/* Road Trip Fuel Stop Planner - Styles */
:root {
  --color-bg: #0f1117;
  --color-surface: #1a1d27;
  --color-surface-raised: #222633;
  --color-border: #2a2e3d;
  --color-text: #e4e6ed;
  --color-text-muted: #8b8fa3;
  --color-text-dim: #5c6078;
  --color-accent: #f5a623;
  --color-accent-hover: #ffc043;
  --color-accent-dim: #3d2e0a;
  --color-success: #34d399;
  --color-danger: #f87171;
  --color-info: #60a5fa;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'SF Mono', SFMono-Regular, Consolas, 'Liberation Mono', Menlo, monospace;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.5);
  --transition: 0.2s ease;
  --max-width: 1200px;
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover, a:focus-visible {
  color: var(--color-accent-hover);
}

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

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: 1rem;
  background: var(--color-accent);
  color: #000;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  z-index: 100;
  font-weight: 600;
}
.skip-link:focus {
  top: 1rem;
}

/* Header */
.site-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 60px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.15rem;
}
.logo:hover {
  color: var(--color-text);
}
.logo-icon {
  color: var(--color-accent);
}
.logo-accent {
  color: var(--color-accent);
}

.main-nav ul {
  display: flex;
  list-style: none;
  gap: 1.5rem;
}
.main-nav a {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  font-weight: 500;
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: all var(--transition);
}
.main-nav a:hover,
.main-nav a:focus-visible {
  color: var(--color-text);
  border-bottom-color: var(--color-accent);
}

/* Hero */
.hero-section {
  padding: 3.5rem 0 2.5rem;
  background: linear-gradient(180deg, var(--color-surface) 0%, var(--color-bg) 100%);
}

.hero-content {
  max-width: 700px;
}

.hero-content h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  letter-spacing: -0.02em;
}

.hero-sub {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* Planner Section */
.planner-section {
  padding: 2rem 0 3rem;
}

.planner-layout {
  display: grid;
  grid-template-columns: 380px 1fr;
  gap: 2rem;
  align-items: start;
}

.planner-inputs,
.planner-results {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
}

.planner-inputs h2,
.planner-results h2 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}

/* Unit Toggle */
.unit-toggle {
  display: flex;
  background: var(--color-surface-raised);
  border-radius: var(--radius-sm);
  padding: 3px;
  margin-bottom: 1.25rem;
}

.unit-btn {
  flex: 1;
  padding: 0.5rem;
  border: none;
  background: transparent;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border-radius: 4px;
  transition: all var(--transition);
  font-family: var(--font-sans);
}

.unit-btn.active {
  background: var(--color-accent);
  color: #000;
}

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

/* Form */
.form-group {
  margin-bottom: 1.1rem;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.35rem;
}

.input-with-unit {
  display: flex;
  align-items: center;
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: border-color var(--transition);
}

.input-with-unit:focus-within {
  border-color: var(--color-accent);
}

.input-with-unit input {
  flex: 1;
  background: transparent;
  border: none;
  color: var(--color-text);
  font-size: 1rem;
  padding: 0.6rem 0.75rem;
  font-family: var(--font-sans);
  min-width: 0;
}

.input-with-unit input:focus {
  outline: none;
}

.input-unit {
  padding: 0.6rem 0.75rem;
  color: var(--color-text-dim);
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
  border-left: 1px solid var(--color-border);
}

.form-group > input[type="number"] {
  width: 100%;
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  color: var(--color-text);
  font-size: 1rem;
  padding: 0.6rem 0.75rem;
  font-family: var(--font-sans);
  transition: border-color var(--transition);
}

.form-group > input[type="number"]:focus {
  outline: none;
  border-color: var(--color-accent);
}

input[type="range"] {
  width: 100%;
  margin-top: 0.25rem;
  accent-color: var(--color-accent);
  height: 6px;
}

.range-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.7rem;
  color: var(--color-text-dim);
  margin-top: 0.2rem;
}

.form-help {
  display: block;
  font-size: 0.75rem;
  color: var(--color-text-dim);
  margin-top: 0.3rem;
  line-height: 1.4;
}

/* Checkbox */
.checkbox-group {
  margin-top: 0.5rem;
}

.checkbox-label {
  display: flex !important;
  align-items: flex-start;
  gap: 0.5rem;
  cursor: pointer;
  font-size: 0.85rem !important;
  font-weight: 500 !important;
}

.checkbox-label input[type="checkbox"] {
  width: 18px;
  height: 18px;
  accent-color: var(--color-accent);
  margin-top: 2px;
  flex-shrink: 0;
}

/* Buttons */
.form-actions {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 1.25rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.55rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  font-family: var(--font-sans);
  transition: all var(--transition);
}

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

.btn-primary {
  background: var(--color-accent);
  color: #000;
}
.btn-primary:hover {
  background: var(--color-accent-hover);
}

.btn-secondary {
  background: var(--color-surface-raised);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}
.btn-secondary:hover {
  background: var(--color-border);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-muted);
}
.btn-ghost:hover {
  color: var(--color-text);
}

.btn-sm {
  padding: 0.4rem 0.75rem;
  font-size: 0.8rem;
}

/* Results */
.results-cards {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.result-card {
  background: var(--color-surface-raised);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
}

.result-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-dim);
  margin-bottom: 0.35rem;
}

.result-value {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--color-text);
}

.result-unit {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-text-muted);
}

