-min-size);
  padding: var(--space-2) var(--space-5);
  font-size: var(--font-size-base);
  font-weight: 600;
  font-family: inherit;
  border: 2px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
}

.btn-primary {
  background-color: var(--color-primary);
  color: var(--color-primary-fg);
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
}

.btn:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.55;
  cursor: not-allowed;
}

/* --- Progress indicator --------------------------------------------- */

.progress {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--color-muted);
}

.progress[hidden] {
  display: none;
}

.spinner {
  width: 1.25rem;
  height: 1.25rem;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* --- Remaining badge ------------------------------------------------ */

.remaining-row {
  margin-top: var(--space-2);
}

.remaining-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  font-size: 0.95rem;
}

.remaining-badge[hidden] {
  display: none;
}

.remaining-label {
  color: var(--color-muted);
}

.remaining-count {
  font-weight: 700;
  color: var(--color-fg);
}

/* --- Result --------------------------------------------------------- */

.result {
  margin-top: var(--space-5);
}

.error-message {
  background-color: var(--color-danger-bg);
  color: var(--color-danger);
  border: 1px solid var(--color-danger);
  border-radius: var(--radius);
  padding: var(--space-3) var(--space-4);
  margin: 0 0 var(--space-4);
}

.error-message[hidden] {
  display: none;
}

.joke-display {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-5);
}

.joke-display[hidden] {
  display: none;
}

.joke-text {
  margin: 0 0 var(--space-4);
  font-size: var(--font-size-lg);
}

.audio-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.audio-controls[hidden] {
  display: none;
}

.joke-audio {
  display: block;
  width: 100%;
  min-height: var(--control-min-size);
}

.btn-secondary {
  align-self: flex-start;
  background-color: var(--color-bg);
  color: var(--color-fg);
  border-color: var(--color-border);
}

.btn-secondary:hover:not(:disabled) {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* --- Footer --------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--color-border);
  margin-top: var(--space-6);
  color: var(--color-muted);
  font-size: 0.9rem;
}

.footer-note {
  margin: 0;
}