/* ============================================================
   extN Technologies — Blueprint Design System
   Classic cyanotype: white linework on deep blueprint blue.
   Clean grotesk primary + monospace drafting annotations.
   ============================================================ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500;600&display=swap');

:root {
  color-scheme: light;

  /* --- Ground (blueprint paper) — LIGHT is the default theme --- */
  --bp-bg:        #ddf0fb;   /* pale cyan blueprint sheet       */
  --bp-bg-2:      #c9e4f5;   /* footer / darker panel           */
  --bp-bg-3:      #ecf7fe;   /* raised panel                    */

  /* --- Ink (linework + type) --- */
  --bp-ink:       #122f63;   /* navy ink                        */
  --bp-ink-soft:  #2c4f86;   /* secondary text                 */
  --bp-ink-faint: #4f6fa0;   /* tertiary / captions            */

  /* --- Lines --- */
  --bp-line:      rgba(20,52,110,0.52);    /* drawn lines      */
  --bp-line-soft: rgba(20,52,110,0.24);
  --bp-grid:      rgba(30,80,150,0.09);    /* fine graph grid  */
  --bp-grid-maj:  rgba(30,80,150,0.16);    /* major grid       */

  /* --- Accent: drafting revision red/orange (use sparingly) --- */
  --bp-accent:      #d9542b;
  --bp-accent-soft: rgba(217,84,43,0.14);

  /* --- Surfaces (theme-able) --- */
  --bp-vignette:        rgba(120,160,210,0.26); /* paper edge shadow  */
  --bp-nav-bg:          rgba(221,240,251,0.85); /* sticky nav         */
  --bp-panel-bg:        rgba(255,255,255,0.58); /* panels / form sheet*/
  --bp-input-bg:        rgba(255,255,255,0.66); /* form fields        */
  --bp-input-bg-focus:  rgba(255,255,255,0.97);
  --bp-hatch:           rgba(20,52,110,0.08);   /* placeholder hatch  */

  /* --- Type --- */
  --font-sans: "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, "SFMono-Regular", Menlo, monospace;

  /* --- Metrics --- */
  --grid-unit: 24px;
  --hair: 1px;
  --rule: 1.5px;
  --maxw: 1200px;
}

/* ============================================================
   DARK THEME — original cyanotype: white linework on deep
   blueprint blue. Opt-in via the nav toggle (data-theme=dark).
   ============================================================ */
:root[data-theme="dark"] {
  color-scheme: dark;
  --bp-bg:        #0c2c57;
  --bp-bg-2:      #0a2548;
  --bp-bg-3:      #0e3262;
  --bp-ink:       #eaf2ff;
  --bp-ink-soft:  #b9d0f0;
  --bp-ink-faint: #7f9ec9;
  --bp-line:      rgba(196,219,255,0.55);
  --bp-line-soft: rgba(196,219,255,0.28);
  --bp-grid:      rgba(150,190,255,0.085);
  --bp-grid-maj:  rgba(150,190,255,0.16);
  --bp-accent:      #ff8a5c;
  --bp-accent-soft: rgba(255,138,92,0.16);
  --bp-vignette:        rgba(4,16,38,0.55);
  --bp-nav-bg:          rgba(10,37,72,0.82);
  --bp-panel-bg:        rgba(14,50,98,0.35);
  --bp-input-bg:        rgba(8,28,58,0.5);
  --bp-input-bg-focus:  rgba(8,28,58,0.8);
  --bp-hatch:           rgba(196,219,255,0.06);
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bp-bg);
  color: var(--bp-ink);
  font-family: var(--font-sans);
  font-size: 17px;
  line-height: 1.6;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background-color .35s ease, color .35s ease;
}
.bp-grid, .bp-nav, .panel, .site-footer, .cta-band { transition: background-color .35s ease, border-color .35s ease; }

