/* ===== OvertimeTaxCalc.com — Design System =====
   Dark navy theme matching GS architecture pattern.
   Fonts: DM Sans (body) + JetBrains Mono (numbers).
   Mobile-first, single breakpoint at 900px for calc grid.
*/

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

:root {
  /* Primary (dark navy) */
  --navy: #0a1628;
  --navy-light: #111d33;
  --slate: #1a2a42;
  --slate-mid: #243656;

  /* Accents */
  --blue-accent: #3b82f6;
  --blue-bright: #60a5fa;
  --green-pay: #34d399;
  --green-bright: #22c55e;
  --amber: #fbbf24;
  --red-soft: #f87171;

  /* Text */
  --text-primary: #e8edf5;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  /* Surfaces / Borders (translucent) */
  --border: rgba(148, 163, 184, 0.12);
  --border-focus: rgba(59, 130, 246, 0.5);
  --surface: rgba(26, 42, 66, 0.6);
  --surface-raised: rgba(36, 54, 86, 0.7);
  --input-bg: rgba(10, 22, 40, 0.7);
  --blue-glow: rgba(59, 130, 246, 0.15);
  --green-glow: rgba(52, 211, 153, 0.2);

  /* Typography */
  --font-body: 'DM Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'SF Mono', 'Consolas', monospace;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;

  /* Radii */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;

  /* Shadows */
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.3);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 30px rgba(59, 130, 246, 0.1);
}

/* --- Base --- */
html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: var(--font-body);
  background: var(--navy);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(ellipse 80% 60% at 50% -20%, rgba(59, 130, 246, 0.06), transparent 70%),
    radial-gradient(ellipse 60% 40% at 80% 100%, rgba(52, 211, 153, 0.04), transparent 60%);
}

a { color: var(--blue-bright); text-decoration: none; }
a:hover { color: var(--blue-accent); text-decoration: underline; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--blue-accent);
  color: #fff;
  padding: var(--space-sm) var(--space-md);
  z-index: 1000;
  border-radius: 0 0 var(--radius-sm) 0;
}
.skip-link:focus { left: 0; }

/* --- Layout --- */
.main-content {
  position: relative;
  z-index: 1;
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md);
}

/* --- Hero --- */
.hero {
  text-align: center;
  margin-bottom: var(--space-xl);
}

.hero h1 {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-sm);
}

.hero .accent { color: var(--green-pay); }

.hero .subtitle {
  font-size: 1rem;
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto;
}

.tax-year-badge {
  display: inline-block;
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: var(--space-xs) var(--space-sm);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--green-pay);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-md);
}

/* --- Calculator Grid --- */
.calc-grid {
  display: grid;
  gap: var(--space-lg);
}

@media (min-width: 900px) {
  .calc-grid {
    grid-template-columns: 380px 1fr;
  }
}

/* --- Form Panel --- */
.form-panel {
  background: var(--surface);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.form-section {
  margin-bottom: var(--space-lg);
}

.form-section:last-child { margin-bottom: 0; }

.form-section-title {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--border);
}

/* --- Form Elements --- */
.form-group {
  margin-bottom: var(--space-md);
}

.form-group:last-child { margin-bottom: 0; }

label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: var(--space-xs);
}

input[type="number"],
input[type="text"],
select {
  width: 100%;
  padding: 10px 12px;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.9rem;
  transition: border-color 0.2s, box-shadow 0.2s;
  -webkit-appearance: none;
  appearance: none;
}

input[type="number"]:focus,
input[type="text"]:focus,
select:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--blue-glow);
}

select {
  padding-right: 32px;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%2394a3b8' fill='none' stroke-width='2' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  cursor: pointer;
}

/* Remove number input spinners */
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}
input[type="number"] { -moz-appearance: textfield; }

