:root {
  --bg-color: #ffffff;
  --bg-secondary: #f8fafc;
  --text-color: #1e293b;
  --text-muted: #475569;
  --accent-color: #0d9488; /* Teal */
  --accent-hover: #0f766e;
  --accent-light: #ccfbf1;
  --border-color: #e2e8f0;
  --font-title: 'Montserrat', sans-serif;
  --font-body: 'Open Sans', sans-serif;
  
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.05);
  --transition: all 0.25s ease-in-out;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-body);
  line-height: 1.6;
  padding-top: 80px; /* Nav spacing */
  overflow-x: hidden;
}

/* Typography */
h1, h2, h3, h4 {
  font-family: var(--font-title);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 1rem;
}

h1 {
  font-size: clamp(2rem, 5vw, 3.5rem);
  color: var(--text-color);
}

h2 {
  font-size: clamp(1.5rem, 3.5vw, 2.2rem);
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
  padding-bottom: 0.75rem;
}

h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 50px;
  height: 3px;
  background-color: var(--accent-color);
  border-radius: 1.5px;
}

p {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 75ch;
  margin-bottom: 1.5rem;
}

a {
  color: inherit;
  text-decoration: none;
  transition: var(--transition);
}

/* Navigation Header */
header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 80px;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  height: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 2rem;
}

.logo {
  font-family: var(--font-title);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-color);
}

.logo span {
  color: var(--accent-color);
}

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

.nav-links a {
  font-weight: 600;
  color: var(--text-muted);
  padding: 0.5rem 0;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent-color);
}

/* Hero Section */
.hero {
  padding: 5rem 2rem;
  background: radial-gradient(circle at 0% 0%, rgba(13, 148, 136, 0.04) 0%, rgba(255,255,255,0) 60%);
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 4rem;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
}

.badge {
  display: inline-block;
  align-self: flex-start;
  background-color: var(--accent-light);
  color: var(--accent-color);
  font-weight: 700;
  font-size: 0.8rem;
  text-transform: uppercase;
  padding: 0.35rem 0.9rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1.5rem;
  letter-spacing: 0.05em;
}

/* Buttons */
.btn {
  display: inline-block;
  font-family: var(--font-title);
  font-weight: 700;
  font-size: 1rem;
  padding: 0.75rem 1.8rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
}

.btn-primary {
  background-color: var(--accent-color);
  color: #ffffff;
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  box-shadow: 0 4px 10px rgba(13, 148, 136, 0.15);
}

.btn-outline {
  background-color: transparent;
  color: var(--text-color);
  border-color: var(--border-color);
}

.btn-outline:hover {
  background-color: var(--bg-secondary);
}

.btn-group {
  display: flex;
  gap: 1rem;
  margin-top: 1.5rem;
}

/* Multi-step Form Widget */
.multi-step-box {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem;
  box-shadow: var(--shadow-lg);
}

.progress-bar-container {
  display: flex;
  justify-content: space-between;
  margin-bottom: 2rem;
  position: relative;
}

.progress-bar-line {
  position: absolute;
  top: 50%;
  left: 0;
  width: 100%;
  height: 3px;
  background-color: var(--border-color);
  z-index: 1;
  transform: translateY(-50%);
}

.progress-bar-fill {
  position: absolute;
  top: 50%;
  left: 0;
  width: 0%;
  height: 3px;
  background-color: var(--accent-color);
  z-index: 2;
  transform: translateY(-50%);
  transition: var(--transition);
}

.progress-dot {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background-color: #ffffff;
  border: 2px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.9rem;
  position: relative;
  z-index: 3;
  transition: var(--transition);
}

.progress-dot.active {
  border-color: var(--accent-color);
  color: var(--accent-color);
  box-shadow: 0 0 0 4px var(--accent-light);
}

.progress-dot.completed {
  background-color: var(--accent-color);
  border-color: var(--accent-color);
  color: #ffffff;
}