/* ---------- Graph-paper grid background ---------- */
.bp-grid {
  background-color: var(--bp-bg);
  background-image:
    linear-gradient(var(--bp-grid) var(--hair), transparent var(--hair)),
    linear-gradient(90deg, var(--bp-grid) var(--hair), transparent var(--hair)),
    linear-gradient(var(--bp-grid-maj) var(--hair), transparent var(--hair)),
    linear-gradient(90deg, var(--bp-grid-maj) var(--hair), transparent var(--hair));
  background-size:
    var(--grid-unit) var(--grid-unit),
    var(--grid-unit) var(--grid-unit),
    calc(var(--grid-unit) * 5) calc(var(--grid-unit) * 5),
    calc(var(--grid-unit) * 5) calc(var(--grid-unit) * 5);
  background-position: -1px -1px;
}

/* faint vignette so edges feel like paper */
.bp-paper {
  position: relative;
}
.bp-paper::after {
  content: "";
  position: absolute; inset: 0;
  pointer-events: none;
  box-shadow: inset 0 0 200px var(--bp-vignette);
}

/* ---------- Typography ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.015em;
  margin: 0 0 0.4em;
}
.display {
  font-size: clamp(40px, 7vw, 92px);
  font-weight: 800;
  letter-spacing: -0.03em;
}
.h2 { font-size: clamp(28px, 4vw, 46px); }
.h3 { font-size: clamp(20px, 2.4vw, 28px); }
p { margin: 0 0 1em; color: var(--bp-ink-soft); }
a { color: inherit; }

/* Monospace drafting annotation */
.anno {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--bp-ink-faint);
}
.anno-accent { color: var(--bp-accent); }

.eyebrow {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--bp-ink-faint);
  display: inline-flex;
  align-items: center;
  gap: 10px;
}
.eyebrow::before {
  content: "";
  width: 28px; height: 1px;
  background: var(--bp-line);
}

/* ---------- Layout helpers ---------- */
.wrap { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 32px; }
.section { padding: clamp(56px, 9vw, 120px) 0; }
.stack > * + * { margin-top: 1rem; }

/* ---------- Wordmark lockup ---------- */
.lockup { display: inline-flex; align-items: center; gap: 12px; text-decoration: none; color: var(--bp-ink); }
.lockup .mark {
  width: 34px; height: 34px;
  flex: 0 0 auto;
  position: relative;
  border: var(--rule) solid var(--bp-ink);
}
.lockup .mark::before,
.lockup .mark::after {
  content: ""; position: absolute; background: var(--bp-line);
}
/* crosshair inside the mark */
.lockup .mark::before { left: 50%; top: 4px; bottom: 4px; width: 1px; transform: translateX(-50%); }
.lockup .mark::after  { top: 50%; left: 4px; right: 4px; height: 1px; transform: translateY(-50%); }
.lockup .mark > span {
  position: absolute; inset: 0;
  display: grid; place-items: center;
  font-family: var(--font-mono); font-weight: 600; font-size: 13px;
  color: var(--bp-accent);
  z-index: 1;
}
.lockup .wordmark {
  font-weight: 800; font-size: 21px; letter-spacing: -0.02em; line-height: 1;
}
.lockup .wordmark .tech {
  font-family: var(--font-mono); font-weight: 500;
  font-size: 10px; letter-spacing: 0.28em; text-transform: uppercase;
  color: var(--bp-ink-faint); display: block; margin-top: 3px;
}

