/* Sellers Fee Calculator — clean, trustworthy, mobile-first (en-US) */
:root {
  --bg: #f6f8fb;
  --surface: #ffffff;
  --text: #1a2332;
  --muted: #5a6577;
  --border: #e2e8f0;
  --primary: #0b6bcb;
  --primary-hover: #0958a8;
  --accent: #0d9488;
  --success-bg: #ecfdf5;
  --warn-bg: #fffbeb;
  --danger: #b91c1c;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(26, 35, 50, 0.08), 0 8px 24px rgba(26, 35, 50, 0.06);
  --font: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, "Cascadia Code", "SF Mono", Menlo, Consolas, monospace;
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; }

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

.container {
  width: min(100% - 2rem, 960px);
  margin-inline: auto;
}

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

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-weight: 700;
  color: var(--text);
  text-decoration: none;
  font-size: 1.05rem;
}

.brand:hover { text-decoration: none; color: var(--primary); }

.brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 0.85rem;
  font-weight: 800;
  flex-shrink: 0;
}

.nav-links {
  display: flex;
  gap: 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.95rem;
}

.nav-links a { color: var(--muted); }
.nav-links a:hover { color: var(--primary); }

/* Hero */
.hero {
  padding: 2rem 0 0.5rem;
  text-align: center;
}

.hero h1 {
  margin: 0 0 0.65rem;
  font-size: clamp(1.55rem, 4vw, 2.15rem);
  line-height: 1.25;
  letter-spacing: -0.02em;
}

.hero .lead {
  margin: 0 auto 1rem;
  max-width: 40rem;
  color: var(--muted);
  font-size: 1.05rem;
}

.disclaimer-banner {
  display: inline-flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.35rem 0.75rem;
  background: var(--warn-bg);
  border: 1px solid #fde68a;
  color: #92400e;
  font-size: 0.85rem;
  padding: 0.5rem 0.9rem;
  border-radius: 999px;
  margin: 0.75rem auto 0;
}

/* Calculator card */
.calc-section { padding: 1.5rem 0 2rem; }

.calc-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.calc-grid {
  display: grid;
  grid-template-columns: 1fr;
}

@media (min-width: 800px) {
  .calc-grid { grid-template-columns: 1.1fr 0.9fr; }
}

.calc-inputs, .calc-results {
  padding: 1.35rem 1.25rem 1.5rem;
}

.calc-results {
  background: linear-gradient(180deg, #f0f7ff 0%, #f8fafc 100%);
  border-top: 1px solid var(--border);
}

@media (min-width: 800px) {
  .calc-results {
    border-top: none;
    border-left: 1px solid var(--border);
  }
}

.calc-inputs h2, .calc-results h2 {
  margin: 0 0 1rem;
  font-size: 1.1rem;
}

.field {
  margin-bottom: 1rem;
}

.field label {
  display: block;
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 0.35rem;
}

.field .hint {
  display: block;
  font-size: 0.8rem;
  color: var(--muted);
  font-weight: 400;
  margin-top: 0.25rem;
}

.field input[type="number"],
.field input[type="text"],
.field select {
  width: 100%;
  padding: 0.7rem 0.85rem;
  font-size: 1.05rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
  font-family: inherit;
}

.field input:focus,
.field select:focus {
  outline: 2px solid rgba(11, 107, 203, 0.35);
  border-color: var(--primary);
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
}

.toggle-row {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  padding: 0.65rem 0.75rem;
  background: #f8fafc;
  border: 1px solid var(--border);
  border-radius: 8px;
  margin-bottom: 1rem;
}

.toggle-row input { margin-top: 0.2rem; flex-shrink: 0; }
.toggle-row label { font-weight: 500; font-size: 0.92rem; cursor: pointer; }
.toggle-row .hint { margin-top: 0.15rem; }

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  margin-top: 0.5rem;
}

.btn {
  appearance: none;
  border: none;
  border-radius: 8px;
  padding: 0.7rem 1.15rem;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: background 0.15s, transform 0.05s;
}

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

.btn-primary {
  background: var(--primary);
  color: #fff;
}

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

.btn-secondary {
  background: #fff;
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover { background: #f1f5f9; }

/* Results */
.result-big {
  text-align: center;
  padding: 0.5rem 0 1rem;
}

.result-big .label {
  font-size: 0.85rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
}

.result-big .value {
  font-size: clamp(1.85rem, 5vw, 2.4rem);
  font-weight: 800;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  margin: 0.15rem 0;
}

.result-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.65rem;
  margin-bottom: 1rem;
}

.stat {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.75rem;
  text-align: center;
}

.stat .label { font-size: 0.78rem; color: var(--muted); }
.stat .value {
  font-size: 1.2rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

.breakdown {
  list-style: none;
  margin: 0;
  padding: 0;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
}

.breakdown li {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.65rem 0.85rem;
  border-bottom: 1px solid var(--border);
  font-size: 0.92rem;
}

.breakdown li:last-child { border-bottom: none; }

.breakdown .amt {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-family: var(--mono);
  font-size: 0.88rem;
}

