/* ============================================================
   SERGE BUASA — Site candidature ArcelorMittal
   Palette ArcelorMittal : orange #E2661A, noir #1A1A1A, blanc #FFFFFF
   ============================================================ */

:root {
  --blue:        #1A1A1A;   /* noir AM — bandeau, sidebar, titres forts */
  --blue-mid:    #1A1A1A;   /* noir AM */
  --blue-light:  #F2F2F2;   /* gris clair AM — fonds alternés */
  --accent:      #E2661A;   /* orange AM officiel */
  --accent-dark: #C04E0E;   /* orange AM foncé — hover */
  --gray-bg:     #F2F2F2;   /* gris clair AM */
  --gray-border: #E0E0E0;   /* séparateur */
  --text:        #1A1A1A;   /* noir AM */
  --text-soft:   #4A4A4A;   /* gris foncé AM */
  --white:       #FFFFFF;
  --radius:      6px;
  --shadow:      0 2px 12px rgba(26,26,26,0.08);
}

/* RESET & BASE */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; font-size: 16px; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  color: var(--text);
  background: var(--white);
  line-height: 1.65;
}

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

ul { list-style: none; }

/* ============================================================
   HEADER
   ============================================================ */

header {
  background: var(--blue);
  color: var(--white);
  padding: 3rem 0 2.5rem;
  border-bottom: 4px solid var(--accent);
}

.header-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  gap: 2rem;
  flex-wrap: wrap;
}

.header-tag {
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  font-weight: 600;
  margin-bottom: 0.5rem;
}

header h1 {
  font-size: 2.4rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.1;
}

.header-subtitle {
  font-size: 1.1rem;
  font-weight: 500;
  color: rgba(255,255,255,0.9);
  margin-top: 0.35rem;
}

.header-location {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.6);
  margin-top: 0.2rem;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--accent);
  color: var(--white);
  font-weight: 600;
  font-size: 0.9rem;
  padding: 0.65rem 1.3rem;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: background 0.2s;
}

.btn-download:hover { background: var(--accent-dark); }

/* ============================================================
   NAVIGATION
   ============================================================ */

nav {
  background: var(--white);
  border-bottom: 1px solid var(--gray-border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 1px 8px rgba(0,51,102,0.06);
}

nav ul {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  gap: 0;
}

nav ul li a {
  display: block;
  padding: 0.9rem 1.2rem;
  font-size: 0.88rem;
  font-weight: 500;
  color: var(--text-soft);
  border-bottom: 3px solid transparent;
  transition: color 0.2s, border-color 0.2s;
}

nav ul li a:hover,
nav ul li a.active {
  color: var(--blue);
  border-bottom-color: var(--accent);
}

/* ============================================================
   SECTIONS
   ============================================================ */

section { padding: 4rem 0; }
.section-alt { background: var(--gray-bg); }

.section-inner {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 2rem;
}

section h2 {
  font-size: 1.7rem;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 1.25rem;
  padding-bottom: 0.6rem;
  border-bottom: 2px solid var(--gray-border);
}

.lead {
  font-size: 1.05rem;
  color: var(--text-soft);
  margin-bottom: 2rem;
  max-width: 780px;
}

/* ============================================================
   PROFIL — TABLE VALEUR
   ============================================================ */

.value-table-wrapper {
  overflow-x: auto;
  margin: 1.5rem 0;
}

.value-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.95rem;
}

.value-table thead tr {
  background: var(--blue);
  color: var(--white);
}

.value-table th {
  padding: 0.75rem 1.2rem;
  text-align: left;
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.value-table tbody tr:nth-child(odd)  { background: var(--white); }
.value-table tbody tr:nth-child(even) { background: var(--blue-light); }

.value-table td {
  padding: 0.65rem 1.2rem;
  border-bottom: 1px solid var(--gray-border);
}

.value-table td.gap  { color: #888; }
.value-table td.plus { color: #1a6e3a; font-weight: 600; }

blockquote {
  margin-top: 2rem;
  border-left: 4px solid var(--accent);
  padding: 1rem 1.5rem;
  background: var(--blue-light);
  border-radius: 0 var(--radius) var(--radius) 0;
  font-style: italic;
  color: var(--text-soft);
  font-size: 0.97rem;
  line-height: 1.7;
}

/* ============================================================
   CAS D'ÉTUDE — PIPELINE
   ============================================================ */

.pipeline {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: 2rem 0;
}

.pipeline-step {
  display: flex;
  gap: 1.5rem;
  background: var(--white);
  border: 1px solid var(--gray-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: var(--shadow);
}

.step-number {
  flex-shrink: 0;
  width: 2.2rem;
  height: 2.2rem;
  background: var(--blue);
  color: var(--white);
  font-weight: 700;
  font-size: 1rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 0.1rem;
}

.step-content h3 {
  font-size: 1rem;
  font-weight: 600;
  color: var(--blue);
  margin-bottom: 0.5rem;
}

.step-content p { font-size: 0.93rem; color: var(--text-soft); margin-bottom: 0.4rem; }
.step-content ul { margin: 0.4rem 0 0.4rem 1rem; list-style: disc; }
.step-content ul li { font-size: 0.93rem; color: var(--text-soft); margin-bottom: 0.2rem; }

.step-output {
  font-size: 0.88rem !important;
  background: var(--blue-light);
  border-radius: var(--radius);
  padding: 0.5rem 0.75rem;
  margin-top: 0.6rem !important;
  color: var(--blue) !important;
}

