/* Sample Size Calculator — Page-Specific Styles */

/* ── Skip Link ────────────────────────────── */

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

.sr-only-focusable:focus {
  position: fixed;
  top: 0.5rem;
  left: 0.5rem;
  z-index: 100;
  width: auto;
  height: auto;
  padding: 0.75rem 1.25rem;
  margin: 0;
  overflow: visible;
  clip: auto;
  white-space: normal;
  background: var(--primary);
  color: #fff;
  font-weight: 600;
  font-size: 0.875rem;
  border-radius: var(--radius-md);
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

/* ── Page Layout ──────────────────────────── */

.calc-page {
  padding-top: 5rem;
  padding-bottom: 3rem;
}

/* ── Breadcrumb ───────────────────────────── */

.calc-breadcrumb {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.calc-breadcrumb a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
}

.calc-breadcrumb a:hover {
  text-decoration: underline;
}

/* ── Compact Hero ─────────────────────────── */

.calc-hero {
  text-align: center;
  margin-bottom: 3rem;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

.calc-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--primary);
  background: var(--primary-wash);
  padding: 0.25rem 0.75rem;
  border-radius: 2rem;
  margin-bottom: 0.75rem;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.calc-hero h1 {
  font-size: 2.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--foreground);
  margin-bottom: 0.75rem;
}

.calc-hero-sub {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

/* ── Calculator Loading / Error ───────────── */

.calc-placeholder {
  text-align: center;
  padding: 3rem 2rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.calc-error {
  color: #dc2626;
  font-weight: 500;
}

/* ── Test Selection ───────────────────────── */

.calc-test-selection {
  max-width: 680px;
  margin: 0 auto 2rem;
}

.calc-mode-toggle {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  font-size: 0.8125rem;
}

.calc-mode-label {
  color: var(--text-secondary);
  font-weight: 500;
}

.calc-toggle-btn {
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.375rem 1rem;
  border: 1.5px solid var(--primary);
  border-radius: 2rem;
  background: var(--bg);
  color: var(--primary);
  cursor: pointer;
  transition: all 0.15s;
}

.calc-toggle-btn.active {
  background: var(--primary);
  color: #fff;
}

.calc-toggle-link {
  font-family: inherit;
  font-size: 0.8125rem;
  color: var(--primary);
  background: none;
  border: none;
  cursor: pointer;
  text-decoration: underline;
  padding: 0;
}

/* ── Flowchart ───────────────────────────── */

.calc-breadcrumb-step {
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 0.625rem 1rem;
  margin-bottom: 0.5rem;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.calc-breadcrumb-label {
  font-weight: 500;
}

.calc-breadcrumb-change {
  font-family: inherit;
  font-size: 0.75rem;
  color: var(--primary);
  background: none;
  border: none;
  cursor: pointer;
  text-decoration: underline;
  padding: 0;
}

.calc-flowchart-step {
  background: var(--primary-wash);
  border: 1px solid rgba(13, 148, 136, 0.2);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
  margin-bottom: 1rem;
}

.calc-flowchart-question {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 1.25rem;
}

.calc-flowchart-options {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
  max-width: 480px;
  margin: 0 auto;
}

.calc-flowchart-separator {
  height: 1px;
  background: rgba(13, 148, 136, 0.15);
  margin: 0.375rem 0;
}

.calc-flowchart-btn {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  text-align: left;
  font-family: inherit;
  padding: 0.75rem 1rem;
  border: 1.5px solid var(--primary);
  border-radius: var(--radius-md);
  background: var(--bg);
  color: var(--foreground);
  cursor: pointer;
  transition: all 0.15s;
}

.calc-flowchart-btn:hover {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.calc-flowchart-btn:hover .calc-flowchart-btn-clarifier {
  color: rgba(255, 255, 255, 0.85);
}

.calc-flowchart-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.calc-flowchart-btn-label {
  font-size: 0.875rem;
  font-weight: 600;
  line-height: 1.3;
}

.calc-flowchart-btn-clarifier {
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.4;
  margin-top: 0.125rem;
}

