/* BiDaFa Ltd site styles.
   No external fonts and no JavaScript: the page should render on first paint.
   Colours are defined as custom properties on :root (light) and overridden for dark. */

:root {
  --bg: #ffffff;
  --bg-alt: #f6f7f9;
  --ink: #16202e;
  --ink-soft: #4a5768;
  --rule: #dfe3e9;
  --accent: #1d4ed8;
  --accent-ink: #ffffff;
  --note-bg: #eef2ff;
  --note-ink: #27357a;
  --note-rule: #c3cdf5;

  --wrap: 68rem;
  --step-0: 1.0625rem;
  --step-1: 1.25rem;
  --step-2: 1.5rem;
  --step-3: 2rem;
  --step-4: clamp(2.1rem, 1.3rem + 3.4vw, 3.4rem);

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

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --bg-alt: #16203a;
    --ink: #e8edf5;
    --ink-soft: #a6b3c8;
    --rule: #2a3550;
    --accent: #93b4ff;
    --accent-ink: #0f172a;
    --note-bg: #1c2a4d;
    --note-ink: #cfdcff;
    --note-rule: #38508c;
  }
}

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

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

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

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: 1.35rem;
}

a { color: var(--accent); }
a:focus-visible, .button:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 3px;
  border-radius: 3px;
}

.skip {
  position: absolute;
  left: -9999px;
}
.skip:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  background: var(--accent);
  color: var(--accent-ink);
  padding: 0.6rem 1rem;
  border-radius: 6px;
}

/* Header */

.site-header {
  border-bottom: 1px solid var(--rule);
  background: var(--bg);
}
.header-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.5rem;
  align-items: center;
  justify-content: space-between;
  padding-block: 1rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 700;
  font-size: var(--step-1);
  letter-spacing: -0.01em;
  color: var(--ink);
  text-decoration: none;
}
.brand-mark {
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  border-radius: 7px;
  background: var(--accent);
  color: var(--accent-ink);
  font-size: 1.05rem;
  font-weight: 700;
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 0.97rem;
}
.nav a { color: var(--ink-soft); text-decoration: none; }
.nav a:hover { color: var(--accent); text-decoration: underline; }

/* Hero */

.hero { padding-block: clamp(3rem, 1.5rem + 6vw, 5.5rem) clamp(2rem, 1rem + 4vw, 3.5rem); }
.eyebrow {
  margin: 0 0 0.9rem;
  font-size: 0.83rem;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.hero h1 {
  margin: 0 0 1.1rem;
  max-width: 20ch;
  font-size: var(--step-4);
  line-height: 1.1;
  letter-spacing: -0.025em;
  font-weight: 700;
}
.lead {
  margin: 0 0 1.5rem;
  max-width: 62ch;
  font-size: var(--step-1);
  color: var(--ink-soft);
}
.status {
  display: inline-block;
  margin: 0;
  padding: 0.7rem 1.05rem;
  border: 1px solid var(--note-rule);
  border-left-width: 4px;
  border-radius: 7px;
  background: var(--note-bg);
  color: var(--note-ink);
  font-size: 0.97rem;
  font-weight: 500;
}

/* Bands */

.band { padding-block: clamp(2.5rem, 1.5rem + 4vw, 4rem); }
.band-alt { background: var(--bg-alt); border-block: 1px solid var(--rule); }

h2 {
  margin: 0 0 1rem;
  font-size: var(--step-3);
  line-height: 1.2;
  letter-spacing: -0.02em;
  font-weight: 700;
}
h3 {
  margin: 0 0 0.4rem;
  font-size: var(--step-1);
  line-height: 1.3;
  font-weight: 650;
}
.prose p { max-width: 68ch; margin: 0 0 1rem; }
.prose p:last-child { margin-bottom: 0; }
.section-intro {
  max-width: 68ch;
  margin: 0 0 1.75rem;
  color: var(--ink-soft);
}

/* Principles */

.principles {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  gap: 1.4rem;
  margin: 0;
  padding: 0;
  list-style: none;
}
.principle {
  padding: 1.35rem;
  border: 1px solid var(--rule);
  border-radius: 11px;
  background: var(--bg);
}
.principle p { margin: 0; color: var(--ink-soft); }

/* Contact */

.button {
  display: inline-block;
  padding: 0.72rem 1.35rem;
  border-radius: 8px;
  background: var(--accent);
  color: var(--accent-ink);
  font-weight: 600;
  text-decoration: none;
}
.button:hover { filter: brightness(1.08); }
.email-plain { font-size: 0.95rem; color: var(--ink-soft); }

/* Footer */

.site-footer {
  padding-block: 2.25rem;
  border-top: 1px solid var(--rule);
  background: var(--bg);
  color: var(--ink-soft);
  font-size: 0.9rem;
}
.site-footer p { margin: 0 0 0.5rem; max-width: 78ch; }
.site-footer p:last-child { margin-bottom: 0; }

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