:root {
  --ink: #12283a;
  --water: #1b7ea8;
  --paper: #f3f6f8;
  --white: #ffffff;
  --marker: #f4c20d;
  --line: #cfdae2;
  --radius: 6px;
  --head: "Bricolage Grotesque", "Segoe UI", sans-serif;
  --body: "Source Sans 3", "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body {
  margin: 0;
  font-family: var(--body);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--ink);
  background: var(--paper);
}
h1, h2, h3 { font-family: var(--head); line-height: 1.1; margin: 0 0 .5em; }
h1 { font-size: clamp(2.2rem, 5vw, 3.8rem); font-weight: 800; letter-spacing: -.02em; }
h2 { font-size: clamp(1.7rem, 3vw, 2.4rem); font-weight: 700; }
h3 { font-size: 1.2rem; font-weight: 700; }
p { margin: 0 0 1em; max-width: 62ch; }
a { color: inherit; }
:focus-visible { outline: 3px solid var(--marker); outline-offset: 2px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; justify-content: space-between;
  padding: .9rem clamp(1rem, 5vw, 4rem);
  background: var(--ink); color: var(--white);
}
.logo { font-family: var(--head); font-weight: 800; font-size: 1.25rem; text-decoration: none; }
.logo span { color: var(--marker); }
.nav { display: flex; gap: 1.5rem; align-items: center; }
.nav a { text-decoration: none; }
.nav a:hover { text-decoration: underline; text-underline-offset: 4px; }
.nav-cta { background: var(--marker); color: var(--ink); padding: .45rem .9rem; border-radius: var(--radius); font-weight: 600; }
.nav-toggle { display: none; background: none; border: 1px solid var(--white); color: var(--white); padding: .4rem .8rem; border-radius: var(--radius); font: inherit; }

/* Buttons */
.btn {
  display: inline-block; cursor: pointer; text-decoration: none;
  background: var(--marker); color: var(--ink);
  border: 2px solid var(--marker); border-radius: var(--radius);
  padding: .75rem 1.4rem; font: 600 1rem var(--body);
}
.btn:hover { background: var(--ink); color: var(--marker); border-color: var(--ink); }
.btn-ghost { background: transparent; border-color: var(--ink); color: var(--ink); }
.btn-ghost:hover { background: var(--ink); color: var(--white); }

/* Hero */
.hero {
  display: grid; grid-template-columns: 1.1fr 1fr; gap: 3rem; align-items: center;
  padding: clamp(2.5rem, 7vw, 5.5rem) clamp(1rem, 5vw, 4rem);
}
.lead { font-size: 1.2rem; }
.hero-actions { display: flex; flex-wrap: wrap; gap: .8rem; margin-top: 1.5rem; }

.schematic {
  background: var(--white); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1rem;
}
.switch { display: inline-flex; border: 2px solid var(--ink); border-radius: var(--radius); overflow: hidden; margin-bottom: .5rem; }
.switch button { border: 0; background: transparent; padding: .4rem 1rem; font: 600 .95rem var(--body); color: var(--ink); cursor: pointer; }
.switch button.is-active { background: var(--ink); color: var(--white); }
#diagram { width: 100%; height: auto; display: block; max-height: 460px; }
.caption { font-size: .95rem; margin: .5rem 0 0; }

/* SVG parts */
.floor { fill: var(--paper); stroke: var(--ink); stroke-width: 2; }
.ground { stroke: var(--ink); stroke-width: 3; }
.pipe { stroke: var(--water); stroke-width: 8; stroke-linecap: round; fill: none; }
.drop { fill: var(--marker); stroke: var(--ink); stroke-width: 1.5; }
.fixture { fill: var(--ink); }
.label { font: 600 12px var(--body); fill: var(--ink); }

/* Sections */
.section { padding: clamp(2.5rem, 6vw, 5rem) clamp(1rem, 5vw, 4rem); }
.section-tint { background: var(--white); border-block: 1px solid var(--line); }
.section-dark { background: var(--ink); color: var(--white); }

.steps { list-style: none; margin: 2rem 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; counter-reset: s; }
.steps li { border-top: 4px solid var(--water); padding-top: 1rem; counter-increment: s; }
.steps h3::before { content: counter(s) ". "; color: var(--water); }

.services { display: grid; grid-template-columns: repeat(3, 1fr); gap: 2rem; margin-top: 2rem; }
.services article { border-left: 4px solid var(--marker); padding-left: 1.2rem; }

.team { list-style: none; margin: 2rem 0 0; padding: 0; display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.5rem; }
.team li { display: flex; align-items: center; gap: .9rem; }
.avatar {
  display: grid; place-items: center; width: 3.4rem; height: 3.4rem; border-radius: 50%;
  background: var(--water); color: var(--white); font: 700 1.05rem var(--head);
}

/* Contact */
.contact-grid { display: grid; grid-template-columns: 1fr 1.2fr; gap: 3rem; }
form { display: grid; gap: 1rem; }
label { display: grid; gap: .3rem; font-weight: 600; }
input, select, textarea {
  font: 400 1rem var(--body); padding: .65rem .8rem; border: 2px solid transparent;
  border-radius: var(--radius); background: var(--white); color: var(--ink);
}
input.invalid, textarea.invalid { border-color: #ff8a80; }
#form-status { min-height: 1.5em; margin: 0; color: var(--marker); }

.site-footer { padding: 1.5rem clamp(1rem, 5vw, 4rem); border-top: 1px solid var(--line); }
.site-footer p { margin: 0; font-size: .95rem; }

/* Responsive */
@media (max-width: 900px) {
  .hero, .contact-grid { grid-template-columns: 1fr; }
  .steps, .team { grid-template-columns: repeat(2, 1fr); }
  .services { grid-template-columns: 1fr; }
  .nav-toggle { display: block; }
  .nav {
    display: none; position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; align-items: flex-start; gap: 1rem;
    padding: 1rem clamp(1rem, 5vw, 4rem) 1.5rem; background: var(--ink);
  }
  .nav.is-open { display: flex; }
}
@media (max-width: 520px) {
  .steps, .team { grid-template-columns: 1fr; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}