/* ===== Tokens ===== */
:root {
  --paper: #EDEAE1;
  --paper-line: rgba(27, 39, 51, 0.16);
  --ink: #1B2733;
  --ink-soft: #4C5A66;
  --blue: #1E4E6B;
  --blue-soft: #3B6E8C;
  --amber: #C77A2E;
  --navy: #0E1A24;
  --navy-line: rgba(237, 234, 225, 0.22);
  --navy-text: #D9DCE0;
  --font-sans: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'IBM Plex Mono', 'SFMono-Regular', Consolas, monospace;
  --max-w: 1120px;
  --gap: clamp(1.5rem, 4vw, 3rem);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--max-w);
  margin: 0 auto;
  padding-left: var(--gap);
  padding-right: var(--gap);
}

h1, h2, h3 { margin: 0; font-weight: 600; letter-spacing: -0.01em; }
p { margin: 0; }

a { color: inherit; }

.mono { font-family: var(--font-mono); font-size: 0.8125rem; letter-spacing: 0.01em; }

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--paper);
  border-bottom: 1px solid var(--paper-line);
}

.header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.wordmark {
  font-weight: 600;
  font-size: 1.0625rem;
  text-decoration: none;
  color: var(--ink);
  letter-spacing: -0.01em;
}
.wordmark span { color: var(--blue); }

.nav { display: flex; gap: clamp(1.25rem, 3vw, 2.25rem); }
.nav a {
  text-decoration: none;
  font-size: 0.9375rem;
  color: var(--ink-soft);
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color 180ms ease, border-color 180ms ease;
}
.nav a:hover { color: var(--ink); border-color: var(--blue); }

/* ===== Hero ===== */
.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
  gap: var(--gap);
  align-items: center;
  padding-top: clamp(3rem, 8vw, 6rem);
  padding-bottom: clamp(3rem, 8vw, 6rem);
}

.hero-tag {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--blue);
  margin-bottom: 1.25rem;
}

.hero-text h1 {
  font-size: clamp(2rem, 4vw, 2.75rem);
  line-height: 1.15;
  max-width: 16ch;
}

.hero-sub {
  margin-top: 1.5rem;
  max-width: 46ch;
  font-size: 1.0625rem;
  color: var(--ink-soft);
}

.btn-primary {
  display: inline-block;
  margin-top: 2.25rem;
  padding: 0.85rem 1.75rem;
  background: var(--ink);
  color: var(--paper);
  text-decoration: none;
  font-size: 0.9375rem;
  font-weight: 500;
  border: none;
  cursor: pointer;
  transition: background 180ms ease;
}
.btn-primary:hover { background: var(--blue); }
.btn-primary:focus-visible { outline: 2px solid var(--amber); outline-offset: 3px; }

.hero-diagram { width: 100%; }
.diagram-svg { width: 100%; height: auto; overflow: visible; }

.d-line, .d-tick {
  fill: none;
  stroke: var(--blue);
  stroke-width: 1;
}
.d-node {
  fill: var(--paper);
  stroke: var(--ink);
  stroke-width: 1.25;
}
.d-label {
  font-family: var(--font-sans);
  font-size: 12px;
  font-weight: 500;
  fill: var(--ink);
}
.d-mono {
  font-family: var(--font-mono);
  font-size: 10px;
  fill: var(--blue-soft);
}

/* draw-in animation */
.diagram-lines .d-line {
  stroke-dasharray: 900;
  stroke-dashoffset: 900;
  animation: draw 1.4s ease forwards;
}
.diagram-nodes .d-node {
  opacity: 0;
  animation: fade-in 0.6s ease forwards;
  animation-delay: 1.1s;
}
.diagram-labels .d-label, .diagram-labels .d-mono {
  opacity: 0;
  animation: fade-in 0.5s ease forwards;
  animation-delay: 1.5s;
}
@keyframes draw { to { stroke-dashoffset: 0; } }
@keyframes fade-in { to { opacity: 1; } }

@media (prefers-reduced-motion: reduce) {
  .diagram-lines .d-line { animation: none; stroke-dashoffset: 0; }
  .diagram-nodes .d-node,
  .diagram-labels .d-label,
  .diagram-labels .d-mono { animation: none; opacity: 1; }
  html { scroll-behavior: auto; }
}

