/* =========================================================
   DATTISSIME PARIS — Feuille de style principale
   Toutes les couleurs sont définies ici, dans :root.
   ========================================================= */

:root {
  /* Palette */
  --night: #24140e;        /* fond sombre (hero, plateforme, Paris-Saclay) */
  --footer: #1e100a;       /* fond du footer */
  --forest: #3a2016;       /* brun profond (titres, cartes sombres) */
  --brown: #7b4824;        /* boutons, italiques des titres */
  --gold: #d6a24d;        /* doré unique du site (traits, puces, icônes, libellés, italiques sur fond sombre) */
  --cream: #fcf7ef;        /* fond des sections claires */
  --pearl: #f7f0e5;        /* fond des cartes claires */
  --sand: #e7d3b0;         /* bordure du menu */
  --ink: #24140e;          /* texte des titres */
  --text: #4b5563;         /* texte courant */
  --text-soft: #6b7280;
  --text-faint: #9ca3af;
  --line: #e5e7eb;

  --serif: "Playfair Display", Georgia, serif;
  --sans: "DM Sans", system-ui, sans-serif;
  --ease: cubic-bezier(.23, 1, .32, 1);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--cream);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
h1, h2, h3, p, ul, blockquote { margin: 0; }
h1, h2, h3 { font-family: var(--serif); font-weight: 500; letter-spacing: -.02em; line-height: 1.15; }
ul { padding: 0; list-style: none; }
a { color: inherit; }
img { display: block; max-width: 100%; }
main { overflow-x: hidden; overflow-x: clip; } /* évite le défilement horizontal dû aux motifs décoratifs */
button { font: inherit; cursor: pointer; }
.icon { width: 20px; height: 20px; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; flex-shrink: 0; }
.icon-sm { width: 16px; height: 16px; }
.icon-lg { width: 24px; height: 24px; }

.container { width: 100%; margin: 0 auto; padding: 0 1.5rem; }
@media (min-width: 640px)  { .container { max-width: 40rem; padding: 0 2rem; } }
@media (min-width: 768px)  { .container { max-width: 48rem; } }
@media (min-width: 1024px) { .container { max-width: 64rem; padding: 0 4rem; } }
@media (min-width: 1280px) { .container { max-width: 80rem; } }
@media (min-width: 1536px) { .container { max-width: 96rem; } }

.section { padding: 8rem 0; background: var(--cream); position: relative; }
.section--dark { background: var(--night); color: #fff; overflow: hidden; }

/* ---------- Éléments communs ---------- */
.label {
  font-family: var(--sans); font-size: .7rem; font-weight: 500;
  letter-spacing: .2em; text-transform: uppercase; color: var(--gold);
}
.section--dark .label { color: var(--gold); }
.sep { display: block; width: 3rem; height: 1px; background: var(--gold); margin: 1.5rem 0 2rem; }

.title { font-size: 2.25rem; line-height: 1.1; color: var(--ink); }
@media (min-width: 768px) { .title { font-size: 3rem; } }
.title em { font-style: italic; color: var(--brown); }
.section--dark .title { color: #fff; }
.section--dark .title em { color: var(--gold); }

.text { color: var(--text); line-height: 1.8; font-size: 1rem; }
.text + .text { margin-top: 1.5rem; }
.section--dark .text { color: rgba(255,255,255,.7); }

.btn {
  display: inline-flex; align-items: center; gap: .5rem;
  padding: .875rem 2rem; font-family: var(--sans); font-size: .85rem; font-weight: 500;
  letter-spacing: .08em; text-transform: uppercase; text-decoration: none;
  border: 1px solid; transition: background-color .25s, color .25s, border-color .25s;
}
.btn-primary { background: var(--gold); border-color: var(--gold); color: var(--night); }
.btn-primary:hover { background: transparent; color: var(--brown); border-color: var(--gold); }
.section--dark .btn-primary:hover, .hero .btn-primary:hover, .contact .btn-primary:hover { color: var(--gold); }
.btn-outline { background: transparent; border-color: rgba(255,255,255,.5); color: #fff; }
.btn-outline:hover { background: rgba(255,255,255,.1); border-color: #fff; }

.icon-box {
  width: 2.5rem; height: 2.5rem; display: flex; align-items: center; justify-content: center;
  border: 1px solid var(--forest); color: var(--forest); flex-shrink: 0;
}

.ornament { position: absolute; pointer-events: none; }
.ornament svg { display: block; fill: none; stroke: currentColor; }

