/* ===================================================================
   UK Driver Tax & Mileage Saver — style.css
   Dark mode, mobile-first, premium financial dashboard
   =================================================================== */

/* -------------------------------------------------------------------
   1. Design Tokens
   ------------------------------------------------------------------- */
:root {
  --color-bg:           #0f172a;
  --color-surface:      #1e293b;
  --color-surface-2:    #263248;
  --color-border:       #334155;
  --color-text:         #f8fafc;
  --color-text-muted:   #94a3b8;
  --color-accent:       #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-glow:  rgba(59, 130, 246, 0.35);
  --color-positive:     #22c55e;
  --color-warning:      #f59e0b;
  --color-danger:       #ef4444;

  --gradient-takehome: linear-gradient(90deg, #22c55e, #16a34a);
  --gradient-tax:      linear-gradient(90deg, #ef4444, #dc2626);
  --gradient-ni:       linear-gradient(90deg, #f59e0b, #d97706);
  --gradient-expenses: linear-gradient(90deg, #3b82f6, #2563eb);

  --radius-card:  16px;
  --radius-btn:   10px;
  --radius-input: 8px;
  --radius-badge: 999px;

  --shadow-card:     0 4px 24px rgba(0, 0, 0, 0.4);
  --shadow-btn-glow: 0 0 20px rgba(59, 130, 246, 0.5);

  --font-family:    'Inter', system-ui, -apple-system, sans-serif;
  --transition-base: 0.2s ease;
}

/* -------------------------------------------------------------------
   2. Reset & Base
   ------------------------------------------------------------------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img, svg {
  display: block;
  max-width: 100%;
}

/* Remove number input spinners */
input[type="number"] {
  -moz-appearance: textfield;
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
}

/* -------------------------------------------------------------------
   3. Layout
   ------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: 680px;
  margin: 0 auto;
  padding: 0 1rem;
}

.main-content {
  padding: 1.5rem 0 2rem;
}

@media (min-width: 640px) {
  .container {
    padding: 0 1.5rem;
  }
  .main-content {
    padding: 2rem 0 3rem;
  }
}

/* -------------------------------------------------------------------
   4. Ad Slots
   ------------------------------------------------------------------- */
.ad-slot {
  width: 100%;
  background: transparent;
  border-top: 1px dashed var(--color-border);
  border-bottom: 1px dashed var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 90px;
  padding: 1rem;
}

.ad-slot--top {
  margin-bottom: 0;
}

.ad-slot--bottom {
  margin-top: 0;
}

.ad-label {
  color: var(--color-text-muted);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-weight: 500;
  border: 1px dashed var(--color-border);
  padding: 0.4rem 1rem;
  border-radius: 4px;
}

/* -------------------------------------------------------------------
   5. Hero Section
   ------------------------------------------------------------------- */
.hero {
  background: linear-gradient(180deg, #1e293b 0%, #0f172a 100%);
  padding: 2rem 0 2.5rem;
  border-bottom: 1px solid var(--color-border);
}

.hero__brand {
  font-size: 0.8rem;
  color: var(--color-accent);
  font-weight: 600;
  letter-spacing: 0.06em;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
}

.hero__title {
  font-size: clamp(1.55rem, 5vw, 2.4rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  letter-spacing: -0.01em;
}

.hero__subtitle {
  color: var(--color-text-muted);
  font-size: clamp(0.875rem, 2.5vw, 1rem);
  max-width: 520px;
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.trust-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  background: rgba(59, 130, 246, 0.12);
  border: 1px solid rgba(59, 130, 246, 0.3);
  color: var(--color-accent);
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-badge);
  font-size: 0.75rem;
  font-weight: 600;
  white-space: nowrap;
}

.badge::before {
  content: '✓';
  font-size: 0.68rem;
  font-weight: 700;
}

/* -------------------------------------------------------------------
   6. Cards
   ------------------------------------------------------------------- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-card);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow-card);
}

.card__heading {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--color-text);
}

