/* engzero — engzero.dev
   Dark, terminal-inflected. No external assets, no JavaScript. */

:root {
  --bg: #0b0d11;
  --surface: #12151b;
  --surface-2: #161a22;
  --border: #1f2430;
  --border-bright: #2c3444;

  --text: #c3ccd8;
  --text-bright: #f0f4f8;
  --muted: #8b93a3;
  --dim: #626c7d;

  --green: #7ee2a8;
  --amber: #e8c66b;
  --rust: #e08a63;

  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, "Times New Roman", serif;

  --measure: 720px;
  --wide: 1040px;
  --gutter: 24px;
}

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

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h1,
h2,
h3 {
  color: var(--text-bright);
  line-height: 1.25;
  letter-spacing: -0.02em;
  margin: 0;
  text-wrap: balance;
}

p {
  margin: 0;
  text-wrap: pretty;
}

a {
  color: var(--green);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--text-bright);
}

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

code {
  font-family: var(--mono);
  font-size: 0.88em;
}

hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 0;
}

/* ---------- layout ---------- */

/* One container width for every section, so the left edge never shifts as you
   scroll. Prose is constrained to a readable measure *inside* it instead. */
.wrap {
  width: 100%;
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

section h2,
.lede,
.moments,
.aside,
.faq,
.roadmap,
.principle,
.demo-note {
  max-width: var(--measure);
}

section {
  padding: 88px 0;
  border-top: 1px solid var(--border);
}

.section-label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--dim);
  margin-bottom: 18px;
}

.section-label::before {
  content: "## ";
  color: var(--border-bright);
}

h2 {
  font-size: clamp(26px, 4vw, 34px);
}

.lede {
  margin-top: 20px;
  font-size: 18px;
  color: var(--muted);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--green);
  color: var(--bg);
  padding: 10px 18px;
  font-weight: 700;
  z-index: 100;
}

.skip-link:focus {
  left: 0;
}

/* ---------- nav ---------- */

.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(11, 13, 17, 0.86);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 14px;
  padding-bottom: 14px;
}

.brand {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 17px;
  color: var(--green);
  text-decoration: none;
  letter-spacing: -0.02em;
}

.brand:hover {
  color: var(--green);
}

.brand span {
  color: var(--dim);
  font-weight: 400;
  font-size: 13px;
  margin-left: 8px;
  letter-spacing: 0;
}

.nav-links {
  display: flex;
  gap: 24px;
  font-family: var(--mono);
  font-size: 13px;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--green);
}

.nav-links a.nav-gh {
  color: var(--green);
}

.nav-links a.nav-gh:hover {
  color: var(--text-bright);
}

/* ---------- hero ---------- */

.hero {
  padding: 104px 0 96px;
  border-top: 0;
}

.kicker {
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--rust);
}

.hero h1 {
  margin-top: 22px;
  font-size: clamp(34px, 6.4vw, 56px);
  letter-spacing: -0.035em;
  line-height: 1.12;
}

.hero h1 .accent {
  color: var(--green);
}

.hero .lede {
  margin-top: 26px;
  max-width: 640px;
  font-size: 19px;
  color: var(--text);
}

.hero-meta {
  margin-top: 22px;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--dim);
}

.cta-row {
  margin-top: 38px;
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  background: var(--green);
  color: #07120c;
  text-decoration: none;
  font-family: var(--mono);
  font-weight: 700;
  font-size: 14.5px;
  padding: 13px 26px;
  border-radius: 7px;
  border: 1px solid transparent;
  transition: background 0.15s ease;
}

.btn:hover {
  background: #9aeebd;
  color: #07120c;
}

.btn--ghost {
  background: transparent;
  color: var(--text-bright);
  border-color: var(--border-bright);
}

.btn--ghost:hover {
  background: var(--surface-2);
  color: var(--text-bright);
  border-color: var(--dim);
}

.hero-status {
  margin-top: 32px;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--muted);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 6px 14px;
}

