/* ============================================================
   RIO CONSTRUCTION BTP — « Du trait à la clé »
   Le fil du maître d'œuvre. Palette olive-charbon + laiton.
   ============================================================ */

:root{
  --ink:#15160e; --ink-2:#1c1d13; --ink-3:#24251a;
  --brass:#c9a227; --brass-bright:#e6c64e; --brass-dark:#9c7c1a;
  --khaki:#b9a06a; --sheet:#f4f2ec; --sheet-ink:#2a2b1f;
  --text:#f1efe6; --text-2:#d6d1c4; --muted:#8d877a;
  --bordeaux:#7a2e38; --wa:#25d366;
  --disp:'Barlow Condensed','Saira Condensed',system-ui,sans-serif;
  --body:'IBM Plex Sans','Saira',system-ui,sans-serif;
  --edge:clamp(1.25rem,5vw,5rem);
  --hair:rgba(201,162,39,.28);
}

*{box-sizing:border-box;margin:0;padding:0}
html{-webkit-text-size-adjust:100%}
body{
  background:var(--ink); color:var(--text);
  font-family:var(--body); font-weight:400;
  font-size:clamp(1rem,.95rem + .3vw,1.15rem); line-height:1.6;
  -webkit-font-smoothing:antialiased; overflow-x:hidden;
}
img{display:block;max-width:100%}
a{color:inherit;text-decoration:none}
::selection{background:var(--brass);color:var(--ink)}

/* ---------- TOPBAR ---------- */
.topbar{
  position:fixed; inset:0 0 auto 0; z-index:50;
  display:flex; align-items:center; gap:1rem;
  padding:.7rem var(--edge);
  background:linear-gradient(180deg,rgba(21,22,14,.92),rgba(21,22,14,0));
  backdrop-filter:blur(2px);
}
.brand{display:flex;align-items:center;gap:.6rem}
.brand img{width:38px;height:38px;object-fit:contain;filter:drop-shadow(0 1px 2px rgba(0,0,0,.5))}
.brand-txt{font-family:var(--disp);font-weight:700;font-size:1.05rem;letter-spacing:.06em;line-height:1;text-transform:uppercase}
.brand-txt i{display:block;font-weight:500;font-size:.62rem;letter-spacing:.22em;color:var(--muted);font-style:normal;margin-top:.18rem}
.nav{display:none;margin-left:auto;gap:1.6rem}
.nav a{font-family:var(--disp);font-weight:500;text-transform:uppercase;letter-spacing:.13em;font-size:.82rem;color:var(--text-2);padding:.3rem 0;border-bottom:1px solid transparent;transition:border-color .2s,color .2s}
.nav a:hover{color:var(--text);border-color:var(--brass)}
.top-cta{display:none;align-items:center;gap:.45rem;margin-left:.4rem;padding:.5rem .85rem;border:1px solid var(--hair);border-radius:2px;font-family:var(--disp);font-weight:600;text-transform:uppercase;letter-spacing:.1em;font-size:.78rem;color:var(--text);transition:background .2s,border-color .2s}
.top-cta:hover{background:var(--brass);color:var(--ink);border-color:var(--brass)}
.top-cta svg{width:16px;height:16px;fill:var(--wa)}
.top-cta:hover svg{fill:var(--ink)}
.burger{margin-left:auto;width:40px;height:34px;display:flex;flex-direction:column;justify-content:center;gap:6px;background:none;border:0;cursor:pointer}
.burger span{height:2px;background:var(--text);display:block}
.burger span:first-child{width:24px}.burger span:last-child{width:16px;align-self:flex-end}

/* mobile nav panel */
body.nav-open .nav{display:flex;flex-direction:column;position:fixed;inset:56px var(--edge) auto var(--edge);background:var(--ink-2);border:1px solid var(--hair);padding:1rem 1.2rem;gap:.4rem;z-index:60}
body.nav-open .nav a{font-size:1rem;border:0}

/* ---------- CHAPTER SHELL ---------- */
.ch{position:relative;padding:clamp(5rem,12vh,9rem) var(--edge);overflow:hidden}
.ch-dark{background:var(--ink);background-image:radial-gradient(130% 80% at 82% 4%,rgba(201,162,39,.055),transparent 58%)}
.ch-dark.alt{background:var(--ink-2);background-image:radial-gradient(120% 80% at 18% 6%,rgba(122,46,56,.07),transparent 60%)}
.ch-sheet{background:var(--sheet);color:var(--sheet-ink)}

