:root {
  --color-primary: #4F46E5;
  --color-primary-hover: #4338CA;
  --color-primary-light: #EEF0FF;
  --color-accent: #F5A623;
  --color-bg: #F6F6FB;
  --color-surface: #FFFFFF;
  --color-border: #E5E7EB;
  --color-text: #16151F;
  --color-text-muted: #6B7280;
  --color-error: #DC2626;
  --color-error-light: #FEF2F2;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --radius-full: 999px;
  --shadow-card: 0 1px 3px rgba(22, 21, 31, 0.06), 0 12px 32px rgba(22, 21, 31, 0.06);
  --font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ---- App shell ---- */

.qf-app {
  max-width: 640px;
  margin: 0 auto;
  padding: 40px 20px 80px;
}

@media (min-width: 720px) {
  .qf-app {
    padding: 64px 20px 96px;
  }
}

.qf-header {
  margin-bottom: 24px;
}

.qf-title {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 12px;
}

.qf-intro {
  color: var(--color-text-muted);
  font-size: 15px;
  line-height: 1.6;
  margin: 0;
}

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

.qf-progress-bar {
  position: sticky;
  top: 0;
  z-index: 10;
  margin: 0 -20px 28px;
  padding: 16px 20px;
  background: rgba(246, 246, 251, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border);
}

.qf-progress-track {
  height: 6px;
  border-radius: var(--radius-full);
  background: var(--color-border);
  overflow: hidden;
  margin-bottom: 14px;
}

.qf-progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), #7C7AFF);
  border-radius: var(--radius-full);
  transition: width 0.35s ease;
}

.qf-progress {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 10px;
  padding: 0;
}

.qf-progress__step {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 7px 14px;
  border-radius: var(--radius-full);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  font-size: 12.5px;
  font-weight: 600;
  white-space: nowrap;
}

.qf-progress__number {
  font-variant-numeric: tabular-nums;
  opacity: 0.7;
}

.qf-progress__step.is-active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(79, 70, 229, 0.3);
}

.qf-progress__step.is-active .qf-progress__number {
  opacity: 0.85;
}

.qf-progress__step.is-complete {
  background: var(--color-primary-light);
  border-color: transparent;
  color: var(--color-primary);
}

.qf-progress__label {
  color: var(--color-text-muted);
  font-size: 13px;
  font-weight: 600;
  margin: 0;
}

/* ---- Step / section ---- */

.qf-section-title {
  font-size: 20px;
  font-weight: 800;
  margin: 8px 0 24px;
}

.qf-form {
  margin-top: 28px;
}

/* ---- Fields ---- */

.qf-field {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-bottom: 16px;
  box-shadow: var(--shadow-card);
  transition: border-color 0.2s ease;
}

.qf-field__label {
  display: block;
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 6px;
}

.qf-field__help {
  color: var(--color-text-muted);
  font-size: 13px;
  font-style: italic;
  margin: 0 0 12px;
}

.qf-field__input {
  width: 100%;
  padding: 12px 14px;
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  color: var(--color-text);
  font-family: inherit;
  font-size: 15px;
  margin-top: 10px;
  transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

textarea.qf-field__input {
  resize: vertical;
  min-height: 96px;
}

.qf-field__input:focus {
  outline: none;
  border-color: var(--color-primary);
  background: var(--color-surface);
  box-shadow: 0 0 0 4px var(--color-primary-light);
}

.qf-field__error {
  color: var(--color-error);
  font-size: 13px;
  font-weight: 600;
  margin: 10px 0 0;
}

.qf-field.has-error {
  border-color: var(--color-error);
}

.qf-field.has-error .qf-field__input {
  border-color: var(--color-error);
}

/* ---- Options (single / multi select) ---- */

.qf-options {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}

.qf-option {
  position: relative;
}

.qf-option__label {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 9px 16px;
  border-radius: var(--radius-full);
  border: 1.5px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease, transform 0.1s ease;
  user-select: none;
}

.qf-option__label input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
  pointer-events: none;
}

.qf-option:hover .qf-option__label {
  border-color: var(--color-primary);
}

.qf-option:has(input:checked) .qf-option__label {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}

.qf-option:has(input:checked) .qf-option__label::before {
  content: "✓";
  font-weight: 800;
}

.qf-option:has(input:focus-visible) .qf-option__label {
  box-shadow: 0 0 0 3px var(--color-primary-light);
}

.qf-field__other-input {
  display: block;
  width: 100%;

  margin-top: 10px;
  padding: 10px 12px;
  border: 1.5px dashed var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-bg);
  font-family: inherit;
  font-size: 14px;
}

.qf-field__other-input:focus {
  outline: none;
  border-style: solid;
  border-color: var(--color-primary);
}

.qf-field__other-input[hidden] {
  display: none;
}

/* ---- Two column text ---- */

.qf-field__cols {
  display: flex;
  gap: 12px;
  margin-top: 12px;
  flex-wrap: wrap;
}

.qf-field__col {
  flex: 1 1 200px;
}

.qf-field__col-label {
  display: block;
  color: var(--color-text-muted);
  font-size: 12.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  margin-bottom: 6px;
}

.qf-field__col .qf-field__input {
  margin-top: 0;
}

/* ---- Navigation ---- */

.qf-form__nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin: 28px -20px 0;
  padding: 16px 20px calc(16px + env(safe-area-inset-bottom, 0px));
  position: sticky;
  bottom: 0;
  background: rgba(246, 246, 251, 0.9);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-top: 1px solid var(--color-border);
}

.qf-btn {
  font-family: inherit;
  font-size: 15px;
  font-weight: 700;
  border-radius: var(--radius-full);
  padding: 14px 26px;
  border: none;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease, box-shadow 0.15s ease;
}

.qf-btn:active {
  transform: scale(0.98);
}

.qf-btn--prev {
  background: var(--color-surface);
  color: var(--color-text);
  border: 1.5px solid var(--color-border);
}

.qf-btn--prev:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.qf-btn--prev::before {
  content: "‹ ";
}

.qf-btn--next {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 8px 20px rgba(79, 70, 229, 0.35);
  margin-left: auto;
}

.qf-btn--next:hover {
  background: var(--color-primary-hover);
}

.qf-btn--next:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* ---- Banner ---- */

.qf-form__banner {
  margin-top: 20px;
  padding: 18px 20px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-weight: 700;
  font-size: 15px;
  text-align: center;
}

.qf-form__banner::before {
  content: "✓  ";
}

.qf-form__banner--error {
  background: var(--color-error-light);
  color: var(--color-error);
}

.qf-form__banner--error::before {
  content: "!  ";
}

/* ---- Home ---- */

.home {
  max-width: 640px;
  margin: 0 auto;
  padding: 64px 20px;
}

.home-title {
  font-size: 26px;
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 12px;
}

.home-intro {
  color: var(--color-text-muted);
  font-size: 15px;
  line-height: 1.6;
  margin: 0 0 32px;
}

.home-links {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.home-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 20px 22px;
  box-shadow: var(--shadow-card);
  text-decoration: none;
  color: var(--color-text);
  transition: border-color 0.15s ease, transform 0.1s ease;
}

.home-link:hover {
  border-color: var(--color-primary);
  transform: translateY(-1px);
}

.home-link__title {
  font-weight: 700;
  font-size: 16px;
  margin: 0 0 4px;
}

.home-link__desc {
  color: var(--color-text-muted);
  font-size: 13px;
  margin: 0;
}

.home-link__arrow {
  color: var(--color-primary);
  font-size: 20px;
  font-weight: 700;
}