/* =========================================================
   Design System
   ========================================================= */

:root {
  --bg: #050505;
  --surface: rgba(255, 255, 255, 0.04);
  --border: rgba(255, 255, 255, 0.1);

  --text-primary: #ffffff;
  --text-secondary: #a1a1a1;

  --accent: #3b82f6;
}

/* =========================================================
   Base Reset
   ========================================================= */

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

body {
  margin: 0;
  font-family: 'Inter', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text-primary);
  line-height: 1.6;
}

/* =========================================================
   Background Accent
   ========================================================= */

#mesh-bg {
  position: fixed;
  inset: 0;
  z-index: -1; /* bring animation above neural-bg */
  opacity: 0.45;
}

.neural-bg {
  position: fixed;
  inset: 0;
  background: radial-gradient(circle at 50% -20%, #1e3a8a 0%, transparent 55%);
  opacity: 0.35;
  z-index: -2; /* push behind canvas */
}

   
/* =========================================================
   Navigation
   ========================================================= */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(5, 5, 5, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav-container {
  max-width: 1200px;
  margin: auto;
  padding: 18px 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  font-size: 1.2rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}

.brand span {
  color: var(--accent);
}

.nav-links a {
  margin-left: 30px;
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.95rem;
  transition: color 0.3s ease;
}

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

/* =========================================================
   Header / Hero
   ========================================================= */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(5,5,5,0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header {
  min-height: 100vh;
  padding: 0 10%;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.tagline {
  font-size: clamp(2.8rem, 6vw, 5rem);
  font-weight: 700;
  letter-spacing: -2px;
  margin: 20px 0;
}

.mission {
  max-width: 700px;
  color: var(--text-secondary);
  font-size: 1.1rem;
  border-left: 2px solid var(--accent);
  padding-left: 30px;
}

.cta-btn {
  margin-top: 40px;
  align-self: flex-start;
  background: var(--text-primary);
  color: var(--bg);
  padding: 14px 38px;
  font-weight: 700;
  text-decoration: none;
}

/* =========================================================
   Sections
   ========================================================= */

.section {
  padding: 120px 10%;
}

.section-header {
  text-align: center;
  margin-bottom: 60px;
}

.section-header h2 {
  font-size: 0.8rem;
  letter-spacing: 4px;
  text-transform: uppercase;
  color: var(--accent);
}

.section-header p {
  color: var(--text-secondary);
  max-width: 700px;
  margin: 15px auto 0;
}

/* =========================================================
   Layout Utilities
   ========================================================= */

.grid {
  display: grid;
  gap: 30px;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.container.narrow {
  max-width: 800px;
  margin: auto;
}

/* =========================================================
   Cards
   ========================================================= */

.card,
.lab-card,
.perspective-card {
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 40px;
  transition: transform 0.35s ease, border-color 0.35s ease, background 0.35s ease;
}

.card h3,
.lab-card h3,
.perspective-card h3 {
  font-weight: 600;
  line-height: 1.3;
}

.card:hover,
.lab-card:hover,
.perspective-card:hover {
  transform: translateY(-8px);
  border-color: var(--accent);
  background: rgba(255, 255, 255, 0.06);
}

.domain-card {
  display: block;
  text-decoration: none;
  color: inherit;
}

/* Arrow indicator */
.lab-card::after {
  content: "→";
  float: right;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.lab-card:hover::after {
  opacity: 1;
}

/* =========================================================
   Engineering Perspectives
   ========================================================= */

.perspectives {
  padding: 120px 10%;
  background: linear-gradient(180deg, #050505 0%, #080808 100%);
}

.perspectives-header {
  text-align: center;
  margin-bottom: 70px;
}

.perspectives-header h2 {
  font-size: 0.8rem;
  letter-spacing: 5px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 15px;
}

.perspectives-header p {
  font-size: 1.4rem;
  max-width: 700px;
  margin: auto;
}

.perspectives-grid {
  display: grid;
  gap: 30px;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
}

.perspective-card span {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 15px;
}

.perspective-card p {
  color: var(--text-secondary);
}

/* =========================================================
   Forms & Contact
   ========================================================= */

.contact {
  background: #080808;
  border-top: 1px solid var(--border);
}

input,
textarea,
select {
  width: 100%;
  padding: 12px;
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-primary);
}

button {
  width: 100%;
  background: var(--accent);
  color: white;
  border: none;
  padding: 14px;
  font-weight: 700;
  cursor: pointer;
}

/* =========================================================
   Chatbot Widget
   ========================================================= */

.chatbot {
  position: fixed;
  bottom: 20px;
  right: 20px;
  width: 280px;
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 20px;
  font-size: 0.9rem;
}

.chatbot h4 {
  margin-top: 0;
  color: var(--accent);
}

/* =========================================================
   Subpages
   ========================================================= */

.lead {
  font-size: 1.2rem;
  color: var(--text-secondary);
  margin: 20px 0 50px;
}

.feature-list .feature {
  margin-bottom: 40px;
}

.feature h3 {
  margin-bottom: 8px;
}

.back-link {
  display: inline-block;
  margin-top: 60px;
  color: var(--accent);
  text-decoration: none;
}

.back-link:hover {
  text-decoration: underline;
}

/* =========================================================
   Accessibility
   ========================================================= */

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}