/* ── Test Confirmation ───────────────────── */

.calc-test-confirmation {
  background: #F0FDF4;
  border: 1px solid #86EFAC;
  border-radius: var(--radius-lg);
  padding: 1.25rem 1.5rem;
  text-align: center;
  margin-bottom: 1rem;
}

.calc-test-confirmation-icon {
  font-size: 1.5rem;
  color: #166534;
  margin-bottom: 0.25rem;
}

.calc-test-confirmation h3 {
  font-size: 1rem;
  color: #166534;
  margin-bottom: 0.375rem;
}

.calc-test-confirmation p {
  font-size: 0.8125rem;
  color: #15803D;
}

/* ── Direct Dropdown ─────────────────────── */

.calc-direct-select {
  margin-bottom: 1rem;
}

.calc-direct-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 0.5rem;
}

.calc-select {
  width: 100%;
  font-family: inherit;
  font-size: 0.9375rem;
  padding: 0.625rem 1rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--bg);
  color: var(--foreground);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1.5L6 6.5L11 1.5' stroke='%23475569' stroke-width='1.5' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  padding-right: 2.5rem;
}

.calc-select:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* ── Calculator Form ─────────────────────── */

.calc-form {
  max-width: 580px;
  margin: 0 auto 2rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.calc-form-heading {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--foreground);
  margin-bottom: 1.5rem;
  text-align: center;
}

.calc-field {
  margin-bottom: 1.25rem;
}

.calc-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 0.375rem;
}

.calc-label-small {
  display: block;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 0.25rem;
}

.calc-field-help {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.calc-field-warning {
  font-size: 0.75rem;
  color: #dc2626;
  margin-top: 0.25rem;
}

.calc-input {
  width: 100%;
  font-family: inherit;
  font-size: 0.9375rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--foreground);
}

.calc-input:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 1px;
}

.calc-input-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.calc-input-group .calc-input {
  max-width: 120px;
}

.calc-input-suffix {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ── Presets ──────────────────────────────── */

.calc-presets {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.calc-preset-btn {
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.375rem 0.875rem;
  border: 1.5px solid var(--border);
  border-radius: 2rem;
  background: var(--bg);
  color: var(--foreground);
  cursor: pointer;
  transition: all 0.15s;
}

.calc-preset-btn.active {
  border-color: var(--primary);
  background: var(--primary-wash);
  color: var(--primary);
  font-weight: 600;
}

.calc-preset-btn:hover {
  border-color: var(--primary);
}

.calc-preset-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.calc-methodology-note {
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-style: italic;
  margin-bottom: 0.75rem;
  line-height: 1.4;
}

.calc-effect-input {
  margin-bottom: 0.5rem;
}

.calc-help-link {
  font-size: 0.75rem;
  margin-top: 0.25rem;
}

.calc-help-link a {
  color: var(--primary);
  text-decoration: none;
}

.calc-help-link a:hover {
  text-decoration: underline;
}

/* ── Segmented Buttons ───────────────────── */

.calc-segmented {
  display: flex;
  flex-wrap: wrap;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: var(--bg);
}

.calc-seg-btn {
  flex: 1;
  min-width: 0;
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 500;
  padding: 0.5rem 0.5rem;
  border: none;
  border-right: 1px solid var(--border);
  background: var(--bg);
  color: var(--foreground);
  cursor: pointer;
  transition: all 0.15s;
  text-align: center;
  white-space: nowrap;
}

.calc-seg-btn:last-child {
  border-right: none;
}

.calc-seg-btn.active {
  background: var(--primary);
  color: #fff;
  font-weight: 600;
}

.calc-seg-btn:hover:not(.active) {
  background: var(--primary-wash);
}

.calc-seg-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: -2px;
  z-index: 1;
}

/* ── Advanced Options ────────────────────── */

.calc-advanced {
  margin-top: 0.5rem;
  margin-bottom: 1.25rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.calc-advanced-summary {
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0.75rem 1rem;
  cursor: pointer;
  background: var(--bg);
  list-style: none;
}