.input-hint {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--space-xs);
}

/* --- Toggle Group (filing status) --- */
.toggle-group {
  display: flex;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.toggle-group input[type="radio"] {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.toggle-group label {
  flex: 1;
  padding: 8px 4px;
  text-align: center;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--input-bg);
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
  margin-bottom: 0;
  border-right: 1px solid var(--border);
}

.toggle-group label:last-of-type { border-right: none; }

.toggle-group input[type="radio"]:checked + label {
  background: var(--blue-accent);
  color: #fff;
  font-weight: 600;
}

.toggle-group input[type="radio"]:focus-visible + label {
  box-shadow: 0 0 0 2px var(--blue-glow);
}

/* --- Results Panel --- */
.results-panel {
  display: flex;
  flex-direction: column;
  gap: var(--space-lg);
}

/* --- Savings Card (hero number) --- */
.savings-card {
  background: linear-gradient(135deg, var(--slate), var(--navy-light));
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-lg);
  text-align: center;
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  position: relative;
  overflow: hidden;
}

.savings-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 0%, var(--green-glow), transparent 70%);
  pointer-events: none;
}

.savings-card .label {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-sm);
  position: relative;
}

.savings-card .hero-amount {
  font-family: var(--font-mono);
  font-size: clamp(2.4rem, 7vw, 3.6rem);
  font-weight: 700;
  color: var(--green-pay);
  line-height: 1;
  position: relative;
}

.savings-card .sub-label {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-top: var(--space-sm);
  position: relative;
}

.per-paycheck-line {
  display: flex;
  justify-content: center;
  align-items: baseline;
  gap: var(--space-sm);
  margin-top: var(--space-md);
  position: relative;
}

.per-paycheck-line .amount {
  font-family: var(--font-mono);
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--green-pay);
}

.per-paycheck-line .freq-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* --- Breakdown Card --- */
.breakdown-card {
  background: var(--surface);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.breakdown-card h3 {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

.result-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-sm) 0;
  border-bottom: 1px solid var(--border);
}

.result-row:last-child { border-bottom: none; }

.result-row .result-label {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.result-row .result-value {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
}

.result-row.highlight .result-value {
  color: var(--green-pay);
  font-weight: 700;
}

.result-row.deduction .result-value {
  color: var(--red-soft);
}

.rate-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.65rem;
  font-weight: 400;
  background: var(--surface-raised);
  border: 1px solid var(--border);
  border-radius: 3px;
  padding: 1px 6px;
  margin-left: var(--space-xs);
  color: var(--text-secondary);
}

.cap-notice {
  font-size: 0.75rem;
  color: var(--amber);
  background: rgba(251, 191, 36, 0.08);
  border-left: 3px solid var(--amber);
  padding: var(--space-xs) var(--space-sm);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin: var(--space-xs) 0;
}

/* --- MFS Warning --- */
.mfs-warning {
  background: rgba(248, 113, 113, 0.08);
  border: 1px solid rgba(248, 113, 113, 0.3);
  border-left: 3px solid var(--red-soft);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  text-align: center;
  color: var(--text-primary);
}

.mfs-warning strong {
  display: block;
  color: var(--red-soft);
  margin-bottom: var(--space-sm);
  font-size: 1rem;
}

.mfs-warning p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* --- FICA Notice --- */
.fica-row {
  background: rgba(248, 113, 113, 0.04);
  border-left: 3px solid var(--red-soft);
  padding: var(--space-sm);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-top: var(--space-sm);
}

.fica-row .result-label {
  font-size: 0.8rem;
}

.fica-row .fica-note {
  font-size: 0.7rem;
  color: var(--text-muted);
  margin-top: 2px;
}

/* --- Sources Card --- */
.sources-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
}

.sources-card h3 {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

.source-item {
  display: flex;
  gap: var(--space-sm);
  padding: var(--space-xs) 0;
  font-size: 0.75rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

.src-label {
  font-weight: 600;
  color: var(--text-muted);
  white-space: nowrap;
  min-width: 100px;
}

