*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #FAFAF8;
  --text: #1A1A18;
  --border: #E0DBD4;
  --muted: #9A958F;
  --progress-h: 2px;
}

html, body {
  height: 100%;
}

body {
  font-family: 'Space Grotesk', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
}

/* ── Progress bar ── */

.progress-track {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--progress-h);
  background: var(--border);
  z-index: 100;
}

.progress-fill {
  height: 100%;
  background: var(--text);
  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  width: 0%;
}

/* ── Form wrapper ── */

.form-wrapper {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 80px 24px 120px;
}

/* ── Steps ── */

.step {
  display: none;
  width: 100%;
  max-width: 640px;
}

.step.active {
  display: block;
  animation: stepIn 0.35s cubic-bezier(0.4, 0, 0.2, 1) both;
}

@keyframes stepIn {
  from { opacity: 0; transform: translateY(12px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Question number ── */

.q-number {
  display: block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.18em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 18px;
}

/* ── Headings ── */

h1 {
  font-size: clamp(42px, 7vw, 68px);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.025em;
  margin-bottom: 28px;
}

h2 {
  font-size: clamp(24px, 3.5vw, 34px);
  font-weight: 700;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 32px;
}

/* ── Intro step ── */

.intro-description {
  font-size: 17px;
  line-height: 1.65;
  color: var(--muted);
  margin-bottom: 52px;
  max-width: 480px;
}

/* ── Fields ── */

.field-group {
  margin-bottom: 32px;
}

.field-group label {
  display: block;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--muted);
  text-transform: uppercase;
  margin-bottom: 10px;
}

input[type="text"],
input[type="email"] {
  width: 100%;
  font-family: inherit;
  font-size: 18px;
  font-weight: 400;
  color: var(--text);
  background: transparent;
  border: none;
  border-bottom: 1.5px solid var(--border);
  padding: 10px 0 12px;
  outline: none;
  transition: border-color 0.2s;
  border-radius: 0;
}

input[type="text"]:focus,
input[type="email"]:focus {
  border-bottom-color: var(--text);
}

input::placeholder {
  color: var(--border);
}

input.error {
  border-bottom-color: #B94040;
}

/* ── Textarea ── */

textarea {
  width: 100%;
  font-family: inherit;
  font-size: 17px;
  line-height: 1.7;
  color: var(--text);
  background: transparent;
  border: 1.5px solid var(--border);
  border-radius: 2px;
  padding: 20px 22px;
  outline: none;
  resize: vertical;
  min-height: 172px;
  transition: border-color 0.2s;
}

textarea:focus {
  border-color: var(--text);
}

textarea::placeholder {
  color: var(--muted);
  font-style: italic;
  font-weight: 400;
}

/* ── Image pairs ── */

.image-step h2 {
  margin-bottom: 12px;
}

.pair-progress {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 24px;
  letter-spacing: 0.04em;
}

.image-pair {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

.image-option {
  position: relative;
  cursor: pointer;
  border: 2.5px solid transparent;
  border-radius: 3px;
  overflow: hidden;
  aspect-ratio: 3 / 4;
  transition: border-color 0.2s ease, opacity 0.25s ease;
  outline: none;
}

.image-option:focus-visible {
  border-color: var(--muted);
}

.image-option img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.3s ease;
}

.image-option:hover img {
  transform: scale(1.02);
}

.image-option.selected {
  border-color: var(--text);
}

.image-option.dimmed {
  opacity: 0.35;
}

.image-check {
  position: absolute;
  bottom: 12px;
  right: 12px;
  width: 34px;
  height: 34px;
  background: var(--text);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  transform: scale(0.6);
  transition: opacity 0.2s ease, transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  pointer-events: none;
}

.image-check svg {
  width: 16px;
  height: 16px;
  color: var(--bg);
}

.image-option.selected .image-check {
  opacity: 1;
  transform: scale(1);
}

/* ── Binary options (Q9) ── */

.binary-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.binary-option {
  padding: 26px 28px;
  border: 1.5px solid var(--border);
  border-radius: 3px;
  cursor: pointer;
  transition: border-color 0.2s, background 0.2s, color 0.2s;
  outline: none;
}

.binary-option:hover {
  border-color: var(--muted);
}

.binary-option:focus-visible {
  border-color: var(--text);
}

.binary-option.selected {
  border-color: var(--text);
  background: var(--text);
  color: var(--bg);
}

.binary-label {
  display: block;
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 6px;
}

.binary-desc {
  display: block;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.55;
}

.binary-option.selected .binary-desc {
  color: rgba(250, 250, 248, 0.6);
}

/* ── Thanks step ── */

.thanks-step h2 {
  font-size: clamp(42px, 7vw, 68px);
  margin-bottom: 20px;
}

.thanks-step p {
  font-size: 18px;
  color: var(--muted);
  line-height: 1.65;
}

/* ── Footer navigation ── */

.form-footer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 40px;
  background: var(--bg);
  border-top: 1px solid var(--border);
  z-index: 50;
}

.form-footer.hidden {
  display: none;
}

.btn-back {
  display: flex;
  align-items: center;
  gap: 7px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  color: var(--muted);
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px 0;
  transition: color 0.2s, opacity 0.2s;
  letter-spacing: 0.02em;
}

.btn-back svg {
  width: 17px;
  height: 17px;
  flex-shrink: 0;
}

.btn-back:hover:not(:disabled) {
  color: var(--text);
}

.btn-back:disabled {
  opacity: 0;
  pointer-events: none;
}

.btn-next {
  font-family: inherit;
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--bg);
  background: var(--text);
  border: none;
  cursor: pointer;
  padding: 15px 36px;
  border-radius: 2px;
  transition: opacity 0.2s;
}

.btn-next:hover {
  opacity: 0.8;
}

.btn-next:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.btn-next.hidden {
  visibility: hidden;
  pointer-events: none;
}

/* ── Responsive ── */

@media (max-width: 600px) {
  .form-wrapper {
    align-items: flex-start;
    padding: 80px 20px 110px;
  }

  .image-pair {
    gap: 10px;
  }

  .form-footer {
    padding: 16px 20px;
  }

  .binary-option {
    padding: 20px 20px;
  }
}