/* Tank Visual */
.buffer-visual {
  margin-bottom: 1.5rem;
}

.tank-bar {
  height: 28px;
  background: var(--color-surface-raised);
  border-radius: var(--radius-sm);
  overflow: hidden;
  display: flex;
  border: 1px solid var(--color-border);
}

.tank-usable {
  background: linear-gradient(90deg, var(--color-accent), #e09500);
  height: 100%;
  transition: width 0.3s ease;
}

.tank-buffer {
  background: repeating-linear-gradient(
    45deg,
    var(--color-accent-dim),
    var(--color-accent-dim) 4px,
    transparent 4px,
    transparent 8px
  );
  height: 100%;
  transition: width 0.3s ease;
}

.tank-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.7rem;
  color: var(--color-text-dim);
  margin-top: 0.3rem;
}

/* Schedule */
.schedule-section {
  margin-top: 0.5rem;
}

.schedule-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
}

.schedule-header h3 {
  font-size: 1rem;
  font-weight: 700;
}

.schedule-table-wrapper {
  overflow-x: auto;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
}

.schedule-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
}

.schedule-table th {
  background: var(--color-surface-raised);
  padding: 0.6rem 0.75rem;
  text-align: left;
  font-weight: 600;
  color: var(--color-text-muted);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

.schedule-table td {
  padding: 0.6rem 0.75rem;
  border-bottom: 1px solid var(--color-border);
  color: var(--color-text);
}

.schedule-table tr:last-child td {
  border-bottom: none;
}

.schedule-table tr:hover td {
  background: rgba(255,255,255,0.02);
}

.schedule-table td:nth-child(4) {
  color: var(--color-accent);
  font-weight: 600;
}

.schedule-table td:nth-child(5) {
  color: var(--color-text-dim);
  font-style: italic;
}

/* Guide Section */
.guide-section {
  padding: 3rem 0;
  border-top: 1px solid var(--color-border);
}

.guide-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
}

.guide-block h2 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  color: var(--color-text);
}

.guide-block p {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.65;
  margin-bottom: 0.75rem;
}

.guide-block p:last-child {
  margin-bottom: 0;
}

.mistake-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.mistake-list li {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
}

.mistake-list strong {
  display: block;
  font-size: 0.9rem;
  color: var(--color-text);
  margin-bottom: 0.2rem;
}

.mistake-list span {
  font-size: 0.85rem;
  color: var(--color-text-muted);
  line-height: 1.5;
}

/* FAQ */
.faq-section {
  padding: 3rem 0;
  border-top: 1px solid var(--color-border);
}

.faq-section h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 1.25rem;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-width: 800px;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.faq-item summary {
  padding: 1rem 1.25rem;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: background var(--transition);
}

.faq-item summary::-webkit-details-marker {
  display: none;
}

.faq-item summary::after {
  content: '+';
  font-size: 1.2rem;
  color: var(--color-accent);
  flex-shrink: 0;
  margin-left: 1rem;
}

.faq-item[open] summary::after {
  content: '−';
}

.faq-item summary:hover {
  background: var(--color-surface-raised);
}

.faq-item p {
  padding: 0 1.25rem 1rem;
  color: var(--color-text-muted);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* Footer */
.site-footer {
  margin-top: auto;
  border-top: 1px solid var(--color-border);
  padding: 1.5rem 0;
  background: var(--color-surface);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.footer-logo {
  font-weight: 700;
  font-size: 0.9rem;
}

.footer-version {
  font-size: 0.75rem;
  color: var(--color-text-dim);
}

.footer-nav ul {
  display: flex;
  list-style: none;
  gap: 1.25rem;
}

.footer-nav a {
  font-size: 0.8rem;
  color: var(--color-text-dim);
}
.footer-nav a:hover {
  color: var(--color-text-muted);
}

/* Print */
@media print {
  .site-header,
  .site-footer,
  .planner-inputs,
  .form-actions,
  .schedule-header .btn,
  .hero-section,
  .guide-section,
  .faq-section,
  .buffer-visual {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }

  .planner-results {
    border: none;
    padding: 0;
  }

  .schedule-table th,
  .schedule-table td {
    border: 1px solid #ccc;
    padding: 0.5rem;
  }

  .schedule-table {
    font-size: 0.8rem;
  }
}

/* Responsive */
@media (max-width: 900px) {
  .planner-layout {
    grid-template-columns: 1fr;
  }

  .guide-grid {
    grid-template-columns: 1fr;
  }

  .results-cards {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 600px) {
  .container {
    padding: 0 1rem;
  }

  .hero-section {
    padding: 2rem 0 1.5rem;
  }

  .planner-inputs,
  .planner-results {
    padding: 1.25rem;
  }

  .results-cards {
    grid-template-columns: 1fr;
  }

  .form-actions {
    flex-direction: column;
  }

  .form-actions .btn {
    width: 100%;
    justify-content: center;
  }

  .header-inner {
    height: 52px;
  }

  .main-nav ul {
    gap: 1rem;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* Focus styles */
*:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* Number input arrows */
input[type="number"]::-webkit-inner-spin-button,
input[type="number"]::-webkit-outer-spin-button {
  opacity: 1;
}



/* Factory-injected deployment helpers. The AI owns the site design above this block. */
.ad-unit {
  width: min(100%, 720px);
  min-height: 120px;
  margin: 24px auto;
  display: block;
}

.legal-page {
  width: min(900px, calc(100% - 32px));
  margin: 40px auto;
}

.factory-fallback-nav {
  width: min(900px, calc(100% - 32px));
  margin: 24px auto 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  font-size: 0.95rem;
}

.factory-fallback-nav a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}