:root {
  --primary: #b5544a;
  --primary-dark: #8f4037;
  --accent: #e8b84b;
  --bg: #faf7f2;
  --card: #ffffff;
  --text: #2b2b2b;
  --muted: #6b6b6b;
  --border: #e5ddd2;
  --radius: 10px;
  --shadow: 0 2px 10px rgba(0, 0, 0, 0.06);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  font-size: 16px;
}

.container {
  max-width: 920px;
  margin: 0 auto;
  padding: 0 20px;
}

header.site-header {
  background: var(--primary);
  color: #fff;
  padding: 16px 0;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

.site-header .logo {
  font-size: 22px;
  font-weight: 800;
  color: #fff;
  text-decoration: none;
  letter-spacing: -0.3px;
}

.site-header nav a {
  color: rgba(255, 255, 255, 0.92);
  text-decoration: none;
  margin-left: 18px;
  font-size: 15px;
  font-weight: 500;
}

.site-header nav a:hover { text-decoration: underline; }

main { padding: 36px 0 60px; }

h1 {
  font-size: 30px;
  line-height: 1.25;
  margin-bottom: 10px;
  letter-spacing: -0.4px;
}

h2 {
  font-size: 22px;
  margin: 34px 0 12px;
  letter-spacing: -0.2px;
}

h3 { font-size: 18px; margin: 22px 0 8px; }

p { margin: 0 0 14px; }

.lead {
  font-size: 17px;
  color: var(--muted);
  max-width: 720px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  gap: 16px;
  margin: 24px 0;
}

.tool-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
  transition: transform 0.12s ease, box-shadow 0.12s ease;
  display: block;
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 16px rgba(0, 0, 0, 0.1);
}

.tool-card .tool-title {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 6px;
  color: var(--primary-dark);
}

.tool-card p {
  font-size: 14px;
  color: var(--muted);
  margin: 0;
}

.calculator {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin: 24px 0;
}

.field {
  margin-bottom: 16px;
}

.field label {
  display: block;
  font-weight: 600;
  font-size: 14px;
  margin-bottom: 6px;
}

.field .unit-hint {
  color: var(--muted);
  font-weight: 400;
  font-size: 13px;
}

.field input,
.field select {
  width: 100%;
  padding: 11px 13px;
  font-size: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #fff;
  color: var(--text);
}

.field input:focus,
.field select:focus {
  outline: 2px solid var(--accent);
  border-color: transparent;
}

.field-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px;
}

@media (max-width: 560px) {
  .field-row { grid-template-columns: 1fr; }
}

.btn {
  display: inline-block;
  background: var(--primary);
  color: #fff;
  border: none;
  padding: 12px 26px;
  font-size: 16px;
  font-weight: 700;
  border-radius: 8px;
  cursor: pointer;
}

.btn:hover { background: var(--primary-dark); }

.btn-secondary {
  background: transparent;
  color: var(--primary-dark);
  border: 1px solid var(--primary);
}

.btn-secondary:hover { background: rgba(181, 84, 74, 0.08); }

.btn-row {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 6px;
}

.result {
  margin-top: 20px;
  padding: 18px;
  background: #f7f1e8;
  border-left: 4px solid var(--accent);
  border-radius: 6px;
  display: none;
}

.result.show { display: block; }

.result .result-value {
  font-size: 26px;
  font-weight: 800;
  color: var(--primary-dark);
}

.result .result-detail {
  margin-top: 8px;
  font-size: 14px;
  color: var(--muted);
}

.note {
  font-size: 13px;
  color: var(--muted);
  margin-top: 12px;
}

.disclaimer {
  font-size: 13px;
  color: var(--muted);
  background: #f3efe8;
  border-radius: 8px;
  padding: 14px 16px;
  margin: 20px 0;
}

.faq details {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 18px;
  margin-bottom: 10px;
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 15px;
}

.faq details p {
  margin-top: 10px;
  font-size: 15px;
  color: #444;
}

footer.site-footer {
  background: #2b2b2b;
  color: #bbb;
  padding: 28px 0;
  font-size: 14px;
}

.site-footer a { color: #ddd; text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }

.site-footer .container {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 10px;
}

ul, ol { margin: 0 0 14px 22px; }
li { margin-bottom: 6px; }

.breadcrumb {
  font-size: 13px;
  color: var(--muted);
  margin-bottom: 16px;
}

.breadcrumb a { color: var(--primary-dark); text-decoration: none; }
.breadcrumb a:hover { text-decoration: underline; }