@media (min-width: 640px) {
  .card {
    padding: 2rem;
  }
}

/* -------------------------------------------------------------------
   7. Form Elements
   ------------------------------------------------------------------- */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.4rem;
  color: var(--color-text);
}

.form-hint {
  color: var(--color-text-muted);
  font-weight: 400;
}

/* Input with £ prefix */
.input-wrapper {
  position: relative;
}

.input-wrapper--prefix .form-input {
  padding-left: 2.25rem;
}

.input-prefix {
  position: absolute;
  left: 0.85rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  font-weight: 500;
  pointer-events: none;
  z-index: 1;
  font-size: 0.95rem;
}

.form-input {
  width: 100%;
  background: var(--color-bg);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-input);
  color: var(--color-text);
  font-family: var(--font-family);
  font-size: 1rem;
  padding: 0.75rem 1rem;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
  outline: none;
}

.form-input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}

.form-input.touched:invalid {
  border-color: var(--color-danger);
}

.form-input::placeholder {
  color: #475569;
}

/* Custom Select */
.select-wrapper {
  position: relative;
}

.select-wrapper::after {
  content: '';
  position: absolute;
  right: 1rem;
  top: 50%;
  transform: translateY(-60%) rotate(45deg);
  width: 8px;
  height: 8px;
  border-right: 2px solid var(--color-text-muted);
  border-bottom: 2px solid var(--color-text-muted);
  pointer-events: none;
}

.form-select {
  width: 100%;
  background: var(--color-bg);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-input);
  color: var(--color-text);
  font-family: var(--font-family);
  font-size: 1rem;
  padding: 0.75rem 2.5rem 0.75rem 1rem;
  appearance: none;
  -webkit-appearance: none;
  cursor: pointer;
  transition: border-color var(--transition-base), box-shadow var(--transition-base);
  outline: none;
}

.form-select:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
}

.form-select option {
  background: var(--color-surface);
  color: var(--color-text);
}

/* Privacy Badge */
.privacy-badge {
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
  background: rgba(34, 197, 94, 0.07);
  border: 1px solid rgba(34, 197, 94, 0.22);
  border-radius: 8px;
  padding: 0.7rem 0.9rem;
  font-size: 0.8rem;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-top: 0.75rem;
}

.privacy-badge strong {
  color: var(--color-positive);
  font-weight: 600;
}

/* Error Message */
.form-error {
  color: var(--color-danger);
  font-size: 0.825rem;
  margin-top: 0.75rem;
  padding: 0.5rem 0.75rem;
  background: rgba(239, 68, 68, 0.1);
  border-radius: 6px;
  border-left: 3px solid var(--color-danger);
  line-height: 1.4;
}

/* -------------------------------------------------------------------
   8. Buttons
   ------------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-family: var(--font-family);
  font-size: 1rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius-btn);
  cursor: pointer;
  transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
  text-decoration: none;
  letter-spacing: 0.01em;
}

.btn--full {
  width: 100%;
  padding: 0.9rem 1.5rem;
}

.btn--primary {
  background: var(--color-accent);
  color: #fff;
  margin-top: 0.5rem;
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  transform: translateY(-1px) scale(1.01);
  box-shadow: var(--shadow-btn-glow);
}

.btn--primary:active {
  transform: translateY(0) scale(0.99);
  box-shadow: none;
}

.btn--secondary {
  background: var(--color-surface-2);
  color: var(--color-text);
  border: 1px solid var(--color-border);
  margin-top: 1.25rem;
}

.btn--secondary:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-1px);
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

/* -------------------------------------------------------------------
   9. Results Dashboard
   ------------------------------------------------------------------- */

/* Entrance animation */
@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.card--results:not([hidden]) {
  animation: slideUp 0.4s ease forwards;
}

/* Take-Home Hero Block */
.results-hero {
  text-align: center;
  padding: 1.5rem 1rem;
  background: linear-gradient(135deg, rgba(59, 130, 246, 0.1), rgba(34, 197, 94, 0.08));
  border-radius: 12px;
  margin-bottom: 1.5rem;
  border: 1px solid rgba(59, 130, 246, 0.2);
}

.results-hero__label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
  font-weight: 500;
}

