:root {
  --navy-950: #081428;
  --navy: #0d2240;
  --navy-700: #16345c;
  --navy-600: #1d4272;
  --green: #2fbf71;
  --green-dark: #1f9d55;
  --blue: #3b82f6;
  --blue-soft: #5ea0ff;
  --amber: #d97706;
  --surface: #f3f5f9;
  --card: #ffffff;
  --ink: #17202e;
  --muted: #5b6778;
  --border: #dfe5ee;
  --radius: 14px;
  --shadow-sm: 0 1px 2px rgba(13, 34, 64, 0.06);
  --shadow-md: 0 1px 3px rgba(13, 34, 64, 0.07), 0 8px 24px -12px rgba(13, 34, 64, 0.18);
  --shadow-lg: 0 2px 6px rgba(13, 34, 64, 0.08), 0 20px 48px -20px rgba(13, 34, 64, 0.28);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: 'Space Grotesk', 'Trebuchet MS', system-ui, sans-serif;
  background: var(--surface);
  color: var(--ink);
  line-height: 1.65;
  font-size: 16.5px;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--blue); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { color: var(--navy); }
:focus-visible { outline: 3px solid var(--blue-soft); outline-offset: 2px; border-radius: 4px; }

.skip-link {
  position: absolute; left: -999px; top: 8px; z-index: 100;
  background: var(--green); color: #fff; padding: 10px 18px; border-radius: 8px;
}
.skip-link:focus { left: 8px; }

/* ---------- Header ---------- */
.site-header {
  background: var(--navy);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  position: sticky; top: 0; z-index: 50;
}
.site-header .wrap {
  max-width: 1120px; margin: 0 auto; padding: 12px 24px;
  display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
}
.brand { display: flex; align-items: center; gap: 11px; text-decoration: none; }
.brand img { display: block; }
.brand-word { font-size: 21px; font-weight: 700; letter-spacing: -0.02em; line-height: 1; }
.brand-word .t1 { color: #ffffff; }
.brand-word .t2 { color: var(--green); }
.site-nav { margin-left: auto; display: flex; gap: 4px; flex-wrap: wrap; }
.site-nav a {
  color: #b9c8de; text-decoration: none; font-size: 15px; font-weight: 500;
  padding: 8px 14px; border-radius: 8px; transition: background 0.15s, color 0.15s;
}
.site-nav a:hover { color: #ffffff; background: rgba(255, 255, 255, 0.08); }

main { display: block; }
.page { max-width: 1120px; margin: 0 auto; padding: 36px 24px 72px; }

/* ---------- Hero (home) ---------- */
.hero {
  background: var(--navy);
  background-image: radial-gradient(ellipse 90% 130% at 85% -20%, rgba(59, 130, 246, 0.28), transparent 55%);
  color: #ffffff;
  position: relative;
  overflow: hidden;
}
.hero .wrap {
  max-width: 1120px; margin: 0 auto; padding: 72px 24px 64px;
  position: relative; z-index: 1;
}
.hero-keys { position: absolute; right: -40px; top: 50%; transform: translateY(-50%); opacity: 0.5; pointer-events: none; }
.hero h1 {
  margin: 0 0 14px; color: #ffffff;
  font-size: clamp(32px, 4.6vw, 48px); line-height: 1.12; letter-spacing: -0.025em; max-width: 640px;
}
.hero h1 em { font-style: normal; color: var(--green); }
.hero .sub { font-size: 18px; color: #b9c8de; max-width: 560px; margin: 0 0 26px; }
.hero-chips { display: flex; gap: 10px; flex-wrap: wrap; }
.hero-chip {
  display: inline-flex; align-items: center; gap: 8px;
  background: rgba(255, 255, 255, 0.07); border: 1px solid rgba(255, 255, 255, 0.14);
  color: #d6e0ef; border-radius: 999px; padding: 7px 15px; font-size: 13.5px;
}
.hero-chip svg { flex: none; }

/* ---------- Page headers (tool pages) ---------- */
.crumb { font-size: 13.5px; color: var(--muted); margin-bottom: 6px; }
.crumb a { color: var(--muted); text-decoration: none; }
.crumb a:hover { color: var(--navy); text-decoration: underline; }
h1 { font-size: clamp(28px, 3.6vw, 38px); letter-spacing: -0.025em; line-height: 1.15; margin: 6px 0 10px; color: var(--navy); }
h2 { font-size: 23px; letter-spacing: -0.015em; color: var(--navy); margin: 44px 0 10px; }
h3 { font-size: 17px; color: var(--navy); }
.lede { font-size: 17.5px; color: var(--muted); max-width: 740px; margin-top: 0; }

