:root {
  --green-950: #0a1f14;
  --green-900: #0f2e1e;
  --green-800: #143d28;
  --green-700: #1c5236;
  --green-600: #257045;
  --green-500: #2f8f56;
  --green-400: #4caf6e;
  --green-300: #86d3a3;
  --green-100: #e6f5eb;
  --cream: #f7f5ee;
  --ink: #12211a;
  --muted: #4d5f56;
  --max-width: 1140px;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(15, 46, 30, 0.12);
  font-size: 16px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--ink);
  background: var(--cream);
  line-height: 1.6;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

h1, h2, h3 { line-height: 1.2; margin: 0 0 0.5em; font-weight: 700; }

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

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--green-600);
  margin: 0 0 0.75rem;
}

.lead {
  font-size: 1.1rem;
  color: var(--muted);
  max-width: 60ch;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 245, 238, 0.9);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid rgba(20, 61, 40, 0.08);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 800;
  font-size: 1.15rem;
  color: var(--green-800);
}

.brand-mark { font-size: 1.4rem; }

.nav-links {
  list-style: none;
  display: flex;
  gap: 2rem;
  margin: 0;
  padding: 0;
}

.nav-links a {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--green-800);
  padding: 0.4rem 0;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease;
}

.nav-links a:hover {
  color: var(--green-500);
  border-color: var(--green-400);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--green-800);
  border-radius: 2px;
}

/* Hero */
.hero {
  position: relative;
  min-height: 88vh;
  display: flex;
  align-items: center;
  overflow: hidden;
  color: #fff;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 20% 20%, rgba(76, 175, 110, 0.35), transparent 45%),
    radial-gradient(circle at 80% 70%, rgba(134, 211, 163, 0.25), transparent 50%),
    linear-gradient(160deg, var(--green-950), var(--green-800) 60%, var(--green-600));
  z-index: -1;
}

.hero-content {
  padding-top: 4rem;
  padding-bottom: 4rem;
  max-width: 760px;
}

.hero .eyebrow { color: var(--green-300); }

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.4rem);
  margin-bottom: 0.6em;
}

.hero-sub {
  font-size: 1.15rem;
  color: rgba(255, 255, 255, 0.85);
  max-width: 55ch;
  margin-bottom: 2rem;
}

.hero-actions {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 0.85rem 1.7rem;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.btn-primary {
  background: var(--green-400);
  color: var(--green-950);
}

.btn-primary:hover {
  background: var(--green-300);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.btn-ghost {
  border: 1.5px solid rgba(255, 255, 255, 0.5);
  color: #fff;
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-2px);
}

.scroll-cue {
  position: absolute;
  bottom: 1.5rem;
  left: 50%;
  transform: translateX(-50%);
  color: rgba(255, 255, 255, 0.7);
  font-size: 1.4rem;
  animation: bounce 2s infinite;
}

@keyframes bounce {
  0%, 100% { transform: translate(-50%, 0); }
  50% { transform: translate(-50%, 8px); }
}

/* Sections */
.section {
  padding: 6rem 0;
}

.section-alt {
  background: var(--green-100);
}

.section-head {
  max-width: 700px;
  margin-bottom: 3rem;
}

.section-head h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
  color: var(--green-900);
}

/* About */
.about-grid {
  display: grid;
  gap: 3rem;
}

.pillars {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.pillar {
  background: #fff;
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  box-shadow: var(--shadow);
}

.pillar-icon {
  font-size: 1.8rem;
  display: block;
  margin-bottom: 0.75rem;
}

.pillar h3 {
  color: var(--green-700);
  margin-bottom: 0.4em;
}

.pillar p {
  color: var(--muted);
  margin: 0;
  font-size: 0.95rem;
}

/* Projects cards */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.card {
  background: #fff;
  border-radius: var(--radius);
  padding: 2rem 1.5rem;
  box-shadow: var(--shadow);
  border-top: 4px solid var(--green-400);
}

.card-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--green-600);
  background: var(--green-100);
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  margin-bottom: 1rem;
}

.card h3 {
  color: var(--green-900);
}

.card p {
  color: var(--muted);
  margin: 0;
  font-size: 0.95rem;
}

/* Carbon section */
.carbon {
  background: linear-gradient(160deg, var(--green-900), var(--green-700));
  color: #fff;
}

.carbon .eyebrow { color: var(--green-300); }

.carbon-content {
  max-width: 760px;
}

.carbon h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.4rem);
}

.carbon .lead {
  color: rgba(255, 255, 255, 0.85);
}

.stats {
  display: flex;
  gap: 3rem;
  margin-top: 2.5rem;
  flex-wrap: wrap;
}

.stat {
  display: flex;
  flex-direction: column;
}

.stat-num {
  font-size: 2.2rem;
  font-weight: 800;
  color: var(--green-300);
}

.stat-label {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
}

/* Contact */
.contact .section-head { margin-bottom: 2rem; }

.contact .btn-primary {
  font-size: 1.05rem;
}

/* Footer */
.site-footer {
  background: var(--green-950);
  color: rgba(255, 255, 255, 0.7);
  padding: 2rem 0;
  font-size: 0.9rem;
}

.footer-content {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* Responsive */
@media (max-width: 860px) {
  .pillars, .cards {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 720px) {
  .nav-toggle { display: flex; }

  .nav-links {
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--cream);
    flex-direction: column;
    gap: 0;
    padding: 0.5rem 1.5rem 1rem;
    border-bottom: 1px solid rgba(20, 61, 40, 0.08);
    display: none;
  }

  .nav-links.open { display: flex; }

  .nav-links li { width: 100%; }

  .nav-links a {
    display: block;
    padding: 0.75rem 0;
  }

  .section { padding: 4rem 0; }
}