:root {
  --yellow: #e5d80e;
  --yellow-dim: #b3a90c;
  --black: #0a0a0a;
  --black-soft: #131311;
  --off-white: #f5f5f2;
  --gray: #948f7a;
  --border: rgba(245, 245, 242, 0.1);
  --font-display: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-body: 'Manrope', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --wrap: 1120px;
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--black);
  color: var(--off-white);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.15;
  margin: 0;
}

p { margin: 0; }

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

img { max-width: 100%; display: block; }

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- language toggling --- */
[lang-en] { display: none; }
html[data-lang="en"] [lang-fr] { display: none; }
html[data-lang="en"] [lang-en] { display: revert; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--yellow);
  color: var(--black);
  padding: 10px 16px;
  z-index: 200;
  font-weight: 600;
}
.skip-link:focus { left: 12px; top: 12px; }

/* --- header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(10, 10, 10, 0.85);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark { width: 36px; height: auto; }

.brand-name {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 16px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  line-height: 1.2;
  display: flex;
  flex-direction: column;
}

.brand-name-sub {
  font-size: 11px;
  font-weight: 400;
  color: var(--yellow);
  letter-spacing: 0.18em;
}

.site-nav {
  display: flex;
  gap: 36px;
}

.site-nav a {
  font-size: 14px;
  letter-spacing: 0.02em;
  color: var(--off-white);
  opacity: 0.8;
  transition: opacity 0.2s, color 0.2s;
}

.site-nav a:hover { opacity: 1; color: var(--yellow); }

.header-actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

.lang-switch {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--off-white);
  font-family: var(--font-display);
  font-size: 12px;
  letter-spacing: 0.08em;
  padding: 8px 14px;
  border-radius: 999px;
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s;
}
.lang-switch:hover { border-color: var(--yellow); color: var(--yellow); }

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
}
.nav-toggle span {
  display: block;
  height: 2px;
  background: var(--off-white);
  border-radius: 2px;
  transition: transform 0.25s, opacity 0.25s;
}

/* --- buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 28px;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.03em;
  border-radius: 999px;
  transition: transform 0.2s, background 0.2s, color 0.2s, border-color 0.2s;
  cursor: pointer;
}

.btn-primary {
  background: var(--yellow);
  color: var(--black);
}
.btn-primary:hover { background: var(--off-white); transform: translateY(-1px); }

.btn-ghost {
  border: 1px solid var(--border);
  color: var(--off-white);
}
.btn-ghost:hover { border-color: var(--yellow); color: var(--yellow); }

.btn-large { padding: 18px 36px; font-size: 15px; }

/* --- hero --- */
.hero {
  position: relative;
  overflow: hidden;
  padding: 96px 0 88px;
  border-bottom: 1px solid var(--border);
}

.hero-ring {
  position: absolute;
  top: 50%;
  right: -18%;
  width: 780px;
  max-width: 90vw;
  transform: translateY(-50%);
  opacity: 0.08;
  pointer-events: none;
  animation: spin 90s linear infinite;
}

@keyframes spin {
  from { transform: translateY(-50%) rotate(0deg); }
  to { transform: translateY(-50%) rotate(360deg); }
}

.hero-inner { position: relative; max-width: 700px; }

.eyebrow {
  font-family: var(--font-display);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--yellow);
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(34px, 5vw, 56px);
  letter-spacing: -0.01em;
  margin-bottom: 22px;
}

.hero-sub {
  font-size: 18px;
  color: var(--gray);
  max-width: 560px;
  margin-bottom: 40px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

/* --- intro --- */
.intro {
  padding: 64px 0;
  border-bottom: 1px solid var(--border);
}
.intro p {
  font-family: var(--font-display);
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 500;
  line-height: 1.5;
  color: var(--off-white);
  max-width: 820px;
}

/* --- section headings --- */
section h2 {
  font-size: clamp(28px, 3.4vw, 38px);
  margin-bottom: 48px;
}

.expertise, .references, .approche { padding: 96px 0; }
.approche { border-top: 1px solid var(--border); background: var(--black-soft); }
.references { border-top: 1px solid var(--border); }

