:root {
  --bg: #0b0d12;
  --bg-soft: #11141b;
  --card: #161a23;
  --card-hover: #1b2030;
  --fg: #f2f4f8;
  --muted: #99a1b3;
  --line: #232838;
  --accent: #5b8cff;
  --accent-2: #9d7bff;
  --good: #34e0a1;
  --radius: 16px;
  --shadow: 0 10px 30px -12px rgba(0, 0, 0, .6);
  --maxw: 800px;
}

* { box-sizing: border-box; }
html, body { overflow-x: hidden; max-width: 100%; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
img, table { max-width: 100%; }
/* Long words / numbers must never force the page wider than the screen. */
h1, h2, h3, p, .result-value, .bd-value { overflow-wrap: anywhere; }
body {
  margin: 0;
  font-family: "Inter", system-ui, -apple-system, Segoe UI, Roboto, sans-serif;
  background:
    radial-gradient(1100px 500px at 80% -10%, rgba(91, 140, 255, .12), transparent 60%),
    radial-gradient(900px 500px at 0% 0%, rgba(157, 123, 255, .10), transparent 55%),
    var(--bg);
  color: var(--fg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--accent); text-decoration: none; }
a:hover { color: #8fb0ff; }
main { max-width: var(--maxw); margin: 0 auto; padding: 2rem 1.25rem 5rem; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11, 13, 18, .72);
  backdrop-filter: saturate(160%) blur(12px);
  border-bottom: 1px solid var(--line);
}
.header-inner {
  display: flex; justify-content: space-between; align-items: center;
  gap: 1rem; flex-wrap: wrap;
  max-width: var(--maxw); margin: 0 auto; padding: .85rem 1.25rem;
}
.logo {
  display: inline-flex; align-items: center; gap: .5rem;
  font-weight: 800; font-size: 1.15rem; letter-spacing: -.02em; color: var(--fg);
}
.logo:hover { color: var(--fg); }
.logo-mark {
  display: grid; place-items: center; width: 1.7rem; height: 1.7rem;
  border-radius: 9px; font-size: 1rem;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #fff;
}
.site-header nav { display: flex; gap: .35rem; flex-wrap: wrap; }
.site-header nav a {
  color: var(--muted); font-size: .88rem; font-weight: 500;
  padding: .35rem .7rem; border-radius: 999px;
}
.site-header nav a:hover { color: var(--fg); background: var(--bg-soft); }

/* ---------- Hero ---------- */
.hero { text-align: center; padding: 3rem 0 2.5rem; }
.eyebrow {
  display: inline-block; font-size: .78rem; font-weight: 600; letter-spacing: .04em;
  text-transform: uppercase; color: var(--muted);
  border: 1px solid var(--line); border-radius: 999px; padding: .35rem .85rem;
  background: var(--bg-soft);
}
.hero h1 {
  margin: 1.1rem 0 .6rem; font-size: clamp(2.1rem, 6vw, 3.2rem);
  font-weight: 800; letter-spacing: -.03em; line-height: 1.08;
}
.grad {
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero p { color: var(--muted); max-width: 36rem; margin: 0 auto 1.6rem; font-size: 1.08rem; }
.hero-cta {
  display: inline-block; font-weight: 600; color: var(--fg);
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  padding: .7rem 1.3rem; border-radius: 999px; box-shadow: var(--shadow);
}
.hero-cta:hover { color: #fff; filter: brightness(1.08); }

/* ---------- Category + cards ---------- */
.category { margin-top: 3.25rem; }
.cat-title {
  font-size: 1.45rem; font-weight: 700; letter-spacing: -.02em; margin: 0 0 1.1rem;
  display: flex; align-items: center; gap: .65rem;
}
.cat-title::before {
  content: ""; width: .55rem; height: 1.4rem; border-radius: 4px;
  background: linear-gradient(180deg, var(--accent), var(--accent-2));
}
.card-grid {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
}
.card {
  display: flex; flex-direction: column; gap: .5rem;
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.25rem; color: var(--fg);
  transition: transform .15s ease, border-color .15s ease, background .15s ease;
}
.card:hover {
  transform: translateY(-3px); border-color: rgba(91, 140, 255, .55);
  background: var(--card-hover); color: var(--fg);
}
.card h3 { margin: 0; font-size: 1.08rem; font-weight: 650; letter-spacing: -.01em; }
.card p { margin: 0; color: var(--muted); font-size: .9rem; flex: 1; }
.card-go { color: var(--accent); font-size: .85rem; font-weight: 600; margin-top: .2rem; }

/* ---------- Calculator page ---------- */
.breadcrumb { color: var(--muted); font-size: .85rem; margin-bottom: .75rem; }
.breadcrumb a { color: var(--muted); }
.breadcrumb a:hover { color: var(--fg); }
.calc h1 { margin: .2rem 0 .7rem; font-size: clamp(1.7rem, 4vw, 2.3rem); font-weight: 800; letter-spacing: -.02em; }
.intro { color: var(--muted); font-size: 1.02rem; max-width: 42rem; }
.updated { color: var(--muted); font-size: .82rem; margin: -.3rem 0 .8rem; }
.updated time { font-weight: 600; color: var(--fg); }