/* ---------- Calculator card ---------- */
.calc-card {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 18px; padding: 28px; margin: 26px 0;
  box-shadow: var(--shadow-lg);
}
.calc-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 18px; }
.field { display: flex; flex-direction: column; gap: 7px; }
.field label { font-size: 13px; font-weight: 700; color: var(--navy); letter-spacing: 0.01em; }
.field input, .field select, .field textarea {
  font: inherit; padding: 11px 14px; border: 1.5px solid var(--border);
  border-radius: 10px; background: #fff; color: var(--ink); min-height: 46px;
  transition: border-color 0.15s, box-shadow 0.15s;
}
.field input:hover, .field select:hover, .field textarea:hover { border-color: #b9c5d6; }
.field input:focus, .field select:focus, .field textarea:focus {
  outline: none; border-color: var(--blue);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.18);
}
.field select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' stroke='%235b6778' stroke-width='2' fill='none' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat; background-position: right 14px center; padding-right: 38px;
}
.seg {
  display: inline-flex; gap: 4px; background: var(--surface);
  border: 1px solid var(--border); border-radius: 10px; padding: 4px; width: max-content;
}
.seg button {
  font: inherit; font-weight: 600; font-size: 15px;
  padding: 8px 18px; border: 0; border-radius: 7px; background: transparent;
  cursor: pointer; min-height: 38px; color: var(--muted);
  transition: background 0.15s, color 0.15s, box-shadow 0.15s;
}
.seg button:hover { color: var(--navy); }
.seg button.active { background: var(--navy); color: #fff; box-shadow: var(--shadow-sm); }

.results {
  margin-top: 24px; display: grid;
  grid-template-columns: repeat(auto-fit, minmax(165px, 1fr)); gap: 12px;
}
.result {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: 12px; padding: 15px 17px; min-width: 0;
}
.result .label {
  font-size: 11.5px; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--muted); font-weight: 600; margin-bottom: 3px;
}
.result .value {
  font-size: clamp(20px, 2.2vw, 26px); font-weight: 700; color: var(--navy);
  letter-spacing: -0.02em; font-variant-numeric: tabular-nums; overflow-wrap: anywhere;
}
.result.primary {
  background: var(--navy); border-color: var(--navy);
  background-image: radial-gradient(ellipse 120% 160% at 100% -30%, rgba(59, 130, 246, 0.35), transparent 60%);
}
.result.primary .label { color: #9fb4d2; }
.result.primary .value { color: var(--green); }

/* ---------- Source line ---------- */
.source-line {
  display: block; font-size: 13.5px; color: var(--muted);
  background: var(--card); border: 1px solid var(--border); border-radius: 10px;
  padding: 10px 16px 10px 36px; margin: 16px 0; position: relative;
  box-shadow: var(--shadow-sm);
}
.source-line::before {
  content: ""; position: absolute; left: 15px; top: 17px;
  width: 9px; height: 9px; border-radius: 50%;
  background: var(--green); box-shadow: 0 0 0 4px rgba(47, 191, 113, 0.18);
}
.source-line.stale::before { background: var(--amber); box-shadow: 0 0 0 4px rgba(217, 119, 6, 0.18); }

/* ---------- Content ---------- */
.content { max-width: 740px; }
.content p { margin: 13px 0; }
.content table {
  border-collapse: separate; border-spacing: 0; width: 100%; margin: 18px 0;
  background: var(--card); font-size: 15px;
  border: 1px solid var(--border); border-radius: 12px; overflow: hidden;
  box-shadow: var(--shadow-sm);
}
.content th, .content td { text-align: left; padding: 11px 14px; }
.content th { background: var(--navy); color: #fff; font-weight: 600; font-size: 13.5px; letter-spacing: 0.02em; }
.content td { border-top: 1px solid var(--border); }
.content tr:nth-child(even) td { background: #f8fafc; }
.table-scroll { overflow-x: auto; }

.formula {
  background: var(--navy); color: #cfdcf0;
  background-image: radial-gradient(ellipse 100% 180% at 100% -40%, rgba(59, 130, 246, 0.25), transparent 55%);
  padding: 18px 22px; border-radius: 12px;
  font-family: ui-monospace, 'SF Mono', Menlo, monospace; font-size: 14.5px;
  line-height: 1.9; overflow-x: auto; box-shadow: var(--shadow-md);
}

.faq details {
  background: var(--card); border: 1px solid var(--border);
  border-radius: 12px; padding: 2px 20px; margin: 10px 0;
  transition: box-shadow 0.15s;
}
.faq details:hover { box-shadow: var(--shadow-sm); }
.faq details[open] { box-shadow: var(--shadow-md); border-color: #c9d4e4; }
.faq summary {
  font-weight: 700; color: var(--navy); cursor: pointer; padding: 13px 0;
  list-style: none; display: flex; align-items: center; justify-content: space-between; gap: 12px;
}
.faq summary::-webkit-details-marker { display: none; }
.faq summary::after {
  content: "+"; flex: none; width: 26px; height: 26px; border-radius: 8px;
  background: var(--surface); color: var(--navy);
  display: grid; place-items: center; font-size: 18px; font-weight: 500;
  transition: transform 0.2s, background 0.2s, color 0.2s;
}
.faq details[open] summary::after { transform: rotate(45deg); background: var(--green); color: #fff; }