/* thread (le fil) */
.thread{position:absolute;inset:0;width:100%;height:100%;z-index:1;pointer-events:none;overflow:visible;filter:drop-shadow(0 0 3px rgba(201,162,39,.45))}
.thread path{fill:none;stroke:var(--brass);stroke-width:1.6;vector-effect:non-scaling-stroke;stroke-linecap:round}
.thread-dark{filter:none}
.thread-dark path{stroke:var(--brass-dark);stroke-width:2.2;stroke-dasharray:0}
.ch>*:not(.thread):not(.media){position:relative;z-index:2}

/* station label (cote) */
.station{font-family:var(--disp);text-transform:uppercase;letter-spacing:.24em;font-size:.78rem;font-weight:600;color:var(--muted);display:flex;align-items:center;gap:.7rem;margin-bottom:2.2rem}
.station i{font-style:normal;color:var(--brass);border:1px solid var(--hair);padding:.18rem .5rem;letter-spacing:.05em;font-weight:700}
.station.dark{color:var(--sheet-ink)}
.station.dark i{color:var(--brass-dark);border-color:rgba(156,124,26,.4)}

/* ---------- MEDIA / GRADE ---------- */
.media{position:relative;overflow:hidden;background:var(--ink-3)}
.media img{width:100%;height:100%;object-fit:cover;filter:saturate(.82) contrast(1.05) brightness(.93)}
.media.warm img{filter:saturate(.94) contrast(1.08) brightness(.9) sepia(.3) hue-rotate(-9deg)}
.media.warm::after{content:"";position:absolute;inset:0;background:
  radial-gradient(120% 90% at 60% 22%,rgba(233,201,90,.26),transparent 60%),
  linear-gradient(180deg,rgba(40,29,12,.16),rgba(21,22,14,.5));mix-blend-mode:multiply}
.media.warm::before{content:"";position:absolute;inset:0;z-index:1;background:linear-gradient(58deg,rgba(201,162,39,.16),rgba(122,46,56,.1) 48%,transparent 72%);mix-blend-mode:soft-light}

/* ---------- CH0 OUVERTURE (split éditorial · ligne de niveau → fil) ---------- */
.ch-open{position:relative;min-height:100svh;padding:0;display:flex;flex-direction:column;justify-content:flex-end;overflow:hidden;background:var(--ink)}
.open-photo{position:absolute;inset:0;width:100%;height:100%;order:0;margin:0;z-index:0}
.open-photo img{width:100%;height:100%;object-fit:cover;object-position:30% 40%}
.open-photo figcaption{display:none;position:absolute;left:0;bottom:0;z-index:3;flex-direction:column;gap:.05rem;padding:.7rem 1rem;font-family:var(--disp);background:linear-gradient(90deg,rgba(21,22,14,.72),transparent 90%)}
.open-photo figcaption b{font-weight:600;font-size:.82rem;letter-spacing:.1em;text-transform:uppercase;color:var(--brass)}
.open-photo figcaption span{font-size:.72rem;letter-spacing:.05em;color:var(--text-2)}
.open-copy{position:relative;z-index:3;display:flex;flex-direction:column;justify-content:flex-end;padding:0 var(--edge) clamp(2.4rem,7vh,3.4rem);text-shadow:0 2px 16px rgba(0,0,0,.6),0 1px 5px rgba(0,0,0,.72),0 0 2px rgba(0,0,0,.6)}
.domains{font-family:var(--disp);text-transform:uppercase;letter-spacing:.2em;font-size:.76rem;color:var(--muted);margin-top:1.4rem}
.open-thread{display:none}
.kicker{font-family:var(--disp);text-transform:uppercase;letter-spacing:.26em;font-size:.8rem;font-weight:600;color:var(--brass);margin-bottom:1.1rem}
.hero-title{font-family:var(--disp);font-weight:500;text-transform:uppercase;font-size:clamp(3.6rem,8vw,6.6rem);line-height:.92;letter-spacing:.01em}
.hero-title em{font-style:normal;font-weight:400;color:var(--text-2);white-space:nowrap}
.od{display:none}.om{display:block}
.hero-sub{max-width:38ch;margin-top:1.5rem;color:var(--text-2);font-size:1.1rem}
.scroll-cue{display:inline-flex;align-items:center;gap:.7rem;margin-top:2rem;font-family:var(--disp);text-transform:uppercase;letter-spacing:.2em;font-size:.78rem;font-weight:600;color:var(--text)}
.scroll-cue span{width:46px;height:1px;background:var(--brass);position:relative}
.scroll-cue span::after{content:"";position:absolute;right:0;top:-3px;width:7px;height:7px;border-right:1px solid var(--brass);border-bottom:1px solid var(--brass);transform:rotate(-45deg)}