.breakdown .total-row {
  background: var(--success-bg);
  font-weight: 700;
}

.error-msg {
  color: var(--danger);
  font-size: 0.9rem;
  margin: 0.5rem 0 0;
  display: none;
}

.error-msg.visible { display: block; }

.rates-meta {
  font-size: 0.8rem;
  color: var(--muted);
  margin-top: 1rem;
  text-align: center;
}

/* Content sections */
.content-section {
  padding: 2rem 0;
}

.content-section h2 {
  margin: 0 0 0.85rem;
  font-size: 1.45rem;
  letter-spacing: -0.015em;
}

.content-section h3 {
  margin: 1.35rem 0 0.5rem;
  font-size: 1.1rem;
}

.content-section p, .content-section li {
  color: var(--muted);
}

.content-section p { margin: 0 0 0.85rem; }

.steps {
  display: grid;
  gap: 0.85rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
}

.steps li {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1rem 1rem 3.2rem;
  position: relative;
  color: var(--text);
}

.steps li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  left: 0.9rem;
  top: 50%;
  transform: translateY(-50%);
  width: 1.7rem;
  height: 1.7rem;
  border-radius: 50%;
  background: var(--primary);
  color: #fff;
  font-weight: 700;
  font-size: 0.85rem;
  display: grid;
  place-items: center;
}

.prose-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem 1.35rem;
}

/* FAQ */
.faq details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0.85rem 1rem;
  margin-bottom: 0.65rem;
}

.faq summary {
  font-weight: 650;
  cursor: pointer;
  list-style: none;
}

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

.faq summary::after {
  content: "+";
  float: right;
  color: var(--muted);
  font-weight: 400;
}

.faq details[open] summary::after { content: "–"; }

.faq details p {
  margin: 0.65rem 0 0.15rem;
  color: var(--muted);
  font-size: 0.95rem;
}

/* Related tools */
.related-grid {
  display: grid;
  gap: 0.75rem;
  grid-template-columns: 1fr;
}

@media (min-width: 600px) {
  .related-grid { grid-template-columns: 1fr 1fr; }
}

.related-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 1.1rem;
}

.related-card .soon {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background: #e0f2fe;
  color: #0369a1;
  padding: 0.15rem 0.45rem;
  border-radius: 4px;
  margin-bottom: 0.35rem;
}

.related-card h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
  color: var(--text);
}

.related-card p {
  margin: 0;
  font-size: 0.9rem;
}

/* AdSense placeholders */
.ad-slot {
  margin: 1.5rem 0;
  min-height: 90px;
  border: 1px dashed var(--border);
  border-radius: 8px;
  display: grid;
  place-items: center;
  color: var(--muted);
  font-size: 0.8rem;
  background: #fafbfc;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding: 2rem 0 2.5rem;
  margin-top: 1rem;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  justify-content: space-between;
  align-items: flex-start;
}

.footer-brand {
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.footer-note {
  font-size: 0.85rem;
  color: var(--muted);
  max-width: 28rem;
  margin: 0;
}

.footer-links {
  display: flex;
  gap: 1.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 0.9rem;
}

.footer-links a { color: var(--muted); }

.legal-page {
  padding: 2rem 0 3rem;
}

.legal-page h1 {
  margin: 0 0 1rem;
  font-size: 1.75rem;
}

.legal-page h2 {
  margin: 1.75rem 0 0.5rem;
  font-size: 1.15rem;
}

.legal-page p, .legal-page li {
  color: var(--muted);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* Mobile nav + touch targets (phones) */
@media (max-width: 640px) {
  .container { width: min(100% - 1.25rem, 960px); }
  .nav {
    flex-wrap: wrap;
    align-items: center;
    gap: 0.5rem 0.75rem;
    padding: 0.7rem 0;
  }
  .brand { font-size: 0.95rem; max-width: 100%; }
  .brand span:last-child { white-space: nowrap; }
  .nav-links {
    width: 100%;
    justify-content: flex-start;
    flex-wrap: nowrap;
    gap: 0.35rem;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
    padding-bottom: 0.15rem;
  }
  .nav-links::-webkit-scrollbar { display: none; }
  .nav-links li { flex: 0 0 auto; }
  .nav-links a {
    display: inline-block;
    white-space: nowrap;
    padding: 0.35rem 0.55rem;
    border-radius: 999px;
    background: #f1f5f9;
    font-size: 0.82rem;
    color: var(--text);
  }
  .nav-links a:hover { text-decoration: none; background: #e2e8f0; }
  .actions { gap: 0.5rem; }
  .actions .btn { flex: 1 1 calc(50% - 0.25rem); text-align: center; }
  .toggle-row { align-items: flex-start; }
  .hero { padding-top: 1.35rem; }
  .calc-inputs, .calc-results { padding: 1.1rem 1rem 1.25rem; }
  .field-row { grid-template-columns: 1fr; }
}

@media (max-width: 380px) {
  .brand span:last-child { font-size: 0.88rem; }
  .result-stats { grid-template-columns: 1fr; }
}