:root {
  --azul: #1f56a5;
  --ciano: #5fc7e6;
  --escuro: #303334;
  --cinza: #767879;
  --linha: #e3e3e3;
  --fundo: #f5f7f8;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font: 16px/1.6 system-ui, -apple-system, "Segoe UI", Ubuntu, Roboto, Arial, sans-serif;
  color: var(--escuro);
  background: #fff;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--azul); }
h1, h2, h3 { line-height: 1.2; margin: 0 0 .6em; }
.wrap { max-width: 1170px; margin: 0 auto; padding: 0 16px; }

/* Topo */
.topo { background: #fff; border-bottom: 1px solid var(--linha); position: sticky; top: 0; z-index: 50; }
.topo-in { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-top: 10px; padding-bottom: 10px; }
.logo img { width: 230px; }
nav ul { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 4px; }
nav a { display: block; padding: 8px 12px; color: var(--azul); text-decoration: none; font-weight: 600; border-radius: 4px; }
nav a:hover, nav a[aria-current] { background: var(--ciano); color: #fff; }
.menu-btn { display: none; }

/* Slider */
.slider { position: relative; height: min(70vh, 560px); overflow: hidden; background: var(--escuro); }
.slide { position: absolute; inset: 0; background: center/cover no-repeat; opacity: 0; transition: opacity 1s; }
.slide.ativo { opacity: 1; }
.slider::after { content: ""; position: absolute; inset: 0; background: linear-gradient(transparent 40%, rgba(0,0,0,.6)); }
.slider-txt { position: absolute; left: 0; right: 0; bottom: 40px; z-index: 2; color: #fff; }
.slider-txt h1 { font-size: clamp(28px, 5vw, 52px); max-width: 700px; text-shadow: 0 2px 8px rgba(0,0,0,.5); }

.btn { display: inline-block; background: var(--ciano); color: #fff; padding: 10px 22px; border-radius: 4px; text-decoration: none; font-weight: 600; }
.btn:hover { background: var(--azul); }

/* Home */
.caixas { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; margin-top: -40px; position: relative; z-index: 3; }
.caixa { background: #fff; padding: 24px; border-top: 4px solid var(--ciano); box-shadow: 0 4px 16px rgba(0,0,0,.1); text-decoration: none; color: var(--escuro); transition: transform .2s; }
.caixa:hover { transform: translateY(-4px); }
.caixa h2 { color: var(--azul); font-size: 22px; }
.caixa span { color: var(--ciano); font-weight: 700; }
.titulo { text-align: center; font-size: clamp(24px, 3vw, 32px); margin: 0 0 30px; }
.obras { background: var(--fundo); padding: 60px 0; margin-top: 60px; }
.obras-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; }
.obras-grid a { position: relative; color: #fff; text-decoration: none; overflow: hidden; border-radius: 4px; }
.obras-grid span { position: absolute; left: 0; right: 0; bottom: 0; padding: 8px 12px; background: rgba(31,86,165,.85); font-size: 14px; }
.seguranca { text-align: center; max-width: 900px; padding-top: 60px; padding-bottom: 20px; }
.tres { display: grid; grid-template-columns: repeat(3, 1fr); gap: 30px; padding-top: 30px; padding-bottom: 60px; }
.tres h3 { color: var(--azul); font-size: 22px; }
.tres a { color: var(--ciano); font-weight: 700; text-decoration: none; }
.clientes-faixa { background: var(--fundo); padding: 50px 0; }
.logos { display: grid; grid-template-columns: repeat(6, 1fr); gap: 16px; }
.logos img { background: #fff; border: 1px solid var(--linha); border-radius: 4px; padding: 6px; width: 100%; aspect-ratio: 1; object-fit: contain; }
.logos-grande { margin-bottom: 60px; }

/* Páginas internas */
.hero { background: var(--escuro) linear-gradient(135deg, var(--azul), var(--escuro)); color: #fff; padding: 40px 0; }
.hero h1 { margin: 0; font-size: clamp(26px, 4vw, 38px); }
.texto { max-width: 900px; padding-top: 40px; padding-bottom: 60px; }
.texto h2 { color: var(--azul); margin-top: 1.4em; }
.texto h2:first-child { margin-top: 0; }
.intro { font-size: 18px; color: var(--cinza); margin: 30px 0; }
.duas { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.valores { padding-left: 1.4em; }
.valores li::marker { color: var(--ciano); font-weight: 700; font-size: 1.3em; }
.lista li { margin: .4em 0; }
.contato { list-style: none; padding: 0; }
.contato li { margin: .5em 0; }
.mapa { margin-top: 30px; aspect-ratio: 16/9; }
.mapa iframe { width: 100%; height: 100%; border: 0; }

/* Fotos */
.capas { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; padding: 40px 0 60px; }
.capas a { text-decoration: none; color: var(--escuro); font-weight: 600; text-align: center; }
.capas img { border-radius: 4px; margin-bottom: 8px; transition: opacity .2s; }
.capas a:hover img { opacity: .8; }
.voltar { margin: 24px 0; }
.galeria { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 60px; }
.galeria a, .logos a { display: block; overflow: hidden; border-radius: 4px; }
.galeria img { transition: transform .3s; }
.galeria a:hover img { transform: scale(1.04); }

/* Lightbox */
.lb { position: fixed; inset: 0; background: rgba(0,0,0,.92); display: none; align-items: center; justify-content: center; z-index: 100; }
.lb.aberto { display: flex; }
.lb img { max-width: 94vw; max-height: 88vh; width: auto; }
.lb button { position: absolute; background: none; border: 0; color: #fff; font-size: 40px; cursor: pointer; padding: 16px; }
.lb .fechar { top: 0; right: 8px; }
.lb .ant { left: 4px; top: 50%; transform: translateY(-50%); }
.lb .prox { right: 4px; top: 50%; transform: translateY(-50%); }
.lb .cont { position: absolute; bottom: 12px; color: #ccc; font-size: 14px; }

/* Rodapé */
.rodape { background: var(--escuro); color: #ccc; padding-top: 40px; }
.rodape a { color: #fff; }
.rodape h3 { color: #fff; }
.rodape-in { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.rodape-clientes { display: grid; grid-template-columns: repeat(4, 81px); gap: 8px; }
.rodape-clientes img { background: #fff; border-radius: 3px; }
.copy { text-align: center; border-top: 1px solid #484b4c; margin: 30px 0 0; padding: 16px; font-size: 14px; }

/* Celular */
@media (max-width: 900px) {
  .caixas, .obras-grid, .capas { grid-template-columns: repeat(2, 1fr); }
  .tres { grid-template-columns: 1fr; }
  .logos { grid-template-columns: repeat(4, 1fr); }
  .galeria { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 760px) {
  .menu-btn { display: block; background: var(--azul); color: #fff; border: 0; padding: 8px 14px; border-radius: 4px; font: inherit; font-weight: 600; }
  .topo nav { display: none; position: absolute; left: 0; right: 0; top: 100%; background: #fff; border-bottom: 1px solid var(--linha); }
  .topo.aberto nav { display: block; }
  nav ul { flex-direction: column; padding: 8px 16px; }
  .logo img { width: 170px; }
  .rodape-in, .duas { grid-template-columns: 1fr; }
}
@media (max-width: 520px) {
  .caixas { grid-template-columns: 1fr; margin-top: 20px; }
  .capas { grid-template-columns: 1fr 1fr; gap: 12px; }
  .galeria { grid-template-columns: 1fr 1fr; gap: 6px; }
  .logos { grid-template-columns: repeat(3, 1fr); }
}