/* --- Disclaimer --- */
.disclaimer {
  border-left: 3px solid var(--amber);
  background: var(--surface);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-md) var(--space-lg);
  margin-top: var(--space-2xl);
  font-size: 0.8rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.disclaimer strong {
  color: var(--amber);
  display: block;
  margin-bottom: var(--space-xs);
}

/* --- Content Pages --- */
.page-content {
  max-width: 800px;
}

.breadcrumb {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: var(--space-lg);
}

.breadcrumb a { color: var(--text-secondary); }
.breadcrumb a:hover { color: var(--blue-bright); }
.breadcrumb .sep { margin: 0 var(--space-xs); color: var(--text-muted); }
.breadcrumb .current { color: var(--text-primary); }

.page-hero {
  margin-bottom: var(--space-xl);
}

.page-hero h1 {
  font-size: clamp(1.5rem, 4vw, 2.1rem);
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: var(--space-sm);
}

.article-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: var(--space-xl);
}

/* --- Content Sections (prose) --- */
.content-section {
  margin-bottom: var(--space-2xl);
}

.content-section h2 {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--border);
}

.content-section h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
}

.content-section p {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--space-md);
}

.content-section ul,
.content-section ol {
  margin: 0 0 var(--space-md) var(--space-lg);
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

.content-section li {
  margin-bottom: var(--space-xs);
}

.content-section li strong {
  color: var(--text-primary);
}

/* --- Info Box --- */
.info-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-left: 3px solid var(--blue-accent);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  padding: var(--space-md) var(--space-lg);
  margin: var(--space-lg) 0;
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.info-box strong {
  display: block;
  color: var(--blue-bright);
  margin-bottom: var(--space-xs);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.info-box.legal {
  border-left-color: var(--amber);
}

.info-box.legal strong {
  color: var(--amber);
}

.info-box.warning {
  border-left-color: var(--red-soft);
  background: rgba(248, 113, 113, 0.05);
}

.info-box.warning strong {
  color: var(--red-soft);
}

/* --- Data Table --- */
.data-table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-md) 0 var(--space-lg);
  font-size: 0.85rem;
}

.data-table th,
.data-table td {
  padding: var(--space-sm) var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.data-table th {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background: var(--surface);
}

.data-table td {
  color: var(--text-secondary);
}

.data-table td:last-child {
  font-family: var(--font-mono);
  color: var(--text-primary);
}

/* --- CTA Banner --- */
.cta-banner {
  background: linear-gradient(135deg, var(--slate), var(--navy-light));
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-xl) var(--space-lg);
  text-align: center;
  margin: var(--space-2xl) 0;
}

.cta-banner p {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-md);
}

.cta-btn {
  display: inline-block;
  background: var(--green-pay);
  color: var(--navy);
  font-weight: 700;
  font-size: 0.95rem;
  padding: 12px 32px;
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: background 0.2s, transform 0.1s;
}

.cta-btn:hover {
  background: var(--green-bright);
  color: var(--navy);
  text-decoration: none;
  transform: translateY(-1px);
}

/* --- FAQ Accordion (details/summary) --- */
.faq-section {
  margin: var(--space-2xl) 0;
}

.faq-section h2 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid var(--border);
}

.faq-item {
  border-bottom: 1px solid var(--border);
}

.faq-item summary {
  padding: var(--space-md) 0;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

.faq-item summary::after {
  content: '+';
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--text-muted);
  transition: transform 0.2s;
  flex-shrink: 0;
  margin-left: var(--space-md);
}

.faq-item[open] summary::after {
  content: '−';
  color: var(--blue-bright);
}

.faq-answer {
  padding: 0 0 var(--space-md);
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Related Pages --- */
.related-pages {
  margin: var(--space-2xl) 0;
}

.related-pages h2 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-md);
}

.related-links {
  display: grid;
  gap: var(--space-sm);
}

.related-links a {
  display: block;
  padding: var(--space-sm) var(--space-md);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: border-color 0.2s, background 0.2s;
}

