/* ==========================================================================
   Exam Insights — Base layer
   Lightweight reset + global element defaults. Depends on tokens.css.
   ========================================================================== */

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

/* The `hidden` attribute must always win — author display rules (e.g. .btn
   { display: inline-flex }) otherwise override the UA [hidden] rule and the
   auth-state nav toggling silently fails for button elements. */
[hidden] { display: none !important; }

html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  scroll-behavior: smooth;
  background: var(--color-bg);
  /* Sticky nav offset so anchored content isn't hidden behind the bar */
  scroll-padding-top: calc(var(--nav-height) + var(--space-4));
}

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: var(--leading-normal);
  color: var(--color-text);
  background: var(--color-bg);
  font-feature-settings: 'cv05' 1, 'ss01' 1; /* Inter: subtle stylistic refinement */
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  min-height: 100dvh;
  overflow-x: hidden;
  /* Own stacking context so the negative-z ambient orbs paint above body's
     background (otherwise they resolve into the root context and the opaque
     body fill covers them). */
  isolation: isolate;
  transition: background-color var(--dur) var(--ease-out),
              color var(--dur) var(--ease-out);
}

/* --- Headings: editorial display face ------------------------------------ */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: var(--weight-semibold);
  line-height: var(--leading-tight);
  letter-spacing: var(--tracking-tight);
  color: var(--color-text);
  /* Fraunces optical sizing + soft character for headline warmth */
  font-optical-sizing: auto;
  text-wrap: balance;
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); letter-spacing: var(--tracking-snug); }
h4 { font-size: var(--text-xl); letter-spacing: var(--tracking-snug); }

h5, h6 {
  font-family: var(--font-sans);
  font-weight: var(--weight-semibold);
  line-height: var(--leading-snug);
}
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
  max-width: var(--container-text);
  text-wrap: pretty;
}

a {
  color: var(--color-accent-text);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}
a:hover { color: var(--color-accent-hover); }

strong, b { font-weight: var(--weight-semibold); }

small { font-size: var(--text-sm); }

code, pre, kbd, samp {
  font-family: var(--font-mono);
  font-size: 0.92em;
}

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

ul, ol { list-style: none; }

button {
  font: inherit;
  color: inherit;
  background: none;
  border: none;
  cursor: pointer;
}

input, select, textarea {
  font: inherit;
  color: inherit;
}

::selection {
  background: var(--color-accent);
  color: var(--color-text-on-accent);
}

/* --- Focus: visible ring for keyboard users only ------------------------- */
:focus-visible {
  outline: 2px solid var(--color-ring);
  outline-offset: 2px;
  border-radius: var(--radius-xs);
}
:focus:not(:focus-visible) { outline: none; }

/* --- Skip link (a11y) ---------------------------------------------------- */
.skip-link {
  position: fixed;
  top: var(--space-3);
  left: var(--space-3);
  z-index: var(--z-toast);
  padding: var(--space-2) var(--space-4);
  background: var(--color-text);
  color: var(--color-bg);
  border-radius: var(--radius-sm);
  font-weight: var(--weight-medium);
  transform: translateY(-150%);
  transition: transform var(--dur) var(--ease-out);
}
.skip-link:focus { transform: translateY(0); color: var(--color-bg); }

/* --- Scrollbar ----------------------------------------------------------- */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
  background: var(--color-border-strong);
  border-radius: var(--radius-full);
  border: 2px solid var(--color-bg);
}
::-webkit-scrollbar-thumb:hover { background: var(--color-text-faint); }

/* --- Layout helpers ------------------------------------------------------ */
.container {
  width: 100%;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: var(--gutter);
}
.container--wide { max-width: var(--container-wide); }
.container--text { max-width: var(--container-text); }

/* Honour iPhone safe areas (notch / Dynamic Island / rounded corners) so
   edge content clears the cutouts in landscape. No effect on devices without
   insets, where env() resolves to 0. */
@supports (padding: max(0px)) {
  .container {
    padding-inline:
      max(var(--gutter), env(safe-area-inset-left))
      max(var(--gutter), env(safe-area-inset-right));
  }
}

/* Ultra-wide displays: give the editorial column a little more presence
   without stretching line lengths past comfortable reading. */
@media (min-width: 1700px) {
  :root { --container: 1240px; --container-wide: 1440px; }
}

