/* Helderlab — one-page company site.
   Placeholder accent colour: the name means "clear/bright" in Dutch, so a
   restrained blue stands in until real brand colours exist. Swap --accent. */

:root {
  --bg:          #ffffff;
  --bg-alt:      #f6f8fa;
  --fg:          #0f1419;
  --fg-muted:    #5b6673;
  --rule:        #e3e8ee;
  --accent:      #1a6acb;
  --accent-fg:   #ffffff;
  --placeholder-bg: #fff6d8;
  --placeholder-fg: #6b5310;
  --placeholder-rule: #e6c761;
  --maxw: 62rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg:        #0d1117;
    --bg-alt:    #131a23;
    --fg:        #e6edf3;
    --fg-muted:  #9aa7b4;
    --rule:      #222b36;
    --accent:    #58a6ff;
    --accent-fg: #0d1117;
    --placeholder-bg: #2a2412;
    --placeholder-fg: #e8cf8a;
    --placeholder-rule: #6b5a24;
  }
}

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 400 clamp(16px, 1.05vw, 17px)/1.65 ui-sans-serif, system-ui, -apple-system,
        "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.wrap { max-width: var(--maxw); margin-inline: auto; padding-inline: clamp(1.25rem, 5vw, 2.5rem); }

a { color: var(--accent); text-decoration-thickness: 1px; text-underline-offset: 2px; }
a:hover { text-decoration-thickness: 2px; }

/* ---------- header ---------- */
.site-header {
  border-bottom: 1px solid var(--rule);
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(8px);
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; min-height: 4rem;
}
.wordmark {
  font-weight: 650; font-size: 1.125rem; letter-spacing: -0.02em;
  color: var(--fg); text-decoration: none;
}
.lang { display: flex; gap: .25rem; font-size: .8125rem; }
.lang a, .lang span {
  padding: .25rem .5rem; border-radius: .375rem; text-decoration: none;
  color: var(--fg-muted);
}
.lang [aria-current="true"] { background: var(--bg-alt); color: var(--fg); font-weight: 600; }

/* ---------- sections ---------- */
section { padding-block: clamp(3rem, 8vw, 5.5rem); border-bottom: 1px solid var(--rule); }
section:last-of-type { border-bottom: 0; }
.alt { background: var(--bg-alt); }

h1 {
  font-size: clamp(2.125rem, 5.5vw, 3.25rem); line-height: 1.12;
  letter-spacing: -0.035em; font-weight: 650; margin: 0 0 1rem; max-width: 20ch;
}
h2 {
  font-size: clamp(1.375rem, 2.6vw, 1.75rem); letter-spacing: -0.02em;
  font-weight: 620; margin: 0 0 1.75rem;
}
h3 { font-size: 1.0625rem; font-weight: 620; margin: 0 0 .5rem; letter-spacing: -0.01em; }
p  { margin: 0 0 1rem; max-width: 68ch; }
.lead { font-size: clamp(1.0625rem, 1.9vw, 1.25rem); color: var(--fg-muted); max-width: 52ch; }

.actions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 2rem; }
.btn {
  display: inline-block; padding: .7rem 1.35rem; border-radius: .5rem;
  font-weight: 560; font-size: .9375rem; text-decoration: none;
  background: var(--accent); color: var(--accent-fg); border: 1px solid transparent;
}
.btn:hover { filter: brightness(1.08); text-decoration: none; }
.btn-secondary { background: transparent; color: var(--fg); border-color: var(--rule); }

.grid { display: grid; gap: 1.5rem; grid-template-columns: repeat(auto-fit, minmax(15rem, 1fr)); }
.card {
  padding: 1.5rem; border: 1px solid var(--rule); border-radius: .75rem;
  background: var(--bg);
}
.card p { margin: 0; color: var(--fg-muted); font-size: .9375rem; }

dl.facts { display: grid; grid-template-columns: auto 1fr; gap: .5rem 1.5rem; margin: 0; font-size: .9375rem; }
dl.facts dt { color: var(--fg-muted); }
dl.facts dd { margin: 0; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--rule); background: var(--bg-alt);
  padding-block: 2.5rem; font-size: .875rem; color: var(--fg-muted);
}
.site-footer .wrap { display: flex; flex-wrap: wrap; gap: 1rem 2rem; justify-content: space-between; }
.site-footer p { margin: 0; }

/* ---------- placeholder marker ----------
   Every span of copy that still needs a real fact from the business is wrapped
   in .todo so nothing invented can silently ship. Delete the wrapper, not just
   the class, once the real text is in. */
.todo {
  background: var(--placeholder-bg);
  color: var(--placeholder-fg);
  box-shadow: inset 0 0 0 1px var(--placeholder-rule);
  border-radius: .25rem;
  padding: .05em .35em;
}
.todo::before { content: "▲ "; opacity: .7; }

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}