:root {
  --black: #05070b;
  --black-soft: #0c1017;
  --navy: #101623;
  --blue: #2f6fed;
  --blue-light: #5b93ff;
  --blue-dark: #1a3f9e;
  --white: #ffffff;
  --gray-50: #f5f7fb;
  --gray-100: #eaedf3;
  --gray-400: #8b93a3;
  --gray-600: #5b6474;
  --text-dark: #12141a;
  --shadow: 0 20px 40px -20px rgba(5, 7, 11, 0.35);
  --radius: 14px;
  --font-head: 'Poppins', sans-serif;
  --font-body: 'Inter', sans-serif;
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--text-dark);
  background: var(--white);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }

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

ul { list-style: none; margin: 0; padding: 0; }

.container {
  width: 100%;
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

h1, h2, h3, h4 {
  font-family: var(--font-head);
  color: var(--text-dark);
  margin: 0;
  line-height: 1.2;
}

.accent { color: var(--white); }
.accent-strong { color: var(--blue); }

/* ---------- HEADER ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(5, 7, 11, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  transition: background 0.3s ease;
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--blue), var(--blue-dark));
  color: var(--white);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 14px;
  letter-spacing: 0.5px;
  box-shadow: 0 6px 16px -4px rgba(47, 111, 237, 0.6);
}

.logo-text {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 20px;
  letter-spacing: 0.5px;
  white-space: nowrap;
}

.logo-word--light { color: var(--white); }
.logo-word--accent { color: var(--blue-light); }

.main-nav ul {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 30px;
  font-weight: 600;
  font-size: 14.5px;
  color: rgba(255, 255, 255, 0.75);
  transition: all 0.25s ease;
}

.nav-link:hover { color: var(--white); }

.nav-link.active {
  background: var(--blue);
  color: var(--white);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: transparent;
  border: none;
  cursor: pointer;
}

.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
}

/* ---------- HERO ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: var(--black);
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(47, 111, 237, 0.18), transparent 45%),
    radial-gradient(circle at 80% 75%, rgba(47, 111, 237, 0.14), transparent 45%),
    linear-gradient(180deg, #05070b 0%, #0b0f18 100%);
}

.hero-bg::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.05) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(ellipse at center, rgba(0,0,0,0.9) 0%, transparent 72%);
}

.hero-content {
  position: relative;
  z-index: 2;
  padding-top: 76px;
}

.hero-icon {
  width: 76px;
  height: 76px;
  margin: 0 auto 28px;
  color: var(--blue-light);
}

.hero-eyebrow {
  font-family: var(--font-head);
  font-weight: 600;
  font-size: 18px;
  letter-spacing: 1px;
  margin-bottom: 14px;
  color: rgba(255, 255, 255, 0.75);
}

.hero-eyebrow .accent-strong { color: var(--blue-light); }

.hero-title {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 800;
  color: var(--white);
  letter-spacing: -1px;
  margin-bottom: 34px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 14px 30px;
  border-radius: 40px;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  transition: all 0.25s ease;
  border: 2px solid transparent;
}

.btn-outline {
  border-color: rgba(255, 255, 255, 0.35);
  color: var(--white);
}

.btn-outline:hover {
  background: var(--blue);
  border-color: var(--blue);
  transform: translateY(-2px);
}

/* ---------- SECTIONS ---------- */
.section {
  padding: 110px 0;
}

.section-light { background: var(--white); }

.section-dark {
  background: var(--black-soft);
  color: rgba(255, 255, 255, 0.85);
}

.section-dark h2, .section-dark h3 { color: var(--white); }
.section-dark .section-intro { color: rgba(255, 255, 255, 0.6); }

.section-heading {
  text-align: center;
  max-width: 640px;
  margin: 0 auto 56px;
}

.section-heading h2 {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
}

.heading-rule {
  display: block;
  width: 56px;
  height: 4px;
  background: var(--blue);
  border-radius: 4px;
  margin: 18px auto 0;
}

.section-intro {
  margin-top: 20px;
  color: var(--gray-600);
  font-size: 16px;
}

/* ---------- ABOUT ---------- */
.about-grid {
  max-width: 780px;
  margin: 0 auto;
  text-align: center;
  color: var(--gray-600);
  font-size: 17px;
}

.about-grid p { margin: 0 0 18px; }
.about-lead { color: var(--text-dark); font-size: 19px; font-weight: 500; }

.tech-block {
  margin-top: 70px;
  text-align: center;
}

.tech-block h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 34px;
}

.tech-list {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 14px;
}

.tech-list li {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  width: 108px;
  padding: 20px 10px;
  border-radius: var(--radius);
  background: var(--gray-50);
  border: 1px solid var(--gray-100);
  color: var(--gray-600);
  transition: all 0.25s ease;
}

.tech-list li:hover {
  transform: translateY(-4px);
  border-color: var(--blue);
  color: var(--blue);
  box-shadow: var(--shadow);
}

.tech-list i { font-size: 26px; color: var(--blue); }
.tech-list span { font-size: 12.5px; font-weight: 600; }

