/* ═══════════════════════════════════════════════════════════════
   base.css — design tokens, layout, header, navigation.
   Clean light theme · pure white · crisp ink · APSEA red accent.
   Mobile-first · no gradients · no gray text · no beige.
   ═══════════════════════════════════════════════════════════════ */

:root {
  /* ── Surfaces + ink (one strong ink for all text) ── */
  --bg: #FFFFFF;
  --surface: #FFFFFF;
  --ink: #0F1419;          /* every piece of text uses this */

  /* Structural hairlines (lines only — never text) */
  --line: #ECEDF1;
  --line-strong: #E0E2E8;
  --wash: #F4F5F7;         /* quiet neutral fill for chrome that isn't feedback */
  --ink-soft: #2A313B;     /* hover/darker companion to --ink for solid buttons */

  /* ── Brand ── */
  --brand: #D9574A;
  --brand-ink: #B8463C;
  --brand-wash: #FCEEEC;   /* faint, clean — for active / "why" surfaces */

  /* ── Semantic accents (dots · badges · borders only) ── */
  --good: #16A34A;   --good-wash: #E9F8EF;
  --warn: #E0A11B;   --warn-wash: #FCF4DF;
  --refer: #E0742E;  --refer-wash: #FCEFE5;
  --stop: #E0483B;   --stop-wash: #FCEAE8;

  /* Guide-track + topic accents */
  --blue: #2563EB;   --blue-wash: #EAF0FE;
  --teal: #0D9488;   --teal-wash: #E2F5F2;
  --indigo: #6366F1; --indigo-wash: #EEF0FE;

  /* ── Radii ── */
  --radius: 14px;
  --radius-sm: 10px;
  --radius-lg: 20px;
  --radius-pill: 999px;

  /* ── Soft, layered shadows (no gradients) ── */
  --shadow-sm: 0 1px 2px rgba(15,20,25,.05);
  --shadow: 0 2px 8px rgba(15,20,25,.06), 0 8px 24px rgba(15,20,25,.05);
  --shadow-lg: 0 12px 36px rgba(15,20,25,.10);

  /* ── Spacing scale ── */
  --s-1: 4px; --s-2: 8px; --s-3: 12px; --s-4: 16px; --s-5: 24px; --s-6: 32px;

  /* ── Motion — the "smooth" system ── */
  --ease: cubic-bezier(.4, 0, .2, 1);
  --ease-spring: cubic-bezier(.22, 1, .36, 1);
  --dur: 180ms;
  --dur-lg: 300ms;

  --maxw: 880px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  /* Editorial display face for headings + the "Your move" prompt — adds
     typographic contrast against the Inter body text. */
  --font-display: 'Fraunces', Georgia, 'Times New Roman', serif;
  /* Single consistent highlighter for key clinical values (readings, stages). */
  --hl: #FFE9A0;
}

* { margin: 0; padding: 0; box-sizing: border-box; }

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

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

a { color: var(--brand); text-underline-offset: 3px; }

:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--brand) 45%, transparent);
  outline-offset: 2px; border-radius: 6px;
}

/* ── Sticky app bar wraps the header + primary nav (keeps the
      hamburger reachable on mobile while scrolling) ── */
.app-bar { position: sticky; top: 0; z-index: 100; background: var(--surface); }

/* ── Header — clean white, hairline divider, red brand mark ── */
.app-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  display: flex;
  align-items: center;
  gap: 0.7rem;
  padding: 0.75rem 1.1rem;
  padding-top: calc(0.75rem + env(safe-area-inset-top));
}
.app-header .header-logo {
  width: 34px; height: 34px; flex-shrink: 0;
  background: var(--brand);
  -webkit-mask: url(../apsea_logo.svg) center / contain no-repeat;
          mask: url(../apsea_logo.svg) center / contain no-repeat;
}
.app-header .header-text { line-height: 1.25; }
.app-header h1 {
  font-size: clamp(1.02rem, 3.4vw, 1.22rem); font-weight: 800;
  letter-spacing: -0.3px; color: var(--ink);
}
.app-header p {
  font-size: clamp(0.7rem, 2.6vw, 0.8rem); font-weight: 600;
  color: var(--brand);
}