/* Animation à l'apparition */
.reveal { opacity: 0; transform: translateY(24px); transition: opacity .7s var(--ease), transform .7s var(--ease); }
.reveal.in-view { opacity: 1; transform: none; }
.d1 { transition-delay: 80ms; } .d2 { transition-delay: 160ms; } .d3 { transition-delay: 240ms; }
.d4 { transition-delay: 320ms; } .d5 { transition-delay: 400ms; } .d6 { transition-delay: 480ms; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } html { scroll-behavior: auto; } }

/* ---------- En-tête ---------- */
.header {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  border-bottom: 1px solid transparent;
  transition: background-color .4s ease, border-color .4s ease;
}
.header.scrolled { background: rgba(252,247,239,.95); backdrop-filter: blur(24px); -webkit-backdrop-filter: blur(24px); border-bottom-color: var(--sand); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 6rem; }
@media (min-width: 768px) { .header-inner { height: 7rem; } }
.logo { display: block; height: 52px; width: auto; user-select: none; -webkit-user-drag: none; }
@media (min-width: 768px) { .logo { height: 60px; } }

.nav { display: none; gap: 1.5rem; align-items: center; }
@media (min-width: 1024px) { .nav { display: flex; } }
.nav a {
  font-size: .75rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase;
  text-decoration: none; color: rgba(255,255,255,.85); transition: color .2s;
}
.nav a:hover { color: var(--gold); }
.header.scrolled .nav a { color: var(--forest); }
.header.scrolled .nav a:hover { color: var(--gold); }

.menu-toggle { background: none; border: 0; padding: .5rem; color: #fff; display: flex; }
.header.scrolled .menu-toggle, .header.menu-open .menu-toggle { color: var(--forest); }
@media (min-width: 1024px) { .menu-toggle { display: none; } }
.menu-toggle .i-close { display: none; }
.header.menu-open .menu-toggle .i-open { display: none; }
.header.menu-open .menu-toggle .i-close { display: block; }

.mobile-menu { position: fixed; inset: 0; z-index: 40; background: var(--cream); padding: 7rem 1.5rem 2rem; display: none; }
.mobile-menu.open { display: block; }
.mobile-menu nav { display: flex; flex-direction: column; gap: 1.5rem; }
.mobile-menu a {
  font-size: .875rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase;
  color: var(--forest); text-decoration: none; border-bottom: 1px solid var(--sand); padding-bottom: 1rem;
}

/* ---------- Hero ---------- */
.hero {
  position: relative; min-height: 100vh; min-height: 100svh; display: flex; flex-direction: column; justify-content: flex-end;
  padding: 96px 0 6rem; background: var(--night); overflow: hidden; color: #fff;
}
.hero-bg { position: absolute; inset: 0; background: url("../images/hero-section-dattissime.jpg") center / cover no-repeat; }
.hero-overlay { position: absolute; inset: 0; background: linear-gradient(105deg, rgba(36,20,14,.94), rgba(36,20,14,.76) 54%, rgba(36,20,14,.42)); }
.hero .container { position: relative; z-index: 2; }
.hero-content { max-width: 48rem; }
.hero .label { color: var(--gold); margin-bottom: 2rem; }
.hero h1 { font-size: 3rem; line-height: 1; letter-spacing: -.03em; margin-bottom: 2rem; }
@media (min-width: 768px)  { .hero h1 { font-size: 4.5rem; } }
@media (min-width: 1024px) { .hero h1 { font-size: 6rem; } }
.hero h1 em { color: var(--gold); }
.hero-lead { font-size: 1rem; font-weight: 300; line-height: 1.625; color: rgba(255,255,255,.7); max-width: 36rem; margin-bottom: 3rem; }
@media (min-width: 768px) { .hero-lead { font-size: 1.125rem; } }
.hero-actions { display: flex; flex-wrap: wrap; gap: 1rem; }
.hero .ornament { right: 0; bottom: 0; color: #fff; opacity: .08; display: none; }
@media (min-width: 768px) { .hero .ornament { display: block; } }
.scroll-hint {
  position: absolute; bottom: 2rem; left: 50%; transform: translateX(-50%); z-index: 2;
  display: flex; flex-direction: column; align-items: center; gap: .5rem; opacity: .5;
  font-size: .75rem; letter-spacing: .1em; text-transform: uppercase; text-decoration: none; color: #fff;
}
.scroll-hint .icon { animation: bounce 1s infinite; }
@keyframes bounce { 0%,100% { transform: translateY(-25%); animation-timing-function: cubic-bezier(.8,0,1,1); } 50% { transform: none; animation-timing-function: cubic-bezier(0,0,.2,1); } }