.results-hero__amount {
  font-size: clamp(2.2rem, 8vw, 3.5rem);
  font-weight: 700;
  color: var(--color-positive);
  letter-spacing: -0.02em;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.results-hero__amount--zero {
  color: var(--color-text-muted);
}

.results-hero__annual {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

.results-hero__annual span {
  color: var(--color-text);
  font-weight: 600;
}

/* Breakdown Grid */
.breakdown-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

@media (min-width: 480px) {
  .breakdown-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.breakdown-item {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 0.875rem 0.75rem;
  text-align: center;
  transition: border-color var(--transition-base);
}

.breakdown-item--positive {
  border-color: rgba(34, 197, 94, 0.25);
}

.breakdown-item__label {
  display: block;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-muted);
  margin-bottom: 0.4rem;
  font-weight: 500;
}

.breakdown-item__value {
  display: block;
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-danger);
}

.breakdown-item__value--positive {
  color: var(--color-positive);
}

/* -------------------------------------------------------------------
   10. Progress Bars
   ------------------------------------------------------------------- */
.progress-section {
  margin-bottom: 0.5rem;
}

.progress-section__heading {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 1rem;
}

.progress-row {
  display: grid;
  grid-template-columns: 110px 1fr 44px;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.75rem;
}

@media (max-width: 380px) {
  .progress-row {
    grid-template-columns: 80px 1fr 36px;
  }
}

.progress-row__label {
  font-size: 0.78rem;
  color: var(--color-text-muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.progress-bar {
  height: 10px;
  background: var(--color-border);
  border-radius: 999px;
  overflow: hidden;
}

.progress-bar__fill {
  height: 100%;
  border-radius: 999px;
  width: 0%;
  transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.progress-bar__fill--takehome  { background: var(--gradient-takehome); }
.progress-bar__fill--tax       { background: var(--gradient-tax); }
.progress-bar__fill--ni        { background: var(--gradient-ni); }
.progress-bar__fill--expenses  { background: var(--gradient-expenses); }

.progress-row__pct {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--color-text-muted);
  text-align: right;
}

/* -------------------------------------------------------------------
   11. Disclaimer
   ------------------------------------------------------------------- */
.results-disclaimer {
  font-size: 0.72rem;
  color: var(--color-text-muted);
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
  line-height: 1.6;
}

/* -------------------------------------------------------------------
   12. Footer
   ------------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 1.5rem 0;
  text-align: center;
  font-size: 0.75rem;
  color: var(--color-text-muted);
}

.footer-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.footer-link {
  color: var(--color-text-muted);
  text-decoration: none;
  font-size: 0.75rem;
  transition: color var(--transition-base);
}

.footer-link:hover,
.footer-link:focus-visible {
  color: var(--color-accent);
  text-decoration: underline;
  outline: none;
}

.footer-link-sep {
  color: var(--color-border);
  user-select: none;
}

/* -------------------------------------------------------------------
   13. Calculation Steps Accordion
   ------------------------------------------------------------------- */

/* details container */
.calc-steps {
  border: 1px solid var(--color-border);
  border-radius: 10px;
  overflow: hidden;
  margin-top: 1.25rem;
  margin-bottom: 0;
}

/* summary trigger row */
.calc-steps__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.825rem 1rem;
  cursor: pointer;
  list-style: none;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text-muted);
  background: var(--color-surface-2);
  transition: color var(--transition-base), background var(--transition-base);
  user-select: none;
  gap: 0.75rem;
}

/* remove default browser triangle in all engines */
.calc-steps__trigger::-webkit-details-marker { display: none; }
.calc-steps__trigger::marker { display: none; }

/* chevron arrow via pseudo-element */
.calc-steps__trigger::after {
  content: '';
  flex-shrink: 0;
  width: 7px;
  height: 7px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translateY(-2px);
  transition: transform 0.25s ease;
  margin-left: auto;
}

.calc-steps__trigger:hover {
  color: var(--color-accent);
  background: rgba(59, 130, 246, 0.07);
}

/* open state: separator + rotated arrow */
.calc-steps[open] > .calc-steps__trigger {
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
}