.calc-form {
  display: grid; gap: 1.1rem; margin: 1.75rem 0;
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.5rem; box-shadow: var(--shadow);
}
@media (min-width: 560px) { .calc-form { grid-template-columns: 1fr 1fr; } }
.field { display: grid; gap: .4rem; font-size: .9rem; }
.field > span { color: var(--muted); font-weight: 500; }
.input-wrap { display: flex; align-items: stretch; }
.input-wrap .affix {
  display: flex; align-items: center; padding: 0 .8rem; background: var(--bg-soft);
  border: 1px solid var(--line); border-right: none;
  border-radius: 10px 0 0 10px; color: var(--muted); font-weight: 600;
}
.field input {
  flex: 1 1 auto; min-width: 0; width: 100%; padding: .7rem .8rem; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg-soft); color: var(--fg);
  font-size: 16px; font-family: inherit; transition: border-color .12s, box-shadow .12s;
}
.input-wrap .affix + input { border-radius: 0 10px 10px 0; }
.field-wide { grid-column: 1 / -1; }
.select-input {
  width: 100%; padding: .7rem .8rem; border-radius: 10px;
  border: 1px solid var(--line); background: var(--bg-soft); color: var(--fg);
  font-size: 16px; font-family: inherit; cursor: pointer;
}
.select-input:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(91, 140, 255, .25);
}
.field input:focus {
  outline: none; border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(91, 140, 255, .25);
}

.result {
  display: flex; justify-content: space-between; align-items: center; gap: 1rem;
  flex-wrap: wrap;
  background: linear-gradient(135deg, rgba(52, 224, 161, .10), rgba(91, 140, 255, .08));
  border: 1px solid rgba(52, 224, 161, .45);
  border-radius: var(--radius); padding: 1.3rem 1.5rem; margin: 1.5rem 0;
}
.result-label { color: var(--muted); font-weight: 500; }
.result-value {
  font-size: clamp(1.8rem, 5vw, 2.4rem); font-weight: 800; letter-spacing: -.02em;
  color: var(--good); font-variant-numeric: tabular-nums;
}

.breakdown {
  display: grid; gap: .75rem; margin: -.5rem 0 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}
.bd-item {
  background: var(--card); border: 1px solid var(--line);
  border-radius: 12px; padding: .9rem 1.1rem;
  display: flex; flex-direction: column; gap: .25rem;
}
.bd-label { color: var(--muted); font-size: .82rem; }
.bd-value {
  font-size: 1.35rem; font-weight: 700; letter-spacing: -.01em;
  color: var(--fg); font-variant-numeric: tabular-nums;
}

.notes {
  font-size: .88rem; color: var(--muted);
  border-left: 3px solid var(--line); padding: .3rem 0 .3rem 1rem; margin: 1.5rem 0;
}
/* ---------- Prose / FAQ (SEO content) ---------- */
.prose { margin-top: 2.5rem; }
.prose h2 { font-size: 1.3rem; font-weight: 700; letter-spacing: -.02em; margin: 0 0 .6rem; }
.prose p { color: var(--muted); max-width: 44rem; }
.faq details {
  border: 1px solid var(--line); border-radius: 12px; padding: 0 1rem;
  margin-bottom: .6rem; background: var(--card);
}
.faq summary {
  cursor: pointer; font-weight: 600; padding: .9rem 0; list-style: none;
  display: flex; justify-content: space-between; align-items: center;
}
.faq summary::after { content: "+"; color: var(--accent); font-size: 1.3rem; }
.faq details[open] summary::after { content: "−"; }
.faq summary::-webkit-details-marker { display: none; }
.faq details p { margin: 0 0 1rem; }

.related { margin-top: 3rem; }
.related h2 { font-size: 1.2rem; font-weight: 700; }
.related ul { list-style: none; padding: 0; display: grid; gap: .5rem; }
.related li a {
  display: block; padding: .7rem 1rem; border: 1px solid var(--line);
  border-radius: 10px; background: var(--card);
}
.related li a:hover { border-color: rgba(91, 140, 255, .5); background: var(--card-hover); }

/* ---------- Ads + footer ---------- */
.ad-slot {
  margin: 1.75rem 0; min-height: 90px; display: flex; align-items: center;
  justify-content: center; border: 1px dashed var(--line); border-radius: 12px;
  color: var(--muted); font-size: .75rem; letter-spacing: .08em; text-transform: uppercase;
}
.site-footer {
  border-top: 1px solid var(--line); text-align: center; color: var(--muted);
  font-size: .85rem; padding: 2rem 1.25rem; margin-top: 3rem;
}
.site-footer .disclaimer { font-size: .78rem; opacity: .8; margin-top: .3rem; }

/* ---------- Small screens / phones ---------- */
@media (max-width: 480px) {
  main { padding: 1.25rem 1rem 4rem; }
  .header-inner { padding: .7rem 1rem; }
  .site-header nav { gap: .15rem; }
  .site-header nav a { padding: .3rem .55rem; font-size: .82rem; }
  .hero { padding: 2rem 0 1.75rem; }
  .calc-form { padding: 1.1rem; gap: .9rem; }
  .result { padding: 1.1rem 1.2rem; }
  .card-grid { grid-template-columns: 1fr; }
  .breakdown { grid-template-columns: 1fr; }
  /* result label + value stack neatly instead of cramping */
  .result { flex-direction: column; align-items: flex-start; gap: .3rem; }
}

/* ---------- Light mode (respects OS preference) ---------- */
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f6f8fc; --bg-soft: #eef2f9; --card: #ffffff; --card-hover: #f3f6fc;
    --fg: #131722; --muted: #5a6275; --line: #e2e8f2;
    --shadow: 0 10px 30px -14px rgba(20, 30, 60, .18);
  }
  body {
    background:
      radial-gradient(1100px 500px at 80% -10%, rgba(91, 140, 255, .10), transparent 60%),
      radial-gradient(900px 500px at 0% 0%, rgba(157, 123, 255, .08), transparent 55%),
      var(--bg);
  }
  .site-header { background: rgba(246, 248, 252, .8); }
}