/* ---------- TITLES ---------- */
.ch-title{font-family:var(--disp);font-weight:500;text-transform:uppercase;font-size:clamp(2.1rem,6.4vw,4.6rem);line-height:.98;letter-spacing:.01em}
.ch-title.small{font-size:clamp(1.85rem,5vw,3.1rem)}
.ch-sheet .ch-title{color:var(--sheet-ink)}
.lead{font-size:1.15rem;max-width:42ch;color:var(--text-2)}
.ch-sheet .lead{color:#54543f}
.lead.light{color:var(--text-2)}
.credo{font-family:var(--disp);font-weight:500;font-size:1.35rem;letter-spacing:.01em;color:var(--brass);margin-top:1.6rem;line-height:1.2}

/* ---------- INDEX (services) ---------- */
.index{list-style:none;margin-top:2rem;border-top:1px solid var(--hair)}
.index li{display:flex;gap:1.1rem;padding:1.15rem 0;border-bottom:1px solid var(--hair);align-items:baseline}
.index i{font-family:var(--disp);font-style:normal;font-weight:700;color:var(--brass);font-size:.95rem;min-width:1.6rem;letter-spacing:.05em}
.index b{display:block;font-family:var(--disp);font-weight:500;font-size:1.25rem;letter-spacing:.02em;line-height:1.1}
.index span{display:block;color:var(--muted);font-size:.98rem;margin-top:.2rem}
.ch-sheet .index{border-color:rgba(156,124,26,.32)}
.ch-sheet .index li{border-color:rgba(156,124,26,.32)}
.ch-sheet .index i{color:var(--brass-dark)}
.ch-sheet .index span{color:#6b6a52}
.index.light b{color:var(--text)}

/* ---------- CH1 OEUVRE ---------- */
.oeuvre-grid{display:grid;gap:2rem}
.oeuvre-body p{margin-bottom:1rem;color:var(--text-2)}
.oeuvre-body b{color:var(--text);font-weight:600}

/* ---------- CH2 PLAN ---------- */
.plan-grid{display:grid;gap:2.5rem}
.sheet-media{border:1px solid rgba(42,43,31,.18);background:#fff}
.sheet-media img{filter:none;mix-blend-mode:multiply}
.sheet-media figcaption{font-family:var(--disp);text-transform:uppercase;letter-spacing:.14em;font-size:.72rem;color:#6b6a52;padding:.7rem .9rem;border-top:1px solid rgba(42,43,31,.15)}

/* ---------- CH3 STRUCTURE ---------- */
.struct-grid{display:grid;gap:2rem}
.struct-media{display:grid;grid-template-columns:1fr 1fr;gap:.9rem}
.struct-media .media{aspect-ratio:3/4}

/* ---------- CH4 BÂTI ---------- */
.bati-grid{display:grid;gap:2rem}
.bati-grid .media.wide{aspect-ratio:4/3}

/* ---------- CH5 CLÉS ---------- */
.ch-key{min-height:92svh;padding:0;display:flex;align-items:flex-end}
.ch-key .media.full{position:absolute;inset:0;z-index:0}
.ch-key .media.full::after{background:linear-gradient(180deg,rgba(21,22,14,.5),rgba(21,22,14,.15) 40%,rgba(21,22,14,.82) 88%,var(--ink) 100%)}
.key-grid{padding:0 var(--edge) clamp(3rem,8vh,6rem);width:100%}
.key-grid .station{color:var(--brass)}
.key-grid .ch-title{margin-top:.6rem}
.key-grid .lead{margin-top:1.2rem}
.key-grid .index{max-width:34rem}

/* ---------- CH6 RÉALISATIONS ---------- */
.real-head{display:flex;justify-content:space-between;align-items:flex-end;flex-wrap:wrap;gap:1rem;margin-bottom:2rem}
.hint{font-family:var(--disp);text-transform:uppercase;letter-spacing:.18em;font-size:.74rem;color:var(--muted)}
.wall{margin:0 calc(var(--edge)*-1) -1px;display:flex;flex-direction:column;gap:3px;background:var(--ink);border-top:1px solid var(--brass-dark);border-bottom:1px solid var(--brass-dark)}
.wall .course{display:flex;gap:3px}
.wall .course.off::before{content:"";flex:0 0 8%}
.wall .media{height:clamp(140px,23vw,240px);flex:1 1 0;min-width:0;background:var(--ink-3)}
.wall .media.b2{flex-grow:1.7}
.wall .media.b3{flex-grow:2.4}
.wall .media img{filter:saturate(.92) contrast(1.07) brightness(.86) sepia(.24) hue-rotate(-8deg)}

