/* ==========================================================================
   DRishti - shared foundation: tokens, type, navigation, buttons, motion.
   System font stacks only, so every page works offline at a demo venue.
   ========================================================================== */

:root {
  /* brand */
  --ink:        #0f2a1f;
  --ink-2:      #16332a;
  --ink-3:      #1f4436;
  --moss:       #4f8c6d;
  --moss-2:     #5fa080;
  --mint:       #cfe3d8;
  --cream:      #f2ede4;
  --paper:      #faf8f3;
  --line:       #e3e8e4;
  --muted:      #62746a;
  --text:       #1c2a22;

  /* feature + clinical accents */
  --amber:      #e6a53a;
  --amber-2:    #f3c162;
  --amber-ink:  #6b4606;
  --coral:      #d9644a;
  --sky:        #5b9fd0;

  /* ICDR severity scale, 0 -> 4 */
  --g0: #4f8c6d;
  --g1: #9bbf6a;
  --g2: #e0b43a;
  --g3: #e07b3a;
  --g4: #c8463a;

  --serif: "Iowan Old Style", "Palatino Linotype", "Book Antiqua", Palatino, Georgia, serif;
  --sans:  "Segoe UI Variable Text", "Segoe UI", system-ui, -apple-system, Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono:  "Cascadia Mono", Consolas, "SFMono-Regular", Menlo, monospace;

  --radius: 14px;
  --radius-lg: 22px;
  --shadow: 0 18px 44px rgba(15, 42, 31, 0.12);
  --ease-out: cubic-bezier(0.16, 1, 0.3, 1);
  --page-x: clamp(16px, 5vw, 56px);
  --max: 1280px;
}

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

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, svg { display: block; max-width: 100%; }

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 600;
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--ink);
  text-wrap: balance;
}

p { text-wrap: pretty; }

a { color: var(--moss); }
a:hover { color: var(--ink); }

:focus-visible {
  outline: 3px solid var(--amber);
  outline-offset: 3px;
  border-radius: 6px;
}

.skip-link {
  position: absolute;
  left: 12px;
  top: -60px;
  z-index: 100;
  background: var(--amber);
  color: var(--ink);
  padding: 10px 16px;
  border-radius: 10px;
  font-weight: 600;
  text-decoration: none;
}
.skip-link:focus { top: 12px; }

.wrap {
  width: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 var(--page-x);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--moss);
}

.lede {
  font-size: clamp(16px, 1.6vw, 19px);
  color: var(--muted);
  max-width: 62ch;
}

.num { font-family: var(--mono); font-variant-numeric: tabular-nums; }

.hidden { display: none !important; }

/* ------------------------------------------------------------ navigation */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(15, 42, 31, 0.86);
  backdrop-filter: saturate(140%) blur(12px);
  -webkit-backdrop-filter: saturate(140%) blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.07);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 68px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--cream);
  text-decoration: none;
  font-family: var(--serif);
  font-size: 21px;
  font-weight: 600;
  letter-spacing: 0.01em;
}
.brand:hover { color: #fff; }
.brand-mark { width: 30px; height: 30px; flex: none; }
.brand-mark .ring { transform-origin: 16px 16px; animation: spin 14s linear infinite; }

.nav-links {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border-radius: 999px;
  color: var(--mint);
  font-size: 14px;
  font-weight: 500;
  text-decoration: none;
  transition: background 0.2s ease, color 0.2s ease;
}
.nav-links a:hover { background: rgba(255, 255, 255, 0.08); color: #fff; }
.nav-links a[aria-current="page"] { color: #fff; background: rgba(255, 255, 255, 0.1); }

/* The Simulink link is the one highlighted item in the whole nav. */
.nav-links a.nav-feature {
  color: var(--ink);
  background: linear-gradient(135deg, var(--amber-2), var(--amber));
  font-weight: 600;
  box-shadow: 0 0 0 0 rgba(230, 165, 58, 0.55);
  animation: feature-pulse 2.8s ease-out infinite;
}
.nav-links a.nav-feature:hover { color: var(--ink); filter: brightness(1.05); }
.nav-links a.nav-feature[aria-current="page"] { animation: none; }

.live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--ink);
  box-shadow: 0 0 0 0 rgba(15, 42, 31, 0.6);
  animation: dot-pulse 1.6s ease-out infinite;
}

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: var(--cream);
  border-radius: 10px;
  width: 44px;
  height: 44px;
  cursor: pointer;
}
.nav-toggle svg { margin: auto; }

@media (max-width: 880px) {
  .nav-toggle { display: grid; place-items: center; }
  .nav-links {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 2px;
    padding: 12px var(--page-x) 18px;
    background: var(--ink);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    display: none;
  }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 12px 14px; border-radius: 12px; }
}