.pipeline-arrow {
  text-align: center;
  font-size: 1.4rem;
  color: var(--accent);
  font-weight: 700;
  padding: 0.3rem 0;
}

/* RESULT BOX */
.result-box {
  background: var(--white);
  border: 1px solid var(--gray-border);
  border-top: 3px solid var(--blue);
  border-radius: var(--radius);
  padding: 1.75rem;
  margin: 2rem 0;
  box-shadow: var(--shadow);
}

.result-box h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 1.25rem;
}

.mechanism-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
}

.mechanism-item {
  background: var(--gray-bg);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
}

.mechanism-item h4 {
  font-size: 0.88rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--blue-mid);
  margin-bottom: 0.5rem;
}

.mechanism-item p { font-size: 0.9rem; color: var(--text-soft); }

.mechanism-full { grid-column: 1 / -1; border-left: 3px solid var(--accent); }

/* CONTINUATION BOX */
.continuation-box {
  background: var(--blue-light);
  border-radius: var(--radius);
  padding: 1.75rem;
  margin-top: 2rem;
}

.continuation-box h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 1.25rem;
}

.continuation-steps {
  display: flex;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.cont-step {
  flex: 1;
  min-width: 220px;
  background: var(--white);
  border-radius: var(--radius);
  padding: 1rem 1.2rem;
  box-shadow: var(--shadow);
}

.cont-label {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  margin-bottom: 0.6rem;
}

.cont-step.done .cont-label { background: #d4edda; color: #155724; }
.cont-step.next .cont-label { background: #cce5ff; color: #004085; }

.cont-step p { font-size: 0.9rem; color: var(--text-soft); }

.cont-arrow {
  font-size: 1.8rem;
  color: var(--accent);
  font-weight: 700;
}

/* ============================================================
   VISION — AXES DE PROJET
   ============================================================ */

.axes-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
  margin: 2rem 0;
}

.axe-card {
  background: var(--white);
  border: 1px solid var(--gray-border);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  box-shadow: var(--shadow);
  position: relative;
}

.axe-num {
  display: inline-block;
  background: var(--blue);
  color: var(--white);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.6rem;
  border-radius: 3px;
  margin-bottom: 0.6rem;
}

.axe-card h3 {
  font-size: 0.97rem;
  font-weight: 700;
  color: var(--blue);
  margin-bottom: 0.5rem;
}

.axe-card p { font-size: 0.88rem; color: var(--text-soft); margin-bottom: 0.4rem; }

.axe-outil {
  font-size: 0.8rem !important;
  color: var(--accent-dark) !important;
  font-weight: 600;
  margin-top: 0.6rem !important;
}

.contrainte-box {
  background: var(--blue);
  color: var(--white);
  border-radius: var(--radius);
  padding: 1.5rem 1.75rem;
  margin-top: 1.5rem;
}

.contrainte-box h3 {
  font-size: 0.97rem;
  font-weight: 700;
  margin-bottom: 0.6rem;
  color: var(--accent);
}

.contrainte-box p { font-size: 0.9rem; color: rgba(255,255,255,0.85); }
.contrainte-box strong { color: var(--white); }

/* ============================================================
   COMPÉTENCES
   ============================================================ */

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

.skill-group {
  background: var(--white);
  border: 1px solid var(--gray-border);
  border-radius: var(--radius);
  padding: 1.4rem 1.5rem;
  box-shadow: var(--shadow);
}

.skill-group h3 {
  font-size: 0.88rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--blue-mid);
  margin-bottom: 0.9rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--gray-border);
}

.skill-group ul { list-style: none; }

.skill-group ul li {
  font-size: 0.9rem;
  color: var(--text-soft);
  padding: 0.3rem 0;
  border-bottom: 1px solid var(--gray-bg);
  display: flex;
  align-items: flex-start;
  gap: 0.5rem;
}

.skill-group ul li::before {
  content: '—';
  color: var(--accent);
  font-weight: 700;
  flex-shrink: 0;
}

/* ============================================================
   CONTACT
   ============================================================ */

.contact-inner { text-align: center; }

.contact-cards {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin: 2rem 0 1.5rem;
}

.contact-card {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background: var(--blue);
  color: var(--white);
  padding: 0.9rem 1.75rem;
  border-radius: var(--radius);
  font-size: 0.95rem;
  font-weight: 500;
  transition: background 0.2s;
  box-shadow: var(--shadow);
}

.contact-card:hover { background: var(--blue-mid); }
.contact-card svg { opacity: 0.8; }

.contact-note {
  font-size: 0.9rem;
  color: var(--text-soft);
  margin-top: 0.5rem;
}

/* ============================================================
   FOOTER
   ============================================================ */

footer {
  background: var(--blue);
  color: rgba(255,255,255,0.5);
  text-align: center;
  padding: 1.5rem 2rem;
  font-size: 0.8rem;
  border-top: 3px solid var(--accent);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 680px) {
  header h1 { font-size: 1.75rem; }
  .header-inner { flex-direction: column; align-items: flex-start; }

  nav ul { overflow-x: auto; flex-wrap: nowrap; }
  nav ul li a { padding: 0.8rem 0.9rem; font-size: 0.82rem; }

  .axes-grid,
  .skills-grid,
  .mechanism-grid { grid-template-columns: 1fr; }

  .mechanism-full { grid-column: 1; }

  .continuation-steps { flex-direction: column; }
  .cont-arrow { transform: rotate(90deg); }

  .pipeline-step { flex-direction: column; gap: 0.8rem; }
  .step-number { width: 1.8rem; height: 1.8rem; font-size: 0.85rem; }
}