/* =========================================================
   Ejemplo: Arista Taller de Arquitectura
   Cemento, negro y un olivo apagado. Rejilla estricta, casi
   sin curvas y con mucho aire: la página tiene que parecerse
   a lo que el despacho dibuja.
   ========================================================= */
:root{
  --cemento:   #E8E6E1;
  --cemento-2: #DAD7D0;
  --negro:     #1A1A18;
  --negro-2:   #242421;
  --gris:      #56564F;   /* 6.9:1 sobre cemento */
  --olivo:     #54603F;   /* 5.4:1 sobre cemento */
  --olivo-cl:  #A8B98A;
  --verde:     #128C4A;
  --linea:     rgba(26,26,24,.18);
  --f-titulo: "Syne", "Segoe UI", system-ui, sans-serif;
  --f-texto:  "Inter", "Segoe UI", system-ui, sans-serif;
  --r: 2px;
  --max: 1180px;
  --pad: clamp(1.1rem, 4vw, 2.4rem);
}

*,*::before,*::after{ box-sizing:border-box; }
html{ -webkit-text-size-adjust:100%; scroll-behavior:smooth; scroll-padding-top:78px; }
@media (prefers-reduced-motion:reduce){ html{ scroll-behavior:auto; } }
body{ margin:0; background:var(--cemento); color:var(--gris);
  font-family:var(--f-texto); font-size:1.02rem; line-height:1.66; overflow-x:hidden; }
img{ display:block; max-width:100%; height:auto; }
h1,h2,h3{ margin:0; font-family:var(--f-titulo); font-weight:700; color:var(--negro);
  line-height:1.05; letter-spacing:-.02em; text-wrap:balance; }
h1{ font-size:clamp(2.2rem, 5vw, 3.8rem); font-weight:800; }
h2{ font-size:clamp(1.7rem, 3.4vw, 2.6rem); }
h3{ font-size:1.15rem; }
p{ margin:0 0 1rem; text-wrap:pretty; }
ul,ol{ margin:0; padding:0; list-style:none; }
a{ color:inherit; }
button,input,output,legend{ font:inherit; color:inherit; }
:focus-visible{ outline:3px solid var(--olivo); outline-offset:3px; }
.wrap{ width:100%; max-width:var(--max); margin-inline:auto; padding-inline:var(--pad); }
.wrap--angosto{ max-width:760px; }
.ico{ width:20px; height:20px; flex:none; fill:none; stroke:currentColor;
  stroke-width:1.6; stroke-linecap:round; stroke-linejoin:round; }
.mini{ font-size:.86rem; }

.sobre{ margin:0 0 .8rem; font-weight:600; font-size:.72rem; letter-spacing:.22em;
  text-transform:uppercase; color:var(--olivo); }
.sobre--claro{ color:var(--olivo-cl); }
.seccion{ padding:clamp(3rem, 7vw, 5.5rem) 0; }
.seccion--cemento{ background:var(--cemento-2); }
.sec-head{ max-width:640px; margin:0 auto clamp(1.8rem,4vw,2.8rem); }

/* ---------- Botones ---------- */
.btn{
  --bg:var(--negro); --fg:#fff; --bd:var(--negro); --bg-h:#33332E;
  display:inline-flex; align-items:center; justify-content:center; gap:.5rem;
  min-height:50px; padding:.8rem 1.6rem;
  background:var(--bg); color:var(--fg); border:1.5px solid var(--bd); border-radius:var(--r);
  font-family:var(--f-texto); font-weight:600; font-size:.86rem; letter-spacing:.08em;
  text-transform:uppercase; text-decoration:none; cursor:pointer;
  transition:background .2s ease, color .2s ease, border-color .2s ease;
}
.btn:hover{ background:var(--bg-h); border-color:var(--bg-h); }
.btn--grande{ min-height:56px; padding:1rem 1.9rem; font-size:.92rem; }
.btn--bloque{ width:100%; }
.btn--olivo{ --bg:var(--olivo); --fg:#fff; --bd:var(--olivo); --bg-h:#66744C; }
.btn--olivo:hover{ border-color:#66744C; }
.btn--linea{ --bg:transparent; --fg:#fff; --bd:rgba(255,255,255,.5); --bg-h:rgba(255,255,255,.14); }
.btn--linea:hover{ border-color:#fff; }
.btn--wa{ --bg:var(--verde); --fg:#fff; --bd:var(--verde); --bg-h:#0E7A3F; }
.btn .ico[href$="i-wa"]{ fill:currentColor; stroke:none; }

