/* Potential Flow — Design System
   Brand: Navy #2e4052 | Orange #fd7e14 | Teal #3d7c8c | White
   Fonts: Exo 2 (headings), Exo (body)
*/

/* ── Reset & Base ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --navy: #2e4052;
  --navy-light: #3a5068;
  --navy-dark: #1e2d3a;
  --orange: #fd7e14;
  --orange-light: #febf8a;
  --orange-dark: #be5f0f;
  --teal: #3d7c8c;
  --teal-light: #5a9eae;
  --teal-dark: #2a5a66;
  --white: #ffffff;
  --off-white: #f8f7f5;
  --gray-100: #f1f0ee;
  --gray-200: #e2e1de;
  --gray-300: #c8c7c3;
  --gray-400: #9a9994;
  --gray-500: #6e6d69;
  --gray-600: #4a4944;
  --text: #1a1a1a;
  --text-muted: #5a5a55;
  --text-on-dark: rgba(255,255,255,0.92);
  --text-muted-on-dark: rgba(255,255,255,0.65);

  --font-heading: 'Exo 2', sans-serif;
  --font-body: 'Exo', sans-serif;

  --max-width: 1200px;
  --section-pad: clamp(60px, 8vw, 120px);
  --gutter: clamp(16px, 4vw, 32px);

  --transition: 0.3s ease;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--text);
  background: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }

.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--text);
}
h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.8rem, 4vw, 2.6rem); letter-spacing: -0.01em; }
h3 { font-size: clamp(1.3rem, 3vw, 1.8rem); }
h4 { font-size: 1.15rem; }
p { margin-bottom: 1em; }
.lead { font-size: clamp(1.05rem, 2vw, 1.25rem); line-height: 1.6; color: var(--text-muted); }

.on-dark h1, .on-dark h2, .on-dark h3, .on-dark h4, .on-dark h5, .on-dark h6 { color: var(--text-on-dark); }
.on-dark p, .on-dark .lead, .on-dark li { color: var(--text-muted-on-dark); }
.on-dark a:not(.btn) { color: var(--text-on-dark); }

.accent-text { color: var(--orange); }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 32px;
  font-family: var(--font-body);
  font-size: 0.95rem;
  font-weight: 600;
  border-radius: 4px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.btn-primary {
  background: var(--orange);
  color: var(--white);
  border-color: var(--orange);
}
.btn-primary:hover {
  background: var(--orange-dark);
  border-color: var(--orange-dark);
  transform: translateY(-1px);
}
.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: var(--white);
}
.btn-outline:hover {
  background: var(--white);
  color: var(--navy);
}
.btn-outline-dark {
  background: transparent;
  color: var(--navy);
  border-color: var(--navy);
}
.btn-outline-dark:hover {
  background: var(--navy);
  color: var(--white);
}
.btn-sm { padding: 10px 24px; font-size: 0.85rem; }
.btn svg, .btn i { width: 16px; height: 16px; }

/* ── Navigation ── */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--navy);
  transition: background var(--transition), box-shadow var(--transition);
}
.site-nav.scrolled {
  background: rgba(46, 64, 82, 0.97);
  box-shadow: 0 2px 20px rgba(0,0,0,0.15);
}
.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--gutter);
  max-width: var(--max-width);
  margin: 0 auto;
  height: 72px;
}
.nav-logo img {
  height: 36px;
  width: auto;
}
.nav-links {
  display: flex;
  align-items: center;
  gap: 0;
  list-style: none;
}
.nav-links a {
  display: block;
  padding: 8px 16px;
  color: var(--text-on-dark);
  font-family: var(--font-body);
  font-size: 0.85rem;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  transition: color var(--transition);
  position: relative;
}
.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 16px;
  right: 16px;
  height: 2px;
  background: var(--orange);
  transform: scaleX(0);
  transition: transform var(--transition);
}
.nav-links a:hover::after,
.nav-links a.active::after {
  transform: scaleX(1);
}
.nav-links a:hover { color: var(--white); }
.nav-links .nav-cta a {
  background: var(--orange);
  color: var(--white);
  border-radius: 4px;
  margin-left: 8px;
  padding: 10px 24px;
  font-weight: 600;
}
.nav-links .nav-cta a::after { display: none; }
.nav-links .nav-cta a:hover {
  background: var(--orange-dark);
}

/* Mobile nav toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  margin: 5px 0;
  transition: all var(--transition);
}

@media (max-width: 900px) {
  .nav-toggle { display: block; }
  .nav-links {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--navy);
    flex-direction: column;
    padding: 16px 0 32px;
    transform: translateY(-120%);
    transition: transform 0.4s ease;
    gap: 0;
  }
  .nav-links.open { transform: translateY(0); }
  .nav-links a { padding: 14px 32px; font-size: 1rem; }
  .nav-links .nav-cta a { margin: 16px 32px 0; display: inline-block; }
}

/* ── Hero ── */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  background: var(--navy);
  overflow: hidden;
}
.hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.35;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, rgba(46,64,82,0.85) 0%, rgba(46,64,82,0.5) 100%);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 720px;
  padding-top: 100px;
}
.hero h1 { color: var(--white); margin-bottom: 24px; }
.hero .lead { color: var(--text-muted-on-dark); font-size: clamp(1.1rem, 2.2vw, 1.35rem); margin-bottom: 40px; }
.hero-buttons { display: flex; gap: 16px; flex-wrap: wrap; }