.calc-advanced-summary::-webkit-details-marker {
  display: none;
}

.calc-advanced-summary::before {
  content: '\25B6';
  display: inline-block;
  margin-right: 0.5rem;
  font-size: 0.625rem;
  transition: transform 0.15s;
}

.calc-advanced[open] .calc-advanced-summary::before {
  transform: rotate(90deg);
}

.calc-advanced-content {
  padding: 0 1rem 1rem;
}

/* ── Submit Button ───────────────────────── */

.calc-submit-btn {
  display: block;
  width: 100%;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 700;
  padding: 0.875rem 2rem;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: background 0.15s;
}

.calc-submit-btn:hover {
  background: var(--primary-hover);
}

.calc-submit-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

/* ── Animal Study Form ───────────────────── */

.calc-animal-header {
  margin-bottom: 1.25rem;
}

.calc-animal-note {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  line-height: 1.5;
  background: var(--primary-wash);
  border: 1px solid rgba(13, 148, 136, 0.15);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
}

/* ── Results Panel ───────────────────────── */

.calc-results {
  max-width: 580px;
  margin: 0 auto 2rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 2rem;
}

.calc-results-error {
  border-color: #FCA5A5;
  background: #FEF2F2;
}

.calc-results-heading {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--foreground);
  margin-bottom: 1.25rem;
  text-align: center;
}

.calc-result-primary {
  display: flex;
  justify-content: center;
  gap: 3rem;
  margin-bottom: 1rem;
}

.calc-result-value {
  text-align: center;
}

.calc-result-n {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--foreground);
  line-height: 1.1;
}

.calc-result-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-top: 0.25rem;
}

.calc-result-label em {
  font-style: italic;
}

.calc-result-note {
  font-size: 0.75rem;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 0.75rem;
}

.calc-result-note em {
  font-style: italic;
}

.calc-result-achieved {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 0.5rem;
}

.calc-result-adjusted {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 0.5rem;
}

.calc-result-adjusted em {
  font-style: italic;
}

.calc-result-warning {
  font-size: 0.8125rem;
  color: #B45309;
  background: #FFFBEB;
  border: 1px solid #FDE68A;
  border-radius: var(--radius-sm);
  padding: 0.5rem 0.75rem;
  margin-top: 0.75rem;
}

.calc-formula-details {
  margin-top: 0.75rem;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.calc-formula-details summary {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 0.5rem 0.75rem;
  cursor: pointer;
  background: var(--bg);
}

.calc-formula-text {
  font-size: 0.8125rem;
  color: var(--foreground);
  padding: 0.75rem;
  font-family: 'DM Sans', system-ui, sans-serif;
  line-height: 1.5;
  word-break: break-word;
}

/* ── Results Details (Power Curve + APA) ─── */

.calc-results-details {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-top: 1.25rem;
  margin-bottom: 1rem;
}

.calc-section-heading {
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 0.5rem;
}

/* ── SVG Power Curve ────────────────────────── */

.calc-power-curve-container {
  min-height: 200px;
}

.calc-power-curve-svg {
  width: 100%;
  height: auto;
  min-height: 200px;
  font-family: 'DM Sans', system-ui, sans-serif;
}

/* ── APA Snippet ────────────────────────────── */

.calc-apa-container {
  display: flex;
  flex-direction: column;
}

.calc-apa-snippet {
  font-size: 0.8125rem;
  color: var(--foreground);
  line-height: 1.6;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem;
  margin-bottom: 0.5rem;
  transition: background-color 0.3s ease;
}

.calc-apa-snippet-highlight {
  background-color: var(--primary-wash);
}

/* ── Copy Button ────────────────────────────── */

.calc-copy-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.375rem 1rem;
  border: 1.5px solid var(--primary);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--primary);
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
  align-self: flex-start;
}

.calc-copy-btn:hover {
  background: var(--primary-wash);
}

.calc-copy-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.calc-copy-btn-success {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}

.calc-copy-btn-small {
  font-size: 0.75rem;
  padding: 0.25rem 0.75rem;
  margin-top: 0.5rem;
}

