:root {
  --green-600: #2E7D32;
  --green-500: #388E3C;
  --green-400: #4CAF50;
  --green-100: #C8E6C9;
  --green-50: #E8F5E9;

  --gray-950: #0C0F0C;
  --gray-900: #141A14;
  --gray-800: #1C261C;
  --gray-700: #2A382A;
  --gray-600: #3D523D;
  --gray-400: #7A937A;
  --gray-300: #9DB09D;
  --gray-200: #BFD0BF;
  --gray-100: #DCE8DC;
  --gray-50: #F0F5F0;

  --border: rgba(76, 175, 80, 0.1);
  --border-hover: rgba(76, 175, 80, 0.25);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', system-ui, -apple-system, sans-serif;
  background: var(--gray-950);
  color: var(--gray-200);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

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

/* ── UTILITY ── */
.container {
  max-width: 1120px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.icon {
  width: 20px;
  height: 20px;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
  flex-shrink: 0;
}

.icon-lg { width: 24px; height: 24px; }
.icon-xl { width: 32px; height: 32px; }

/* ═══════════════ NAV ═══════════════ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding: 0.9rem 0;
  transition: all 0.3s ease;
}

.nav.scrolled {
  background: rgba(12, 15, 12, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
}

.nav-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--gray-100);
  letter-spacing: -0.01em;
}

.nav-logo span { color: var(--green-400); }

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
  align-items: center;
}

.nav-links a {
  font-size: 0.875rem;
  color: var(--gray-400);
  font-weight: 450;
  transition: color 0.2s;
}

.nav-links a:hover { color: var(--gray-100); }

.nav-cta {
  background: var(--green-600);
  color: var(--gray-50) !important;
  padding: 0.45rem 1rem;
  border-radius: 6px;
  font-weight: 550;
  font-size: 0.85rem;
  transition: background 0.2s;
}

.nav-cta:hover { background: var(--green-500); }

.menu-toggle {
  display: none;
  background: none;
  border: 1px solid var(--border);
  color: var(--gray-300);
  border-radius: 6px;
  padding: 0.35rem 0.5rem;
  cursor: pointer;
  line-height: 1;
}

/* ═══════════════ HERO ═══════════════ */
.hero {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  position: relative;
  overflow: hidden;
  padding-top: 5rem;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: url('mobile_app/assets/field.jpg') center/cover no-repeat;
  filter: brightness(0.2) saturate(0.4);
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg,
    rgba(12, 15, 12, 0.4) 0%,
    rgba(12, 15, 12, 0.6) 60%,
    var(--gray-950) 100%
  );
}

.hero-container {
  flex: 1;
  display: flex;
  align-items: center;
  width: 100%;
}

.hero-content {
  position: relative;
  max-width: 800px;
  padding: 2rem 0;
}

.hero-label {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.45rem 1rem;
  border: 1px solid var(--border);
  border-radius: 100px;
  font-size: 0.9rem;
  color: var(--gray-300);
  margin-bottom: 1.5rem;
  background: rgba(12, 15, 12, 0.5);
}

.hero-label .dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--green-400);
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  color: var(--gray-50);
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 1.2rem;
}

.hero h1 .accent { color: var(--green-400); }

.hero p {
  font-size: 1.2rem;
  color: var(--gray-300);
  line-height: 1.7;
  margin-bottom: 2.5rem;
  max-width: 650px;
}

.hero-actions {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.6rem;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 550;
  transition: all 0.2s;
  border: none;
  cursor: pointer;
}

.btn-primary {
  background: var(--green-600);
  color: white;
}

.btn-primary:hover { background: var(--green-500); }

.btn-ghost {
  background: transparent;
  color: var(--gray-200);
  border: 1px solid var(--gray-700);
}

.btn-ghost:hover {
  border-color: var(--gray-600);
  background: var(--gray-900);
}

.hero-metrics-bar {
  position: relative;
  border-top: 1px solid var(--border);
  background: rgba(12, 15, 12, 0.4);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  padding: 1.5rem 0;
  width: 100%;
}

.metrics-container {
  display: flex;
  gap: 3rem;
  flex-wrap: wrap;
}

.metric {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
}

.metric h3 {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--gray-50);
  letter-spacing: -0.02em;
}

.metric p {
  font-size: 0.85rem;
  color: var(--gray-400);
}

/* ═══════════════ SECTIONS ═══════════════ */
section { padding: 5rem 0; }

.section-header { margin-bottom: 3rem; }

.section-label {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--green-400);
  margin-bottom: 0.6rem;
}

.section-title {
  font-size: clamp(1.2rem, 2vw, 1.5rem);
  font-weight: 700;
  color: var(--gray-50);
  letter-spacing: -0.015em;
  line-height: 1.25;
  margin-bottom: 0.5rem;
}

.section-desc {
  font-size: 0.9rem;
  color: var(--gray-400);
  max-width: 500px;
  line-height: 1.6;
}

/* ═══════════════ FEATURES ═══════════════ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.feature-card {
  background: var(--gray-900);
  padding: 2rem;
  transition: background 0.25s;
}

.feature-card:hover { background: var(--gray-800); }

.feature-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: rgba(46, 125, 50, 0.12);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  color: var(--green-400);
}

.feature-icon svg {
  stroke: var(--green-400);
  fill: none;
  width: 18px;
  height: 18px;
}

.feature-card h3 {
  font-size: 0.95rem;
  font-weight: 650;
  color: var(--gray-100);
  margin-bottom: 0.5rem;
}

.feature-card p {
  font-size: 0.875rem;
  color: var(--gray-400);
  line-height: 1.55;
}

/* ═══════════════ ARCHITECTURE ═══════════════ */
.arch-tiers {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.tier {
  background: var(--gray-900);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.4rem 1rem;
  text-align: center;
  transition: border-color 0.25s;
}

