/* ===== Design tokens ===== */
:root {
  --stone:      #EDE6DA;
  --stone-deep: #E1D7C4;
  --ink:        #211E1B;
  --ink-soft:   #4A443C;
  --bronze:     #8A6A3F;
  --bronze-lt:  #B08A54;
  --patina:     #5B7A6B;
  --brick:      #B5482F;
  --line:       rgba(33,30,27,0.14);
  --card-bg:    #F6F1E7;
  --shadow-1:   0 1px 0 rgba(255,255,255,0.5) inset, 0 8px 24px rgba(33,30,27,0.10);

  --font-display: 'Cinzel', serif;
  --font-body:    'Source Serif 4', Georgia, serif;
  --font-mono:    'JetBrains Mono', ui-monospace, monospace;

  --radius: 6px;
  color-scheme: light;
}

[data-theme="dark"] {
  --stone:      #1B1815;
  --stone-deep: #15120F;
  --ink:        #EDE6DA;
  --ink-soft:   #C9C0AE;
  --bronze:     #D2A968;
  --bronze-lt:  #E4C58C;
  --patina:     #7FA391;
  --brick:      #D97656;
  --line:       rgba(237,230,218,0.14);
  --card-bg:    #221E19;
  --shadow-1:   0 1px 0 rgba(255,255,255,0.03) inset, 0 8px 28px rgba(0,0,0,0.45);
  color-scheme: dark;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--stone);
  background-image:
    radial-gradient(circle at 20% 10%, rgba(138,106,63,0.06), transparent 40%),
    radial-gradient(circle at 85% 60%, rgba(91,122,107,0.05), transparent 45%);
  color: var(--ink);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.6;
  transition: background 0.25s ease, color 0.25s ease;
}
.wrap { max-width: 960px; margin: 0 auto; padding: 0 24px; }

a { color: inherit; text-decoration: none; }
h1, h2, h3, h4 { font-family: var(--font-display); letter-spacing: 0.02em; margin: 0 0 0.5em; font-weight: 600; }

::selection { background: var(--bronze); color: var(--stone); }

/* focus visibility */
a:focus-visible, button:focus-visible, input:focus-visible {
  outline: 2px solid var(--bronze);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; transition-duration: 0.001ms !important; }
}

/* ===== Header ===== */
.site-header {
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--stone) 92%, transparent);
  backdrop-filter: blur(6px);
  position: sticky; top: 0; z-index: 50;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; padding-top: 14px; padding-bottom: 14px; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark {
  width: 38px; height: 38px; border-radius: 50%;
  background: linear-gradient(155deg, var(--bronze-lt), var(--bronze));
  color: var(--stone);
  display: flex; align-items: center; justify-content: center;
  font-family: var(--font-display); font-weight: 700; font-size: 13px;
  box-shadow: var(--shadow-1);
  border: 1px solid var(--line);
}
.brand-mark.small { width: 28px; height: 28px; font-size: 11px; margin-bottom: 10px; }
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-name { font-family: var(--font-display); font-weight: 600; font-size: 15px; letter-spacing: 0.03em; }
.brand-sub { font-size: 11px; color: var(--ink-soft); letter-spacing: 0.04em; }

.site-nav { display: flex; gap: 24px; }
.site-nav a { font-size: 14px; letter-spacing: 0.02em; color: var(--ink-soft); border-bottom: 1px solid transparent; padding-bottom: 2px; transition: color 0.15s, border-color 0.15s; }
.site-nav a:hover { color: var(--bronze); border-color: var(--bronze); }

.theme-toggle {
  width: 36px; height: 36px; border-radius: 50%;
  border: 1px solid var(--line); background: var(--card-bg);
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; color: var(--bronze);
}
.theme-toggle svg { fill: none; stroke: currentColor; stroke-width: 1.6; stroke-linecap: round; }
.theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

/* ===== Hero / tool card ===== */
.hero { padding: 56px 0 24px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px;
  font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em;
  text-transform: uppercase; color: var(--patina);
  margin-bottom: 14px;
}
.eyebrow::before { content: ''; width: 18px; height: 1px; background: var(--patina); }
.hero h1 { font-size: clamp(28px, 4.4vw, 42px); max-width: 14ch; }
.hero p.lede { color: var(--ink-soft); max-width: 56ch; font-size: 18px; margin-top: 8px; }

/* the tablet: signature element */
.tablet {
  margin-top: 36px;
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow-1);
  padding: 32px;
  position: relative;
  overflow: hidden;
}
.tablet::before {
  content: '';
  position: absolute; inset: 8px;
  border: 1px solid var(--line);
  border-radius: 4px;
  pointer-events: none;
}
.tablet-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
@media (max-width: 720px) { .tablet-grid { grid-template-columns: 1fr; } }

.field-label {
  display: block; font-family: var(--font-mono); font-size: 11px;
  letter-spacing: 0.1em; text-transform: uppercase; color: var(--ink-soft);
  margin-bottom: 8px;
}
.field-input {
  width: 100%;
  font-family: var(--font-mono);
  font-size: 26px;
  padding: 14px 16px;
  background: var(--stone);
  border: 1px solid var(--line);
  border-radius: 4px;
  color: var(--ink);
  letter-spacing: 0.02em;
}
.field-input:invalid, .field-input.is-invalid { border-color: var(--brick); color: var(--brick); }

.arrow-divider {
  display: flex; align-items: center; justify-content: center;
  color: var(--bronze); font-family: var(--font-mono); font-size: 13px;
  margin: 4px 0 18px; letter-spacing: 0.1em;
}
.arrow-divider .rule { flex: 1; height: 1px; background: var(--line); }
.arrow-divider span.label { padding: 0 12px; text-transform: uppercase; }

