:root {
  --bg: #f7f8fb;
  --surface: #ffffff;
  --surface-2: #eef3f7;
  --text: #18212b;
  --muted: #5a6675;
  --primary: #0f4c81;
  --primary-2: #1669af;
  --accent: #d98a17;
  --dark: #0d1b2a;
  --success: #138a36;
  --danger: #c0392b;
  --border: #dbe2ea;
  --shadow: 0 10px 30px rgba(13, 27, 42, 0.08);
  --radius: 18px;
  --radius-sm: 12px;
  --container: 1140px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #f9fbfd 0%, #f2f6fa 100%);
  line-height: 1.6;
}
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-2); }
img { max-width: 100%; display: block; }
.container { width: min(100% - 1.5rem, var(--container)); margin: 0 auto; }
.section { padding: 4rem 0; }
.section-sm { padding: 2.5rem 0; }
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  background: rgba(15, 76, 129, .08);
  color: var(--primary);
  padding: .45rem .8rem;
  border-radius: 999px;
  font-size: .85rem;
  font-weight: 700;
  margin-bottom: 1rem;
}
h1, h2, h3 {
  line-height: 1.2;
  margin: 0 0 1rem;
  color: var(--dark);
}
h1 { font-size: clamp(2rem, 4.5vw, 3.3rem); }
h2 { font-size: clamp(1.6rem, 3.2vw, 2.4rem); }
h3 { font-size: clamp(1.15rem, 2vw, 1.35rem); }
p { margin: 0 0 1rem; color: var(--muted); }
small { color: var(--muted); }
.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--dark);
  color: #fff;
  padding: .75rem 1rem;
  z-index: 1000;
}
.skip-link:focus { left: .75rem; top: .75rem; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: saturate(180%) blur(10px);
  background: rgba(255,255,255,.88);
  border-bottom: 1px solid rgba(219, 226, 234, .9);
}
.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  gap: 1rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: .85rem;
  color: var(--dark);
  font-weight: 800;
}
.brand img { width: 44px; height: 44px; }
.brand-text strong { display: block; font-size: 1rem; }
.brand-text span { display: block; font-size: .8rem; color: var(--muted); }
.nav-toggle {
  border: 1px solid var(--border);
  background: #fff;
  width: 46px;
  height: 46px;
  border-radius: 12px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}
.nav-toggle span,
.nav-toggle span::before,
.nav-toggle span::after {
  content: "";
  display: block;
  width: 20px;
  height: 2px;
  background: var(--dark);
  border-radius: 999px;
  position: relative;
  transition: .25s ease;
}
.nav-toggle span::before { position: absolute; top: -6px; }
.nav-toggle span::after { position: absolute; top: 6px; }
.nav-toggle.active span { background: transparent; }
.nav-toggle.active span::before { top: 0; transform: rotate(45deg); }
.nav-toggle.active span::after { top: 0; transform: rotate(-45deg); }
.nav-menu {
  display: none;
  position: absolute;
  left: .75rem;
  right: .75rem;
  top: calc(100% + .5rem);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: .85rem;
}
.nav-menu.open { display: block; }
.nav-menu a {
  display: block;
  padding: .85rem 1rem;
  border-radius: 12px;
  font-weight: 600;
}
.nav-menu a:hover,
.nav-menu a.active { background: var(--surface-2); }
.hero {
  padding: 4rem 0 3rem;
}
.hero-grid,
.content-grid,
.feature-grid,
.tool-grid,
.footer-grid,
.calc-layout {
  display: grid;
  gap: 1.5rem;
}
.hero-card,
.card,
.calculator-card,
.faq-item,
.info-card,
.contact-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.hero-card {
  padding: 1.4rem;
}
.hero-copy p { max-width: 65ch; }
.hero-points {
  display: grid;
  grid-template-columns: repeat(2, minmax(0,1fr));
  gap: .75rem;
  margin-top: 1.25rem;
}
.hero-points div {
  background: rgba(255,255,255,.65);
  border: 1px solid var(--border);
  padding: .85rem;
  border-radius: 14px;
  font-size: .95rem;
}
.btn,
button,
input,
select,
textarea {
  font: inherit;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .55rem;
  border-radius: 12px;
  padding: .9rem 1.1rem;
  font-weight: 700;
  transition: .2s ease;
  border: 1px solid transparent;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-2); color: #fff; }
.btn-secondary { background: #fff; border-color: var(--border); color: var(--dark); }
.btn-secondary:hover { background: var(--surface-2); }
.btn-row { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.25rem; }
.card { padding: 1.35rem; }
.feature-grid,
.tool-grid { grid-template-columns: 1fr; }
.tool-card {
  display: flex;
  flex-direction: column;
  height: 100%;
}
.tool-card .badge,
.mini-badge {
  display: inline-flex;
  width: fit-content;
  margin-bottom: .9rem;
  background: rgba(217,138,23,.12);
  color: #8b5a09;
  padding: .35rem .65rem;
  border-radius: 999px;
  font-size: .78rem;
  font-weight: 700;
}
.tool-card p { flex-grow: 1; }
.list-check,
.link-list,
.calc-links {
  display: grid;
  gap: .65rem;
  padding-left: 0;
  list-style: none;
}
.list-check li,
.link-list li,
.calc-links li {
  background: rgba(238,243,247,.6);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: .8rem .9rem;
}
.calc-links li { background: transparent; }
.calculator-card {
  padding: 1.25rem;
}
.calc-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem;
