:root {
  color-scheme: dark;
  --obsidian: #0a0c10;
  --graphite: #1b2129;
  --titanium: #b8c2cc;
  --cyan: #00c2ff;
  --lime: #cbff00;
  --ember: #ff6b35;
  --frost: #f2f5f7;
  --border: #2a3340;
  --border-bright: #3d4a5c;
  --font-serif: Georgia, "Times New Roman", serif;
  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --header-h: 4rem;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-serif);
  background: var(--obsidian);
  color: var(--frost);
  line-height: 1.65;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 1000;
  padding: 0.5rem 1rem;
  background: var(--lime);
  color: var(--obsidian);
  font-family: var(--font-sans);
  font-weight: 700;
  text-decoration: none;
}

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

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* Site header */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-h);
  background: rgba(10, 12, 16, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: 72rem;
  height: 100%;
  margin: 0 auto;
  padding: 0 1.25rem;
}

.logo {
  font-family: var(--font-sans);
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--frost);
  text-decoration: none;
}

.nav-cta {
  padding: 0.5rem 0.875rem;
  font-family: var(--font-sans);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--obsidian);
  background: var(--lime);
  border-radius: 0.25rem;
  transition: background 0.15s ease;
}

.nav-cta:hover {
  background: #d8ff4d;
}

/* Hero */

.hero {
  padding: 3.5rem 1.25rem 4rem;
  background: linear-gradient(180deg, var(--graphite) 0%, var(--obsidian) 100%);
  border-bottom: 1px solid var(--border);
}

.hero__inner {
  max-width: 44rem;
  margin: 0 auto;
}

.eyebrow {
  margin: 0 0 1rem;
  font-family: var(--font-sans);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.hero__headline {
  margin: 0 0 1.25rem;
  font-size: clamp(1.75rem, 5.5vw, 2.75rem);
  font-weight: 400;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.hero__subheadline {
  margin: 0 0 1rem;
  font-size: 1.0625rem;
  color: var(--titanium);
}

.hero__support {
  margin: 0 0 2rem;
  font-size: 1rem;
  color: var(--titanium);
}

.hero__actions {
  margin-bottom: 1.5rem;
}

.hero__microcopy {
  margin: 0.875rem 0 0;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  color: var(--titanium);
}

.hero__domain {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 0.6875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #6b7580;
}

/* Sections */

.section {
  padding: 3.5rem 1.25rem;
  border-bottom: 1px solid var(--border);
}

.section--panel {
  background: var(--graphite);
}

.section--form {
  background: linear-gradient(180deg, var(--obsidian) 0%, var(--graphite) 100%);
  padding-bottom: 4.5rem;
}

.section__inner {
  max-width: 44rem;
  margin: 0 auto;
}

.section__label {
  margin: 0 0 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--cyan);
}

.section h2 {
  margin: 0 0 1rem;
  font-size: clamp(1.25rem, 3vw, 1.625rem);
  font-weight: 400;
  line-height: 1.2;
}

.section__intro {
  margin: 0 0 1.5rem;
  font-size: 0.9375rem;
  color: var(--titanium);
}

/* Diagnostic matrix */

.diag-matrix {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.75rem;
}

.diag-matrix__cell {
  padding: 1.125rem 1.25rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: rgba(27, 33, 41, 0.6);
  border-left: 3px solid var(--cyan);
}

.diag-matrix__label {
  display: block;
  margin-bottom: 0.375rem;
  font-family: var(--font-sans);
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #6b7580;
}

.diag-matrix__title {
  margin: 0 0 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--frost);
}

.diag-matrix__desc {
  margin: 0;
  font-size: 0.875rem;
  color: var(--titanium);
  line-height: 1.5;
}

/* Lists */

.bullet-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.bullet-list li {
  position: relative;
  margin-bottom: 0.875rem;
  padding-left: 1.125rem;
  color: var(--titanium);
}

.bullet-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 0.375rem;
  height: 0.375rem;
  background: var(--ember);
  border-radius: 50%;
}

.bullet-list li:last-child {
  margin-bottom: 0;
}

/* Capability matrix */

.capability-grid {
  display: flex;
  flex-direction: column;
  gap: 0;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  overflow: hidden;
}