/* carved relief output */
.relief-output {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 34px;
  letter-spacing: 0.06em;
  color: var(--bronze);
  text-shadow:
    0 1px 0 rgba(255,255,255,0.6),
    0 -1px 0 rgba(33,30,27,0.35);
  min-height: 44px;
  word-break: break-all;
}
[data-theme="dark"] .relief-output {
  text-shadow: 0 1px 0 rgba(0,0,0,0.6), 0 -1px 0 rgba(255,255,255,0.08);
}
.output-row { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 6px; }

.icon-btn {
  border: 1px solid var(--line);
  background: var(--stone);
  color: var(--ink-soft);
  border-radius: 4px;
  padding: 8px 10px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  display: inline-flex; align-items: center; gap: 6px;
  transition: color 0.15s, border-color 0.15s;
  flex-shrink: 0;
}
.icon-btn:hover { color: var(--bronze); border-color: var(--bronze); }
.icon-btn.copied { color: var(--patina); border-color: var(--patina); }

.error-msg { color: var(--brick); font-family: var(--font-mono); font-size: 13px; margin-top: 8px; min-height: 18px; }

/* toolbar under tablet */
.tool-meta { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; margin-top: 22px; padding-top: 18px; border-top: 1px dashed var(--line); }
.checkbox-row { display: flex; align-items: center; gap: 8px; font-size: 13px; color: var(--ink-soft); font-family: var(--font-mono); }
.share-row { display: flex; gap: 8px; }

/* ===== History ===== */
.history-panel { margin-top: 18px; }
.history-panel h4 { font-family: var(--font-mono); font-size: 11px; text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-soft); font-weight: 500; margin-bottom: 10px; }
.history-list { display: flex; flex-wrap: wrap; gap: 8px; list-style: none; padding: 0; margin: 0; }
.history-list li button {
  font-family: var(--font-mono); font-size: 13px;
  background: var(--stone); border: 1px solid var(--line); border-radius: 4px;
  padding: 6px 10px; cursor: pointer; color: var(--ink-soft);
}
.history-list li button:hover { color: var(--bronze); border-color: var(--bronze); }
.history-clear { background: none; border: none; font-family: var(--font-mono); font-size: 12px; color: var(--brick); cursor: pointer; padding: 6px; }

/* ===== Breakdown / plaque sections ===== */
section.plaque {
  padding: 44px 0;
  border-top: 1px solid var(--line);
}
.plaque h2 { font-size: 22px; }
.breakdown-list { list-style: none; padding: 0; margin: 18px 0; display: flex; flex-direction: column; gap: 8px; }
.breakdown-list li {
  display: flex; align-items: baseline; justify-content: space-between;
  font-family: var(--font-mono); font-size: 15px;
  padding: 10px 14px;
  background: var(--card-bg);
  border: 1px solid var(--line);
  border-left: 3px solid var(--patina);
  border-radius: 3px;
}
.breakdown-total {
  margin-top: 6px; padding-top: 14px; border-top: 1px dashed var(--line);
  font-family: var(--font-mono); font-size: 15px; color: var(--bronze); font-weight: 700;
}

/* related links */
.related-grid { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 16px; }
.related-grid a {
  font-family: var(--font-mono); font-size: 13px;
  border: 1px solid var(--line); border-radius: 4px; padding: 8px 14px;
  background: var(--card-bg); color: var(--ink-soft);
  transition: color 0.15s, border-color 0.15s;
}
.related-grid a:hover { color: var(--bronze); border-color: var(--bronze); }

/* ===== Chart table ===== */
.chart-table { width: 100%; border-collapse: collapse; margin-top: 18px; font-family: var(--font-mono); font-size: 14px; }
.chart-table th, .chart-table td { text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--line); }
.chart-table th { text-transform: uppercase; letter-spacing: 0.08em; font-size: 11px; color: var(--ink-soft); font-weight: 500; }
.chart-table td.roman-col { color: var(--bronze); font-weight: 700; }
.chart-table tr:hover td { background: var(--card-bg); }

/* FAQ */
.faq-item { border-bottom: 1px solid var(--line); padding: 16px 0; }
.faq-item h3 { font-size: 16px; font-family: var(--font-body); font-weight: 600; margin-bottom: 6px; }
.faq-item p { color: var(--ink-soft); margin: 0; }

/* ===== Footer ===== */
.site-footer { border-top: 1px solid var(--line); margin-top: 60px; padding: 44px 0 0; background: var(--stone-deep); }
.footer-inner { display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 32px; padding-bottom: 32px; }
@media (max-width: 640px) { .footer-inner { grid-template-columns: 1fr; } }
.footer-col p { color: var(--ink-soft); font-size: 14px; max-width: 34ch; }
.footer-col h3 { font-family: var(--font-mono); font-size: 12px; text-transform: uppercase; letter-spacing: 0.08em; color: var(--ink-soft); font-weight: 500; margin-bottom: 12px; }
.footer-col a { display: block; font-size: 14px; color: var(--ink-soft); margin-bottom: 8px; }
.footer-col a:hover { color: var(--bronze); }
.footer-bottom { border-top: 1px solid var(--line); padding: 16px 24px; font-size: 12px; color: var(--ink-soft); font-family: var(--font-mono); }

/* breadcrumb */
.breadcrumb { font-family: var(--font-mono); font-size: 12px; color: var(--ink-soft); padding-top: 20px; letter-spacing: 0.02em; }
.breadcrumb a:hover { color: var(--bronze); }
.breadcrumb .sep { margin: 0 6px; opacity: 0.5; }