/* ---------- Cabecera ---------- */
.cabecera{ position:sticky; top:0; z-index:100; background:var(--negro); color:#fff; }
.cabecera__inner{ display:flex; align-items:center; gap:1.2rem; min-height:74px; }
.marca{ display:flex; align-items:center; gap:.7rem; text-decoration:none; color:#fff; }
.marca__ico{ display:grid; place-items:center; width:40px; height:40px;
  border:1px solid rgba(255,255,255,.4); color:var(--olivo-cl); }
.marca__txt{ display:flex; flex-direction:column; font-family:var(--f-titulo); font-weight:800;
  font-size:1.3rem; line-height:1; letter-spacing:-.02em; }
.marca__txt small{ font-family:var(--f-texto); font-weight:500; font-size:.6rem;
  letter-spacing:.22em; text-transform:uppercase; color:rgba(255,255,255,.62); margin-top:.3rem; }
.nav{ display:flex; align-items:center; gap:1.6rem; margin-left:auto; }
.nav a{ text-decoration:none; color:rgba(255,255,255,.8); font-weight:500; font-size:.84rem;
  letter-spacing:.08em; text-transform:uppercase; }
.nav a:not(.btn):hover{ color:var(--olivo-cl); }
.nav a.nav__cta{ color:var(--fg); min-height:40px; padding:.45rem 1.1rem; font-size:.76rem; }
.nav-toggle{ display:none; margin-left:auto; width:44px; height:44px; padding:11px;
  background:transparent; border:1px solid rgba(255,255,255,.3); border-radius:var(--r); cursor:pointer; }
.nav-toggle span{ display:block; height:2px; background:#fff;
  transition:transform .25s ease, opacity .2s ease; }
.nav-toggle span + span{ margin-top:5px; }
.nav-toggle[aria-expanded="true"] span:nth-child(1){ transform:translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] span:nth-child(2){ opacity:0; }
.nav-toggle[aria-expanded="true"] span:nth-child(3){ transform:translateY(-7px) rotate(-45deg); }
@media (max-width:940px){
  .nav-toggle{ display:block; }
  .nav{ position:absolute; left:0; right:0; top:100%; flex-direction:column; align-items:stretch; gap:0;
    background:var(--negro); padding:.4rem var(--pad) 1.1rem;
    max-height:0; overflow:hidden; visibility:hidden; transition:max-height .3s ease, visibility 0s linear .3s; }
  .nav.is-abierto{ max-height:80vh; visibility:visible; transition:max-height .35s ease, visibility 0s; }
  .nav a{ padding:.95rem 0; border-bottom:1px solid rgba(255,255,255,.14); }
  .nav a.nav__cta{ margin-top:.9rem; border-bottom:0; }
}

/* ---------- Hero ---------- */
.hero{ position:relative; isolation:isolate; overflow:hidden; display:flex; align-items:flex-end;
  min-height:clamp(520px, 80vh, 700px); padding:clamp(3rem,7vw,5rem) 0; color:#fff; }
.hero__foto{ position:absolute; inset:0; z-index:-1; }
.hero__foto img{ width:100%; height:100%; object-fit:cover; }
.hero::after{ content:""; position:absolute; inset:0; z-index:0;
  background:linear-gradient(180deg, rgba(26,26,24,.4) 0%, rgba(26,26,24,.78) 55%, rgba(26,26,24,.96) 100%); }
.hero__inner{ position:relative; z-index:1; max-width:680px; }
.hero h1{ color:#fff; }
.hero .lede{ margin:1.3rem 0 2rem; font-size:1.06rem; max-width:52ch; color:rgba(255,255,255,.86); }
.hero__acciones{ display:flex; flex-wrap:wrap; gap:.7rem; }
@media (max-width:560px){ .hero__acciones .btn{ width:100%; } }

