/* =============================
   DELTA – Style CSS Premium
   Ingénierie moderne & crédibilité
   ============================= */

:root {
  --black: #0d0d0d;
  --gray: #6b6b6b;
  --light-gray: #f5f5f5;
  --border-gray: #e5e5e5;
  --white: #ffffff;
}

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

body {
  font-family: 'Inter', sans-serif;
  background-color: var(--white);
  color: var(--black);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* =============================
   Header & Navigation
   ============================= */

header {
  padding: 36px 64px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid var(--border-gray);
}

header img {
  height: 48px;
}

nav a {
  margin-left: 36px;
  text-decoration: none;
  color: var(--black);
  font-size: 13px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  position: relative;
}

nav a::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--black);
  transition: width 0.3s ease;
}

nav a:hover::after {
  width: 100%;
}

/* =============================
   Hero
   ============================= */

.hero {
  padding: 140px 64px 120px;
  max-width: 1200px;
  margin: auto;
}

.hero h1 {
  font-size: 44px;
  font-weight: 500;
  max-width: 820px;
}

.hero p {
  margin-top: 32px;
  font-size: 18px;
  color: var(--gray);
  max-width: 680px;
}

/* =============================
   CTA
   ============================= */

.cta {
  margin-top: 56px;
  display: flex;
  gap: 28px;
}

.cta a {
  padding: 16px 36px;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  text-decoration: none;
  border: 1px solid var(--black);
  transition: all 0.3s ease;
}

.cta a.primary {
  background-color: var(--black);
  color: var(--white);
}

.cta a.secondary {
  color: var(--black);
}

.cta a:hover {
  transform: translateY(-2px);
}

/* =============================
   Content Sections
   ============================= */

section.content {
  padding: 100px 64px;
  max-width: 1200px;
  margin: auto;
}

section.content h2 {
  font-size: 34px;
  font-weight: 500;
  margin-bottom: 36px;
}

section.content h3 {
  font-size: 20px;
  font-weight: 500;
  margin-bottom: 18px;
}

section.content p {
  font-size: 16px;
  color: var(--gray);
  max-width: 760px;
  margin-bottom: 24px;
}

/* =============================
   Services Blocks
   ============================= */

section.content {
  border-bottom: 1px solid var(--border-gray);
}

/* =============================
   Values / Credibility
   ============================= */

.values {
  background-color: var(--light-gray);
  padding: 110px 64px;
}

.values-grid {
  max-width: 1200px;
  margin: auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 72px;
}

.value h3 {
  font-size: 19px;
  font-weight: 500;
  margin-bottom: 16px;
}

.value p {
  font-size: 15px;
  color: var(--gray);
}

/* =============================
   Formulaire
   ============================= */

form {
  max-width: 640px;
}

form label {
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

form input,
form textarea {
  width: 100%;
  margin-top: 8px;
  margin-bottom: 28px;
  padding: 12px 14px;
  border: 1px solid var(--border-gray);
  font-family: 'Inter', sans-serif;
  font-size: 14px;
}

form button {
  padding: 14px 36px;
  background: var(--black);
  color: var(--white);
  border: none;
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  cursor: pointer;
}

form button:hover {
  opacity: 0.85;
}

/* =============================
   Footer
   ============================= */

footer {
  padding: 64px;
  font-size: 13px;
  color: var(--gray);
}

footer div {
  max-width: 1200px;
  margin: auto;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 20px;
}

/* =============================
   Responsive
   ============================= */

@media (max-width: 768px) {

  header {
    padding: 28px;
    flex-direction: column;
    gap: 24px;
  }

  nav a {
    margin-left: 20px;
  }

  .hero {
    padding: 100px 28px 80px;
  }

  .hero h1 {
    font-size: 32px;
  }

  section.content,
  .values {
    padding: 80px 28px;
  }

  footer {
    padding: 48px 28px;
  }
}