.tier:hover { border-color: var(--border-hover); }

.tier-icon {
  width: 36px;
  height: 36px;
  border-radius: 8px;
  margin: 0 auto 0.8rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--green-400);
  background: rgba(46, 125, 50, 0.1);
}

.tier h4 {
  font-size: 0.85rem;
  font-weight: 650;
  color: var(--gray-100);
  margin-bottom: 0.25rem;
}

.tier .tech-name {
  font-size: 0.78rem;
  color: var(--green-400);
  font-weight: 500;
}

.tier .deploy-to {
  font-size: 0.73rem;
  color: var(--gray-600);
  margin-top: 0.3rem;
}

.arch-connectors {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  padding: 0.6rem 0;
  flex-wrap: wrap;
}

.connector-node {
  font-size: 0.78rem;
  font-weight: 550;
  color: var(--gray-300);
  padding: 0.3rem 0.8rem;
  background: var(--gray-900);
  border: 1px solid var(--border);
  border-radius: 6px;
}

.connector-arrow {
  color: var(--gray-600);
  font-size: 0.85rem;
}

/* ═══════════════ SCREENSHOTS ═══════════════ */
.screenshots-track {
  display: flex;
  gap: 1.25rem;
  overflow-x: auto;
  padding-bottom: 1.5rem;
  scroll-snap-type: x mandatory;
  scrollbar-width: thin;
  scrollbar-color: var(--gray-600) transparent;
}

.screenshots-track::-webkit-scrollbar { height: 8px; }
.screenshots-track::-webkit-scrollbar-track { background: var(--gray-900); border-radius: 4px; }
.screenshots-track::-webkit-scrollbar-thumb { background: var(--gray-600); border-radius: 4px; }
.screenshots-track::-webkit-scrollbar-thumb:hover { background: var(--gray-400); }

.screenshot {
  flex: 0 0 auto;
  scroll-snap-align: start;
  text-align: center;
}

.screenshot img {
  width: 200px;
  height: 420px;
  object-fit: cover;
  object-position: center top;
  border-radius: 12px;
  border: 1px solid var(--border);
  transition: border-color 0.25s, transform 0.3s;
}

.screenshot img:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
}

.screenshot figcaption {
  margin-top: 0.6rem;
  font-size: 0.78rem;
  color: var(--gray-400);
  font-weight: 500;
}

/* ═══════════════ PIPELINE ═══════════════ */
.pipeline-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.75rem;
}

.step {
  background: var(--gray-900);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1.5rem;
  position: relative;
}

.step.highlight { border-color: var(--border-hover); }

.step-num {
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--green-400);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.6rem;
}

.step h4 {
  font-size: 0.9rem;
  font-weight: 650;
  color: var(--gray-100);
  margin-bottom: 0.4rem;
}

.step p {
  font-size: 0.82rem;
  color: var(--gray-400);
  line-height: 1.5;
}

.step-meta {
  margin-top: 0.8rem;
  padding-top: 0.8rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--gray-600);
  font-family: 'SF Mono', 'Fira Code', monospace;
}

/* ═══════════════ TECH STACK ═══════════════ */
.stack-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 0.75rem;
}

.stack-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--gray-900);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.85rem 1rem;
  transition: border-color 0.2s;
}

.stack-item:hover { border-color: var(--border-hover); }

.stack-icon {
  width: 32px;
  height: 32px;
  border-radius: 7px;
  background: rgba(46, 125, 50, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--green-400);
  flex-shrink: 0;
}

.stack-item h5 {
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--gray-200);
}

.stack-item span {
  font-size: 0.72rem;
  color: var(--gray-600);
  display: block;
}

/* ═══════════════ CTA ═══════════════ */
.cta {
  text-align: center;
  padding: 4rem 0 3rem;
  border-top: 1px solid var(--border);
}

.cta .section-desc {
  max-width: 400px;
  margin: 0 auto;
}

.cta-actions {
  display: flex;
  gap: 0.75rem;
  justify-content: center;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

/* ═══════════════ FOOTER ═══════════════ */
footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 0;
  text-align: center;
  font-size: 0.8rem;
  color: var(--gray-600);
}

footer a { color: var(--gray-400); }
footer a:hover { color: var(--gray-200); }

/* ═══════════════ ANIMATIONS ═══════════════ */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.reveal.visible {
  opacity: 1;
  transform: none;
}

/* stagger children */
.stagger > .reveal:nth-child(2) { transition-delay: 0.06s; }
.stagger > .reveal:nth-child(3) { transition-delay: 0.12s; }
.stagger > .reveal:nth-child(4) { transition-delay: 0.18s; }
.stagger > .reveal:nth-child(5) { transition-delay: 0.24s; }
.stagger > .reveal:nth-child(6) { transition-delay: 0.3s; }

@keyframes pulse {
  0%, 100% { opacity: 1; transform: translateX(0); }
  50% { opacity: 0.5; transform: translateX(4px); }
}

/* ═══════════════ RESPONSIVE ═══════════════ */
@media (max-width: 900px) {
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .arch-tiers { grid-template-columns: repeat(3, 1fr); }
  .pipeline-steps { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 640px) {
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: rgba(12, 15, 12, 0.97);
    backdrop-filter: blur(16px);
    padding: 1rem 1.5rem 1.5rem;
    gap: 0.75rem;
    border-bottom: 1px solid var(--border);
  }
  .menu-toggle { display: block; }
  .features-grid { grid-template-columns: 1fr; }
  .arch-tiers { grid-template-columns: repeat(2, 1fr); }
  .pipeline-steps { grid-template-columns: 1fr; }
  .hero-metrics { gap: 1.5rem; }
  .screenshot img { width: 160px; }
}