/* ---------- Servicios ---------- */
.servicios{ display:grid; gap:0; grid-template-columns:repeat(auto-fit, minmax(250px,1fr));
  border-top:1px solid var(--linea); }
.servicio{ padding:1.8rem 1.4rem; border-bottom:1px solid var(--linea);
  border-right:1px solid var(--linea); }
.servicio:last-child{ border-right:0; }
.servicio__ico{ display:grid; place-items:center; width:44px; height:44px; margin-bottom:1.1rem;
  border:1px solid var(--linea); color:var(--olivo); }
.servicio h3{ margin-bottom:.4rem; }
.servicio p{ margin:0; font-size:.94rem; }

/* ---------- Presupuesto ---------- */
.presupuesto{ background:var(--negro); color:rgba(255,255,255,.82); padding:clamp(3rem,7vw,5.5rem) 0; }
.presupuesto__inner{ display:grid; grid-template-columns:1fr 1.1fr; gap:clamp(1.8rem,4vw,3.6rem);
  align-items:start; }
.presupuesto h2{ color:#fff; }
.lista-check{ display:grid; gap:.55rem; margin-top:1.2rem; }
.lista-check li{ position:relative; padding-left:1.8rem; }
.lista-check li::before{ content:""; position:absolute; left:.15rem; top:.6em; width:.8rem; height:.42rem;
  border-left:2px solid var(--olivo-cl); border-bottom:2px solid var(--olivo-cl); transform:rotate(-45deg); }
.presupuesto__caja{ background:var(--negro-2); border:1px solid rgba(255,255,255,.14);
  padding:clamp(1.3rem,3vw,2rem); }
.campo{ display:block; margin:0 0 1.4rem; padding:0; border:0; }
.campo legend, .campo > span{ display:flex; align-items:baseline; justify-content:space-between;
  gap:1rem; width:100%; margin-bottom:.6rem; padding:0;
  font-weight:600; font-size:.74rem; letter-spacing:.14em; text-transform:uppercase; color:#fff; }
.campo output{ font-family:var(--f-titulo); font-weight:700; font-size:1.3rem; letter-spacing:-.02em;
  color:var(--olivo-cl); }
.campo input[type="range"]{ width:100%; accent-color:var(--olivo-cl); height:28px; cursor:pointer; }
.opciones{ display:grid; grid-template-columns:repeat(3,1fr); gap:.4rem; }
.opciones label{ position:relative; }
.opciones input{ position:absolute; opacity:0; width:100%; height:100%; margin:0; cursor:pointer; }
.opciones span{ display:block; min-height:46px; padding:.7rem .6rem; text-align:center;
  background:var(--negro); border:1px solid rgba(255,255,255,.22); border-radius:var(--r);
  font-size:.86rem; font-weight:500; color:#fff; cursor:pointer;
  transition:background .2s, border-color .2s; }
.opciones input:checked + span{ background:var(--olivo); border-color:var(--olivo); }
.opciones input:focus-visible + span{ outline:3px solid var(--olivo-cl); outline-offset:2px; }

