:root {
  color-scheme: light;
  --color-bg: #ffffff;
  --color-text: #1a1a1a;
  --color-muted: #555555;
  --color-accent: #2563eb;
  --color-border: #d4d4d4;
  --font-size-base: 20px;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: 'Open Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Arial, sans-serif;
  font-size: var(--font-size-base);
  line-height: 1.5;
}

#placeholder {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  text-align: center;
  padding: 2rem;
}

#jspsych-target {
  max-width: 900px;
  margin: 0 auto;
}

button {
  font-size: 1rem;
  font-family: inherit;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  background: var(--color-accent);
  color: #ffffff;
  cursor: pointer;
}

button:disabled {
  background: var(--color-border);
  color: var(--color-muted);
  cursor: not-allowed;
}

button:hover:not(:disabled) {
  filter: brightness(1.08);
}

p {
  max-width: 640px;
  margin: 0 auto 1rem auto;
}

/* IAT trial layout: category labels pinned to top corners, stimulus centered. */
.iat-trial {
  position: relative;
  min-height: 60vh;
  display: flex;
  align-items: center;
  justify-content: center;
}

.iat-label {
  position: fixed;
  top: 1.5rem;
  font-weight: 700;
  font-size: 1.1rem;
  text-align: center;
  line-height: 1.3;
  color: var(--color-text);
}

.iat-label-left {
  left: 1.5rem;
  text-align: left;
}

.iat-label-right {
  right: 1.5rem;
  text-align: right;
}

.iat-center {
  text-align: center;
}

.iat-stimulus-word {
  font-size: 2.5rem;
  font-weight: 600;
}

.iat-error-x {
  margin-top: 1rem;
  font-size: 3rem;
  font-weight: 700;
  color: #dc2626;
}

.iat-instructions p {
  text-align: left;
}

.iat-continue-prompt {
  font-weight: 700;
  margin-top: 1.5rem;
}

/* Generic vanilla screens: consent, eligibility, gates, demographics, behavioral choice,
   completion, dead ends. */
.screen {
  max-width: 720px;
  margin: 2rem auto;
  padding: 0 1.5rem;
}

.screen-actions {
  display: flex;
  gap: 1rem;
  justify-content: center;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

button.secondary {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.consent-checkbox {
  display: block;
  margin: 1.5rem auto;
  max-width: 640px;
  text-align: left;
}

.consent-checkbox input {
  margin-right: 0.5rem;
}

.app-form {
  max-width: 640px;
  margin: 0 auto;
  text-align: left;
}

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

.form-field label,
.form-field-label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.4rem;
}

.form-field select,
.form-field input[type='number'] {
  font-size: 1rem;
  font-family: inherit;
  padding: 0.5rem 0.75rem;
  border-radius: 8px;
  border: 1px solid var(--color-border);
  width: 100%;
  max-width: 320px;
}

.radio-option {
  display: inline-block;
  font-weight: 400;
  margin-right: 1.5rem;
}

.radio-option input {
  margin-right: 0.4rem;
}

.screen-keytest-prompt {
  font-size: 2rem;
  font-weight: 700;
  text-align: center;
}

.sd-error-text {
  color: #dc2626;
  font-weight: 600;
}

/* SD-II video + rating page. */
.sd-video-wrap {
  max-width: 640px;
  margin: 0 auto 1rem auto;
}

.sd-video {
  width: 100%;
  height: auto;
  background: #000;
  border-radius: 8px;
}

.sd-rating-form {
  max-width: 720px;
  margin: 1.5rem auto 0 auto;
  text-align: left;
}

.sd-rating-hidden {
  display: none;
}

.sd-rating-table {
  margin-top: 1rem;
}

.sd-rating-row {
  display: grid;
  grid-template-columns: minmax(110px, 1fr) auto minmax(110px, 1fr);
  align-items: center;
  gap: 0.75rem;
  padding: 0.6rem 0.5rem;
}

.sd-rating-row:nth-child(odd) {
  background: #f5f5f5;
}

.sd-endpoint-label {
  font-weight: 600;
  font-size: 0.95rem;
}

.sd-endpoint-left {
  text-align: right;
}

.sd-endpoint-right {
  text-align: left;
}

.sd-scale {
  display: flex;
  gap: 0.4rem;
  justify-content: center;
}

.sd-scale-btn {
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 50%;
  border: 2px solid var(--color-border);
  background: #ffffff;
}

.sd-scale-btn.selected {
  background: var(--color-accent);
  border-color: var(--color-accent);
}

/* Blocking busy overlay during API waits (assign, checkpoint, complete). */
.busy-overlay {
  position: fixed;
  inset: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  display: flex;
  align-items: center;
  justify-content: center;
}

.busy-box {
  text-align: center;
}

.busy-spinner {
  width: 44px;
  height: 44px;
  margin: 0 auto 1rem auto;
  border: 4px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: 50%;
  animation: busy-spin 0.9s linear infinite;
}

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