.disclaimer {
  font-size: 13.5px; color: var(--muted); background: var(--card);
  border: 1px dashed var(--border); border-radius: 12px; padding: 14px 18px; margin-top: 36px;
}

/* ---------- Tool cards ---------- */
.tool-cards {
  display: grid; grid-template-columns: repeat(auto-fill, minmax(310px, 1fr));
  gap: 18px; margin-top: 26px;
}
.tool-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  padding: 24px; text-decoration: none; color: var(--ink);
  display: flex; flex-direction: column; gap: 10px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.18s, box-shadow 0.18s, border-color 0.18s;
}
.tool-card:hover { transform: translateY(-3px); box-shadow: var(--shadow-lg); border-color: #c4d0e2; }
.tool-icon {
  width: 44px; height: 44px; border-radius: 12px; background: var(--navy);
  display: grid; place-items: center; margin-bottom: 2px;
}
.tool-card:nth-child(3n+2) .tool-icon { background: var(--navy-700); }
.tool-card h3 { margin: 0; font-size: 18px; letter-spacing: -0.01em; }
.tool-card p { margin: 0; font-size: 14.5px; color: var(--muted); flex: 1; }
.tool-card .go { font-size: 14px; font-weight: 700; color: var(--green-dark); display: inline-flex; align-items: center; gap: 6px; }
.tool-card:hover .go { color: var(--green-dark); }
.tool-card .go::after { content: "→"; transition: transform 0.18s; }
.tool-card:hover .go::after { transform: translateX(4px); }

.related { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 14px; }
.related a {
  background: var(--card); border: 1px solid var(--border); border-radius: 999px;
  padding: 9px 18px; font-size: 14px; font-weight: 500; text-decoration: none; color: var(--navy);
  transition: border-color 0.15s, box-shadow 0.15s, transform 0.15s;
}
.related a:hover { border-color: var(--green); box-shadow: var(--shadow-sm); transform: translateY(-1px); }

/* ---------- Contact ---------- */
.contact-grid {
  display: grid; grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  gap: 22px; align-items: start; margin-top: 26px; max-width: 1000px;
}
.contact-form { margin: 0; display: flex; flex-direction: column; gap: 18px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.label-hint { font-weight: 500; color: var(--muted); }
.field .errorlist { color: #b91c1c; font-size: 13px; margin: 2px 0 0; padding-left: 0; list-style: none; }
.contact-aside { display: flex; flex-direction: column; gap: 16px; }
.aside-card {
  background: var(--card); border: 1px solid var(--border); border-radius: 14px;
  padding: 20px 22px; font-size: 14.5px; color: var(--muted); box-shadow: var(--shadow-sm);
}
.aside-card h3 { margin: 0 0 8px; font-size: 16px; }
.aside-card p { margin: 8px 0; }
.aside-card ul { margin: 8px 0; padding-left: 20px; display: flex; flex-direction: column; gap: 4px; }
@media (max-width: 760px) {
  .contact-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
}

/* ---------- Buttons ---------- */
.btn-primary {
  font: inherit; font-weight: 700; font-size: 16px;
  background: var(--green-dark); color: #fff; border: 0; border-radius: 10px;
  padding: 13px 28px; cursor: pointer; min-height: 48px;
  box-shadow: var(--shadow-sm); transition: background 0.15s, transform 0.15s, box-shadow 0.15s;
}
.btn-primary:hover { background: var(--green); transform: translateY(-1px); box-shadow: var(--shadow-md); }

/* ---------- Footer ---------- */
.site-footer { background: var(--navy); color: #9fb4d2; margin-top: 56px; }
.site-footer .wrap {
  max-width: 1120px; margin: 0 auto; padding: 44px 24px 32px;
  display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 36px; font-size: 14px;
}
.site-footer h4 {
  color: #ffffff; font-size: 12.5px; letter-spacing: 0.1em; text-transform: uppercase;
  margin: 0 0 12px; font-weight: 700;
}
.site-footer ul { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 8px; }
.site-footer a { color: #b9c8de; text-decoration: none; }
.site-footer a:hover { color: #ffffff; text-decoration: underline; }
.footer-brand { display: flex; align-items: center; gap: 10px; margin-bottom: 12px; }
.footer-blurb { max-width: 300px; line-height: 1.7; }
.site-footer .legal {
  grid-column: 1 / -1; border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 18px; font-size: 12.5px; color: #7e93b3;
}

@media (max-width: 820px) {
  .site-footer .wrap { grid-template-columns: 1fr 1fr; }
  .hero-keys { display: none; }
}
@media (max-width: 560px) {
  .site-footer .wrap { grid-template-columns: 1fr; gap: 24px; }
  .hero .wrap { padding: 48px 20px 44px; }
  .page { padding: 28px 20px 56px; }
  .calc-card { padding: 20px; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
  html { scroll-behavior: auto; }
}