:root {
  --noir: #0e0e0e;
  --blanc: #f7f6f2;
  --rouge: #c8391a;
  --g1: #222;
  --g2: #444;
  --g3: #777;
  --g4: #bbb;
  --g5: #e6e6e2;
  --serif: 'Instrument Serif', Georgia, serif;
  --mono: 'DM Mono', monospace;
  --b: 1.5px solid #0e0e0e;
  --bl: 1px solid #d8d8d4;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: var(--mono); background: var(--blanc); color: var(--noir); font-size: 13px; line-height: 1.5; }

.masthead { display: grid; grid-template-columns: 1fr 1fr; border-bottom: var(--b); }
.mast-l { padding: 2rem 2.5rem 1.75rem; border-right: var(--b); }
.mast-eyebrow { font-size: 10px; letter-spacing: .14em; text-transform: uppercase; color: var(--g3); margin-bottom: .5rem; }
.mast-titre { font-family: var(--serif); font-size: clamp(32px, 3.5vw, 52px); font-weight: 400; line-height: .95; letter-spacing: -.01em; }
.mast-titre em { font-style: italic; color: var(--rouge); }
.mast-r { padding: 2rem 2.5rem 1.75rem; display: flex; flex-direction: column; justify-content: space-between; }
.mast-desc { font-size: 12px; color: var(--g2); line-height: 1.75; max-width: 480px; }

.topbar {
  display: flex; align-items: stretch; border-bottom: var(--b);
  background: var(--blanc); position: sticky; top: 0; z-index: 100; height: 46px;
}
.tbtn {
  font-size: 10px; letter-spacing: .1em; text-transform: uppercase;
  padding: 0 1.25rem; background: none; border: none; border-right: var(--b);
  cursor: pointer; color: var(--g3); transition: background .1s, color .1s;
  display: flex; align-items: center; text-decoration: none; font-family: var(--mono);
}
.tbtn:hover { background: var(--g5); color: var(--noir); }
.tbtn.atlas { color: var(--noir); }
.tbtn.atlas:hover { color: var(--rouge); }

.page { max-width: 1100px; margin: 0 auto; }

.section { border-bottom: var(--b); display: grid; grid-template-columns: 280px 1fr; }
.sec-head { padding: 3rem 2.5rem; border-right: var(--b); }
.sec-label { font-size: 9px; letter-spacing: .16em; text-transform: uppercase; color: var(--rouge); margin-bottom: .75rem; display: block; font-weight: 500; }
.sec-titre { font-family: var(--serif); font-size: clamp(24px, 2.5vw, 36px); font-weight: 400; line-height: 1.05; }
.sec-titre em { font-style: italic; }
.sec-body { padding: 3rem 2.5rem; }

.etape { display: flex; gap: 1.5rem; margin-bottom: 2rem; padding-bottom: 2rem; border-bottom: var(--bl); }
.etape:last-child { border: none; margin-bottom: 0; padding-bottom: 0; }
.etape-n { font-size: 28px; font-weight: 300; color: var(--g4); letter-spacing: -.03em; flex-shrink: 0; width: 2rem; line-height: 1; padding-top: 2px; }
.etape-content {}
.etape-titre { font-family: var(--serif); font-size: 17px; font-weight: 400; font-style: italic; margin-bottom: .4rem; }
.etape-desc { font-family: var(--serif); font-size: 13px; color: var(--g2); line-height: 1.7; }

.charte-grille { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1px; background: var(--bl); border: var(--bl); }
.charte-item { background: var(--blanc); padding: 1.25rem 1.5rem; }
.charte-item-label { font-size: 9px; letter-spacing: .12em; text-transform: uppercase; color: var(--rouge); margin-bottom: .5rem; display: block; font-weight: 500; }
.charte-item-val { font-size: 13px; color: var(--g1); line-height: 1.6; }
.charte-item-hint { font-size: 11px; color: var(--g3); margin-top: .2rem; }

.workflow { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--bl); border: var(--bl); }
.workflow-step { background: var(--blanc); padding: 1.25rem; display: flex; flex-direction: column; gap: 1.25rem; min-height: 210px; }
.workflow-n { font-size: 10px; letter-spacing: .12em; color: var(--rouge); }
.workflow-title { font-size: 12px; font-weight: 500; margin-bottom: .45rem; }
.workflow-desc { font-size: 10px; color: var(--g2); line-height: 1.65; }
.checklist { margin-top: 1.5rem; border: var(--bl); padding: 1.25rem; }
.checklist-label { display: block; font-size: 9px; letter-spacing: .12em; text-transform: uppercase; color: var(--rouge); margin-bottom: .85rem; font-weight: 500; }
.checklist-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--bl); }
.checklist-grid div { background: var(--blanc); padding: .75rem .9rem; font-size: 10px; color: var(--g2); }

.gabarit-grille { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--bl); border: var(--bl); }
.gabarit-card { background: var(--blanc); padding: 1.5rem; display: flex; flex-direction: column; gap: .75rem; }
.gabarit-placeholder { aspect-ratio: 4/3; background: var(--g5); border: 1px dashed var(--g4); display: flex; align-items: center; justify-content: center; }
.gabarit-placeholder span { font-size: 10px; letter-spacing: .08em; text-transform: uppercase; color: var(--g4); }
.gabarit-preview { aspect-ratio: 4/3; background: #fff; border: var(--bl); display: flex; align-items: center; justify-content: center; overflow: hidden; transition: border-color .1s, background .1s; }
.gabarit-preview:hover { border-color: var(--rouge); background: var(--g5); }
.gabarit-preview img { width: 100%; height: 100%; object-fit: contain; display: block; }
.gabarit-titre { font-size: 11px; font-weight: 500; }
.gabarit-desc { font-size: 10px; color: var(--g3); line-height: 1.5; }
.gabarit-actions { margin-top: auto; display: flex; gap: 5px; flex-wrap: wrap; align-items: center; }
.gabarit-download {
  border: 1px solid var(--noir); color: var(--noir);
  text-decoration: none; font-size: 9px; letter-spacing: .09em; text-transform: uppercase;
  padding: 5px 9px; transition: background .1s, color .1s, border-color .1s;
}
.gabarit-download:hover { background: var(--rouge); border-color: var(--rouge); color: #fff; }
.gabarit-pending { font-size: 9px; letter-spacing: .07em; text-transform: uppercase; color: var(--g4); padding: 5px 0; }

.site-footer { border-top: var(--bl); padding: .75rem 2.5rem; display: flex; justify-content: flex-end; }
.site-footer a { font-size: 10px; letter-spacing: .06em; color: var(--g4); text-decoration: none; }
.site-footer a:hover { color: var(--g2); }

@media (max-width: 980px) {
  .gabarit-grille, .workflow { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 760px) {
  .masthead, .section { grid-template-columns: 1fr; }
  .mast-l, .sec-head { border-right: none; border-bottom: var(--b); }
  .charte-grille, .gabarit-grille, .workflow, .checklist-grid { grid-template-columns: 1fr; }
}