:root {
  --bg: #0f1117;
  --bg-card: #181b24;
  --bg-card-2: #1f2330;
  --border: #2a2f3d;
  --text: #e7e9ee;
  --text-muted: #9aa0ad;
  --accent: #d97757;        /* warm Claude-ish clay */
  --accent-soft: #f0a988;
  --good: #7bd88f;
  --radius: 14px;
  --maxw: 760px;
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  padding: 0 1rem 4rem;
}

main, .site-header, .site-footer {
  max-width: var(--maxw);
  margin: 0 auto;
}

/* ---------- header ---------- */
.site-header {
  padding: 2.5rem 0 1.5rem;
  text-align: center;
}
.site-header h1 {
  font-size: clamp(1.6rem, 5vw, 2.4rem);
  line-height: 1.15;
  margin: 0 0 0.6rem;
}
.subtitle {
  color: var(--text-muted);
  margin: 0 auto;
  max-width: 48ch;
}

/* ---------- cards ---------- */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  margin-bottom: 1.25rem;
}

/* ---------- fields ---------- */
.field { margin-bottom: 1.25rem; }
.field:last-child { margin-bottom: 0; }

label {
  display: block;
  font-weight: 600;
  margin-bottom: 0.5rem;
}
.muted { color: var(--text-muted); font-weight: 400; }

.hint {
  color: var(--text-muted);
  font-size: 0.85rem;
  margin: 0.4rem 0 0;
}

input[type="text"],
input[type="number"],
select {
  width: 100%;
  background: var(--bg-card-2);
  border: 1px solid var(--border);
  color: var(--text);
  border-radius: 10px;
  padding: 0.7rem 0.8rem;
  font-size: 1rem;
  font-family: inherit;
}
input:focus, select:focus {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.input-prefix {
  display: flex;
  align-items: center;
  background: var(--bg-card-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding-left: 0.8rem;
}
.input-prefix span { color: var(--text-muted); font-size: 1.05rem; }
.input-prefix input {
  border: none;
  background: transparent;
  padding-left: 0.4rem;
}
.input-prefix:focus-within { outline: 2px solid var(--accent); outline-offset: 1px; }
.input-prefix input:focus { outline: none; }

/* range */
input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
  margin: 0.3rem 0 0;
}

/* ---------- headline result ---------- */
.result { text-align: center; }
.result-eyebrow {
  color: var(--text-muted);
  margin: 0 0 0.3rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  font-size: 0.8rem;
}
.result-big {
  font-size: clamp(1.8rem, 7vw, 3rem);
  font-weight: 700;
  margin: 0;
  color: var(--accent-soft);
}
.result-breakdown {
  color: var(--text-muted);
  margin: 0.3rem 0 0;
}

.comparison {
  margin-top: 1.75rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}
.comparison-lead { color: var(--text-muted); margin: 0; }
.comparison-big {
  font-size: clamp(1.6rem, 6vw, 2.6rem);
  font-weight: 700;
  margin: 0.2rem 0;
}
.comparison-big #unit-count { color: var(--good); }
.comparison-sub { color: var(--text-muted); margin: 0; }

/* ---------- dev section ---------- */
.dev-section h2 {
  margin: 0 0 0.4rem;
  font-size: 1.3rem;
}
.section-intro { color: var(--text-muted); margin: 0 0 1.25rem; }

.dev-controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.dev-results {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
  text-align: center;
}
.stat {
  background: var(--bg-card-2);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem 0.5rem;
}
.stat-num {
  display: block;
  font-size: clamp(1.2rem, 4.5vw, 1.7rem);
  font-weight: 700;
  color: var(--accent-soft);
}
.stat-label {
  display: block;
  color: var(--text-muted);
  font-size: 0.8rem;
  margin-top: 0.3rem;
}

.dev-sentence {
  margin: 1.25rem 0 0;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
  font-size: 1.05rem;
}

/* ---------- about ---------- */
.about h2 { margin: 0 0 0.6rem; font-size: 1.3rem; }
.about h3 { margin: 1.5rem 0 0.4rem; font-size: 1.05rem; }
.about p { margin: 0 0 0.8rem; }
.about ul { margin: 0 0 0.8rem; padding-left: 1.2rem; }
.about li { margin-bottom: 0.6rem; }
.about a { color: var(--accent-soft); }
.about a:hover { color: var(--accent); }

/* ---------- built-with disclaimer ---------- */
.built-with {
  text-align: center;
  color: var(--text-muted);
}
.built-with p { margin: 0; }
.built-with strong { color: var(--accent-soft); }

/* ---------- footer ---------- */
.site-footer {
  color: var(--text-muted);
  font-size: 0.8rem;
  text-align: center;
  padding-top: 1rem;
}

/* ---------- mobile ---------- */
@media (max-width: 480px) {
  .dev-results { grid-template-columns: 1fr; }
  .dev-controls { grid-template-columns: 1fr; }
}