/* ---------- CH7 CONTACT ---------- */
.ch-contact{background:var(--ink-2)}
.contact-grid{display:grid;gap:2.5rem}
.lines{margin:1.9rem 0 0}
.lines a,.lines div{display:flex;align-items:center;gap:.95rem;padding:1rem 0;border-bottom:1px solid var(--hair);color:inherit}
.lines a:hover .val{color:var(--brass)}
.lines .ic{width:24px;height:24px;flex:none;color:var(--brass)}
.lines .lab{font-family:var(--disp);text-transform:uppercase;letter-spacing:.18em;font-size:.7rem;color:var(--muted)}
.lines .val{font-family:var(--disp);font-size:1.2rem;font-weight:500;letter-spacing:.01em;color:var(--text);transition:color .2s}
.confirm{color:var(--khaki);font-size:.72rem;font-style:italic;letter-spacing:.05em}

.form{display:flex;flex-direction:column;gap:1rem}
.form label{display:flex;flex-direction:column;gap:.4rem;font-family:var(--disp);text-transform:uppercase;letter-spacing:.14em;font-size:.72rem;color:var(--muted)}
.form input,.form textarea,.form select{font-family:var(--body);font-size:1rem;color:var(--text);background:var(--ink);border:1px solid var(--hair);padding:.8rem .9rem;border-radius:2px}
.form input:focus,.form textarea:focus,.form select:focus{outline:none;border-color:var(--brass)}
.form textarea{resize:vertical}
.form select{appearance:none;-webkit-appearance:none;cursor:pointer;padding-right:2.4rem;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23c9a227' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right .85rem center;background-size:1.05rem}
.form select option{background:var(--ink-2);color:var(--text)}
.form button{font-family:var(--disp);text-transform:uppercase;letter-spacing:.13em;font-weight:700;font-size:.95rem;background:var(--brass);color:var(--ink);border:0;padding:.95rem;border-radius:2px;cursor:pointer;transition:background .2s}
.form button:hover{background:var(--brass-bright)}
.form-or{font-size:.9rem;color:var(--muted);text-align:center}
.form-or a{color:var(--text-2);border-bottom:1px solid var(--brass)}

.footer{display:flex;justify-content:space-between;flex-wrap:wrap;gap:.6rem;margin-top:3.5rem;padding-top:1.4rem;border-top:1px solid var(--hair);font-family:var(--disp);text-transform:uppercase;letter-spacing:.12em;font-size:.74rem;color:var(--muted)}

/* ---------- DOCK ---------- */
.dock{position:fixed;right:.8rem;bottom:.8rem;z-index:45;display:flex;gap:.5rem}
.dock a{width:46px;height:46px;display:grid;place-items:center;background:var(--ink-3);border:1px solid var(--hair);border-radius:50%;box-shadow:0 4px 14px rgba(0,0,0,.4)}
.dock a svg{width:20px;height:20px;fill:var(--text)}
.dock a.wa{background:var(--wa);border-color:var(--wa)}
.dock a.wa svg{fill:#0a3d24}
.dock a:hover{border-color:var(--brass)}

/* ============================================================
   BREAKPOINTS
   ============================================================ */
@media(min-width:760px){
  .burger{display:none}
  .nav{display:flex}
  .top-cta{display:flex}
  .oeuvre-grid{grid-template-columns:1.05fr 1fr;align-items:center;gap:4rem}
  .plan-grid{grid-template-columns:1.3fr 1fr;align-items:center;gap:3.5rem}
  .struct-grid{grid-template-columns:repeat(12,1fr);gap:2.5rem 3rem;align-items:center}
  .struct-grid .ch-title{grid-column:1/13;margin-bottom:.5rem}
  .struct-media{grid-column:1/8;grid-row:2}
  .struct-side{grid-column:8/13;grid-row:2}
  .bati-grid{grid-template-columns:1.2fr 1fr;align-items:center;gap:3rem}
  .contact-grid{grid-template-columns:1fr 1fr;gap:4rem;align-items:start}
}
@media(min-width:1024px){
  .ch-open{position:relative;min-height:100svh;height:100svh;overflow:hidden}
  .open-photo{position:absolute;inset:0;width:100%;height:100%;margin:0}
  .open-photo img{width:100%;height:100%;object-fit:cover;object-position:50% 18%}
  .open-copy{position:absolute;left:0;right:auto;top:auto;bottom:0;z-index:3;box-sizing:border-box;width:min(56%,620px);
    display:flex;flex-direction:column;justify-content:flex-end;
    padding:0 var(--edge) clamp(2.4rem,6vh,3.6rem) clamp(.45rem,1.5vw,.85rem);
    text-shadow:0 2px 14px rgba(0,0,0,.5),0 1px 4px rgba(0,0,0,.66),0 0 2px rgba(0,0,0,.5)}
  .open-photo figcaption{display:flex;left:auto;right:0;bottom:0;text-align:left;align-items:flex-start;
    padding:.7rem 1.6rem 1.2rem;
    background:none;
    text-shadow:0 1px 3px rgba(0,0,0,.9),0 0 12px rgba(0,0,0,.7),0 0 2px rgba(0,0,0,.8)}
  .dock{bottom:clamp(5rem,11vh,6.4rem)}
  .open-thread{display:none}
  .open-copy .kicker{margin-bottom:.9rem}
  .open-copy .hero-title{font-size:clamp(3.4rem,5.2vw,6rem)}
  .open-copy .hero-sub{font-size:1.05rem;max-width:42ch;margin-top:1.1rem}
  .open-copy .domains{margin-top:1.3rem}
  .od{display:block}.om{display:none}
}
@media(min-width:1100px){
  .hero-sub{font-size:1.2rem}
  .struct-media{grid-column:1/8}
  .struct-side{grid-column:8/13}
}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}

