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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.7;
  color: #2d3436;
  background-color: #f8f9fa;
}

/* ── Navigation ── */
nav {
  position: fixed;
  top: 0;
  width: 100%;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
  z-index: 1000;
  padding: 0 2rem;
}

nav ul {
  display: flex;
  justify-content: center;
  gap: 2rem;
  list-style: none;
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem 0;
}

nav a {
  text-decoration: none;
  color: #555;
  font-weight: 500;
  font-size: 0.95rem;
  transition: color 0.3s;
  padding: 0.3rem 0;
  border-bottom: 2px solid transparent;
}

nav a:hover,
nav a.active {
  color: #2ecc71;
  border-bottom-color: #2ecc71;
}

/* ── Hero ── */
.hero {
  background: linear-gradient(135deg, #0a1628 0%, #1a3a2a 50%, #0d2818 100%);
  color: #fff;
  text-align: center;
  padding: 8rem 2rem 5rem;
  margin-top: 60px;
}

.hero h1 {
  font-size: 2.8rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.hero .subtitle {
  font-size: 1.2rem;
  opacity: 0.85;
  max-width: 700px;
  margin: 0 auto 2rem;
}

.hero .team {
  display: inline-block;
  background: rgba(46, 204, 113, 0.2);
  border: 1px solid rgba(46, 204, 113, 0.4);
  border-radius: 50px;
  padding: 0.5rem 1.5rem;
  font-size: 0.95rem;
}

/* ── Sections ── */
section {
  max-width: 1100px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  color: #1a3a2a;
}

.section-subtitle {
  color: #555;
  margin-bottom: 2.5rem;
  font-size: 1.05rem;
}

.divider {
  width: 60px;
  height: 4px;
  background: #2ecc71;
  border-radius: 2px;
  margin-bottom: 2rem;
}

/* ── Cards ── */
.card {
  background: #fff;
  border-radius: 12px;
  padding: 2rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.06);
  border: 1px solid #eee;
  transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.card h3 {
  font-size: 1.3rem;
  color: #1a3a2a;
  margin-bottom: 0.8rem;
}

.card p, .card li {
  color: #555;
}

.card ul {
  padding-left: 1.5rem;
  margin-top: 0.5rem;
}

.card li {
  margin-bottom: 0.4rem;
}

/* ── Grid layouts ── */
.grid-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

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

/* ── Proposition header ── */
.proposition-header {
  background: linear-gradient(135deg, #1a3a2a, #2d6a4f);
  color: #fff;
  border-radius: 16px;
  padding: 2.5rem;
  margin-bottom: 2rem;
  text-align: center;
}

.proposition-header.water {
  background: linear-gradient(135deg, #0a2647, #144272);
}

.proposition-header h2 {
  font-size: 1.8rem;
  margin-bottom: 0.3rem;
}

.proposition-header .badge {
  display: inline-block;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 50px;
  padding: 0.3rem 1rem;
  font-size: 0.85rem;
  margin-bottom: 1rem;
}

.proposition-header p {
  max-width: 700px;
  margin: 0 auto;
  opacity: 0.9;
  font-size: 1.05rem;
}

/* ── Tags ── */
.tag-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 1rem;
}

.tag {
  background: #e8f5e9;
  color: #2e7d32;
  padding: 0.3rem 0.8rem;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 500;
}

.tag.blue {
  background: #e3f2fd;
  color: #1565c0;
}

/* ── Tables ── */
table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
}

th, td {
  padding: 0.8rem 1rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

th {
  background: #f1f8e9;
  color: #2e7d32;
  font-weight: 600;
  font-size: 0.9rem;
}

.water-section th {
  background: #e3f2fd;
  color: #1565c0;
}

/* ── Schéma placeholder ── */
.schema-box {
  background: #f5f5f5;
  border: 1px solid #ddd;
  border-radius: 12px;
  padding: 2.5rem;
  text-align: center;
  color: #444;
  font-family: 'Courier New', Courier, monospace;
  font-style: normal;
  white-space: pre;
  margin-top: 1rem;
}

/* ── Interaction flow ── */
.flow {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.flow-step {
  background: #e8f5e9;
  color: #2e7d32;
  padding: 0.5rem 1rem;
  border-radius: 8px;
  font-size: 0.9rem;
  font-weight: 500;
}

.flow-step.blue {
  background: #e3f2fd;
  color: #1565c0;
}

.flow-arrow {
  color: #666;
  font-size: 1.2rem;
}

/* ── Footer ── */
footer {
  background: #1a3a2a;
  color: rgba(255, 255, 255, 0.7);
  text-align: center;
  padding: 2rem;
  font-size: 0.9rem;
}

footer a {
  color: #2ecc71;
  text-decoration: none;
}

/* ── Responsive ── */
@media (max-width: 768px) {
  .grid-2, .grid-3 {
    grid-template-columns: 1fr;
  }

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

  nav ul {
    gap: 1rem;
    font-size: 0.85rem;
    flex-wrap: wrap;
    justify-content: center;
  }

  .flow {
    flex-direction: column;
    align-items: flex-start;
  }

  .flow-arrow {
    transform: rotate(90deg);
  }
}