/* ==========================================================================
   Riveran — base.css
   Design tokens, reset, typography, layout primitives, utilities.
   ========================================================================== */

:root {
  /* Brand palette */
  --color-primary: #0B3D5C;       /* deep river blue */
  --color-primary-700: #082F47;
  --color-primary-900: #052233;
  --color-secondary: #1A9FA6;     /* flowing teal */
  --color-secondary-600: #16858B;
  --color-accent: #E2A23B;        /* warm amber — human craftsmanship */
  --color-accent-600: #C9892A;

  --color-ink: #16202A;           /* headings / dark text */
  --color-body: #33454F;          /* body text */
  --color-muted: #5E727E;         /* secondary text */
  --color-mist: #F5F8FA;          /* light background */
  --color-mist-200: #E7EEF2;
  --color-surface: #FFFFFF;
  --color-border: #DCE5EB;
  --color-border-strong: #C3D1DA;

  --color-on-dark: #EAF2F6;
  --color-on-dark-muted: #A9C2D1;

  /* Typography */
  --font-heading: "Space Grotesk", ui-sans-serif, system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --font-body: "Inter", ui-sans-serif, system-ui, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  /* Type scale (fluid) */
  --fs-xs: 0.8125rem;
  --fs-sm: 0.9375rem;
  --fs-base: 1.0625rem;
  --fs-md: clamp(1.125rem, 0.5vw + 1rem, 1.25rem);
  --fs-lg: clamp(1.35rem, 1vw + 1.1rem, 1.6rem);
  --fs-xl: clamp(1.7rem, 2vw + 1rem, 2.3rem);
  --fs-2xl: clamp(2.1rem, 3.5vw + 1rem, 3.2rem);
  --fs-3xl: clamp(2.6rem, 5vw + 1rem, 4rem);

  /* Spacing scale */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4rem;
  --space-9: 6rem;

  /* Layout */
  --container: 1180px;
  --container-narrow: 760px;
  --radius-sm: 8px;
  --radius: 14px;
  --radius-lg: 22px;
  --radius-pill: 999px;

  --shadow-sm: 0 1px 2px rgba(11, 61, 92, 0.06), 0 2px 8px rgba(11, 61, 92, 0.06);
  --shadow: 0 6px 24px rgba(11, 61, 92, 0.10);
  --shadow-lg: 0 18px 50px rgba(11, 61, 92, 0.16);

  --header-h: 72px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ----- Reset ----- */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}

body {
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.65;
  color: var(--color-body);
  background: var(--color-surface);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg, video { display: block; max-width: 100%; height: auto; }
input, button, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; }

/* ----- Typography ----- */
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  color: var(--color-ink);
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.01em;
}
h1 { font-size: var(--fs-3xl); }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-lg); }
h4 { font-size: var(--fs-md); }

p { color: var(--color-body); }
a { color: var(--color-secondary-600); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* ----- Layout primitives ----- */
.container { width: 100%; max-width: var(--container); margin-inline: auto; padding-inline: var(--space-5); }
.container-narrow { max-width: var(--container-narrow); }

.section { padding-block: clamp(3rem, 7vw, 6rem); }
.section--tight { padding-block: clamp(2rem, 4vw, 3.5rem); }
.section--mist { background: var(--color-mist); }
.section--ink { background: var(--color-primary-900); color: var(--color-on-dark); }
.section--ink h2, .section--ink h3 { color: #fff; }

.section-head { max-width: 720px; margin-bottom: var(--space-7); }
.section-head.center { margin-inline: auto; text-align: center; }

.eyebrow {
  display: inline-block;
  font-family: var(--font-heading);
  font-size: var(--fs-xs);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-secondary-600);
  margin-bottom: var(--space-3);
}
.section--ink .eyebrow { color: var(--color-accent); }

.lead { font-size: var(--fs-md); color: var(--color-muted); }
.section--ink .lead { color: var(--color-on-dark-muted); }

/* ----- Grids ----- */
.grid { display: grid; gap: var(--space-5); }
@media (min-width: 640px) { .grid-2 { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 860px) {
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid-2-wide { grid-template-columns: 1.1fr 0.9fr; align-items: center; }
}

/* ----- Utilities ----- */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-4 { margin-top: var(--space-4); }
.mt-5 { margin-top: var(--space-5); }
.mt-6 { margin-top: var(--space-6); }
.visually-hidden {
  position: absolute !important; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* Accessibility: skip link + focus */
.skip-link {
  position: absolute; left: var(--space-4); top: -120%;
  background: var(--color-primary); color: #fff; padding: 0.6rem 1rem;
  border-radius: var(--radius-sm); z-index: 1000; transition: top 0.2s var(--ease);
}
.skip-link:focus { top: var(--space-4); text-decoration: none; }

:focus-visible {
  outline: 3px solid var(--color-secondary);
  outline-offset: 2px;
  border-radius: 4px;
}