.calc-formula-content {
  padding: 0.75rem;
}

.calc-formula-content .calc-formula-text {
  padding: 0;
}

/* ── Loading / Disabled State ───────────────── */

.calc-submit-btn:disabled,
.calc-submit-btn-loading {
  opacity: 0.65;
  cursor: not-allowed;
}

/* ── Large-N Warning ────────────────────────── */

.calc-result-large-n {
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.5;
  margin-top: 0.5rem;
}

/* ── Cohen Caveat ───────────────────────────── */

.calc-result-caveat {
  color: var(--text-secondary);
  font-style: italic;
  line-height: 1.5;
}

/* ── CTA Section ────────────────────────────── */

.calc-cta {
  max-width: 580px;
  margin: 0 auto 2rem;
  text-align: center;
  padding: 2rem;
  background: var(--primary-wash);
  border: 1px solid rgba(13, 148, 136, 0.2);
  border-radius: var(--radius-lg);
}

.calc-cta-heading {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--foreground);
  margin-bottom: 0.5rem;
}

.calc-cta-subtitle {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 0.75rem;
  line-height: 1.5;
}

.calc-cta-value-prop {
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
  line-height: 1.5;
}

.calc-cta-buttons {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.calc-cta-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 700;
  text-decoration: none;
}

.calc-cta-secondary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.75rem 1.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
}

.btn-outline {
  background: var(--bg);
  color: var(--primary);
  border: 1.5px solid var(--primary);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.15s;
}

.btn-outline:hover {
  background: var(--primary-wash);
}

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

/* ── F7: Feedback ────────────────────────── */

.calc-feedback {
  margin-top: 2.5rem;
  padding: 2rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

.calc-feedback-heading {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 1rem;
}

.calc-feedback-rating {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.calc-feedback-btn {
  padding: 0.625rem 1.25rem;
  font-size: 0.9375rem;
  font-weight: 500;
  font-family: inherit;
  color: var(--text-secondary);
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all 0.15s;
}

.calc-feedback-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-wash);
}

.calc-feedback-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.calc-feedback-confirmation {
  margin-top: 0.5rem;
}

.calc-feedback-thanks {
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.5rem;
}

.calc-feedback-expand-link {
  color: var(--text-secondary);
  font-size: 0.875rem;
  text-decoration: underline;
  text-underline-offset: 2px;
  cursor: pointer;
}

.calc-feedback-expand-link:hover {
  color: var(--primary);
}

.calc-feedback-panel {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}

.calc-feedback-categories {
  border: none;
  padding: 0;
  margin: 0 0 1rem 0;
}

.calc-feedback-category-legend {
  font-weight: 600;
  font-size: 0.9375rem;
  color: var(--foreground);
  margin-bottom: 0.625rem;
}

.calc-feedback-category-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.25rem 0;
  font-size: 0.875rem;
  color: var(--text-secondary);
  cursor: pointer;
}

.calc-feedback-category-label input[type="radio"] {
  accent-color: var(--primary);
}

.calc-feedback-text-group {
  margin-bottom: 0.75rem;
}

.calc-feedback-text-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--foreground);
  margin-bottom: 0.375rem;
}

.calc-feedback-textarea {
  width: 100%;
  padding: 0.75rem;
  font-size: 0.875rem;
  font-family: inherit;
  color: var(--foreground);
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  resize: vertical;
  min-height: 5rem;
  transition: border-color 0.15s;
  box-sizing: border-box;
}

.calc-feedback-textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.1);
}

.calc-feedback-email-group {
  margin-bottom: 1rem;
}

.calc-feedback-email-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--text-secondary);
  margin-bottom: 0.375rem;
}

.calc-feedback-email-input {
  width: 100%;
  padding: 0.625rem 0.75rem;
  font-size: 0.875rem;
  font-family: inherit;
  color: var(--foreground);
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: var(--radius-md);
  transition: border-color 0.15s;
  box-sizing: border-box;
}

.calc-feedback-email-input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.1);
}

