/* ==========================================================================
   Clément Helsens — style.css
   Palette sobre & professionnelle, Inter, responsive
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:ital,wght@0,300;0,400;0,500;0,600;0,700;1,400&display=swap');

/* ---------- Variables ---------------------------------------------------- */
:root {
  --bg:          #ffffff;
  --bg-alt:      #f8fafc;
  --text:        #0f172a;
  --text-muted:  #64748b;
  --accent:      #2563eb;
  --accent-dark: #1d4ed8;
  --border:      #e2e8f0;
  --nav-bg:      #0f172a;
  --nav-text:    rgba(255,255,255,0.75);
  --nav-active:  #ffffff;
  --radius:      10px;
  --radius-sm:   6px;
  --max-w:       1080px;
  --shadow:      0 4px 24px rgba(15,23,42,0.07);
  --shadow-hover:0 8px 36px rgba(15,23,42,0.12);
  --transition:  0.2s ease;
}

/* ---------- Reset --------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
img { max-width: 100%; display: block; }
a { color: var(--accent); }

/* ---------- Navigation --------------------------------------------------- */
nav {
  background: var(--nav-bg);
  position: sticky;
  top: 0;
  z-index: 200;
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 62px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  color: #fff;
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9375rem;
  letter-spacing: -0.01em;
  white-space: nowrap;
}
.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}
.nav-links a {
  color: var(--nav-text);
  text-decoration: none;
  font-size: 0.875rem;
  font-weight: 400;
  transition: color var(--transition);
  padding: 4px 0;
  border-bottom: 2px solid transparent;
}
.nav-links a:hover { color: var(--nav-active); }
.nav-links a.active {
  color: var(--nav-active);
  border-bottom-color: var(--accent);
}

/* Mobile burger */
.nav-burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}
.nav-burger span {
  display: block;
  width: 22px;
  height: 2px;
  background: #fff;
  border-radius: 2px;
  transition: all var(--transition);
}

@media (max-width: 680px) {
  .nav-burger { display: flex; }
  .nav-links {
    display: none;
    position: absolute;
    top: 62px;
    left: 0;
    right: 0;
    background: var(--nav-bg);
    flex-direction: column;
    gap: 0;
    padding: 8px 0 16px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    display: block;
    padding: 10px 24px;
    font-size: 0.9375rem;
    border-bottom: none;
  }
}

/* ---------- Layout helpers ----------------------------------------------- */
.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}
section { padding: 80px 24px; }
section.section-alt { background: var(--bg-alt); }
section.section-dark {
  background: var(--nav-bg);
  color: #fff;
}

/* ---------- Typography --------------------------------------------------- */
.label {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 12px;
}
h1 {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.08;
}
h2 {
  font-size: clamp(1.625rem, 3vw, 2.25rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.2;
  margin-bottom: 14px;
}
h3 {
  font-size: 1.0625rem;
  font-weight: 600;
  line-height: 1.35;
  margin-bottom: 8px;
}
.lead {
  font-size: 1.125rem;
  color: var(--text-muted);
  line-height: 1.65;
  max-width: 560px;
  margin-bottom: 40px;
}
.lead-white {
  color: rgba(255,255,255,0.65);
}

/* ---------- Buttons ------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 11px 22px;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
  transition: all var(--transition);
  cursor: pointer;
  border: none;
  white-space: nowrap;
}
.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover {
  background: var(--accent-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(37,99,235,0.35);
}
.btn-outline-dark {
  border: 1.5px solid rgba(255,255,255,0.25);
  color: rgba(255,255,255,0.9);
  background: transparent;
}
.btn-outline-dark:hover {
  border-color: rgba(255,255,255,0.55);
  background: rgba(255,255,255,0.06);
}
.btn-outline {
  border: 1.5px solid var(--border);
  color: var(--text);
  background: transparent;
}
.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.btn-group {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-top: 8px;
}

/* ---------- Hero ---------------------------------------------------------- */
.hero {
  background: var(--nav-bg);
  color: #fff;
  padding: 100px 24px 96px;
}
.hero-label { color: var(--accent); }
.hero h1 { margin: 0 0 22px; max-width: 680px; }
.hero .lead {
  color: rgba(255,255,255,0.65);
  max-width: 520px;
  margin-bottom: 36px;
}

/* ---------- Cards --------------------------------------------------------- */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(288px, 1fr));
  gap: 20px;
  margin-top: 40px;
}
.card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 26px 28px;
  transition: box-shadow var(--transition), transform var(--transition);
}
.card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-2px);
}
.card-emoji {
  font-size: 1.625rem;
  margin-bottom: 14px;
  line-height: 1;
}
.card p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
  margin-bottom: 16px;
}
.card-link {
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-top: auto;
}
.card-link:hover { color: var(--accent-dark); }

/* ---------- Tags ---------------------------------------------------------- */
.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 14px;
}
.tag {
  font-size: 0.6875rem;
  font-weight: 500;
  padding: 3px 9px;
  border-radius: 100px;
  background: var(--bg-alt);
  color: var(--text-muted);
  border: 1px solid var(--border);
}
.tag-accent {
  background: #eff6ff;
  color: var(--accent);
  border-color: #bfdbfe;
}

/* ---------- Expertise grid ----------------------------------------------- */
.expertise-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 32px;
  margin-top: 48px;
}
.expertise-item { }
.expertise-icon {
  font-size: 1.5rem;
  margin-bottom: 12px;
  line-height: 1;
}
.expertise-item h3 { margin-bottom: 6px; }
.expertise-item p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