/* ===== Section heads ===== */
.section-head {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  margin-bottom: clamp(2rem, 5vw, 3rem);
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--paper-line);
}
.section-head.light { border-bottom-color: var(--navy-line); }
.section-num {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--blue);
}
.section-head.light .section-num { color: var(--amber); }
.section-head h2 { font-size: 1.5rem; }
.section-head.light h2 { color: var(--paper); }

/* ===== Specialties ===== */
.specialties { padding: clamp(3rem, 7vw, 5rem) var(--gap); }

.spec-list { list-style: none; margin: 0; padding: 0; }
.spec-list li {
  display: grid;
  grid-template-columns: 3rem minmax(0, 1fr);
  gap: 1.5rem;
  padding: 1.75rem 0;
  border-bottom: 1px solid var(--paper-line);
  position: relative;
}
.spec-list li:first-child { border-top: 1px solid var(--paper-line); }

.spec-index {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  color: var(--blue);
  padding-top: 0.15rem;
}

.spec-body h3 { font-size: 1.0625rem; margin-bottom: 0.4rem; }
.spec-body p { color: var(--ink-soft); max-width: 58ch; font-size: 0.9375rem; }

/* ===== Approach (dark section) ===== */
.approach {
  background: var(--navy);
  color: var(--navy-text);
  padding: clamp(3rem, 7vw, 5rem) 0;
}

.approach-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 2.5rem;
}
.approach-steps li { display: flex; flex-direction: column; gap: 0.6rem; }
.step-n {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--amber);
}
.approach-steps h3 { color: var(--paper); font-size: 1rem; }
.approach-steps p { color: rgba(217, 220, 224, 0.75); font-size: 0.9375rem; }

/* ===== Contact ===== */
.contact { padding: clamp(3rem, 7vw, 5rem) var(--gap); }

.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: clamp(2rem, 5vw, 4rem);
  align-items: start;
}

.contact-side { display: flex; flex-direction: column; gap: 2rem; }
.contact-intro { font-size: 1.0625rem; color: var(--ink-soft); max-width: 32ch; }

.contact-direct {
  padding-top: 1.5rem;
  border-top: 1px solid var(--paper-line);
  max-width: 32ch;
}
.contact-direct-label {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--blue);
  margin-bottom: 0.6rem;
}
.contact-direct p.mono {
  color: var(--ink);
  margin-bottom: 0.3rem;
  word-break: break-word;
}
.contact-direct a { color: var(--blue); text-decoration: none; border-bottom: 1px solid var(--paper-line); }
.contact-direct a:hover { border-color: var(--blue); }

.contact-form { display: grid; gap: 1.25rem; }
.field { display: grid; gap: 0.4rem; }
.field label { font-size: 0.875rem; color: var(--ink-soft); }
.field .optional { color: var(--ink-soft); font-weight: 400; }

.field input,
.field textarea {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  padding: 0.7rem 0.85rem;
  border: 1px solid var(--paper-line);
  background: #fff;
  color: var(--ink);
  border-radius: 0;
}
.field input:focus,
.field textarea:focus {
  outline: none;
  border-color: var(--blue);
  box-shadow: 0 0 0 1px var(--blue);
}
.field textarea { resize: vertical; min-height: 120px; }

.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }

.captcha-field label { font-family: var(--font-sans); }
#captcha-question { font-family: var(--font-mono); color: var(--ink); }

.contact-form .btn-primary { justify-self: start; margin-top: 0.5rem; }

.form-status { font-size: 0.875rem; min-height: 1.2em; }
.form-status.ok { color: var(--blue); }
.form-status.err { color: #A8402B; }

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--paper-line);
  padding: 1.75rem 0;
}
.footer-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.875rem;
  color: var(--ink-soft);
}

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .hero { grid-template-columns: 1fr; }
  .hero-diagram { order: -1; max-width: 380px; margin: 0 auto; }
  .contact-grid { grid-template-columns: 1fr; }
  .nav { gap: 1.25rem; }
}

@media (max-width: 520px) {
  .header-row { height: 64px; }
  .wordmark { font-size: 0.9375rem; }
  .nav a { font-size: 0.85rem; }
  .spec-list li { grid-template-columns: 2.25rem minmax(0, 1fr); }
}