.viz-root {
  color-scheme: light;
  --page:            #f9f9f7;
  --surface-1:       #fcfcfb;
  --text-primary:    #0b0b0b;
  --text-secondary:  #52514e;
  --text-muted:      #898781;
  --gridline:        #e1e0d9;
  --baseline:        #c3c2b7;
  --border:          rgba(11,11,11,0.10);
  --series-1:        #2a78d6;
  --series-savings:  #1baf7a;
  --series-borrowing:#eb6834;
  --good:            #006300;
  --critical:        #d03b3b;
}
@media (prefers-color-scheme: dark) {
  :root:where(:not([data-theme="light"])) .viz-root {
    color-scheme: dark;
    --page:            #0d0d0d;
    --surface-1:       #1a1a19;
    --text-primary:    #ffffff;
    --text-secondary:  #c3c2b7;
    --text-muted:      #898781;
    --gridline:        #2c2c2a;
    --baseline:        #383835;
    --border:          rgba(255,255,255,0.10);
    --series-1:        #3987e5;
    --series-savings:  #199e70;
    --series-borrowing:#d95926;
    --good:            #0ca30c;
    --critical:        #e66767;
  }
}

* { box-sizing: border-box; }

body.viz-root {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", sans-serif;
  background: var(--page);
  color: var(--text-primary);
}

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  flex-wrap: wrap;
  gap: 12px;
  padding: 28px 32px 20px;
  border-bottom: 1px solid var(--border);
}
.header-inner h1 { margin: 0 0 4px; font-size: 1.6rem; }
.app-version { font-size: 0.6rem; font-weight: 400; color: var(--text-muted); vertical-align: middle; }
.tagline { margin: 0; color: var(--text-secondary); font-size: 0.95rem; }
.header-meta { display: flex; align-items: center; gap: 12px; color: var(--text-muted); font-size: 0.85rem; }
#refresh-btn {
  background: var(--surface-1);
  border: 1px solid var(--border);
  color: var(--text-primary);
  border-radius: 6px;
  padding: 6px 12px;
  cursor: pointer;
  font-size: 0.85rem;
}
#refresh-btn:hover { border-color: var(--series-1); color: var(--series-1); }

main { max-width: 1200px; margin: 0 auto; padding: 24px 32px 60px; }

section.curve-section, section.spread-section { margin-bottom: 28px; }
.curve-section h2, .column-title { margin: 0 0 4px; font-size: 1.15rem; }
.section-sub, .column-sub { margin: 0 0 16px; color: var(--text-secondary); font-size: 0.88rem; }

.yield-curve-chart {
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 24px 8px;
}

.spread-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 14px;
}
.spread-card {
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
}
.spread-card .spread-label { font-size: 0.8rem; color: var(--text-secondary); }
.spread-card .spread-value { font-size: 1.8rem; font-weight: 700; margin-top: 2px; }
.spread-card .spread-date { font-size: 0.72rem; color: var(--text-muted); margin-top: 1px; }
.spread-card .spread-explain { font-size: 0.78rem; color: var(--text-muted); margin-top: 6px; }
.spread-card .spread-real {
  display: flex; justify-content: space-between; align-items: baseline;
  margin-top: 10px; padding-top: 10px; border-top: 1px solid var(--border);
}
.spread-card .spread-real-label { font-size: 0.78rem; color: var(--text-secondary); }
.spread-card .spread-real-value { font-size: 1rem; font-weight: 600; }
.spread-card .spread-real-explain { font-size: 0.74rem; color: var(--text-muted); margin-top: 3px; }

.picks-section { margin-bottom: 32px; }
table.picks {
  width: 100%;
  border-collapse: collapse;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
  font-size: 0.88rem;
}
table.picks th, table.picks td {
  text-align: left;
  padding: 10px 16px;
  border-top: 1px solid var(--border);
}
table.picks thead th {
  border-top: none;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
}
table.picks .picks-bank { font-weight: 600; }
table.picks .picks-note { font-weight: 400; font-size: 0.76rem; color: var(--text-muted); margin-top: 2px; }
table.picks .picks-value { font-weight: 600; white-space: nowrap; }
table.picks .picks-term { font-weight: 400; color: var(--text-muted); font-size: 0.78rem; }

