:root {
  --c-mist: #F2F5F7;
  --c-slate-800: #37474F;
  --c-slate-500: #78909C;
  --c-amber: #FFB300;
  --c-ink-900: #263238;
  --font-display: 'IBM Plex Sans KR', 'Noto Sans KR', system-ui, sans-serif;
  --font-body: 'Noto Sans KR', system-ui, -apple-system, 'Malgun Gothic', sans-serif;
}

body {
  font-family: var(--font-body);
  background: var(--c-mist);
  color: var(--c-ink-900);
}
h1, h2, .logo { font-family: var(--font-display); font-weight: 700; }
h3 { font-family: var(--font-body); font-weight: 700; }

header { background: var(--c-mist); border-bottom: 1px solid #d7dfe3; }
header .logo { font-size: 1.15rem; color: var(--c-slate-800); }
header nav a { color: var(--c-slate-500); font-size: 0.9rem; font-family: var(--font-body); font-weight: 400; }
header nav a:hover, header nav a:focus-visible { color: var(--c-amber); }

.hero { background: var(--c-ink-900); color: #fff; }
.hero .container { max-width: 720px; }
.hero h1 { font-size: clamp(1.85rem, 4vw, 2.4rem); }
.hero .lead { margin-top: 0.9rem; color: #b6c2c7; max-width: 34rem; font-family: var(--font-body); font-weight: 400; }
.hero .btn-tel {
  margin-top: 1.4rem;
  display: inline-block;
  background: var(--c-amber);
  color: var(--c-ink-900);
  padding: 0.85em 1.7em;
  border-radius: 2px;
  font-weight: 700;
  font-family: var(--font-body);
}
.hero .btn-tel:hover { background: #e0a000; }

/* slim side index + single column */
.pipe-layout { display: grid; grid-template-columns: 140px 1fr; gap: 2rem; align-items: start; }
.pipe-index {
  position: sticky;
  top: 1.5rem;
  display: grid;
  gap: 0.5rem;
  border-left: 2px solid #d7dfe3;
  padding-left: 0.9rem;
}
.pipe-index a { font-size: 0.85rem; color: var(--c-slate-500); }
.pipe-index a:hover { color: var(--c-amber); }
.pipe-main section { padding-block: 1.8rem; border-top: 1px solid #d7dfe3; }
.pipe-main section:first-child { border-top: none; padding-top: 0; }
.pipe-main h2 { font-size: 1.4rem; color: var(--c-slate-800); margin-bottom: 1.1rem; }
.pipe-main p { color: #45575f; }
.pipe-main p + p { margin-top: 0.8rem; }

/* CSS cross-section diagram, trap to sewer */
.cross-section { display: grid; gap: 0; margin-bottom: 1rem; }
.cs-segment {
  display: grid;
  grid-template-columns: 100px 1fr;
  align-items: center;
  gap: 1rem;
  padding: 0.9rem 0;
  border-bottom: 2px dashed #c3ced3;
}
.cs-segment:last-child { border-bottom: none; }
.cs-pipe {
  height: 22px;
  border-radius: 11px;
  background: var(--c-slate-500);
  position: relative;
}
.cs-pipe.narrow { width: 60%; background: var(--c-slate-800); }
.cs-pipe.wide { width: 100%; background: var(--c-amber); }
.cs-segment h3 { font-size: 0.98rem; margin-bottom: 0.2rem; }
.cs-segment p { font-size: 0.85rem; color: #45575f; margin: 0; }

.issue-list { display: grid; gap: 0.8rem; }
.issue-list li {
  border-left: 3px solid var(--c-amber);
  padding-left: 1rem;
  color: #45575f;
  font-size: 0.94rem;
}

.review-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 1rem; }
blockquote.review {
  background: #fff;
  border: 1px solid #d7dfe3;
  padding: 1rem 1.1rem;
  font-size: 0.9rem;
  color: #45575f;
}
blockquote.review cite { display: block; margin-top: 0.5rem; font-style: normal; font-size: 0.8rem; color: var(--c-slate-800); }

.related-links { display: flex; flex-wrap: wrap; gap: 0.6rem; }
.related-links a {
  border: 1px solid var(--c-slate-500);
  color: var(--c-slate-800);
  border-radius: 2px;
  padding: 0.5em 1.1em;
  font-size: 0.88rem;
}
.related-links a:hover { background: var(--c-slate-800); color: #fff; }

.cta { background: var(--c-slate-800); color: #fff; }
.cta h3 { color: #fff; margin-bottom: 0.6rem; font-size: 1.3rem; }
.cta p { color: #cfd8dc; margin-bottom: 1.1rem; font-family: var(--font-body); font-weight: 400; }
.cta a[href^="tel:"] { background: var(--c-amber); color: var(--c-ink-900); border-radius: 2px; font-weight: 700; }
.cta a[href^="tel:"]:hover { background: #e0a000; }

footer { background: var(--c-ink-900); color: #9fb0b6; font-size: 0.85rem; }
footer a { color: #9fb0b6; }
footer nav a { margin-right: 0.2rem; }

figcaption { color: #45575f; margin-top: 0.5rem; }

@media (max-width: 780px) {
  .pipe-layout { grid-template-columns: 1fr; }
  .pipe-index { position: static; display: flex; flex-wrap: wrap; border-left: none; padding-left: 0; gap: 1rem; }
  .review-grid { grid-template-columns: 1fr; }
}