.calc-feedback-submit-row {
  display: flex;
  justify-content: flex-start;
}

.calc-feedback-submit {
  font-size: 0.875rem;
  padding: 0.625rem 1.5rem;
}

.calc-feedback-submit:disabled {
  opacity: 0.7;
  cursor: not-allowed;
}

.calc-feedback-error {
  margin-top: 0.75rem;
  padding: 0.75rem;
  font-size: 0.8125rem;
  color: #dc2626;
  background: #fef2f2;
  border: 1px solid #fecaca;
  border-radius: var(--radius-md);
}

.calc-feedback-error a {
  color: #dc2626;
  font-weight: 500;
}

/* ── F8: Educational Content ─────────────── */

.calc-educational {
  margin-top: 3rem;
}

.calc-educational-heading {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--foreground);
  margin-bottom: 1.5rem;
}

.calc-edu-section {
  margin-bottom: 1rem;
}

.calc-edu-section details {
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.calc-edu-section summary {
  padding: 1rem 1.25rem;
  font-size: 1rem;
  font-weight: 600;
  color: var(--foreground);
  background: var(--bg);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: background 0.15s;
}

.calc-edu-section summary::-webkit-details-marker {
  display: none;
}

.calc-edu-section summary::before {
  content: "\25B6";
  font-size: 0.625rem;
  color: var(--text-secondary);
  transition: transform 0.2s;
  flex-shrink: 0;
}

.calc-edu-section details[open] > summary::before {
  transform: rotate(90deg);
}

.calc-edu-section summary:hover {
  background: var(--bg-subtle);
}

.calc-edu-section .calc-edu-body {
  padding: 1.25rem;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--text-secondary);
  border-top: 1px solid var(--border);
}

.calc-edu-section .calc-edu-body p {
  margin-bottom: 0.75rem;
}

.calc-edu-section .calc-edu-body p:last-child {
  margin-bottom: 0;
}

.calc-edu-section .calc-edu-body h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--foreground);
  margin-top: 1.25rem;
  margin-bottom: 0.5rem;
}

.calc-edu-section .calc-edu-body h3:first-child {
  margin-top: 0;
}

.calc-edu-section .calc-edu-body ul,
.calc-edu-section .calc-edu-body ol {
  margin: 0.5rem 0 0.75rem 1.25rem;
}

.calc-edu-section .calc-edu-body li {
  margin-bottom: 0.375rem;
}

.calc-edu-section .calc-edu-body a {
  color: var(--primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.calc-edu-section .calc-edu-body a:hover {
  color: var(--primary-hover);
}

.calc-edu-section .calc-edu-body .edu-citation {
  font-style: italic;
  color: var(--text-secondary);
  font-size: 0.8125rem;
}

.calc-edu-section .calc-edu-body .edu-table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.75rem 0;
  font-size: 0.875rem;
}

.calc-edu-section .calc-edu-body .edu-table th,
.calc-edu-section .calc-edu-body .edu-table td {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  text-align: left;
}

.calc-edu-section .calc-edu-body .edu-table th {
  background: var(--bg-subtle);
  font-weight: 600;
  color: var(--foreground);
}

/* Highlighted first section ("How to Choose an Effect Size") */
.calc-edu-highlighted details {
  border-left: 3px solid var(--primary);
}

.calc-edu-highlighted summary {
  background: var(--primary-wash);
}

.calc-edu-highlighted .calc-edu-badge {
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--primary);
  background: var(--bg);
  padding: 0.125rem 0.5rem;
  border-radius: 999px;
  border: 1px solid var(--primary);
  flex-shrink: 0;
  margin-left: auto;
}

/* ── F11: Share Buttons ────────────────────── */

.calc-share {
  margin-top: 1.25rem;
  padding: 1rem 1.25rem;
  background: var(--bg-subtle);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
}

.calc-share-heading {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--foreground);
  margin-bottom: 0.75rem;
}

.calc-share-buttons {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  align-items: center;
}

.calc-share-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  font-family: inherit;
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.375rem 0.875rem;
  border: 1.5px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--bg);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
  text-decoration: none;
  line-height: 1.4;
}

.calc-share-btn:hover {
  border-color: var(--primary);
  color: var(--primary);
  background: var(--primary-wash);
}

.calc-share-btn:focus-visible {
  outline: 2px solid var(--primary);
  outline-offset: 2px;
}