/* ── Hamburger toggle (mobile only) ── */
.nav-toggle {
  margin-left: auto; flex-shrink: 0;
  width: 44px; height: 44px; padding: 0;
  display: inline-flex; align-items: center; justify-content: center;
  background: transparent; border: 1px solid var(--line);
  border-radius: var(--radius-sm); cursor: pointer; color: var(--ink);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.nav-toggle:hover { border-color: var(--line-strong); background: var(--brand-wash); }
.nav-toggle:active { transform: scale(0.95); }
.nav-toggle-bars { position: relative; width: 20px; height: 14px; }
.nav-toggle-bars span {
  position: absolute; left: 0; width: 100%; height: 2px; border-radius: 2px;
  background: currentColor;
  transition: transform var(--dur) var(--ease), opacity var(--dur) var(--ease), top var(--dur) var(--ease);
}
.nav-toggle-bars span:nth-child(1) { top: 0; }
.nav-toggle-bars span:nth-child(2) { top: 6px; }
.nav-toggle-bars span:nth-child(3) { top: 12px; }
.nav-toggle[aria-expanded="true"] { color: var(--brand); border-color: var(--brand); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(1) { top: 6px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars span:nth-child(3) { top: 6px; transform: rotate(-45deg); }

/* ── Primary nav — a dropdown menu on mobile (hidden until opened) ── */
.top-nav { display: none; }
.top-nav.open {
  display: flex; flex-direction: column;
  gap: 2px; padding: 0.4rem;
  border-bottom: 1px solid var(--line);
  box-shadow: var(--shadow);
  animation: navDrop var(--dur) var(--ease) both;
}
@keyframes navDrop { from { opacity: 0; transform: translateY(-6px); } to { opacity: 1; transform: none; } }
.top-nav .nav-btn {
  border: none; background: transparent; cursor: pointer;
  font-family: inherit; font-size: 1rem; font-weight: 600; color: var(--ink);
  width: 100%; text-align: left;
  display: flex; align-items: center; gap: 0.8rem;
  padding: 0.8rem 1rem; min-height: 48px; border-radius: var(--radius-sm);
  transition: background var(--dur) var(--ease), color var(--dur) var(--ease), transform var(--dur) var(--ease);
}
.top-nav .nav-btn:hover { background: var(--brand-wash); color: var(--brand); }
.top-nav .nav-btn:active { transform: scale(0.99); }
.top-nav .nav-btn.active { background: var(--brand); color: #fff; }

/* ── Desktop: persistent horizontal nav bar, no hamburger ── */
@media (min-width: 720px) {
  .app-bar { position: static; background: transparent; }
  .nav-toggle { display: none; }
  .top-nav, .top-nav.open {
    display: flex; flex-direction: row;
    position: sticky; top: 0; z-index: 90;
    justify-content: center; align-items: center; gap: 4px;
    padding: 0.5rem 1rem;
    background: color-mix(in srgb, var(--surface) 90%, transparent);
    -webkit-backdrop-filter: saturate(150%) blur(12px);
            backdrop-filter: saturate(150%) blur(12px);
    border-bottom: 1px solid var(--line);
    box-shadow: none; animation: none;
  }
  .top-nav .nav-btn {
    width: auto; min-height: 0; text-align: center;
    font-size: 0.9rem; gap: 0.45rem;
    padding: 0.55rem 1.05rem; border-radius: var(--radius-pill);
    display: inline-flex;
  }
  .top-nav .nav-btn.active { box-shadow: var(--shadow-sm); }
}

/* ── Sections + container ── */
.container { max-width: var(--maxw); margin: 0 auto; padding: 1.25rem 1rem 2.75rem; }
.section-panel { display: none; }
.section-panel.active { display: block; animation: fadeUp var(--dur-lg) var(--ease-spring) both; }
@keyframes fadeUp { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }

.section-intro {
  font-size: clamp(0.9rem, 2.6vw, 0.98rem);
  font-weight: 500; color: var(--ink);
  max-width: 660px; margin: 0 auto 1.6rem;
  padding: 0.95rem 1.15rem;
  background: var(--surface); border: 1px solid var(--line);
  border-left: 3px solid var(--brand);
  border-radius: var(--radius-sm); line-height: 1.55;
  box-shadow: var(--shadow-sm);
}
.section-intro strong { color: var(--ink); font-weight: 700; }

h2.section-heading {
  font-size: clamp(1.4rem, 5vw, 1.8rem); font-weight: 800; letter-spacing: -0.6px;
  margin: 0 0 0.3rem; text-align: center; color: var(--ink);
}
.section-sub {
  text-align: center; color: var(--ink); margin-bottom: 1.5rem;
  font-size: 0.95rem; font-weight: 500;
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
  .section-panel.active { animation: none; }
}