/* ============================================================
   CH6.5 — LA DIRECTION (ceux qui tiennent le fil)
   ============================================================ */
.direction .dir-head{max-width:50ch}
.direction .lead{margin-top:1.1rem}
.dir-grid{display:grid;grid-template-columns:1fr;gap:3.2rem 2rem;margin-top:3rem;position:relative}
.dir-card{position:relative;transition:transform .25s ease}
.dir-photo{position:relative;aspect-ratio:3/4;overflow:hidden;background:var(--ink-3)}
.dir-photo img{width:100%;height:100%;object-fit:cover;object-position:50% 26%;filter:saturate(.9) contrast(1.04) brightness(.96);transition:filter .3s ease,transform .4s ease}
.dir-card:hover .dir-photo img{filter:saturate(1) contrast(1.05) brightness(1.03);transform:scale(1.018)}
/* four laiton corner-brackets, drawn in one pseudo */
.dir-photo::after{content:"";position:absolute;inset:-8px;pointer-events:none;--c:24px;--t:2px;
  background:
    linear-gradient(var(--brass),var(--brass)) 0 0/var(--c) var(--t),
    linear-gradient(var(--brass),var(--brass)) 0 0/var(--t) var(--c),
    linear-gradient(var(--brass),var(--brass)) 100% 0/var(--c) var(--t),
    linear-gradient(var(--brass),var(--brass)) 100% 0/var(--t) var(--c),
    linear-gradient(var(--brass),var(--brass)) 0 100%/var(--c) var(--t),
    linear-gradient(var(--brass),var(--brass)) 0 100%/var(--t) var(--c),
    linear-gradient(var(--brass),var(--brass)) 100% 100%/var(--c) var(--t),
    linear-gradient(var(--brass),var(--brass)) 100% 100%/var(--t) var(--c);
  background-repeat:no-repeat}
.dir-cap{display:flex;gap:.9rem;align-items:baseline;margin-top:1.15rem}
.dir-cap i{font-family:var(--disp);font-style:normal;font-weight:700;color:var(--brass);font-size:1.1rem;letter-spacing:.04em;min-width:1.4rem}
.dir-cap b{display:block;font-family:var(--disp);font-weight:500;text-transform:uppercase;letter-spacing:.06em;font-size:1.32rem;line-height:1;color:var(--text)}
.dir-cap span{display:block;font-family:var(--disp);text-transform:uppercase;letter-spacing:.16em;font-size:.72rem;font-weight:600;color:var(--brass-dark);margin-top:.42rem}
/* rail à nœuds — desktop only */
.dir-node{display:none}
@media(min-width:760px){
  .dir-grid{grid-template-columns:repeat(3,1fr);gap:0 2.4rem;padding-top:74px}
  .dir-grid::before{content:"";position:absolute;top:20px;left:3%;right:3%;height:2px;
    background:linear-gradient(90deg,transparent,var(--brass) 5%,var(--brass) 95%,transparent);
    filter:drop-shadow(0 0 3px rgba(201,162,39,.4))}
  .dir-node{display:block;position:absolute;top:-58px;left:50%;transform:translateX(-50%);
    width:15px;height:15px;border:2px solid var(--brass);border-radius:50%;background:var(--ink);z-index:2}
  .dir-node::after{content:"";position:absolute;top:100%;left:50%;transform:translateX(-50%);width:2px;height:34px;background:var(--brass)}
}