.related-links a:hover {
  border-color: var(--blue-accent);
  background: var(--surface-raised);
  text-decoration: none;
}

/* --- Site Header --- */
.site-header {
  position: relative;
  z-index: 10;
  border-bottom: 1px solid var(--border);
}

.site-nav {
  max-width: 1100px;
  margin: 0 auto;
  padding: var(--space-sm) var(--space-md);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  flex-wrap: wrap;
}

.nav-brand {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--green-pay);
  text-decoration: none;
  letter-spacing: -0.02em;
}
.nav-brand:hover { color: var(--green-bright); text-decoration: none; }

.nav-links {
  display: flex;
  gap: var(--space-xs);
  flex-wrap: wrap;
}

.nav-links a {
  font-size: 0.8rem;
  color: var(--text-secondary);
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  transition: background 0.15s, color 0.15s;
  white-space: nowrap;
}
.nav-links a:hover { background: var(--surface); color: var(--text-primary); text-decoration: none; }
.nav-links a.active { color: var(--blue-bright); }

/* --- Site Footer --- */
.site-footer {
  position: relative;
  z-index: 1;
  border-top: 1px solid var(--border);
  margin-top: var(--space-2xl);
  padding: var(--space-2xl) var(--space-md) var(--space-lg);
}

.footer-content {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: var(--space-xl);
}

.footer-col h4 {
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
}

.footer-col a {
  display: block;
  font-size: 0.85rem;
  color: var(--text-secondary);
  padding: 3px 0;
  transition: color 0.15s;
}
.footer-col a:hover { color: var(--text-primary); text-decoration: none; }

.footer-bottom {
  max-width: 1100px;
  margin: var(--space-xl) auto 0;
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--text-muted);
  text-align: center;
}

/* --- 404 Page --- */
.error-page {
  text-align: center;
  padding: var(--space-2xl) 0;
}

.error-page h1 {
  font-family: var(--font-mono);
  font-size: clamp(3rem, 10vw, 6rem);
  font-weight: 700;
  color: var(--text-muted);
  line-height: 1;
  margin-bottom: var(--space-md);
}

.error-page p {
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
}

.error-links {
  display: flex;
  justify-content: center;
  gap: var(--space-md);
  flex-wrap: wrap;
}

/* --- Contact Form --- */
.contact-form {
  max-width: 500px;
}

.contact-form .form-group {
  margin-bottom: var(--space-md);
}

.contact-form textarea {
  width: 100%;
  min-height: 150px;
  padding: 10px 12px;
  background: var(--input-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.9rem;
  resize: vertical;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.contact-form textarea:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--blue-glow);
}

.contact-form button {
  display: inline-block;
  background: var(--blue-accent);
  color: #fff;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 10px 28px;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background 0.2s;
}

.contact-form button:hover { background: var(--blue-bright); }

/* --- Print Styles --- */
@media print {
  body { background: #fff; color: #000; }
  body::before { display: none; }
  .form-panel, .site-header, .site-footer, .disclaimer, .sources-card { display: none; }
  .savings-card { background: #fff; border: 2px solid var(--green-pay); box-shadow: none; color: #000; }
  .savings-card .label, .savings-card .sub-label { color: #333; }
  .savings-card .hero-amount { color: #059669; }
  .breakdown-card { background: #fff; border: 1px solid #ccc; color: #000; }
  .result-row .result-label { color: #333; }
  .result-row .result-value { color: #000; }
}

/* --- Responsive --- */
@media (max-width: 899px) {
  .main-content {
    padding: var(--space-md);
  }
}

@media (max-width: 480px) {
  .main-content {
    padding: var(--space-sm);
  }

  .form-panel, .breakdown-card, .savings-card, .sources-card {
    padding: var(--space-md);
  }

  .toggle-group label {
    font-size: 0.7rem;
    padding: 6px 2px;
  }
}