.pill::before {
  content: "";
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--amber);
  flex: none;
}

/* ---------- moments ---------- */

.moments {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.moments li {
  position: relative;
  padding: 14px 0 14px 32px;
  border-bottom: 1px solid var(--border);
  color: var(--text-bright);
  font-size: 17.5px;
}

.moments li:first-child {
  border-top: 1px solid var(--border);
}

.moments li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--rust);
  font-family: var(--mono);
}

.aside {
  margin-top: 30px;
  color: var(--muted);
  font-size: 16.5px;
}

/* ---------- manifesto ---------- */

.manifesto {
  background: var(--surface);
}

.manifesto h2 {
  font-family: var(--serif);
  font-weight: 600;
  font-size: clamp(27px, 4.2vw, 37px);
  line-height: 1.28;
  letter-spacing: -0.01em;
}

.letter {
  margin-top: 30px;
  max-width: 640px;
  font-family: var(--serif);
  font-size: 19.5px;
  line-height: 1.72;
  color: #cdd5df;
}

.letter p + p {
  margin-top: 20px;
}

.letter em {
  color: var(--text-bright);
}

.letter strong {
  color: var(--text-bright);
  font-weight: 600;
}

.sig {
  margin-top: 30px;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--dim);
}

/* ---------- primitives grid ---------- */

.grid {
  margin-top: 40px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 22px 22px 24px;
}

.card h3 {
  margin-top: 14px;
  font-size: 17.5px;
  letter-spacing: -0.01em;
}

.card p {
  margin-top: 9px;
  font-size: 15.5px;
  color: var(--muted);
  line-height: 1.65;
}

.chip {
  display: inline-block;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 3px 9px;
  border-radius: 5px;
  border: 1px solid;
}

.chip--built {
  color: var(--green);
  border-color: rgba(126, 226, 168, 0.35);
  background: rgba(126, 226, 168, 0.08);
}

.chip--wip {
  color: var(--amber);
  border-color: rgba(232, 198, 107, 0.35);
  background: rgba(232, 198, 107, 0.08);
}

.chip--next {
  color: var(--muted);
  border-color: var(--border-bright);
  background: var(--surface-2);
}

.chip--vision {
  color: var(--rust);
  border-color: rgba(224, 138, 99, 0.32);
  background: rgba(224, 138, 99, 0.08);
}

.legend {
  margin-top: 26px;
  display: flex;
  gap: 20px;
  flex-wrap: wrap;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--dim);
  align-items: center;
}

/* ---------- terminal / artifact ---------- */

.demo {
  margin-top: 40px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(360px, 1fr));
  gap: 18px;
  align-items: start;
}

.panel {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 11px;
  overflow: hidden;
}

.panel-bar {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 11px 16px;
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
  font-family: var(--mono);
  font-size: 12px;
  color: var(--dim);
}

.dot {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--border-bright);
  flex: none;
}

.panel-bar .name {
  margin-left: 6px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

pre {
  margin: 0;
  padding: 18px 20px 22px;
  overflow-x: auto;
  font-family: var(--mono);
  font-size: 12.5px;
  line-height: 1.72;
  color: var(--text);
  tab-size: 2;
}

.p {
  color: var(--green);
  user-select: none;
}

.c {
  color: var(--text-bright);
}

.cm {
  color: var(--dim);
}

.ok {
  color: var(--green);
}

.key {
  color: var(--amber);
}

.hd {
  color: var(--rust);
}

.demo-note {
  margin-top: 24px;
  color: var(--muted);
  font-size: 16px;
}

/* ---------- roadmap ---------- */

.roadmap {
  margin-top: 40px;
  display: grid;
  gap: 0;
}

.stage {
  display: grid;
  grid-template-columns: 130px 1fr;
  gap: 28px;
  padding: 26px 0;
  border-top: 1px solid var(--border);
}