/* --------------------------------------------------------------- buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 12px 24px;
  border-radius: 999px;
  border: 1px solid transparent;
  font: 600 15px/1.2 var(--sans);
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.2s var(--ease-out), background 0.2s ease,
              box-shadow 0.2s ease, border-color 0.2s ease, color 0.2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn:disabled { opacity: 0.55; cursor: not-allowed; transform: none; }
.btn svg { flex: none; }

.btn-primary { background: var(--moss); color: #fff; box-shadow: 0 10px 24px rgba(79, 140, 109, 0.35); }
.btn-primary:hover { background: var(--moss-2); color: #fff; }

.btn-ghost { background: transparent; color: var(--cream); border-color: rgba(255, 255, 255, 0.32); }
.btn-ghost:hover { border-color: var(--cream); color: #fff; }

.btn-outline { background: transparent; color: var(--ink); border-color: #c9d6ce; }
.btn-outline:hover { border-color: var(--ink); color: var(--ink); }

/* Highlighted feature button: amber, animated sheen and an outer pulse. */
.btn-feature {
  position: relative;
  overflow: hidden;
  color: var(--ink);
  background: linear-gradient(135deg, var(--amber-2), var(--amber));
  box-shadow: 0 12px 30px rgba(230, 165, 58, 0.42);
  animation: feature-pulse 2.8s ease-out infinite;
}
.btn-feature:hover { color: var(--ink); box-shadow: 0 16px 38px rgba(230, 165, 58, 0.55); }
.btn-feature::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(105deg, transparent 35%, rgba(255, 255, 255, 0.55) 50%, transparent 65%);
  transform: translateX(-120%);
  animation: sheen 3.6s ease-in-out infinite;
}
.feature-tag {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 3px 8px;
  border-radius: 999px;
  background: var(--ink);
  color: var(--amber-2);
}

.cta-row { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }

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

.site-footer {
  background: var(--ink);
  color: var(--mint);
  padding: 48px 0 36px;
  font-size: 14px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 32px;
}
.site-footer h4 {
  margin: 0 0 12px;
  font: 600 12px/1 var(--sans);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--cream);
}
.site-footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 8px; }
.site-footer a { color: var(--mint); text-decoration: none; }
.site-footer a:hover { color: #fff; text-decoration: underline; }
.footer-note {
  margin-top: 36px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: #93a99c;
  font-size: 13px;
}
@media (max-width: 760px) {
  .footer-grid { grid-template-columns: 1fr; }
}

/* ------------------------------------------------------ section helpers */

.section { padding: clamp(64px, 9vw, 112px) 0; }
.section-dark { background: var(--ink); color: var(--cream); }
.section-dark h2, .section-dark h3 { color: var(--cream); }
.section-dark .lede { color: #a9c2b4; }
.section-head { max-width: 760px; margin-bottom: clamp(32px, 5vw, 56px); }
.section-head h2 { font-size: clamp(30px, 4.2vw, 48px); margin: 12px 0 14px; }

/* Dark page header shared by the inner pages. */
.page-head {
  background: linear-gradient(160deg, #13362a, var(--ink));
  color: var(--cream);
  padding: clamp(40px, 6vw, 72px) 0 clamp(88px, 10vw, 120px);
}
.page-head h1 { color: #fff; font-size: clamp(36px, 5vw, 56px); margin: 12px 0 12px; }
.page-head .eyebrow { color: var(--amber-2); }
.page-head .lede { color: #b9cfc3; }

/* ------------------------------------------------------------ reveal FX */

.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.8s var(--ease-out), transform 0.8s var(--ease-out);
  transition-delay: var(--delay, 0s);
}
.reveal.in { opacity: 1; transform: none; }

.reveal-scale { opacity: 0; transform: scale(0.94); transition: opacity 0.9s var(--ease-out), transform 0.9s var(--ease-out); transition-delay: var(--delay, 0s); }
.reveal-scale.in { opacity: 1; transform: none; }

.rise { animation: rise-in 0.9s var(--ease-out) both; animation-delay: var(--delay, 0s); }
@keyframes rise-in { from { opacity: 0; transform: translateY(22px); } to { opacity: 1; transform: none; } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes sheen { 0%, 55% { transform: translateX(-120%); } 85%, 100% { transform: translateX(120%); } }
@keyframes feature-pulse {
  0%   { box-shadow: 0 0 0 0 rgba(230, 165, 58, 0.55); }
  70%  { box-shadow: 0 0 0 14px rgba(230, 165, 58, 0); }
  100% { box-shadow: 0 0 0 0 rgba(230, 165, 58, 0); }
}
@keyframes dot-pulse {
  0%   { box-shadow: 0 0 0 0 rgba(15, 42, 31, 0.55); }
  100% { box-shadow: 0 0 0 8px rgba(15, 42, 31, 0); }
}

/* Anyone who asked for less motion gets the finished state immediately. */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  .reveal, .reveal-scale { opacity: 1; transform: none; }
}