.expertise, .references, .approche, .contact { position: relative; overflow: hidden; }
.expertise .wrap, .references .wrap, .approche .wrap, .contact .wrap { position: relative; z-index: 1; }

/* --- decorative section photos --- */
.section-photo {
  display: none;
  position: absolute;
  top: 0;
  bottom: 0;
  width: 30%;
  min-width: 340px;
  max-width: 480px;
  z-index: 0;
  pointer-events: none;
}
.section-photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(0.4) brightness(0.5) contrast(1.05);
}
.section-photo.is-right {
  right: 0;
  mask-image: linear-gradient(to left, black 35%, transparent 92%);
  -webkit-mask-image: linear-gradient(to left, black 35%, transparent 92%);
}
.section-photo.is-left {
  left: 0;
  mask-image: linear-gradient(to right, black 35%, transparent 92%);
  -webkit-mask-image: linear-gradient(to right, black 35%, transparent 92%);
}

@media (min-width: 1400px) {
  .section-photo { display: block; }
}

/* --- references --- */
.ref-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--border);
}

.ref-item {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 24px;
  padding: 28px 4px;
  border-bottom: 1px solid var(--border);
  border-left: 2px solid transparent;
  transition: border-color 0.2s, padding-left 0.2s;
}
.ref-item:hover {
  border-left-color: var(--yellow);
  padding-left: 20px;
}

.ref-main h3 {
  font-size: 19px;
  margin-bottom: 6px;
}
.ref-main p {
  color: var(--gray);
  font-size: 14px;
}

.ref-years {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  font-family: var(--font-display);
  font-size: 13px;
  color: var(--gray);
  white-space: nowrap;
}

.ref-badge {
  background: rgba(229, 216, 14, 0.12);
  color: var(--yellow);
  border-radius: 999px;
  padding: 4px 12px;
  font-size: 12px;
  letter-spacing: 0.03em;
}

.ref-cta {
  margin-top: 48px;
  text-align: center;
}

/* --- cards --- */
.cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
}

.card {
  background: var(--black);
  padding: 40px 32px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: background 0.25s;
}
.card:hover { background: var(--black-soft); }

.card-index {
  font-family: var(--font-display);
  color: var(--yellow-dim);
  font-size: 13px;
  letter-spacing: 0.1em;
}

.card h3 { font-size: 21px; }

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

/* --- approche grid --- */
.approche-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 40px 56px;
}

.approche-item h3 {
  font-size: 18px;
  color: var(--yellow);
  margin-bottom: 10px;
}
.approche-item p { color: var(--gray); font-size: 15px; }

/* --- contact --- */
.contact {
  padding: 110px 0;
  text-align: center;
}
.contact h2 { margin-bottom: 18px; }
.contact p {
  color: var(--gray);
  font-size: 16px;
  max-width: 480px;
  margin: 0 auto 40px;
}

/* --- footer --- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 32px 0;
}
.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  color: var(--gray);
}
.footer-brand {
  font-family: var(--font-display);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--off-white);
  font-size: 12px;
}

/* --- responsive --- */
@media (max-width: 860px) {
  .cards { grid-template-columns: 1fr; }
  .approche-grid { grid-template-columns: 1fr; }
  .hero-ring { opacity: 0.06; }
}

@media (max-width: 720px) {
  .site-nav {
    position: absolute;
    top: 76px;
    left: 0;
    right: 0;
    background: var(--black);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    gap: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }
  .site-nav.is-open { max-height: 320px; }
  .site-nav a {
    padding: 16px 24px;
    border-top: 1px solid var(--border);
  }
  .nav-toggle { display: flex; }
  .nav-toggle.is-open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .nav-toggle.is-open span:nth-child(2) { opacity: 0; }
  .nav-toggle.is-open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

  .hero { padding: 64px 0 56px; }
  .expertise, .references, .approche { padding: 64px 0; }
  .contact { padding: 72px 0; }
  .btn-large { width: 100%; }

  .ref-item {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
}

@media (max-width: 480px) {
  .brand-name { font-size: 14px; }
  .hero-sub { font-size: 16px; }
}