.capability-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.375rem;
  padding: 1rem 1.125rem;
  border-bottom: 1px solid var(--border);
  background: rgba(27, 33, 41, 0.4);
}

.capability-row:last-child {
  border-bottom: none;
}

.capability-row__name {
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--cyan);
}

.capability-row__desc {
  font-size: 0.875rem;
  color: var(--titanium);
  line-height: 1.5;
}

/* Process */

.process-list {
  margin: 0 0 1.25rem;
  padding-left: 1.25rem;
  color: var(--titanium);
}

.process-list li {
  margin-bottom: 0.5rem;
  padding-left: 0.25rem;
}

.process-list strong {
  color: var(--frost);
  font-weight: 600;
}

.process-note {
  margin: 0;
  padding: 1rem 1.125rem;
  font-size: 0.875rem;
  color: var(--titanium);
  border: 1px solid var(--border-bright);
  border-left: 3px solid var(--ember);
  border-radius: 0.25rem;
  background: rgba(10, 12, 16, 0.5);
}

/* Founder */

.founder {
  margin: 0;
  padding: 1.25rem 1.5rem;
  border-left: 3px solid var(--lime);
  background: rgba(27, 33, 41, 0.5);
}

.founder p {
  margin: 0;
  font-size: 1rem;
  color: var(--titanium);
}

.founder strong {
  color: var(--frost);
}

/* Form */

.form-intro {
  margin: 0 0 1.5rem;
  color: var(--titanium);
}

.interest-form {
  display: grid;
  gap: 1.125rem;
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--graphite);
}

.field label {
  display: block;
  margin-bottom: 0.375rem;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--frost);
}

.required {
  color: var(--ember);
}

.optional {
  font-weight: 400;
  color: var(--titanium);
}

.field input,
.field select {
  width: 100%;
  padding: 0.75rem 0.875rem;
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--frost);
  background: var(--obsidian);
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}

.field input::placeholder {
  color: #5c6570;
}

.field input:focus,
.field select:focus {
  outline: none;
  border-color: var(--cyan);
  box-shadow: 0 0 0 2px rgba(0, 194, 255, 0.2);
}

/* Buttons */

.btn {
  display: inline-block;
  padding: 0.875rem 1.5rem;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  text-align: center;
  border: none;
  border-radius: 0.375rem;
  cursor: pointer;
  transition: background 0.15s ease, transform 0.1s ease;
}

.btn--primary {
  color: var(--obsidian);
  background: var(--lime);
}

.btn--primary:hover {
  background: #d8ff4d;
}

.btn--primary:active {
  transform: translateY(1px);
}

.btn--full {
  width: 100%;
  margin-top: 0.25rem;
}

/* Footer */

.site-footer {
  padding: 2.5rem 1.25rem;
  background: var(--graphite);
  border-top: 1px solid var(--border);
}

.site-footer__inner {
  max-width: 44rem;
  margin: 0 auto;
}

.site-footer__brand {
  margin: 0 0 0.375rem;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.site-footer__tag {
  margin: 0 0 1rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--titanium);
}

.site-footer__disclaimer,
.site-footer__scope {
  margin: 0 0 0.5rem;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: #7a8490;
  line-height: 1.5;
}

.site-footer__scope {
  margin-bottom: 0;
}

/* Responsive */

@media (min-width: 36rem) {
  .diag-matrix {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 48rem) {
  .hero {
    padding: 4.5rem 2rem 5rem;
  }

  .section {
    padding: 4rem 2rem;
  }

  .diag-matrix {
    grid-template-columns: repeat(3, 1fr);
  }

  .diag-matrix__cell:nth-child(4),
  .diag-matrix__cell:nth-child(5) {
    grid-column: span 1;
  }

  .capability-row {
    grid-template-columns: 11rem 1fr;
    gap: 1.5rem;
    align-items: start;
  }
}

@media (min-width: 64rem) {
  .diag-matrix {
    grid-template-columns: repeat(5, 1fr);
  }

  .diag-matrix__cell:nth-child(4),
  .diag-matrix__cell:nth-child(5) {
    grid-column: auto;
  }
}