/* ---------- Grilles ---------- */
.grid-2 { display: grid; gap: 6rem; }
@media (min-width: 1024px) { .grid-2 { grid-template-columns: 1fr 1fr; } }
.grid-2.center { align-items: center; }
.head-row { display: grid; gap: 4rem; margin-bottom: 5rem; align-items: end; }
@media (min-width: 1024px) { .head-row { grid-template-columns: 3fr 2fr; } }
.head { max-width: 42rem; margin-bottom: 5rem; }

/* ---------- Mission ---------- */
.mission .text:last-of-type { margin-bottom: 2.5rem; }
.mission .title { margin-bottom: 2rem; }
.mission-visual { position: relative; }
.mission-visual .ornament { top: -2rem; right: -2rem; color: var(--forest); opacity: .07; }
.mission-photo { position: relative; z-index: 1; aspect-ratio: 4 / 3; overflow: hidden; background: var(--pearl); }
.mission-photo img { width: 100%; height: 100%; object-fit: contain; filter: saturate(.55) contrast(1.05) sepia(.05); }
.mission-tag {
  position: absolute; z-index: 2; bottom: -1.5rem; left: -1.5rem; background: #fff; padding: 1.5rem;
  border: 1px solid var(--line); box-shadow: 0 10px 15px -3px rgba(0,0,0,.1), 0 4px 6px -4px rgba(0,0,0,.1);
}
.mission-tag .label { color: var(--gold); margin-bottom: .25rem; }
.mission-tag strong { display: block; font-family: var(--serif); font-weight: 500; font-size: 1.125rem; color: var(--forest); }
.mission-tag span { display: block; font-size: .75rem; color: var(--text-soft); margin-top: .25rem; }

/* ---------- Technologie ---------- */
.technologie .grid-2 { align-items: start; }
.technologie .title { margin-bottom: 2rem; }
.quote { margin-top: 2.5rem; padding-left: 1.5rem; border-left: 2px solid var(--gold); }
.quote p { font-family: var(--serif); font-style: italic; font-weight: 500; font-size: 1.125rem; line-height: 1.5; color: var(--forest); }
.steps li { display: flex; gap: 1.5rem; align-items: flex-start; }
.step-rail { display: flex; flex-direction: column; align-items: center; align-self: stretch; }
.step-icon { width: 3rem; height: 3rem; display: flex; align-items: center; justify-content: center; background: #fff; border: 1px solid var(--gold); color: var(--gold); }
.steps li:first-child .step-icon, .steps li:last-child .step-icon { background: var(--gold); border-color: var(--gold); color: var(--night); }
.step-line { width: 1px; flex: 1; min-height: 2rem; margin: .25rem 0; background: var(--gold); }
.step-body { padding-bottom: 1.5rem; }
.step-num { font-size: .75rem; font-weight: 500; letter-spacing: .1em; color: var(--gold); margin-bottom: .125rem; }
.step-body strong { display: block; font-family: var(--serif); font-weight: 500; font-size: 1.125rem; color: var(--ink); }
.step-body span { font-size: .875rem; color: var(--text-soft); }

/* ---------- Plateforme ---------- */
.plateforme { position: relative; background: var(--night); overflow: hidden; }
.plateforme::before { content: ""; position: absolute; inset: 0; background: linear-gradient(105deg, rgba(36,20,14,.9), rgba(36,20,14,.72)), url("../images/platform-section-dattissime.jpg") center / cover no-repeat; pointer-events: none; }
.plateforme > .container { position: relative; z-index: 1; }
.plateforme .ornament { top: 0; right: 0; color: #fff; opacity: .06; }
.plateforme .title { margin-bottom: 1.5rem; }
.plateforme .text { color: rgba(255,255,255,.6); }
.pillars { display: grid; gap: 1px; background: rgba(255,255,255,.08); }
@media (min-width: 768px)  { .pillars { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .pillars { grid-template-columns: repeat(4, 1fr); } }
.pillar { background: rgba(36,20,14,.78); padding: 2rem; backdrop-filter: blur(2px); }
.pillar .icon-box { color: var(--gold); border-color: rgba(214,162,77,.4); margin-bottom: 1.5rem; }
.pillar h3 { font-size: 1.125rem; color: #fff; margin-bottom: 1rem; }
.pillar p { font-size: .875rem; line-height: 1.625; color: rgba(255,255,255,.55); }