/* ---------- Nav ---------- */
.bp-nav {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 32px;
  background: var(--bp-nav-bg);
  backdrop-filter: blur(8px);
  border-bottom: var(--hair) solid var(--bp-line-soft);
}
.bp-nav .links { display: flex; gap: 28px; align-items: center; }
.bp-nav .links a {
  font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.12em;
  text-transform: uppercase; text-decoration: none; color: var(--bp-ink-soft);
  padding: 6px 2px; position: relative; transition: color .2s;
}
.bp-nav .links a:hover { color: var(--bp-ink); }
.bp-nav .links a::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: -2px; height: 1px;
  background: var(--bp-accent); transform: scaleX(0); transform-origin: left; transition: transform .25s;
}
.bp-nav .links a:hover::after { transform: scaleX(1); }
.bp-nav .links a.active { color: var(--bp-ink); }
.bp-nav .links a.active::after { transform: scaleX(1); background: var(--bp-line); }
.nav-toggle { display: none; background: none; border: var(--hair) solid var(--bp-line); color: var(--bp-ink); font-family: var(--font-mono); font-size: 12px; letter-spacing: .12em; padding: 8px 12px; cursor: pointer; }

/* ---------- Theme toggle ---------- */
.theme-toggle {
  display: inline-flex; align-items: center; gap: 8px;
  background: none; border: var(--hair) solid var(--bp-line-soft);
  color: var(--bp-ink-soft); cursor: pointer;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: .14em;
  text-transform: uppercase; padding: 7px 12px; transition: color .2s, border-color .2s;
}
.theme-toggle:hover { color: var(--bp-ink); border-color: var(--bp-line); }
.theme-toggle .tt-dot {
  width: 11px; height: 11px; border-radius: 50%;
  border: 1.5px solid currentColor; position: relative; flex: 0 0 auto;
  background:
    linear-gradient(90deg, currentColor 0 50%, transparent 50% 100%);
}
.theme-toggle .tt-label { line-height: 1; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  font-family: var(--font-mono); font-size: 13px; font-weight: 500;
  letter-spacing: 0.14em; text-transform: uppercase; text-decoration: none;
  padding: 14px 22px; cursor: pointer; border: var(--rule) solid var(--bp-ink);
  background: transparent; color: var(--bp-ink); transition: all .2s;
}
.btn:hover { background: var(--bp-ink); color: var(--bp-bg); }
.btn-accent { border-color: var(--bp-accent); color: var(--bp-accent); }
.btn-accent:hover { background: var(--bp-accent); color: var(--bp-bg-2); }
.btn .arrow { font-family: var(--font-mono); }

/* ---------- Dimension line (decorative) ---------- */
.dimline {
  display: flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em;
  color: var(--bp-ink-faint);
}
.dimline .bar { flex: 1; height: 1px; background: var(--bp-line); position: relative; }
.dimline .bar::before, .dimline .bar::after {
  content: ""; position: absolute; top: -4px; width: 1px; height: 9px; background: var(--bp-line);
}
.dimline .bar::before { left: 0; }
.dimline .bar::after  { right: 0; }

/* blinking dimension tick */
@keyframes bp-blink { 0%,100% { opacity: 1; } 50% { opacity: 0.25; } }
.blink { animation: bp-blink 1.6s steps(1,end) infinite; }

/* ---------- Card / panel ---------- */
.panel {
  border: var(--hair) solid var(--bp-line-soft);
  background: var(--bp-panel-bg);
  position: relative;
}
.panel .corner {
  position: absolute; width: 9px; height: 9px; border: 1px solid var(--bp-line);
}
.panel .corner.tl { top: -1px; left: -1px; border-right: 0; border-bottom: 0; }
.panel .corner.tr { top: -1px; right: -1px; border-left: 0; border-bottom: 0; }
.panel .corner.bl { bottom: -1px; left: -1px; border-right: 0; border-top: 0; }
.panel .corner.br { bottom: -1px; right: -1px; border-left: 0; border-top: 0; }

/* ---------- Title block (drafting sheet metadata) ---------- */
.titleblock {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border: var(--hair) solid var(--bp-line);
  font-family: var(--font-mono);
}
.titleblock .cell { padding: 10px 14px; border-right: var(--hair) solid var(--bp-line-soft); }
.titleblock .cell:last-child { border-right: 0; }
.titleblock .k { font-size: 9.5px; letter-spacing: 0.2em; color: var(--bp-ink-faint); text-transform: uppercase; }
.titleblock .v { font-size: 14px; color: var(--bp-ink); margin-top: 3px; }

