:root {
  --bg: #f8fafc;
  --surface: #ffffff;
  --surface-hover: #f1f5f9;
  --border: #e2e8f0;
  --text: #0f172a;
  --text-muted: #64748b;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-soft: rgba(37, 99, 235, 0.08);
  --success: #16a34a;
  --warning: #d97706;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 4px 24px rgba(15, 23, 42, 0.08);
  --font: "DM Sans", system-ui, -apple-system, sans-serif;
  --max-width: 1120px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

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

a:hover {
  color: var(--accent-hover);
}

img {
  max-width: 100%;
}

/* Header & Nav */
.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 64px;
}

.logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo span {
  color: var(--accent);
}

.nav-tabs {
  display: flex;
  gap: 0.25rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-tabs a {
  display: block;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.9rem;
  transition: background 0.15s, color 0.15s;
}

.nav-tabs a:hover,
.nav-tabs a.active {
  background: var(--accent-soft);
  color: var(--accent);
}

/* Main layout */
main {
  flex: 1;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 2rem 1.25rem 3rem;
  width: 100%;
}

.page-hero {
  text-align: center;
  margin-bottom: 2.5rem;
}

.page-hero h1 {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  margin: 0 0 0.5rem;
}

.page-hero p {
  color: var(--text-muted);
  font-size: 1.05rem;
  max-width: 560px;
  margin: 0 auto;
}

/* Category blocks (home) */
.category-grid {
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 768px) {
  .category-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.category-block {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  transition: border-color 0.2s, transform 0.2s;
}

.category-block:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.category-block h2 {
  font-size: 1.15rem;
  margin: 0 0 0.35rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.category-block h2 a {
  color: var(--text);
}

.category-block h2 a:hover {
  color: var(--accent);
}

.category-block > p {
  color: var(--text-muted);
  font-size: 0.875rem;
  margin: 0 0 1rem;
}

.calc-links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  max-height: 280px;
  overflow-y: auto;
}

.calc-links a {
  display: block;
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-muted);
  transition: background 0.15s, color 0.15s;
}

.calc-links a:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.view-all {
  display: inline-block;
  margin-top: 0.75rem;
  font-size: 0.85rem;
  font-weight: 600;
}

/* Calculator listing (category pages) */
.calc-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
}

.calc-card {
  display: block;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.25rem;
  text-decoration: none;
  color: inherit;
  transition: border-color 0.2s, transform 0.2s, box-shadow 0.2s;
}

.calc-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.calc-card:hover h3 {
  color: var(--accent);
}

.calc-card h3 {
  margin: 0 0 0.35rem;
  font-size: 1rem;
  color: var(--text);
  transition: color 0.15s;
}

.calc-card p {
  margin: 0;
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Calculator page */
.calc-layout {
  display: grid;
  gap: 1.5rem;
}

@media (min-width: 900px) {
  .calc-layout {
    grid-template-columns: 1fr 300px;
    align-items: start;
  }
}

.calc-panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: var(--shadow);
}

.calc-panel h1 {
  font-size: 1.5rem;
  margin: 0 0 0.35rem;
  letter-spacing: -0.02em;
}

.calc-panel .lead {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin: 0 0 1.5rem;
}

.form-grid {
  display: grid;
  gap: 1rem;
}

.form-grid.cols-2 {
  grid-template-columns: 1fr 1fr;
}

@media (max-width: 500px) {
  .form-grid.cols-2 {
    grid-template-columns: 1fr;
  }
}

.form-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.form-group input,
.form-group select {
  width: 100%;
  padding: 0.65rem 0.85rem;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-family: inherit;
  font-size: 1rem;
  transition: border-color 0.15s;
}

.form-group input:focus,
.form-group select:focus {
  outline: none;
  border-color: var(--accent);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: var(--radius-sm);
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, transform 0.1s;
  margin-top: 0.5rem;
}

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

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

.results {
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  display: none;
}

.results.visible {
  display: block;
}

.results h2 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin: 0 0 1rem;
}

.result-grid {
  display: grid;
  gap: 0.75rem;
}

.result-item {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.65rem 0.85rem;
  background: var(--bg);
  border-radius: var(--radius-sm);
}

.result-item .label {
  color: var(--text-muted);
  font-size: 0.9rem;
}

.result-item .value {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--success);
}

.result-highlight {
  text-align: center;
  padding: 1.25rem;
  background: var(--accent-soft);
  border-radius: var(--radius);
  margin-bottom: 1rem;
}

.result-highlight .big {
  font-size: 2rem;
  font-weight: 700;
  color: var(--accent);
  line-height: 1.2;
}

.result-highlight .sub {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 0.25rem;
}

.results table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.85rem;
  margin-top: 1rem;
}

.results table th,
.results table td {
  padding: 0.5rem 0.65rem;
  text-align: left;
  border-bottom: 1px solid var(--border);
}

.results table th {
  color: var(--text-muted);
  font-weight: 600;
  font-size: 0.75rem;
  text-transform: uppercase;
}

.table-wrap {
  max-height: 320px;
  overflow-y: auto;
  margin-top: 1rem;
}

/* Sidebar ads */
.sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Ad units */
.ad-slot {
  background: var(--surface);
  border: 1px dashed var(--border);
  border-radius: var(--radius);
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

.ad-slot.vertical {
  min-height: 250px;
}

.ad-slot.banner {
  min-height: 90px;
  margin: 1.5rem 0;
}

.ad-label {
  font-size: 0.65rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 0.25rem;
}

/* Breadcrumb */
.breadcrumb {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.breadcrumb a {
  color: var(--text-muted);
}

.breadcrumb a:hover {
  color: var(--accent);
}

.breadcrumb span {
  margin: 0 0.35rem;
}

/* Footer */
.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--border);
  padding: 1.5rem 1.25rem;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
}

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

.site-footer a:hover {
  color: var(--accent);
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.35rem 1.25rem;
  margin-top: 0.75rem;
}

.footer-nav a {
  font-weight: 500;
}

/* Mobile nav */
.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--text);
  padding: 0.4rem 0.6rem;
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 1.1rem;
}

@media (max-width: 640px) {
  .menu-toggle {
    display: block;
  }

  .nav-tabs {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 0.5rem;
  }

  .nav-tabs.open {
    display: flex;
  }

  .header-inner {
    position: relative;
    flex-wrap: wrap;
  }
}

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

/* Legal / disclaimer page */
.legal-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 2rem;
  max-width: 720px;
  margin: 0 auto;
}

.legal-content h1 {
  margin: 0 0 0.5rem;
  font-size: 1.75rem;
  letter-spacing: -0.02em;
}

.legal-content .lead {
  color: var(--text-muted);
  font-size: 1.05rem;
  margin: 0 0 2rem;
}

.legal-content h2 {
  font-size: 1.1rem;
  margin: 1.75rem 0 0.65rem;
  color: var(--text);
}

.legal-content p,
.legal-content li {
  color: var(--text-muted);
  font-size: 0.95rem;
  line-height: 1.7;
}

.legal-content ul {
  margin: 0.5rem 0 1rem;
  padding-left: 1.25rem;
}

.legal-content li {
  margin-bottom: 0.5rem;
}

.legal-content strong {
  color: var(--text);
}

.legal-content em {
  font-size: 0.85rem;
}