  margin-bottom: 1rem;
}
.tab-btn {
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 999px;
  padding: .6rem .8rem;
  font-size: .92rem;
  cursor: pointer;
}
.tab-btn.active {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}
.form-grid {
  display: grid;
  gap: .95rem;
}
.field label {
  display: inline-block;
  margin-bottom: .45rem;
  font-weight: 700;
  color: var(--dark);
}
.field input,
.field select,
.field textarea {
  width: 100%;
  border: 1px solid var(--border);
  background: #fff;
  border-radius: 12px;
  padding: .9rem .95rem;
  color: var(--text);
}
.field input:focus,
.field select:focus,
.field textarea:focus {
  outline: 2px solid rgba(22,105,175,.18);
  border-color: var(--primary-2);
}
.help-text { font-size: .88rem; color: var(--muted); margin-top: .4rem; }
.result-box {
  margin-top: 1rem;
  background: linear-gradient(135deg, rgba(15,76,129,.08), rgba(217,138,23,.08));
  border: 1px solid rgba(15,76,129,.14);
  border-radius: 16px;
  padding: 1rem;
}
.result-box strong {
  display: block;
  font-size: 1.7rem;
  color: var(--dark);
  line-height: 1.2;
}
.result-meta {
  display: grid;
  gap: .55rem;
  margin-top: .7rem;
  color: var(--muted);
  font-size: .95rem;
}
.error-text { color: var(--danger); font-size: .9rem; min-height: 1.2rem; display: block; }
.success-text { color: var(--success); font-weight: 700; }
.formula-box,
.note-box,
.cta-strip {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
}
.formula-box code {
  display: block;
  padding: .85rem;
  border-radius: 12px;
  background: var(--surface-2);
  color: var(--dark);
  overflow: auto;
}
.faq-list { display: grid; gap: 1rem; }
.faq-item { padding: 1.1rem 1.15rem; }
.breadcrumbs {
  padding: 1rem 0 0;
  font-size: .92rem;
  color: var(--muted);
}
.breadcrumbs a { color: var(--muted); }
.page-hero {
  padding: 2.2rem 0 1.2rem;
}
.site-footer {
  background: var(--dark);
  color: rgba(255,255,255,.82);
  margin-top: 3rem;
}
.site-footer p,
.site-footer a,
.site-footer li,
.site-footer small,
.site-footer h3 { color: rgba(255,255,255,.82); }
.site-footer h3 { color: #fff; }
.footer-grid {
  padding: 3rem 0 1.2rem;
}
.footer-links,
.footer-meta {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: .6rem;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,.12);
  padding: 1rem 0 2rem;
  display: flex;
  flex-direction: column;
  gap: .5rem;
}
.contact-grid,
.policy-grid {
  display: grid;
  gap: 1.5rem;
}
.contact-card,
.info-card { padding: 1.25rem; }
.form-status { margin-top: .8rem; font-weight: 700; }
.toc {
  display: grid;
  gap: .75rem;
  position: sticky;
  top: 100px;
}
.toc a {
  display: block;
  border: 1px solid var(--border);
  background: #fff;
  padding: .8rem .9rem;
  border-radius: 12px;
}
.table-wrap {
  overflow-x: auto;
  border: 1px solid var(--border);
  border-radius: 16px;
}
table {
  width: 100%;
  border-collapse: collapse;
  min-width: 640px;
  background: #fff;
}
th, td {
  padding: .95rem 1rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}
th { background: var(--surface-2); color: var(--dark); }
.scroll-top {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  box-shadow: var(--shadow);
  display: none;
  cursor: pointer;
  z-index: 80;
}
.scroll-top.show { display: inline-flex; align-items: center; justify-content: center; }
.text-center { text-align: center; }
.muted { color: var(--muted); }
.highlight {
  color: var(--primary);
}
@media (min-width: 760px) {
  .hero { padding: 5rem 0 3.5rem; }
  .hero-grid,
  .content-grid,
  .footer-grid,
  .calc-layout,
  .contact-grid,
  .policy-grid { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .feature-grid,
  .tool-grid { grid-template-columns: repeat(3, minmax(0,1fr)); }
  .form-grid.two-col { grid-template-columns: repeat(2, minmax(0,1fr)); }
  .nav-toggle { display: none; }
  .nav-menu {
    display: flex !important;
    position: static;
    border: 0;
    box-shadow: none;
    padding: 0;
    gap: .25rem;
    background: transparent;
  }
  .nav-menu a { padding: .65rem .85rem; }
  .hero-grid { grid-template-columns: 1.1fr .9fr; align-items: start; }
  .content-grid { grid-template-columns: 1.1fr .9fr; }
  .footer-bottom { flex-direction: row; justify-content: space-between; align-items: center; }
  .calc-layout { grid-template-columns: 1.15fr .85fr; }
  .contact-grid { grid-template-columns: 1.1fr .9fr; }
  .policy-grid { grid-template-columns: .7fr 1.3fr; align-items: start; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}


.nav-menu {
  max-width: 100%;
  overflow: auto;
}
.nav-menu a {
  white-space: nowrap;
}
.blog-grid {
  align-items: stretch;
}
.site-footer .brand-text span {
  color: rgba(255,255,255,.72);
}
@media (min-width: 760px) {
  .navbar {
    align-items: center;
  }
  .nav-menu {
    flex-wrap: wrap;
    justify-content: flex-end;
  }
  .nav-menu a {
    font-size: .92rem;
  }
}
@media (min-width: 1120px) {
  .nav-menu a {
    padding: .65rem .7rem;
    font-size: .88rem;
  }
}