/* ---------- Applications ---------- */
.markets { display: grid; gap: 2rem; }
@media (min-width: 768px) { .markets { grid-template-columns: 1fr 1fr; } }
.market { position: relative; overflow: hidden; min-height: 420px; padding: 2.5rem; background: var(--pearl); }
.market .icon-box { margin-bottom: 2rem; }
.market .label { color: var(--gold); margin-bottom: 1rem; }
.market h3 { font-size: 1.875rem; color: var(--ink); margin-bottom: 1.5rem; line-height: 1.2; }
.market p { font-size: .875rem; line-height: 1.625; color: var(--text); margin-bottom: 1.5rem; }
.market li { display: flex; align-items: center; gap: .75rem; font-size: .875rem; color: var(--text); line-height: 1.9; }
.market li::before { content: ""; width: 4px; height: 4px; border-radius: 50%; background: var(--gold); flex-shrink: 0; }
.market-glow { position: absolute; right: 0; bottom: 0; width: 8rem; height: 8rem; opacity: .05; background: radial-gradient(circle, var(--forest) 0%, transparent 70%); }
.market--dark { background: var(--forest); }
.market--dark .icon-box { color: var(--gold); border-color: rgba(214,162,77,.5); }
.market--dark .label { color: var(--gold); }
.market--dark h3 { color: #fff; }
.market--dark p, .market--dark li { color: rgba(255,255,255,.65); }

/* ---------- Impact ---------- */
.impact .head-row .ornament-wrap { display: flex; justify-content: flex-end; padding-bottom: .5rem; color: var(--forest); }
.impact .ornament-wrap svg { opacity: .1; fill: none; stroke: currentColor; }
@media (max-width: 1023px) { .impact .ornament-wrap { display: none; } }
.impact-grid { display: grid; gap: 2rem; }
@media (min-width: 768px)  { .impact-grid { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 1024px) { .impact-grid { grid-template-columns: repeat(3, 1fr); } }
.impact-card { background: var(--pearl); border-left: 2px solid var(--gold); padding: 2rem; }
.impact-card .icon-box { margin-bottom: 1.5rem; }
.impact-card h3 { font-size: 1.125rem; color: var(--ink); margin-bottom: .75rem; }
.impact-card p { font-size: .875rem; line-height: 1.625; color: var(--text); }

/* ---------- Paris-Saclay ---------- */
.saclay-bg { position: absolute; inset: 0; opacity: .2; background: url("../images/paris-saclay.jpg") center / cover no-repeat; }
.saclay .container { position: relative; z-index: 1; }
.saclay .title { margin-bottom: 2rem; }
.assets { display: grid; grid-template-columns: 1fr 1fr; gap: 1rem; }
.asset { padding: 1.5rem; background: rgba(255,255,255,.05); border: 1px solid rgba(214,162,77,.2); }
.asset strong { display: block; font-size: .75rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); margin-bottom: .75rem; }
.asset p { font-size: .875rem; line-height: 1.625; color: rgba(255,255,255,.55); }
@media (max-width: 480px) { .assets { grid-template-columns: 1fr; } }

/* ---------- Actualités ---------- */
.filters { display: flex; flex-direction: column; gap: .75rem; padding-bottom: .5rem; }
.filters > p { font-size: .75rem; letter-spacing: .1em; text-transform: uppercase; color: var(--text-faint); }
.filter-list { display: flex; flex-wrap: wrap; gap: .5rem; }
.filter {
  font-size: .75rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase;
  padding: .375rem .75rem; border: 1px solid var(--forest); color: var(--forest); background: transparent;
  transition: background-color .2s, color .2s;
}
.filter:hover, .filter.active { background: var(--forest); color: #fff; }
.news { display: grid; gap: 2rem; }
@media (min-width: 768px) { .news { grid-template-columns: repeat(3, 1fr); } }
.article { background: #fff; border: 1px solid var(--line); padding: 2rem; display: flex; flex-direction: column; }
.article[hidden] { display: none; }
.article-meta { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: 1.5rem; font-size: .75rem; }
.article-meta .source { font-weight: 500; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); }
.article-meta time { color: var(--text-faint); white-space: nowrap; }
.article h3 { font-size: 1.25rem; line-height: 1.3; color: var(--ink); margin-bottom: 1rem; }
.article p { font-size: .875rem; line-height: 1.625; color: var(--text); margin-bottom: 1.5rem; }
.article a { margin-top: auto; display: inline-flex; align-items: center; gap: .5rem; font-size: .75rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase; color: var(--forest); text-decoration: none; }
.article a:hover { color: var(--gold); }
.news-empty { grid-column: 1 / -1; color: var(--text-soft); font-size: .95rem; }

