/* ==========================================================================
   Alliance Test Equipment — Design System
   Brand palette sampled directly from the Alliance Test logo:
     Engineering blue  #0060A8
     Signal orange     #E47824
   ========================================================================== */

/* ---------- Tokens ---------- */
:root {
  /* Brand */
  --brand-blue:      #0060A8;
  --brand-blue-600:  #005490;
  --brand-blue-700:  #004884;
  --brand-blue-800:  #003C78;
  --brand-accent:    #E47824;
  --brand-accent-600:#D06A1C;

  /* Neutrals — deep navy through warm white */
  --navy-950: #060B14;
  --navy-900: #0A1220;
  --navy-850: #0E1929;
  --navy-800: #132134;
  --navy-700: #1B2C43;
  --navy-600: #263A54;

  --steel-500: #5A6B82;
  --steel-400: #7C8CA2;
  --steel-300: #A6B2C2;
  --steel-200: #CBD3DE;
  --steel-100: #E3E8EF;
  --steel-50:  #F1F4F8;
  --paper:     #FAFBFC;
  --white:     #FFFFFF;

  /* Semantic */
  --bg:            var(--white);
  --bg-alt:        var(--paper);
  --bg-tint:       var(--steel-50);
  --bg-dark:       var(--navy-900);
  --text:          var(--navy-900);
  --text-muted:    var(--steel-500);
  --text-subtle:   var(--steel-400);
  --text-invert:   #FFFFFF;
  --line:          var(--steel-100);
  --line-strong:   var(--steel-200);
  --line-dark:     rgba(255,255,255,.10);

  --ok:      #1B7F4C;
  --ok-bg:   #E7F4ED;
  --warn:    #A6690C;
  --warn-bg: #FDF3E3;

  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  /* Scale (fluid) */
  --fs-display: clamp(2.5rem, 1.2rem + 4.2vw, 5.5rem);
  --fs-h1:      clamp(2rem, 1.3rem + 2.8vw, 3.6rem);
  --fs-h2:      clamp(1.65rem, 1.15rem + 2vw, 2.7rem);
  --fs-h3:      clamp(1.2rem, 1.02rem + .7vw, 1.6rem);
  --fs-h4:      clamp(1.05rem, .98rem + .3vw, 1.2rem);
  --fs-body:    1rem;
  --fs-sm:      .9125rem;
  --fs-xs:      .8125rem;
  --fs-label:   .6875rem;

  /* Space */
  --sp-1: .25rem;  --sp-2: .5rem;   --sp-3: .75rem;  --sp-4: 1rem;
  --sp-5: 1.5rem;  --sp-6: 2rem;    --sp-7: 2.75rem; --sp-8: 4rem;
  --sp-9: 6rem;    --sp-10: 8rem;
  --section-y: clamp(4.5rem, 3rem + 6vw, 9rem);

  /* Structure */
  --container: 1500px;
  --container-wide: 1500px;
  --radius-xs: 1px;
  --radius-sm: 2px;
  --radius:    3px;
  --radius-lg: 4px;

  /* Elevation — very subtle, engineering-grade */
  --shadow-xs: 0 1px 1px rgba(10,18,32,.03);
  --shadow-sm: 0 1px 2px rgba(10,18,32,.04);
  --shadow:    0 2px 8px rgba(10,18,32,.05);
  --shadow-md: 0 6px 20px rgba(10,18,32,.06);
  --shadow-lg: 0 18px 48px rgba(10,18,32,.10);

  /* Motion */
  --ease:      cubic-bezier(.22,.61,.36,1);
  --ease-out:  cubic-bezier(.16,1,.3,1);
  --ease-in-out: cubic-bezier(.65,0,.35,1);
  --t-fast: 150ms;
  --t:      280ms;
  --t-slow: 480ms;

  --header-h: 88px;
  --header-h-sm: 66px;
}

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

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-h-sm) + 20px);
}

html, body {
  max-width: 100%;
  overflow-x: clip;   /* clip (not hidden) keeps position: sticky working */
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-feature-settings: 'kern' 1, 'liga' 1, 'cv05' 1;
  overflow-x: hidden;
}

img, svg, video, canvas { display: block; max-width: 100%; height: auto; }
input, button, textarea, select { font: inherit; color: inherit; }
button { background: none; border: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; padding: 0; }
table { border-collapse: collapse; width: 100%; }

:focus-visible {
  outline: 2px solid var(--brand-blue);
  outline-offset: 3px;
  border-radius: var(--radius-xs);
}
::selection { background: var(--brand-blue); color: #fff; }

/* ---------- Typography ---------- */
h1, h2, h3, h4, h5 {
  font-weight: 680;
  line-height: 1.12;
  letter-spacing: -0.022em;
  text-wrap: balance;
}
h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); letter-spacing: -.015em; }
h4 { font-size: var(--fs-h4); letter-spacing: -.01em; }
p { text-wrap: pretty; }
/* Model numbers and long tokens wrap rather than widening the layout */
h1, h2, h3, h4, h5, p, li, td, th, a { overflow-wrap: break-word; }

