/* -------------------------------------------------------------
   Premium, Utility-Centric Style Sheet for US Paycheck Calculator
   Focus: Extreme legibility, trustworthy layout, clean typography
   ------------------------------------------------------------- */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap');

:root {
  --bg-primary: #f8fafc;
  --bg-card: #ffffff;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  
  --color-indigo: #4f46e5;
  --color-indigo-hover: #4338ca;
  --color-indigo-light: #e0e7ff;
  
  --color-emerald: #059669;
  --color-emerald-light: #ecfdf5;
  
  --border-color: #e2e8f0;
  --border-focus: #6366f1;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --max-width: 1200px;
}

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

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

a {
  color: var(--color-indigo);
  text-decoration: none;
  transition: color 0.15s ease;
}

a:hover {
  color: var(--color-indigo-hover);
  text-decoration: underline;
}

/* -------------------------------------------------------------
   Layout & Navigation
   ------------------------------------------------------------- */

.navbar {
  background-color: var(--bg-card);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: var(--shadow-sm);
}

.navbar-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.75rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-brand {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-brand span {
  color: var(--color-indigo);
}

.nav-links {
  display: flex;
  gap: 1rem;
  align-items: center;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all 0.15s ease;
}

.nav-link:hover {
  background-color: var(--bg-primary);
  color: var(--color-indigo);
  text-decoration: none;
}

.nav-link.active {
  background-color: var(--color-indigo-light);
  color: var(--color-indigo);
}

/* -------------------------------------------------------------
   Main Page Layout
   ------------------------------------------------------------- */

.hero-section {
  max-width: var(--max-width);
  margin: 2rem auto 1.5rem auto;
  padding: 0 1.5rem;
}

.hero-section h1 {
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
  margin-bottom: 0.75rem;
  letter-spacing: -0.025em;
}

.hero-section p {
  color: var(--text-secondary);
  font-size: 1.1rem;
  max-width: 800px;
}

.main-layout {
  max-width: var(--max-width);
  margin: 0 auto 3rem auto;
  padding: 0 1.5rem;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 2rem;
  align-items: start;
}

@media (max-width: 900px) {
  .main-layout {
    grid-template-columns: 1fr;
  }
  .hero-section h1 {
    font-size: 1.75rem;
  }
}

/* -------------------------------------------------------------
   Interactive Form Elements
   ------------------------------------------------------------- */

.calculator-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
}

.section-title {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.input-prefix {
  position: absolute;
  left: 1rem;
  color: var(--text-muted);
  font-weight: 500;
  font-size: 1rem;
  pointer-events: none;
}

.input-field {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  font-family: var(--font-family);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  outline: none;
  transition: all 0.15s ease;
  color: var(--text-primary);
  background-color: var(--bg-card);
}

.input-wrapper .input-field {
  padding-left: 2rem;
}

.input-field:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

.radio-group {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
}

.radio-group-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem;
}

.radio-card {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.5rem;
  text-align: center;
  cursor: pointer;
  transition: all 0.15s ease;
  font-size: 0.875rem;
  font-weight: 500;
  user-select: none;
  background-color: var(--bg-card);
}

.radio-card:hover {
  background-color: var(--bg-primary);
  border-color: var(--text-muted);
}

.radio-input {
  display: none;
}

.radio-input:checked + .radio-card {
  border-color: var(--color-indigo);
  background-color: var(--color-indigo-light);
  color: var(--color-indigo);
}

/* -------------------------------------------------------------
   Output Result Panel
   ------------------------------------------------------------- */

.results-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  position: sticky;
  top: 90px;
}

.net-pay-banner {
  background-color: var(--color-emerald-light);
  border: 1px solid rgba(5, 150, 105, 0.15);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  margin-bottom: 1.5rem;
}

.net-pay-label {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-weight: 600;
  color: var(--color-emerald);
}

.net-pay-amount {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--color-emerald);
  line-height: 1.1;
  margin-top: 0.25rem;
}

.pay-breakdown-bar {
  display: flex;
  height: 1rem;
  border-radius: 9999px;
  overflow: hidden;
  background-color: var(--bg-primary);
  margin-bottom: 2rem;
  border: 1px solid var(--border-color);
}

.bar-segment {
  height: 100%;
  transition: width 0.3s ease;
}

.bar-net-pay { background-color: var(--color-emerald); }
.bar-fed-tax { background-color: #f59e0b; }
.bar-state-tax { background-color: #3b82f6; }
.bar-local-tax { background-color: #8b5cf6; }
.bar-fica { background-color: #ec4899; }
.bar-deductions { background-color: #64748b; }

.legend-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.legend-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.75rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.legend-color {
  width: 0.75rem;
  height: 0.75rem;
  border-radius: 2px;
}

.breakdown-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
}

.breakdown-table th {
  text-align: left;
  padding: 0.5rem 0;
  color: var(--text-secondary);
  font-weight: 500;
  border-bottom: 1px solid var(--border-color);
}

.breakdown-table td {
  padding: 0.75rem 0;
  border-bottom: 1px dashed var(--border-color);
}

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

.breakdown-table td.value {
  text-align: right;
  font-weight: 600;
  color: var(--text-primary);
}

.breakdown-table tr.total-row td {
  border-top: 1px solid var(--border-color);
  font-weight: 700;
  padding-top: 1rem;
}

/* -------------------------------------------------------------
   AdSense Placement Placeholders
   ------------------------------------------------------------- */

.adsense-placeholder {
  background-color: var(--bg-primary);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 500;
  margin: 2rem 0;
  min-height: 90px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 0.25rem;
  user-select: none;
}

.adsense-placeholder::before {
  content: "ADVERTISING SPONSOR";
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-secondary);
}

/* -------------------------------------------------------------
   SEO Rich Content Styling
   ------------------------------------------------------------- */

.seo-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem 4rem 1.5rem;
  border-top: 1px solid var(--border-color);
  margin-top: 3rem;
}

.seo-content {
  max-width: 850px;
  margin: 0 auto;
}

.seo-content h2 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  margin: 2.5rem 0 1rem 0;
  letter-spacing: -0.015em;
}

.seo-content p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1.5rem;
}

.faq-section {
  margin-top: 3rem;
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
}

.faq-item {
  margin-bottom: 1.5rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem 1.5rem;
}

.faq-question {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.faq-answer {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

/* -------------------------------------------------------------
   Footer
   ------------------------------------------------------------- */

footer {
  background-color: var(--bg-card);
  border-top: 1px solid var(--border-color);
  padding: 3rem 0;
  margin-top: auto;
}

.footer-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: var(--text-secondary);
}

.footer-links {
  display: flex;
  gap: 1.5rem;
}

@media (max-width: 600px) {
  .footer-container {
    flex-direction: column;
    gap: 1.5rem;
    text-align: center;
  }
}