.stage:last-child {
  border-bottom: 1px solid var(--border);
}

.stage-id {
  font-family: var(--mono);
  font-size: 13px;
  color: var(--dim);
  padding-top: 2px;
}

.stage-id strong {
  display: block;
  color: var(--text-bright);
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 8px;
}

.stage h3 {
  font-size: 18px;
}

.stage p {
  margin-top: 8px;
  color: var(--muted);
  font-size: 15.5px;
}

.stage ul {
  margin: 12px 0 0;
  padding-left: 18px;
  color: var(--muted);
  font-size: 15px;
}

.stage li {
  margin-top: 5px;
}

/* ---------- split ---------- */

.principle {
  margin-top: 36px;
  border-left: 2px solid var(--green);
  padding: 4px 0 4px 22px;
  font-size: 19px;
  color: var(--text-bright);
  font-family: var(--serif);
  line-height: 1.6;
}

.split {
  margin-top: 34px;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.col {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 11px;
  padding: 22px;
}

.col h3 {
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0;
}

.col ul {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
  font-size: 15.5px;
  color: var(--muted);
}

.col li {
  padding: 7px 0 7px 20px;
  position: relative;
}

.col li::before {
  position: absolute;
  left: 0;
  font-family: var(--mono);
}

.col--open li::before {
  content: "+";
  color: var(--green);
}

.col--private li::before {
  content: "\00d7";
  color: var(--rust);
}

.col--open {
  border-color: rgba(126, 226, 168, 0.22);
}

.col--private {
  border-color: rgba(224, 138, 99, 0.22);
}

/* ---------- faq ---------- */

.faq {
  margin-top: 36px;
  display: grid;
  gap: 10px;
}

details {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 0 20px;
}

details[open] {
  background: var(--surface-2);
  border-color: var(--border-bright);
}

summary {
  cursor: pointer;
  list-style: none;
  padding: 16px 0;
  font-size: 16.5px;
  font-weight: 600;
  color: var(--text-bright);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
}

summary::-webkit-details-marker {
  display: none;
}

summary::after {
  content: "+";
  font-family: var(--mono);
  font-size: 19px;
  color: var(--dim);
  font-weight: 400;
  flex: none;
}

details[open] summary::after {
  content: "\2013";
}

details > p {
  padding: 0 0 18px;
  font-size: 16px;
  color: var(--muted);
}

details > p + p {
  margin-top: 12px;
}

details.honest {
  border-left: 2px solid var(--rust);
}

/* ---------- closing cta ---------- */

.closing {
  text-align: center;
  background: var(--surface);
}

.closing h2 {
  font-size: clamp(26px, 4.4vw, 36px);
  margin-left: auto;
  margin-right: auto;
}

.closing .lede {
  margin-left: auto;
  margin-right: auto;
  max-width: 560px;
}

.closing .cta-row {
  justify-content: center;
}

.fine {
  margin-top: 20px;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--dim);
}

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

footer {
  border-top: 1px solid var(--border);
  padding: 40px 0 56px;
  font-family: var(--mono);
  font-size: 12.5px;
  color: var(--dim);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  flex-wrap: wrap;
}

footer a {
  color: var(--muted);
  text-decoration: none;
}

footer a:hover {
  color: var(--green);
}

/* ---------- responsive ---------- */

@media (max-width: 720px) {
  body {
    font-size: 16px;
  }

  section {
    padding: 64px 0;
  }

  .hero {
    padding: 72px 0 64px;
  }

  .nav-links {
    gap: 16px;
    font-size: 12px;
  }

  .stage {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .letter {
    font-size: 18px;
  }

  .btn {
    display: block;
    width: 100%;
    text-align: center;
  }

  .cta-row {
    gap: 12px;
  }
}

@media (max-width: 420px) {
  .nav-links a[data-optional] {
    display: none;
  }

  .brand span {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  * {
    transition-duration: 0.01ms !important;
  }
}

@media print {
  .nav,
  .cta-row {
    display: none;
  }

  body {
    background: #fff;
    color: #000;
  }
}