.display {
  font-size: var(--fs-display);
  font-weight: 700;
  line-height: 1.04;
  letter-spacing: -0.035em;
}

/* Small uppercase technical label */
.label {
  display: inline-flex;
  align-items: center;
  gap: .55em;
  font-family: var(--font-mono);
  font-size: var(--fs-label);
  font-weight: 500;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--brand-blue);
}
.label--accent { color: var(--brand-accent); }
.label--invert { color: var(--steel-300); }
.label::before {
  content: '';
  width: 22px; height: 1px;
  background: currentColor;
  opacity: .6;
  flex: none;
}
.label--bare::before { display: none; }

.lede {
  font-size: clamp(1.02rem, .96rem + .35vw, 1.19rem);
  line-height: 1.62;
  color: var(--text-muted);
}
.mono { font-family: var(--font-mono); font-variant-numeric: tabular-nums; }

/* ---------- Layout ---------- */
.container {
  width: 100%;
  max-width: min(var(--container), 100%);
  margin-inline: auto;
  padding-inline: clamp(1.15rem, .6rem + 2.2vw, 2.5rem);
}
.container--wide { max-width: var(--container-wide); }
.container--narrow { max-width: 860px; }

.section { padding-block: var(--section-y); }
.section--tight { padding-block: clamp(3rem, 2rem + 3vw, 4.75rem); }
.section--alt { background: var(--bg-alt); }
.section--tint { background: var(--bg-tint); }
.section--dark { background: var(--bg-dark); color: var(--text-invert); }
.section--dark p, .section--dark .lede { color: var(--steel-300); }

.section-head { max-width: 680px; margin-bottom: clamp(2.75rem, 1.8rem + 2.6vw, 4.25rem); }
.section-head--center { margin-inline: auto; text-align: center; }
.section-head .label { margin-bottom: var(--sp-4); }
.section-head h2 { margin-bottom: var(--sp-4); }

.section-head--split {
  max-width: none;
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--sp-6);
  flex-wrap: wrap;
}
.section-head--split > div:first-child { max-width: 660px; }

.grid { display: grid; gap: var(--sp-5); }
/* Grid and flex children default to min-content width, which forces
   horizontal overflow on narrow screens. Let them shrink instead. */
.grid > *, .split > *, .listing > * { min-width: 0; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 1080px) { .grid-4 { grid-template-columns: repeat(2, 1fr); } .grid-3 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 700px)  { .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; } }

.stack > * + * { margin-top: var(--sp-4); }
.hide-sm { }
@media (max-width: 860px) { .hide-sm { display: none !important; } }
.only-sm { display: none !important; }
@media (max-width: 860px) { .only-sm { display: block !important; } }

.sr-only {
  position: absolute; width: 1px; height: 1px;
  padding: 0; margin: -1px; overflow: hidden;
  clip: rect(0,0,0,0); white-space: nowrap; border: 0;
}
.skip-link {
  position: absolute; left: 12px; top: -60px; z-index: 200;
  background: var(--navy-900); color: #fff;
  padding: .7rem 1.1rem; border-radius: var(--radius);
  transition: top var(--t-fast) var(--ease);
}
.skip-link:focus { top: 12px; }

/* ---------- Buttons ---------- */
.btn {
  --btn-bg: var(--brand-blue);
  --btn-fg: #fff;
  --btn-bd: var(--brand-blue);
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .6em;
  padding: .88rem 1.75rem;
  font-size: var(--fs-sm);
  font-weight: 560;
  letter-spacing: .005em;
  line-height: 1.2;
  color: var(--btn-fg);
  background: var(--btn-bg);
  border: 1px solid var(--btn-bd);
  border-radius: var(--radius);
  cursor: pointer;
  white-space: nowrap;
  transition: background var(--t) var(--ease), border-color var(--t) var(--ease),
              color var(--t) var(--ease), transform var(--t) var(--ease),
              box-shadow var(--t) var(--ease);
}
.btn:hover { box-shadow: var(--shadow-sm); }
.btn:active { transform: translateY(.5px); }
.btn svg { flex: none; }
.btn .arrow { transition: transform var(--t) var(--ease); }
.btn:hover .arrow { transform: translateX(3px); }

.btn--primary { --btn-bg: var(--brand-blue); --btn-bd: var(--brand-blue); }
.btn--primary:hover { --btn-bg: var(--brand-blue-700); --btn-bd: var(--brand-blue-700); }

.btn--accent { --btn-bg: var(--brand-accent); --btn-bd: var(--brand-accent); }
.btn--accent:hover { --btn-bg: var(--brand-accent-600); --btn-bd: var(--brand-accent-600); }

.btn--dark { --btn-bg: var(--navy-900); --btn-bd: var(--navy-900); }
.btn--dark:hover { --btn-bg: var(--navy-800); --btn-bd: var(--navy-800); }

.btn--ghost {
  --btn-bg: transparent; --btn-fg: var(--text); --btn-bd: var(--line-strong);
}
.btn--ghost:hover { --btn-bd: var(--navy-900); --btn-bg: transparent; }