/* ---------- Timeline ----------------------------------------------------- */
.timeline { max-width: 680px; }
.timeline-item {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 20px;
  padding: 22px 0;
  border-bottom: 1px solid var(--border);
}
.timeline-item:first-child { padding-top: 0; }
.timeline-item:last-child { border-bottom: none; }
.timeline-date {
  font-size: 0.8125rem;
  color: var(--text-muted);
  font-weight: 500;
  padding-top: 2px;
  line-height: 1.4;
}
.timeline-content .org {
  font-size: 0.8125rem;
  color: var(--accent);
  font-weight: 500;
  margin-bottom: 6px;
}
.timeline-content p {
  font-size: 0.875rem;
  color: var(--text-muted);
  line-height: 1.65;
}

@media (max-width: 600px) {
  .timeline-item { grid-template-columns: 1fr; gap: 4px; }
  .timeline-date { font-size: 0.75rem; }
}

/* ---------- Skills -------------------------------------------------------- */
.skills-section { margin-top: 56px; }
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 24px;
  margin-top: 28px;
}
.skill-col h4 {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.07em;
  color: var(--text-muted);
  margin-bottom: 12px;
}
.skill-col ul { list-style: none; }
.skill-col li {
  font-size: 0.875rem;
  padding: 5px 0;
  border-bottom: 1px solid var(--border);
  color: var(--text);
}
.skill-col li:last-child { border-bottom: none; }

/* ---------- Contact ------------------------------------------------------- */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 2fr;
  gap: 56px;
  align-items: start;
  margin-top: 48px;
}
.contact-info p {
  font-size: 0.9375rem;
  color: var(--text-muted);
  line-height: 1.7;
  margin-bottom: 28px;
}
.contact-row {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-size: 0.875rem;
  margin-bottom: 14px;
  transition: color var(--transition);
}
.contact-row:hover { color: var(--accent); }
.contact-row-icon {
  width: 34px;
  height: 34px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.9375rem;
  flex-shrink: 0;
}
.tally-box {
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px;
}
.tally-box h3 { margin-bottom: 6px; }
.tally-box > p {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}
.tally-placeholder {
  background: var(--bg);
  border: 2px dashed var(--border);
  border-radius: var(--radius-sm);
  padding: 32px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.875rem;
  line-height: 1.7;
}
.tally-placeholder code {
  display: inline-block;
  background: #f1f5f9;
  border-radius: 4px;
  padding: 2px 7px;
  font-family: 'Menlo', 'Consolas', monospace;
  font-size: 0.8125rem;
  color: var(--accent);
  margin-top: 8px;
}

@media (max-width: 768px) {
  .contact-layout { grid-template-columns: 1fr; gap: 36px; }
}

/* ---------- CTA strip ----------------------------------------------------- */
.cta-strip {
  text-align: center;
  max-width: 560px;
  margin: 0 auto;
}
.cta-strip h2 { margin-bottom: 14px; }
.cta-strip p {
  font-size: 1.0625rem;
  color: var(--text-muted);
  margin-bottom: 32px;
}

/* ---------- Footer -------------------------------------------------------- */
footer {
  background: var(--nav-bg);
  color: rgba(255,255,255,0.55);
  padding: 28px 24px;
}
.footer-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}
footer p { font-size: 0.8125rem; }
.footer-links {
  display: flex;
  gap: 20px;
  list-style: none;
}
.footer-links a {
  color: rgba(255,255,255,0.5);
  text-decoration: none;
  font-size: 0.8125rem;
  transition: color var(--transition);
}
.footer-links a:hover { color: #fff; }

/* ---------- Project page header ------------------------------------------ */
.page-header {
  background: var(--nav-bg);
  color: #fff;
  padding: 72px 24px 64px;
}
.page-header h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: 14px;
  max-width: 640px;
}
.page-header .lead { color: rgba(255,255,255,0.65); margin-bottom: 0; }

/* ---------- About profile ------------------------------------------------- */
.about-header {
  display: flex;
  align-items: flex-start;
  gap: 36px;
  margin-bottom: 48px;
  padding-bottom: 40px;
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
}
.avatar {
  width: 88px;
  height: 88px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1d4ed8 0%, #7c3aed 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: #fff;
  flex-shrink: 0;
}
.about-meta h2 {
  font-size: 1.75rem;
  margin-bottom: 4px;
}
.about-meta .role {
  font-size: 1rem;
  color: var(--text-muted);
  margin-bottom: 16px;
}
.about-meta .bio {
  font-size: 0.9375rem;
  color: var(--text-muted);
  max-width: 520px;
  line-height: 1.7;
  margin: 0;
}

/* ---------- Divider ------------------------------------------------------- */
.divider {
  height: 1px;
  background: var(--border);
  margin: 0 24px;
  max-width: var(--max-w);
  margin-left: auto;
  margin-right: auto;
}

/* ---------- Utility ------------------------------------------------------- */
.mt-4  { margin-top: 16px; }
.mt-8  { margin-top: 32px; }
.mt-12 { margin-top: 48px; }
.text-muted { color: var(--text-muted); }
.text-small { font-size: 0.875rem; }

/* ---------- Bilingual toggle --------------------------------------------- */
html.lang-en .fr { display: none; }
html.lang-fr .en { display: none; }

.lang-btn {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.22);
  color: rgba(255,255,255,0.8);
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 4px 9px;
  border-radius: 5px;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  margin-left: 16px;
  flex-shrink: 0;
}
.lang-btn:hover {
  background: rgba(255,255,255,0.16);
  border-color: rgba(255,255,255,0.4);
  color: #fff;
}