/* ── Sections ── */
.section {
  padding: var(--section-pad) 0;
}
.section-dark {
  background: var(--navy);
}
.section-light {
  background: var(--off-white);
}
.section-header {
  max-width: 640px;
  margin-bottom: 48px;
}
.section-header.centered {
  text-align: center;
  margin-left: auto;
  margin-right: auto;
}
.section-label {
  display: inline-block;
  font-family: var(--font-body);
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--orange);
  margin-bottom: 12px;
}
.section-header h2 { margin-bottom: 16px; }
.separator {
  width: 60px;
  height: 4px;
  background: var(--orange);
  margin: 20px 0;
  border-radius: 2px;
}
.centered .separator { margin-left: auto; margin-right: auto; }

/* ── Grid / Cards ── */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 32px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 32px; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; }

@media (max-width: 900px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .grid-4 { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .grid-4 { grid-template-columns: 1fr; }
}

.card {
  background: var(--white);
  border-radius: 6px;
  padding: 36px 32px;
  border: 1px solid var(--gray-200);
  transition: all var(--transition);
}
.card:hover {
  border-color: var(--gray-300);
  transform: translateY(-2px);
  box-shadow: 0 8px 32px rgba(0,0,0,0.06);
}
.card-dark {
  background: rgba(255,255,255,0.06);
  border-color: rgba(255,255,255,0.1);
}
.card-dark:hover {
  background: rgba(255,255,255,0.1);
  border-color: rgba(255,255,255,0.2);
  box-shadow: 0 8px 32px rgba(0,0,0,0.2);
}
.card-icon {
  width: 48px;
  height: 48px;
  background: rgba(253,126,20,0.1);
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  color: var(--orange);
  font-size: 1.2rem;
}
.card-dark .card-icon {
  background: rgba(253,126,20,0.15);
}
.card h3, .card h4 { margin-bottom: 12px; }
.card p:last-child { margin-bottom: 0; }

/* ── Pillar split section ── */
.pillars {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: 480px;
}
@media (max-width: 900px) {
  .pillars { grid-template-columns: 1fr; }
}
.pillar {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--section-pad) var(--gutter);
  overflow: hidden;
  transition: all 0.5s ease;
}
.pillar-naval {
  background: var(--navy);
}
.pillar-ai {
  background: var(--teal-dark);
}
.pillar-content {
  position: relative;
  z-index: 2;
  max-width: 440px;
}
.pillar h2 { color: var(--white); margin-bottom: 16px; font-size: clamp(1.6rem, 3vw, 2.2rem); }
.pillar p { color: var(--text-muted-on-dark); margin-bottom: 24px; }
.pillar ul {
  list-style: none;
  margin-bottom: 32px;
}
.pillar li {
  color: var(--text-muted-on-dark);
  padding: 6px 0;
  padding-left: 20px;
  position: relative;
  font-size: 0.95rem;
}
.pillar li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 14px;
  width: 8px;
  height: 2px;
  background: var(--orange);
}

/* ── Stats row ── */
.stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  text-align: center;
}
@media (max-width: 768px) {
  .stats { grid-template-columns: 1fr 1fr; }
}
.stat-number {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--orange);
  line-height: 1;
  margin-bottom: 8px;
}
.stat-label {
  font-size: 0.9rem;
  color: var(--text-muted-on-dark);
}

/* ── CTA Band ── */
.cta-band {
  background: var(--orange);
  padding: 48px 0;
  text-align: center;
}
.cta-band h2 { color: var(--white); margin-bottom: 16px; }
.cta-band p { color: rgba(255,255,255,0.85); margin-bottom: 24px; }

/* ── Contact bar ── */
.contact-bar {
  background: var(--navy-dark);
  padding: 32px 0;
}
.contact-bar-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
}
.contact-item {
  display: flex;
  align-items: center;
  gap: 12px;
  color: var(--text-muted-on-dark);
  font-size: 0.9rem;
}
.contact-item svg {
  width: 20px;
  height: 20px;
  color: var(--orange);
  flex-shrink: 0;
}

/* ── Footer ── */
.site-footer {
  background: var(--navy);
  padding: 64px 0 0;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}
@media (max-width: 900px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 600px) {
  .footer-grid { grid-template-columns: 1fr; }
}
.footer-brand img { height: 32px; margin-bottom: 16px; }
.footer-brand p { color: var(--text-muted-on-dark); font-size: 0.9rem; }
.footer-col h5 {
  color: var(--text-on-dark);
  font-family: var(--font-heading);
  font-size: 0.9rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}
.footer-col ul { list-style: none; }
.footer-col li { margin-bottom: 8px; }
.footer-col a {
  color: var(--text-muted-on-dark);
  font-size: 0.9rem;
  transition: color var(--transition);
}
.footer-col a:hover { color: var(--orange); }
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding: 24px 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-bottom p { color: var(--text-muted-on-dark); font-size: 0.8rem; margin: 0; }
.footer-social { display: flex; gap: 16px; }
.footer-social a {
  color: var(--text-muted-on-dark);
  transition: color var(--transition);
}
.footer-social a:hover { color: var(--orange); }
.footer-social svg { width: 20px; height: 20px; }

/* ── Animations ── */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}
.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}
.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }

/* ── Utility ── */
.text-center { text-align: center; }
.mb-0 { margin-bottom: 0; }
.mt-2 { margin-top: 16px; }
.mt-4 { margin-top: 32px; }