.salida{ margin:1.6rem 0; padding-top:1.4rem; border-top:1px solid rgba(255,255,255,.16); }
.salida__rotulo{ margin:0; font-weight:600; font-size:.72rem; letter-spacing:.2em;
  text-transform:uppercase; color:var(--olivo-cl); }
.salida__total{ margin:.2rem 0 .2rem; font-family:var(--f-titulo); font-weight:800;
  font-size:clamp(2.2rem,6vw,3.2rem); line-height:1; letter-spacing:-.03em; color:#fff; }
.salida__m2{ margin:0 0 1.3rem; font-size:.9rem; color:rgba(255,255,255,.7); }
.barra{ display:flex; width:100%; height:26px; overflow:hidden; border-radius:var(--r); }
.barra__tramo{ display:block; height:100%; transition:width .3s ease; }
.barra__tramo--gris{ background:#8C8C82; }
.barra__tramo--inst{ background:#5E6B72; }
.barra__tramo--acab{ background:var(--olivo-cl); }
.barra__tramo--hono{ background:#C9A227; }
.reparto{ display:grid; gap:.1rem; margin:1rem 0 1.2rem; }
.reparto li{ display:flex; align-items:center; gap:.7rem; padding:.55rem 0;
  border-bottom:1px solid rgba(255,255,255,.1); font-size:.92rem; }
.reparto__que{ flex:1; }
.reparto b{ font-weight:600; color:#fff; font-variant-numeric:tabular-nums; }
.punto{ width:12px; height:12px; flex:none; border-radius:2px; }
.punto--gris{ background:#8C8C82; }
.punto--inst{ background:#5E6B72; }
.punto--acab{ background:var(--olivo-cl); }
.punto--hono{ background:#C9A227; }
.salida__plazo{ display:flex; align-items:center; gap:.6rem; margin:0;
  font-size:.94rem; color:#fff; }
.salida__plazo .ico{ color:var(--olivo-cl); }
.presupuesto__nota{ margin:.9rem 0 0; font-size:.82rem; color:rgba(255,255,255,.58); }
@media (max-width:920px){
  .presupuesto__inner{ grid-template-columns:1fr; }
  .opciones{ grid-template-columns:1fr; }
}

/* ---------- Obras ---------- */
.obras{ display:grid; gap:1rem; grid-template-columns:repeat(auto-fit, minmax(260px,1fr)); }
.obra{ background:var(--cemento); }
.obra--ancha{ grid-column:span 2; }
.obra figure{ margin:0; overflow:hidden; }
.obra img{ width:100%; height:100%; aspect-ratio:3/2; object-fit:cover; }
.obra__pie{ padding:1rem .2rem 0; }
.obra__pie h3{ margin-bottom:.15rem; font-size:1.05rem; }
.obra__pie p{ margin:0; font-size:.86rem; letter-spacing:.04em; }
@media (max-width:760px){ .obra--ancha{ grid-column:span 1; } }

/* ---------- Preguntas ---------- */
.faq{ display:grid; gap:.4rem; }
.faq__item{ background:#fff; border:1px solid var(--linea); border-radius:var(--r); overflow:hidden; }
.faq__item summary{ position:relative; cursor:pointer; list-style:none; min-height:44px;
  padding:1rem 3rem 1rem 1.2rem; font-weight:600; color:var(--negro); }
.faq__item summary::-webkit-details-marker{ display:none; }
.faq__item summary::after{ content:""; position:absolute; right:1.3rem; top:50%; width:10px; height:10px;
  margin-top:-7px; border-right:2px solid var(--olivo); border-bottom:2px solid var(--olivo);
  transform:rotate(45deg); transition:transform .25s ease; }
.faq__item[open] summary::after{ transform:rotate(-135deg); margin-top:-2px; }
.faq__a{ padding:0 1.2rem 1.1rem; }
.faq__a p{ margin:0; }

/* ---------- Pie ---------- */
.pie{ background:var(--negro); color:rgba(255,255,255,.74); padding:2.2rem 0 2.6rem; }
.pie__inner{ display:flex; flex-wrap:wrap; gap:1rem 2rem; justify-content:space-between; }
.pie__marca{ margin:0 0 .2rem; font-family:var(--f-titulo); font-weight:800; font-size:1.3rem;
  letter-spacing:-.02em; color:#fff; }
.pie__datos{ display:grid; gap:.4rem; font-size:.92rem; }
.pie__datos li{ display:flex; align-items:center; gap:.5rem; }
.pie__datos .ico{ color:var(--olivo-cl); }