.calc-share-btn-success {
  border-color: var(--primary);
  background: var(--primary);
  color: #fff;
}

.calc-share-btn svg {
  flex-shrink: 0;
}

.calc-share-feedback {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-top: 0.375rem;
  min-height: 1rem;
}

/* ── Responsive ───────────────────────────── */

@media (max-width: 768px) {
  .calc-page {
    padding-top: 4.5rem;
    padding-bottom: 2rem;
  }

  .calc-hero h1 {
    font-size: 1.75rem;
  }

  .calc-hero-sub {
    font-size: 1rem;
  }

  .calc-hero {
    margin-bottom: 2rem;
  }

  .calc-form {
    padding: 1.25rem;
  }

  .calc-results {
    padding: 1.25rem;
  }

  .calc-result-primary {
    gap: 1.5rem;
  }

  .calc-result-n {
    font-size: 2rem;
  }

  .calc-flowchart-options {
    max-width: 100%;
  }

  .calc-seg-btn {
    font-size: 0.75rem;
    padding: 0.375rem 0.25rem;
  }

  .calc-results-details {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .calc-power-curve-container {
    min-height: 200px;
  }

  .calc-cta {
    padding: 1.5rem;
  }

  .calc-cta-heading {
    font-size: 1.25rem;
  }

  .calc-cta-buttons {
    flex-direction: column;
    align-items: center;
  }

  .calc-cta-primary,
  .calc-cta-secondary {
    width: 100%;
    text-align: center;
  }

  .calc-feedback {
    padding: 1.25rem;
  }

  .calc-feedback-rating {
    gap: 0.5rem;
  }

  .calc-feedback-btn {
    flex: 1;
    padding: 0.5rem 0.75rem;
    font-size: 0.875rem;
  }

  .calc-educational {
    margin-top: 2rem;
  }

  .calc-educational-heading {
    font-size: 1.25rem;
  }

  .calc-edu-section summary {
    padding: 0.875rem 1rem;
    font-size: 0.9375rem;
  }

  .calc-edu-section .calc-edu-body {
    padding: 1rem;
    font-size: 0.875rem;
  }

  .calc-edu-section .calc-edu-body .edu-table {
    font-size: 0.8125rem;
  }

  .calc-edu-section .calc-edu-body .edu-table th,
  .calc-edu-section .calc-edu-body .edu-table td {
    padding: 0.375rem 0.5rem;
  }

  .calc-share {
    padding: 0.875rem 1rem;
  }

  .calc-share-buttons {
    gap: 0.375rem;
  }
}

@media (max-width: 375px) {
  .calc-hero h1 {
    font-size: 1.5rem;
  }

  .calc-presets {
    display: grid;
    grid-template-columns: 1fr 1fr;
  }

  .calc-segmented {
    flex-wrap: wrap;
  }

  .calc-seg-btn {
    flex: 0 0 auto;
    min-width: 33%;
  }

  .calc-flowchart-btn {
    width: 100%;
  }

  .calc-result-n {
    font-size: 1.75rem;
  }

  .calc-power-curve-svg {
    min-height: 180px;
  }

  .calc-cta {
    padding: 1.25rem;
  }

  .calc-cta-heading {
    font-size: 1.125rem;
  }

  .calc-feedback {
    padding: 1rem;
  }

  .calc-feedback-heading {
    font-size: 1rem;
  }

  .calc-feedback-rating {
    flex-direction: column;
  }

  .calc-feedback-btn {
    width: 100%;
  }

  .calc-share-buttons {
    flex-direction: column;
  }

  .calc-share-btn {
    width: 100%;
    justify-content: center;
  }
}

/* ── Reduced Motion ──────────────────────── */

@media (prefers-reduced-motion: reduce) {
  .calc-copy-btn,
  .calc-share-btn,
  .calc-submit-btn,
  .calc-flowchart-btn,
  .calc-preset-btn,
  .calc-seg-btn,
  .calc-feedback-btn,
  .calc-cta-primary,
  .calc-cta-secondary,
  .btn-outline {
    transition: none;
  }

  .calc-apa-snippet {
    transition: none;
  }
}