:root {
  --navy: #0a1f3d;
  --navy-dark: #061428;
  --blue: #2563eb;
  --blue-light: #3b82f6;
  --gray-100: #f5f7fa;
  --gray-200: #e5e9f0;
  --gray-600: #5a6a85;
  --text-dark: #101828;
  --white: #ffffff;
  --radius: 10px;
  --max-width: 1120px;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--text-dark);
  line-height: 1.6;
  background: var(--white);
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3 {
  font-weight: 700;
  color: var(--navy);
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  background: var(--navy);
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

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

.logo {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--white);
  white-space: nowrap;
}

.logo span {
  font-weight: 400;
  color: var(--blue-light);
}

#main-nav ul {
  display: flex;
  gap: 32px;
}

#main-nav a {
  color: var(--gray-200);
  font-weight: 600;
  font-size: 0.95rem;
  transition: color 0.2s;
}

#main-nav a:hover {
  color: var(--white);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--white);
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 14px 30px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 1rem;
  transition: transform 0.15s, box-shadow 0.15s;
}

.btn-primary {
  background: var(--blue);
  color: var(--white);
}

.btn-primary:hover {
  background: var(--blue-light);
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(37, 99, 235, 0.35);
}

/* Hero */
.hero {
  background:
    linear-gradient(135deg, rgba(10, 31, 61, 0.92) 0%, rgba(6, 20, 40, 0.94) 100%),
    url("OPS-Puzzle.jpg");
  background-size: cover;
  background-position: center;
  color: var(--white);
  padding: 110px 0;
  text-align: center;
}

.hero-inner {
  max-width: 720px;
}

.hero h1 {
  color: var(--white);
  font-size: 2.6rem;
  line-height: 1.2;
  margin-bottom: 20px;
}

.hero-sub {
  font-size: 1.15rem;
  color: var(--gray-200);
  margin-bottom: 36px;
}

/* Sections */
section {
  padding: 90px 0;
}

section h2 {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 12px;
}

.section-sub {
  text-align: center;
  color: var(--gray-600);
  max-width: 640px;
  margin: 0 auto 50px;
  font-size: 1.05rem;
}

/* Services */
.services {
  background: var(--gray-100);
}

.service-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 28px;
}

.service-card {
  background: var(--white);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: 0 4px 16px rgba(10, 31, 61, 0.06);
  border: 1px solid var(--gray-200);
  transition: transform 0.2s, box-shadow 0.2s;
}

.service-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 28px rgba(10, 31, 61, 0.12);
}

.service-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

.service-card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

.service-card p {
  color: var(--gray-600);
  font-size: 0.98rem;
}

/* About */
.about-inner {
  max-width: 760px;
  text-align: center;
}

.about p {
  color: var(--gray-600);
  font-size: 1.08rem;
}

/* Contact */
.contact {
  background: var(--navy);
  color: var(--white);
  text-align: center;
}

.contact h2 {
  color: var(--white);
}

.contact .section-sub {
  color: var(--gray-200);
}

.contact-details {
  display: flex;
  justify-content: center;
  gap: 48px;
  flex-wrap: wrap;
  margin-bottom: 40px;
}

.contact-item {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.contact-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--blue-light);
  font-weight: 600;
}

.contact-value {
  font-size: 1.25rem;
  font-weight: 600;
  transition: color 0.2s;
}

.contact-item:hover .contact-value {
  color: var(--blue-light);
}

/* Footer */
.site-footer {
  background: var(--navy-dark);
  color: var(--gray-200);
  padding: 24px 0;
  text-align: center;
  font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  #main-nav {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--navy);
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }

  #main-nav.open {
    max-height: 240px;
  }

  #main-nav ul {
    flex-direction: column;
    padding: 12px 24px 20px;
    gap: 18px;
  }

  .hero {
    padding: 80px 0;
  }

  .hero h1 {
    font-size: 2rem;
  }

  section {
    padding: 60px 0;
  }

  .contact-details {
    gap: 28px;
  }
}