/* Sparks Analytics — one page, no framework, no build step, no external requests.
   Written to still work untouched in ten years: system fonts, inline SVG,
   plain flexbox/grid, one media query. */

:root {
  --ink:       #16202c;
  --ink-soft:  #495768;
  --ink-faint: #78849a;
  --rule:      #dfe4ec;
  --paper:     #ffffff;
  --paper-alt: #f6f8fb;
  --accent:    #1c5f8b;
  --accent-lit:#2b7fb8;
  --measure:   36rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink:       #e6ecf4;
    --ink-soft:  #a9b5c7;
    --ink-faint: #7d8899;
    --rule:      #26313f;
    --paper:     #10161d;
    --paper-alt: #161e27;
    --accent:    #6fb4dd;
    --accent-lit:#8ecbef;
  }
}

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

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  padding: 0 1.5rem;
  background: var(--paper);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
               "Helvetica Neue", Arial, sans-serif;
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

/* ---------------------------------------------------------------- masthead */

.masthead {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 4rem 0 2.5rem;
  border-bottom: 1px solid var(--rule);
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  margin-bottom: 2rem;
}

.mark {
  width: 1.9rem;
  height: auto;
  flex: none;
  fill: var(--accent);
}

.mark-notch { opacity: 0.5; }

.wordmark {
  margin: 0;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
}

.masthead h1 {
  margin: 0 0 1.4rem;
  font-size: 1.75rem;
  line-height: 1.28;
  font-weight: 600;
  letter-spacing: -0.012em;
  text-wrap: balance;
}

.lede {
  margin: 0;
  font-size: 1.125rem;
  line-height: 1.6;
  color: var(--ink-soft);
}

/* -------------------------------------------------------------------- main */

main { max-width: var(--measure); margin: 0 auto; }

section {
  padding: 2.5rem 0;
  border-bottom: 1px solid var(--rule);
}

section:last-of-type { border-bottom: 0; }

h2 {
  margin: 0 0 1rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ink-faint);
}

p { margin: 0 0 1.1rem; color: var(--ink-soft); }
p:last-child { margin-bottom: 0; }

strong { color: var(--ink); font-weight: 600; }

/* ------------------------------------------------------------------- range */

.range {
  margin: 0;
  padding: 0;
  list-style: none;
}

.range li {
  padding: 1rem 0;
  border-top: 1px solid var(--rule);
  color: var(--ink-soft);
}

.range li:first-child { border-top: 0; padding-top: 0; }
.range li:last-child  { padding-bottom: 0; }

.range-k {
  display: block;
  margin-bottom: 0.2rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--ink);
}

/* ----------------------------------------------------------------- tagline */

.tagline {
  margin: 0 0 1.2rem;
  padding-left: 1rem;
  border-left: 3px solid var(--accent);
  font-size: 1.0625rem;
  font-style: italic;
  color: var(--ink);
}

/* ----------------------------------------------------------------- contact */

.contact {
  background: var(--paper-alt);
  margin: 0 -1.25rem;
  padding: 2.25rem 1.25rem;
  border-radius: 6px;
  border-bottom: 0;
}

.email {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  word-break: break-word;
}

.email:hover,
.email:focus-visible {
  color: var(--accent-lit);
  border-bottom-color: currentColor;
}

.muted {
  margin-top: 0.85rem;
  font-size: 0.9375rem;
  color: var(--ink-faint);
}

/* ------------------------------------------------------------------ footer */

footer { max-width: var(--measure); margin: 0 auto; padding: 2.5rem 0 3.5rem; }
footer p { margin: 0; font-size: 0.8125rem; color: var(--ink-faint); }

/* -------------------------------------------------------- focus visibility */

a:focus-visible {
  outline: 2px solid var(--accent-lit);
  outline-offset: 3px;
  border-radius: 2px;
}

/* --------------------------------------------------------------- wide view */

@media (min-width: 40rem) {
  body { padding: 0 2rem; }

  .masthead { padding: 5.5rem 0 3rem; }
  .masthead h1 { font-size: 2.125rem; }

  .mark { width: 2.2rem; }

  .range li {
    display: grid;
    grid-template-columns: 11rem 1fr;
    gap: 0 1.5rem;
  }

  .range-k { margin-bottom: 0; }

  .contact { margin: 0; padding: 2.25rem 2rem; }
}