.step-panel {
  display: none;
}

.step-panel.active {
  display: block;
  animation: fadeIn 0.3s ease-in-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.options-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-top: 1.5rem;
}

.option-select-btn {
  padding: 1.25rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  background-color: #ffffff;
  cursor: pointer;
  text-align: center;
  font-weight: 700;
  font-family: var(--font-title);
  font-size: 0.95rem;
  transition: var(--transition);
}

.option-select-btn:hover {
  border-color: var(--accent-color);
  background-color: var(--bg-secondary);
}

.option-select-btn.selected {
  border-color: var(--accent-color);
  background-color: var(--accent-light);
  color: var(--accent-color);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.1);
}

/* Sections */
section.main-section {
  padding: 6rem 2rem;
  border-top: 1px solid var(--border-color);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 2.5rem;
}

/* Cards */
.batipack-card {
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 2.5rem;
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.batipack-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--accent-color);
}

/* Case study layout */
.case-study {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 3rem;
  align-items: center;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 3rem;
  margin-bottom: 3rem;
}

/* Forms */
.form-container {
  max-width: 600px;
  margin: 0 auto;
  border: 1px solid var(--border-color);
  padding: 2.5rem;
  background-color: var(--bg-secondary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

.form-group {
  margin-bottom: 1.5rem;
}

.form-label {
  display: block;
  font-weight: 700;
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
  color: var(--text-color);
}

.form-input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: #ffffff;
  color: var(--text-color);
  font-family: var(--font-body);
  transition: var(--transition);
}

.form-input:focus {
  outline: none;
  border-color: var(--accent-color);
}

.form-state {
  margin-top: 1.5rem;
  padding: 1rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  display: none;
  text-align: center;
}

.form-state.success {
  background-color: rgba(16, 185, 129, 0.1);
  border-color: #10b981;
  color: #10b981;
  display: block;
}

.form-state.error {
  background-color: rgba(239, 68, 68, 0.1);
  border-color: #ef4444;
  color: #ef4444;
  display: block;
}

.form-state.loading {
  background-color: var(--border-color);
  color: var(--text-muted);
  display: block;
}

/* Footer */
footer {
  border-top: 1px solid var(--border-color);
  background-color: #1e293b;
  color: #94a3b8;
  padding: 5rem 2rem 2rem;
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 4rem;
  margin-bottom: 4rem;
}

.footer-brand h3 {
  color: #ffffff;
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

.footer-brand h3 span {
  color: var(--accent-color);
}

.footer-links h4,
.footer-contact h4 {
  color: #ffffff;
  font-size: 1.1rem;
  margin-bottom: 1.25rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-links ul {
  list-style: none;
}

.footer-links li {
  margin-bottom: 0.8rem;
}

.footer-links a:hover {
  color: #ffffff;
}

.footer-bottom {
  max-width: 1200px;
  margin: 0 auto;
  border-top: 1px solid #334155;
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.9rem;
}

.footer-bottom-links {
  display: flex;
  gap: 1.5rem;
}

.footer-bottom-links a {
  color: #94a3b8;
}

.footer-bottom-links a:hover {
  color: #ffffff;
}

/* Visuels réalistes — cadre commun pour les emplacements photo (hero + slots) */
.visual-frame {
  overflow: hidden;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.visual-media {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* Mobile Navigation Toggle */
.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  border: 1px solid var(--border-color);
  background: #ffffff;
  border-radius: var(--radius-sm);
  padding: 0.6rem;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background-color: var(--text-color);
}

/* Responsive */
@media (max-width: 1024px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  
  .multi-step-box {
    max-width: 600px;
    margin: 0 auto;
  }
  
  .case-study {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 80px;
    left: 0;
    width: 100%;
    background-color: #ffffff;
    border-bottom: 1px solid var(--border-color);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    box-shadow: var(--shadow-md);
  }
  
  .nav-links.active {
    display: flex;
  }
  
  .menu-toggle {
    display: flex;
  }
  
  .footer-container {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
}