/* ---------- SERVICES ---------- */
.services-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 26px;
}

.service-card {
  background: var(--navy);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  padding: 36px 26px;
  text-align: center;
  transition: all 0.3s ease;
}

.service-card:hover {
  transform: translateY(-6px);
  border-color: var(--blue);
  box-shadow: 0 20px 40px -18px rgba(47, 111, 237, 0.45);
}

.service-icon {
  width: 62px;
  height: 62px;
  margin: 0 auto 22px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--blue), var(--blue-dark));
  color: var(--white);
  font-size: 24px;
}

.service-card h3 {
  font-size: 18px;
  margin-bottom: 12px;
}

.service-card p {
  font-size: 14.5px;
  color: rgba(255, 255, 255, 0.6);
  margin: 0;
}

/* ---------- OUR WORK ---------- */
.work-filter {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-bottom: 50px;
}

.work-filter a {
  display: inline-block;
  padding: 9px 20px;
  border-radius: 30px;
  font-size: 14px;
  font-weight: 600;
  color: var(--gray-600);
  border: 1px solid var(--gray-100);
  transition: all 0.25s ease;
}

.work-filter a:hover,
.work-filter a.active {
  background: var(--blue);
  border-color: var(--blue);
  color: var(--white);
}

.work-note {
  text-align: center;
  color: var(--gray-400);
  font-size: 13.5px;
  font-style: italic;
  margin: -30px 0 40px;
}

.work-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 26px;
}

.work-card {
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--gray-50);
  border: 1px solid var(--gray-100);
  transition: all 0.3s ease;
}

.work-card.is-hidden { display: none; }

.work-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow);
  border-color: var(--blue);
}

.work-thumb {
  position: relative;
  aspect-ratio: 4 / 3;
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, 0.9);
}

.work-thumb i:first-child { font-size: 40px; }

.work-thumb--a { background: linear-gradient(135deg, #1a3f9e, #2f6fed); }
.work-thumb--b { background: linear-gradient(135deg, #101623, #2f6fed); }
.work-thumb--c { background: linear-gradient(135deg, #05070b, #1a3f9e); }
.work-thumb--d { background: linear-gradient(135deg, #2f6fed, #5b93ff); }
.work-thumb--e { background: linear-gradient(135deg, #101623, #1a3f9e); }
.work-thumb--f { background: linear-gradient(135deg, #1a3f9e, #05070b); }

.work-link {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(5, 7, 11, 0.55);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.work-link i {
  width: 46px;
  height: 46px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  background: var(--blue);
  color: var(--white);
  font-size: 16px;
}

.work-card:hover .work-link { opacity: 1; }

.work-info {
  padding: 20px 22px;
}

.work-info h3 {
  font-size: 16.5px;
  margin-bottom: 6px;
}

.work-info span {
  font-size: 13px;
  font-weight: 600;
  color: var(--blue);
}

/* ---------- CONTACT ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  max-width: 900px;
  margin: 0 auto;
}

.contact-card {
  background: var(--navy);
  border: 1px solid rgba(255, 255, 255, 0.06);
  border-radius: var(--radius);
  padding: 34px 22px;
  text-align: center;
}

.contact-card i {
  font-size: 26px;
  color: var(--blue-light);
  margin-bottom: 16px;
}

.contact-card h3 {
  font-size: 16px;
  margin-bottom: 8px;
}

.contact-card p {
  margin: 0;
  font-size: 14.5px;
  color: rgba(255, 255, 255, 0.6);
}

/* ---------- FOOTER ---------- */
.site-footer {
  background: var(--black);
  padding: 34px 0;
  text-align: center;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}

.footer-logo {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 17px;
}

.site-footer p {
  margin: 0;
  color: rgba(255, 255, 255, 0.45);
  font-size: 13.5px;
}

/* ---------- BACK TO TOP ---------- */
.back-to-top {
  position: fixed;
  right: 26px;
  bottom: 26px;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: none;
  background: var(--blue);
  color: var(--white);
  font-size: 16px;
  cursor: pointer;
  box-shadow: 0 10px 26px -8px rgba(47, 111, 237, 0.7);
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: all 0.3s ease;
  z-index: 900;
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

/* ---------- RESPONSIVE ---------- */
@media (max-width: 900px) {
  .services-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-grid { grid-template-columns: 1fr; }
  .work-grid { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 780px) {
  .nav-toggle { display: flex; }

  .main-nav {
    position: fixed;
    top: 76px;
    left: 0;
    right: 0;
    background: rgba(5, 7, 11, 0.98);
    backdrop-filter: blur(10px);
    transform: translateY(-130%);
    transition: transform 0.3s ease;
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  }

  .main-nav.open { transform: translateY(0); }

  .main-nav ul {
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    gap: 6px;
  }

  .nav-link { text-align: center; padding: 14px; }

  .services-grid { grid-template-columns: 1fr; }
  .work-grid { grid-template-columns: 1fr; }
}

@media (max-width: 520px) {
  .section { padding: 80px 0; }
  .tech-list li { width: 88px; padding: 16px 8px; }
}