.calc-steps[open] > .calc-steps__trigger::after {
  transform: rotate(225deg) translateY(-2px);
}

/* accordion body */
.calc-steps__body {
  padding: 1.1rem 1rem 1.25rem;
  background: var(--color-bg);
}

/* ---- Step groups ---- */
.calc-step-group {
  /* no extra margin — dividers handle spacing */
}

.calc-step-group__title {
  font-size: 0.66rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  color: var(--color-accent);
  margin-bottom: 0.6rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid rgba(59, 130, 246, 0.15);
}

/* thin horizontal rule between steps */
.calc-steps__divider {
  height: 1px;
  background: var(--color-border);
  margin: 0.875rem 0;
  opacity: 0.45;
}

/* ---- Individual rows ---- */
.calc-step-row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  padding: 0.28rem 0;
}

/* total/summary row — dashed top separator, bolder weight */
.calc-step-row--total {
  border-top: 1px dashed rgba(255, 255, 255, 0.08);
  margin-top: 0.35rem;
  padding-top: 0.5rem;
}

.calc-step-row--total .calc-step-row__desc {
  font-weight: 600;
  color: var(--color-text);
}

.calc-step-row--total .calc-step-row__val {
  font-size: 0.9rem;
}

/* description / equation text */
.calc-step-row__desc {
  font-size: 0.8rem;
  color: var(--color-text-muted);
  line-height: 1.4;
  min-width: 0;
}

/* result value */
.calc-step-row__val {
  font-size: 0.835rem;
  font-weight: 700;
  color: var(--color-text);
  text-align: right;
  white-space: nowrap;
  flex-shrink: 0;
}

/* value colour modifiers */
.calc-step-row__val--positive  { color: var(--color-positive); }
.calc-step-row__val--deduction { color: var(--color-danger); }
.calc-step-row__val--accent    { color: var(--color-accent); }

/* -------------------------------------------------------------------
   14. Print Styles
   ------------------------------------------------------------------- */
@media print {
  * {
    -webkit-print-color-adjust: exact;
    print-color-adjust: exact;
  }

  body {
    background: #fff;
    color: #111;
    font-size: 12pt;
  }

  body::before {
    content: "UK Driver Tax Report — " attr(data-report-date);
    display: block;
    text-align: center;
    font-size: 14pt;
    font-weight: 700;
    margin-bottom: 1.5rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid #334155;
    color: #111;
  }

  .ad-slot,
  #calculate-btn,
  #pdf-btn,
  .site-footer,
  .hero__brand,
  .trust-badges,
  .privacy-badge,
  .calc-steps,
  .card--input {
    display: none !important;
  }

  .hero {
    background: #fff;
    border-bottom: 1px solid #ccc;
    padding: 0.5rem 0 1rem;
  }

  .hero__title {
    color: #111;
    font-size: 20pt;
  }

  .hero__subtitle {
    color: #555;
  }

  .card {
    border: 1px solid #ccc;
    box-shadow: none;
    background: #fff;
    color: #111;
    border-radius: 8px;
    page-break-inside: avoid;
  }

  .card__heading {
    color: #111;
  }

  .results-hero {
    background: #f0fdf4;
    border: 1px solid #86efac;
    border-radius: 8px;
  }

  .results-hero__amount {
    color: #15803d;
    font-size: 28pt;
  }

  .results-hero__label,
  .results-hero__annual {
    color: #555;
  }

  .results-hero__annual span {
    color: #111;
  }

  .breakdown-item {
    border: 1px solid #ccc;
    background: #f9fafb;
    border-radius: 6px;
  }

  .breakdown-item__label {
    color: #555;
  }

  .breakdown-item__value {
    color: #dc2626;
  }

  .breakdown-item__value--positive {
    color: #15803d;
  }

  .progress-bar {
    background: #e5e7eb;
  }

  .progress-section__heading,
  .progress-row__label,
  .progress-row__pct {
    color: #555;
  }

  .results-disclaimer {
    color: #777;
    border-top-color: #ccc;
  }
}