/* ---------- Contact ---------- */
.contact { position: relative; background: var(--night); color: #fff; overflow: hidden; }
.contact-bg { position: absolute; inset: 0; background: linear-gradient(rgba(36,20,14,.76), rgba(36,20,14,.84)), url("../images/contact-section-dattissime.jpg") center / cover no-repeat; }
.contact .container { position: relative; z-index: 1; }
.contact .ornament { left: 0; bottom: 0; color: #fff; opacity: .08; }
.contact-grid { display: grid; gap: 4rem; position: relative; }
@media (min-width: 1024px) { .contact-grid { grid-template-columns: 2fr 3fr; } }
.contact .title { margin-bottom: 2rem; color: #fff; }
.contact .text { margin-bottom: 3rem; color: rgba(255,255,255,.72); }
.coords { display: flex; flex-direction: column; gap: 1.5rem; }
.coord { display: flex; align-items: flex-start; gap: 1rem; font-size: .875rem; }
.coord .icon-box { color: var(--gold); border-color: var(--gold); }
.coord strong { display: block; font-weight: 500; color: #fff; margin-bottom: .25rem; }
.coord p, .coord a { color: rgba(255,255,255,.7); text-decoration: none; line-height: 1.5; }
.coord a { color: var(--gold); }
.coord a:hover { text-decoration: underline; }

.form { display: flex; flex-direction: column; gap: 1.5rem; }
.form-row { display: grid; gap: 1.5rem; }
@media (min-width: 768px) { .form-row { grid-template-columns: 1fr 1fr; } }
.field label { display: block; font-size: .75rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); margin-bottom: .5rem; }
.field input, .field select, .field textarea {
  width: 100%; padding: .75rem 1rem; font: inherit; font-size: .875rem; color: var(--ink);
  background: #fff; border: 1px solid var(--line); border-radius: 0; outline: none; transition: border-color .2s;
  -webkit-appearance: none; appearance: none;
}
.field select { background: #fff url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%233a2016' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E") no-repeat right 1rem center; padding-right: 2.5rem; }
.field textarea { resize: none; }
.field input:focus, .field select:focus, .field textarea:focus { border-color: var(--forest); }
.hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
.form .btn { width: 100%; justify-content: center; }
.form .btn[disabled] { opacity: .6; cursor: wait; }
.form-status { font-size: .875rem; min-height: 1.5em; }
.form-status.ok { color: #2f6b3a; }
.form-status.err { color: #a23a2a; }

/* ---------- Footer ---------- */
.footer { background: var(--footer); padding: 4rem 0; font-size: .875rem; }
.footer-grid { display: grid; gap: 3rem; margin-bottom: 4rem; }
@media (min-width: 768px) { .footer-grid { grid-template-columns: 2fr 1fr 1fr; } }
.footer-logo { display: block; height: 72px; width: auto; margin-bottom: 1.5rem; }
.footer-about { color: rgba(255,255,255,.45); line-height: 1.625; max-width: 320px; margin-bottom: 1.5rem; }
.footer-tag { font-size: .75rem; letter-spacing: .1em; text-transform: uppercase; color: var(--gold); }
.social {
  margin-top: 1.5rem; width: 32px; height: 32px; display: flex; align-items: center; justify-content: center;
  border: 1px solid rgba(214,162,77,.35); color: rgba(255,255,255,.5); transition: all .2s;
}
.social:hover { border-color: var(--gold); color: #fff; background: rgba(214,162,77,.1); }
.footer h4 { margin: 0 0 1.5rem; font-size: .75rem; font-weight: 500; letter-spacing: .1em; text-transform: uppercase; color: rgba(255,255,255,.3); }
.footer li + li { margin-top: .75rem; }
.footer li a, .footer li span { color: rgba(255,255,255,.5); text-decoration: none; transition: color .2s; }
.footer li a:hover { color: #fff; }
.footer-bottom {
  padding-top: 2rem; border-top: 1px solid rgba(255,255,255,.08);
  display: flex; flex-direction: column; align-items: center; justify-content: space-between; gap: 1rem;
  font-size: .75rem; color: rgba(255,255,255,.25);
}
@media (min-width: 768px) { .footer-bottom { flex-direction: row; } }

/* ---------- Mobile ---------- */
@media (max-width: 767px) {
  .section { padding: 5rem 0; }
  .hero h1 { font-size: 2.6rem; }
  .grid-2 { gap: 4rem; }
  .mission-tag { left: 0; }
  .market { padding: 2rem; min-height: 0; }
}

/* Lisibilité sur le fond sombre de la section Contact */
.contact .title em { color: var(--gold); }
.contact .form-status.ok { color: rgba(255,255,255,.85); }
.contact .form-status.err { color: #f0a58f; }
.contact .form-status a { color: var(--gold); }