/* ---------- Line-draw animation utility (SVG) ---------- */
.draw-path {
  stroke-dasharray: var(--len, 1200);
  stroke-dashoffset: var(--len, 1200);
  animation: bp-draw 2.2s ease forwards;
}
@keyframes bp-draw { to { stroke-dashoffset: 0; } }

/* reveal-on-scroll */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .7s ease, transform .7s ease; }
.reveal.in { opacity: 1; transform: none; }

/* footer */
.bp-footer {
  background: var(--bp-bg-2);
  border-top: var(--hair) solid var(--bp-line-soft);
  padding: 56px 0 40px;
}
.bp-footer .anno { color: var(--bp-ink-faint); }

/* ---------- Page header (interior pages) ---------- */
.page-head { padding: 56px 0 40px; }
.page-head .titleblock { max-width: 640px; margin-bottom: 34px; }
.page-head h1 { font-size: clamp(40px, 6vw, 76px); font-weight: 800; letter-spacing: -0.03em; }
.page-head .lede { max-width: 620px; font-size: clamp(18px,2vw,21px); color: var(--bp-ink); margin-top: 18px; }

/* ---------- Process steps ---------- */
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 0; border: var(--hair) solid var(--bp-line); }
.steps .step { padding: 30px 26px 28px; border-right: var(--hair) solid var(--bp-line-soft); }
.steps .step:last-child { border-right: 0; }
.steps .step .n { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.2em; color: var(--bp-accent); }
.steps .step h3 { margin-top: 14px; font-size: 21px; }
.steps .step p { font-size: 16px; margin-bottom: 0; }
@media (max-width: 760px){ .steps { grid-template-columns: 1fr; } .steps .step { border-right: 0; border-bottom: var(--hair) solid var(--bp-line-soft); } .steps .step:last-child{border-bottom:0;} }

/* ---------- CTA band ---------- */
.cta-band { border-top: var(--hair) solid var(--bp-line); border-bottom: var(--hair) solid var(--bp-line); background: var(--bp-bg-3); }
.cta-band .inner { display: flex; align-items: center; justify-content: space-between; gap: 30px; padding-top: 56px; padding-bottom: 56px; flex-wrap: wrap; }
.cta-band h2 { font-size: clamp(28px,4vw,44px); margin: 0; max-width: 620px; }

/* ---------- Full footer ---------- */
.site-footer { background: var(--bp-bg-2); border-top: var(--hair) solid var(--bp-line-soft); padding: 64px 0 36px; }
.site-footer .cols { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; padding-bottom: 40px; border-bottom: var(--hair) solid var(--bp-line-soft); }
.site-footer h4 { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase; color: var(--bp-ink-faint); font-weight: 500; margin-bottom: 16px; }
.site-footer a { color: var(--bp-ink-soft); text-decoration: none; display: block; padding: 5px 0; font-size: 15px; }
.site-footer a.lockup { display: inline-flex; padding: 0; }
.site-footer a:hover { color: var(--bp-ink); }
.site-footer .botline { display: flex; justify-content: space-between; padding-top: 24px; flex-wrap: wrap; gap: 12px; }
@media (max-width: 760px){ .site-footer .cols { grid-template-columns: 1fr; gap: 28px; } }

@media (max-width: 720px) {
  .bp-nav { flex-wrap: wrap; }
  .nav-toggle { display: block; }
  .bp-nav .links { display: none; flex-direction: column; gap: 4px; width: 100%; order: 3; padding-top: 14px; }
  .bp-nav .links.open { display: flex; }
  .bp-nav .links a { padding: 10px 0; }
  .titleblock { grid-template-columns: repeat(2, 1fr); }
  body { font-size: 16px; }
}