.section { padding-block: var(--section-y); }

.stack > * + * { margin-top: var(--space-4); }
.stack-sm > * + * { margin-top: var(--space-2); }
.stack-lg > * + * { margin-top: var(--space-8); }

.cluster {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
}

/* --- Typographic utilities ----------------------------------------------- */
.eyebrow {
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  letter-spacing: var(--tracking-eyebrow);
  text-transform: uppercase;
  color: var(--color-accent-text);
}
.lead {
  font-size: var(--text-md);
  line-height: var(--leading-relaxed);
  color: var(--color-text-soft);
}
.text-muted { color: var(--color-text-muted); }
.text-balance { text-wrap: balance; }
.tabular { font-variant-numeric: tabular-nums; }

/* Visually hidden but available to screen readers */
.visually-hidden {
  position: absolute !important;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

/* ==========================================================================
   AMBIENT BACKGROUND — drifting liquid-glass orbs behind every page.
   Fixed full-viewport, painted above the page fill (z-index:-1) but below all
   content. Each orb drifts on its own slow keyframe loop.
   ========================================================================== */
.bg-orbs {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  overflow: hidden;
}
.orb {
  position: absolute;
  border-radius: var(--radius-full);
  opacity: var(--orb-opacity);
  will-change: transform;
  filter: blur(10px);
}
.orb--1 { width: 44vmax; height: 44vmax; left: -8vmax; top: -8vmax;
  background: radial-gradient(circle at 50% 50%, var(--orb-1), transparent 68%);
  animation: orb-a 30s var(--ease-in-out) infinite; }
.orb--2 { width: 38vmax; height: 38vmax; right: -6vmax; top: -4vh;
  background: radial-gradient(circle at 50% 50%, var(--orb-2), transparent 68%);
  animation: orb-b 38s var(--ease-in-out) infinite; }
.orb--3 { width: 36vmax; height: 36vmax; left: 4vw; bottom: -12vmax;
  background: radial-gradient(circle at 50% 50%, var(--orb-3), transparent 68%);
  animation: orb-c 34s var(--ease-in-out) infinite; }
.orb--4 { width: 30vmax; height: 30vmax; right: 6vw; bottom: -8vmax;
  background: radial-gradient(circle at 50% 50%, var(--orb-4), transparent 68%);
  animation: orb-d 42s var(--ease-in-out) infinite; }

@keyframes orb-a { 0%,100% { transform: translate3d(0,0,0) scale(1); }
  50% { transform: translate3d(6vmax, 4vmax, 0) scale(1.12); } }
@keyframes orb-b { 0%,100% { transform: translate3d(0,0,0) scale(1); }
  50% { transform: translate3d(-5vmax, 6vmax, 0) scale(0.9); } }
@keyframes orb-c { 0%,100% { transform: translate3d(0,0,0) scale(1); }
  50% { transform: translate3d(5vmax, -5vmax, 0) scale(1.1); } }
@keyframes orb-d { 0%,100% { transform: translate3d(0,0,0) scale(1); }
  50% { transform: translate3d(-6vmax, -4vmax, 0) scale(0.94); } }

/* ==========================================================================
   LIQUID GLASS — frosted surface utility. Corner sheen + bright edge + blur,
   so the drifting orbs refract through it (the Apple "liquid glass" look).
   ========================================================================== */
.glass {
  background:
    radial-gradient(130% 90% at 0% 0%, var(--glass-sheen), transparent 55%),
    var(--glass-bg);
  -webkit-backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  backdrop-filter: blur(var(--glass-blur)) saturate(180%);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow), var(--glass-inset);
}
.glass--strong { background:
    radial-gradient(130% 90% at 0% 0%, var(--glass-sheen), transparent 55%),
    var(--glass-bg-strong); }

/* Browsers without backdrop-filter: fall back to an opaque surface so text
   never sits on a see-through panel. */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .glass, .glass--strong { background: var(--color-surface); }
}

/* ==========================================================================
   REVEAL — entrance motion for content (arming + stagger in motion.js).
   Only hides content when motion is allowed, so reduced-motion users always
   see it even if the observer never fires.
   ========================================================================== */
[data-animate] {
  transition: opacity 0.6s var(--ease-out), transform 0.6s var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
}
@media (prefers-reduced-motion: no-preference) {
  [data-animate] { opacity: 0; transform: translate3d(0, 18px, 0); }
}
[data-animate].is-in { opacity: 1; transform: none; }

/* --- Reduced motion: global guard ---------------------------------------- */
@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;
  }
}