:root {
  --bg: #f7f6f2;
  --surface: #ffffff;
  --text: #1f2328;
  --muted: #5f6670;
  --border: #e2e0d8;
  --accent: #1f7a5a;
  --accent-soft: #e4f2ec;
  --warn-soft: #fff6e0;
  --danger: #b42318;
  --radius: 12px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #15171a;
    --surface: #1e2125;
    --text: #e8e6e1;
    --muted: #a0a6ad;
    --border: #33373d;
    --accent: #4cc497;
    --accent-soft: #1d3a2f;
    --warn-soft: #3a3220;
    --danger: #ff8a80;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Hiragino Sans", "Yu Gothic UI", "Meiryo", sans-serif;
  line-height: 1.75;
}

a { color: var(--accent); }

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}
.site-header .inner {
  max-width: 760px;
  margin: 0 auto;
  padding: 12px 16px;
  display: flex;
  align-items: baseline;
  gap: 12px;
}
.logo {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text);
  text-decoration: none;
}
.tagline { color: var(--muted); font-size: 0.85rem; }

main {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}

h1 { font-size: 1.5rem; line-height: 1.4; margin: 0 0 8px; }
h2 { font-size: 1.2rem; margin: 40px 0 12px; }
h3 { font-size: 1rem; margin: 20px 0 4px; }
.lead { color: var(--muted); margin: 0 0 24px; }

.card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
}

.field { margin-bottom: 16px; }
.field label { display: block; font-weight: 600; margin-bottom: 4px; }
.field .hint { color: var(--muted); font-size: 0.85rem; }
.row { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }

input[type="number"], select {
  font: inherit;
  font-size: 1rem;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  min-width: 0;
}
input[type="number"] { width: 7em; }
input[type="text"] {
  font: inherit;
  font-size: 1rem;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  min-width: 0;
}
.remove { background: none; border: none; color: var(--muted); font-size: 1.2rem; cursor: pointer; }
.add {
  margin-top: 12px;
  font: inherit;
  padding: 8px 16px;
  border-radius: 8px;
  border: 1px dashed var(--accent);
  background: none;
  color: var(--accent);
  cursor: pointer;
  width: 100%;
}
select { width: 100%; }

.results {
  margin-top: 20px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.result {
  background: var(--accent-soft);
  border-radius: 10px;
  padding: 12px 8px;
  text-align: center;
}
.result .label { font-size: 0.8rem; color: var(--muted); }
.result .value { font-size: 1.3rem; font-weight: 700; }
.result .unit { font-size: 0.8rem; margin-left: 2px; }

@media (max-width: 520px) {
  .results { grid-template-columns: repeat(2, 1fr); }
}

.saving {
  margin-top: 16px;
  background: var(--warn-soft);
  border-radius: 10px;
  padding: 12px 16px;
}
.saving strong { font-size: 1.1rem; }

.bars { margin: 20px 0 12px; display: grid; gap: 10px; }
.bar-row { display: grid; grid-template-columns: 7.5em 1fr auto; gap: 8px; align-items: center; }
.bar-label { font-size: 0.9rem; font-weight: 600; }
.bar-track { background: var(--bg); border-radius: 6px; height: 20px; overflow: hidden; }
.bar-fill { background: var(--accent); height: 100%; width: 0; transition: width 0.2s; }
.bar-value { font-size: 0.9rem; white-space: nowrap; }

@media (max-width: 520px) {
  .bar-row { grid-template-columns: 1fr auto; }
  .bar-track { grid-column: 1 / -1; grid-row: 2; }
}

.error { color: var(--danger); }
input.invalid { border-color: var(--danger); }
.alert {
  margin-top: 16px;
  padding: 10px 14px;
  border: 1px solid var(--danger);
  border-radius: 10px;
}

.formula {
  font-size: 0.9rem;
  color: var(--muted);
  margin-top: 12px;
}

table { width: 100%; border-collapse: collapse; font-size: 0.95rem; }
th, td { border-bottom: 1px solid var(--border); padding: 8px 6px; text-align: left; }
td.num, th.num { text-align: right; }

.tool-list { list-style: none; padding: 0; margin: 0; display: grid; gap: 12px; }
.tool-list a { display: block; text-decoration: none; color: var(--text); }
.tool-list a:hover .card { border-color: var(--accent); }
.tool-list .soon .card { opacity: 0.55; }
.tool-list h3 { margin: 0 0 4px; }
.tool-list p { margin: 0; color: var(--muted); font-size: 0.9rem; }

.site-footer {
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: 0.8rem;
  text-align: center;
  padding: 20px 16px;
}