.btn--ghost-invert {
  --btn-bg: transparent; --btn-fg: #fff; --btn-bd: rgba(255,255,255,.26);
}
.btn--ghost-invert:hover { --btn-bd: rgba(255,255,255,.6); --btn-bg: rgba(255,255,255,.06); }

.btn--sm { padding: .58rem 1.15rem; font-size: var(--fs-xs); }
.btn--lg { padding: 1.05rem 2.15rem; font-size: .975rem; }
.btn--block { width: 100%; }

/* Text link with animated underline */
.link-arrow {
  display: inline-flex;
  align-items: center;
  gap: .5em;
  font-size: var(--fs-sm);
  font-weight: 580;
  color: var(--brand-blue);
  position: relative;
}
.link-arrow::after {
  content: '';
  position: absolute; left: 0; bottom: -2px;
  width: 100%; height: 1px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--t) var(--ease);
}
.link-arrow:hover::after { transform: scaleX(1); transform-origin: left; }
.link-arrow .arrow { transition: transform var(--t) var(--ease); }
.link-arrow:hover .arrow { transform: translateX(3px); }
.link-arrow--invert { color: #fff; }

/* ---------- Surfaces ---------- */
.card {
  position: relative;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color var(--t) var(--ease), box-shadow var(--t) var(--ease),
              transform var(--t) var(--ease);
}
.card--hover:hover {
  border-color: var(--navy-900);
  box-shadow: var(--shadow-md);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: .4em;
  padding: .28rem .6rem;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 500;
  letter-spacing: .09em;
  text-transform: uppercase;
  border-radius: 0;
  background: var(--steel-50);
  color: var(--steel-500);
  border: 1px solid var(--line);
  white-space: nowrap;
}
.tag--ok   { background: var(--ok-bg);   color: var(--ok);   border-color: transparent; }
.tag--warn { background: var(--warn-bg); color: var(--warn); border-color: transparent; }
.tag--blue { background: rgba(0,96,168,.08); color: var(--brand-blue); border-color: transparent; }
.tag--accent { background: rgba(228,120,36,.10); color: var(--brand-accent-600); border-color: transparent; }

/* Fine engineering grid pattern */
.grid-pattern {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(to right, rgba(255,255,255,.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 56px 56px;
  pointer-events: none;
}
.grid-pattern--light {
  background-image:
    linear-gradient(to right, rgba(10,18,32,.045) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(10,18,32,.045) 1px, transparent 1px);
}
.grid-pattern--fade {
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 20%, transparent 78%);
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 20%, transparent 78%);
}

/* ---------- Forms ---------- */
.field { display: block; }
.field + .field { margin-top: var(--sp-4); }
.field-label {
  display: block;
  font-size: var(--fs-xs);
  font-weight: 580;
  color: var(--text);
  margin-bottom: .4rem;
}
.field-label .req { color: var(--brand-accent); }
.input, .select, .textarea {
  width: 100%;
  padding: .72rem .9rem;
  font-size: var(--fs-sm);
  color: var(--text);
  background: var(--white);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  transition: border-color var(--t-fast) var(--ease), box-shadow var(--t-fast) var(--ease);
}
.input::placeholder, .textarea::placeholder { color: var(--text-subtle); }
.input:focus, .select:focus, .textarea:focus {
  outline: none;
  border-color: var(--brand-blue);
  box-shadow: 0 0 0 3px rgba(0,96,168,.12);
}
.textarea { resize: vertical; min-height: 118px; }
.select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath d='M1 1.5 6 6.5l5-5' stroke='%235A6B82' stroke-width='1.6' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right .85rem center;
  padding-right: 2.2rem;
}
.field-hint { font-size: var(--fs-xs); color: var(--text-subtle); margin-top: .35rem; }
.field-error { font-size: var(--fs-xs); color: #B3261E; margin-top: .35rem; display: none; }
.field.is-invalid .input,
.field.is-invalid .textarea,
.field.is-invalid .select { border-color: #B3261E; }
.field.is-invalid .field-error { display: block; }
.honeypot { position: absolute !important; left: -9999px !important; }

/* ---------- Scroll reveal ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 700ms var(--ease-out), transform 700ms var(--ease-out);
  transition-delay: var(--reveal-delay, 0ms);
  will-change: opacity, transform;
}
[data-reveal].is-in { opacity: 1; transform: none; }

/* ---------- Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
    scroll-behavior: auto !important;
  }
  [data-reveal] { opacity: 1 !important; transform: none !important; }
}

/* ---------- Utilities ---------- */
.text-center { text-align: center; }
.text-muted { color: var(--text-muted); }
.mt-0 { margin-top: 0; } .mt-4 { margin-top: var(--sp-4); }
.mt-5 { margin-top: var(--sp-5); } .mt-6 { margin-top: var(--sp-6); }
.mb-4 { margin-bottom: var(--sp-4); } .mb-5 { margin-bottom: var(--sp-5); }
.flex { display: flex; }
.items-center { align-items: center; }
.gap-3 { gap: var(--sp-3); } .gap-4 { gap: var(--sp-4); }
.wrap { flex-wrap: wrap; }
.rule { height: 1px; background: var(--line); border: 0; }