/* TKTech — tktech.ai
   Hand-written, no framework, matching the house pattern in gate-tktechnology
   and tktech-health. Tokens are defined on bare :root so a colour always has a
   definition outside a media query; the dark block only redefines them. */

:root {
  --ink:        #14181d;
  --ink-soft:   #4a5461;
  --ink-faint:  #6b7684;
  --bg:         #ffffff;
  --bg-soft:    #f5f7f9;
  --line:       #e2e7ec;
  --accent:     #1f6feb;
  --accent-ink: #ffffff;

  --wrap: 68rem;
  --measure: 38rem;

  --font: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink:        #e8edf3;
    --ink-soft:   #a8b3c0;
    --ink-faint:  #7d8894;
    --bg:         #101418;
    --bg-soft:    #171c22;
    --line:       #262d35;
    --accent:     #5a9bff;
    --accent-ink: #0b0e11;
  }
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--font);
  font-size: 1.0625rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: 1.5rem;
}

.skip-link {
  position: absolute;
  left: -9999px;
}
.skip-link:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 0.5rem 0.9rem;
  border-radius: 4px;
}

/* ---------- header ---------- */

.site-header {
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.header-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
  padding-block: 1.1rem;
}
.brand {
  font-weight: 700;
  font-size: 1.2rem;
  letter-spacing: -0.02em;
  color: var(--ink);
  text-decoration: none;
}
.site-header nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.4rem;
}
.site-header nav a {
  color: var(--ink-soft);
  text-decoration: none;
  font-size: 0.95rem;
}
.site-header nav a:hover,
.site-header nav a[aria-current="page"] {
  color: var(--ink);
}

/* ---------- hero ---------- */

.hero {
  background: var(--bg-soft);
  border-bottom: 1px solid var(--line);
  padding-block: clamp(3rem, 8vw, 5.5rem);
}
.hero h1 {
  margin: 0 0 1rem;
  font-size: clamp(1.9rem, 5vw, 3rem);
  line-height: 1.15;
  letter-spacing: -0.025em;
  max-width: 22ch;
}
.lede {
  color: var(--ink-soft);
  font-size: 1.15rem;
  max-width: var(--measure);
}

.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}
.btn {
  display: inline-block;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 0.7rem 1.3rem;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.98rem;
}
.btn:hover { filter: brightness(1.08); }
.btn-quiet {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}

/* ---------- prose ---------- */

.prose { padding-block: 3rem; }
.prose > * { max-width: var(--measure); }
.prose h1 {
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin: 0 0 0.75rem;
}
.prose h2 {
  font-size: 1.4rem;
  letter-spacing: -0.01em;
  margin: 2.75rem 0 0.6rem;
}
.prose h3 { font-size: 1.1rem; margin: 2rem 0 0.4rem; }
.prose p { margin: 0 0 1.1rem; }
.prose hr {
  border: 0;
  border-top: 1px solid var(--line);
  margin: 3rem 0;
}

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

/* ---------- cards ---------- */

section > h2 {
  font-size: 1.4rem;
  letter-spacing: -0.01em;
  margin: 3rem 0 1.25rem;
}
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
  gap: 1.25rem;
  padding-bottom: 4rem;
}
.card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 1.5rem;
  background: var(--bg-soft);
}
.card h3 { margin: 0 0 0.3rem; font-size: 1.15rem; }
.card p { margin: 0 0 0.8rem; font-size: 0.97rem; }
.card-what { color: var(--ink); font-weight: 600; }
.card p:not(.card-what) { color: var(--ink-soft); }
.card a { font-weight: 600; text-decoration: none; }
.card a:hover { text-decoration: underline; }

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

.site-footer {
  border-top: 1px solid var(--line);
  margin-top: auto;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 0.5rem 1.5rem;
  padding-block: 2rem;
  color: var(--ink-faint);
  font-size: 0.92rem;
}
.site-footer p { margin: 0; }

/* Wide content must scroll in its own container, never the page body. */
table, pre { display: block; max-width: 100%; overflow-x: auto; }
img { max-width: 100%; height: auto; }