.calculator-section { margin-bottom: 32px; }
.calc-controls { display: flex; align-items: center; gap: 10px; margin-bottom: 16px; }
.calc-controls label { font-size: 0.85rem; color: var(--text-secondary); }
.calc-input-wrap {
  display: flex; align-items: center;
  background: var(--surface-1); border: 1px solid var(--border); border-radius: 8px;
  padding: 4px 10px;
}
.calc-dollar { color: var(--text-muted); margin-right: 4px; }
.calc-input-wrap input {
  border: none; background: transparent; color: var(--text-primary);
  font-size: 1rem; width: 140px; outline: none;
}
.calc-results { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; }
.calc-group {
  background: var(--surface-1); border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px;
}
.calc-group h3 {
  font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.04em; color: var(--text-muted);
  margin: 0 0 10px;
}
.calc-row {
  display: flex; justify-content: space-between; align-items: baseline; gap: 10px;
  padding: 6px 0; border-top: 1px solid var(--border); font-size: 0.85rem;
}
.calc-row:first-child { border-top: none; }
.calc-row-label { color: var(--text-secondary); }
.calc-row-rate { color: var(--text-muted); font-size: 0.78rem; }
.calc-row-value { font-weight: 600; white-space: nowrap; }
.calc-row-earned { font-weight: 400; color: var(--good); font-size: 0.78rem; }

.columns {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 32px;
}
@media (max-width: 820px) {
  .columns { grid-template-columns: 1fr; }
  main { padding: 20px 16px 40px; }
  .site-header { padding: 20px 16px 16px; }
}

.dot { display: inline-block; width: 10px; height: 10px; border-radius: 50%; margin-right: 8px; }
.dot-savings { background: var(--series-savings); }
.dot-borrowing { background: var(--series-borrowing); }

.rate-group { margin-bottom: 22px; }
.rate-group h3 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  margin: 0 0 10px;
}
.rate-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 12px; }

.rate-card {
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px 16px;
}
.rate-card .rate-label { font-size: 0.82rem; color: var(--text-secondary); margin-bottom: 2px; }
.rate-card .rate-value { font-size: 1.5rem; font-weight: 600; }
.rate-card .rate-meta { display: flex; justify-content: space-between; align-items: center; margin-top: 6px; }
.rate-card .rate-date { font-size: 0.72rem; color: var(--text-muted); }
.rate-card .rate-deltas { display: flex; flex-wrap: wrap; gap: 8px; font-size: 0.75rem; }
.rate-card .rate-deltas .delta-sep { color: var(--text-muted); }
.delta-up { color: var(--good); }
.delta-down { color: var(--critical); }
.delta-flat { color: var(--text-muted); }
.savings-column .delta-up { color: var(--good); }
.savings-column .delta-down { color: var(--critical); }
.borrowing-column .delta-up { color: var(--critical); }
.borrowing-column .delta-down { color: var(--good); }

.rate-card svg.sparkline { display: block; margin-top: 8px; width: 100%; height: auto; overflow: visible; }
.sparkline path.line { fill: none; stroke: var(--series-1); stroke-width: 2px; stroke-linecap: round; stroke-linejoin: round; }
.sparkline circle.end-dot { fill: var(--series-1); stroke: none; }
.sparkline .spark-axis-label { fill: var(--text-muted); font-size: 7px; }
.savings-column .sparkline path.line { stroke: var(--series-savings); fill: none; }
.savings-column .sparkline circle.end-dot { fill: var(--series-savings); }
.borrowing-column .sparkline path.line { stroke: var(--series-borrowing); fill: none; }
.borrowing-column .sparkline circle.end-dot { fill: var(--series-borrowing); }

.rate-card.unavailable { opacity: 0.5; }

.note {
  font-size: 0.78rem;
  color: var(--text-muted);
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  margin-top: 8px;
}

.site-footer { margin-top: 40px; border-top: 1px solid var(--border); padding-top: 16px; }
.site-footer p { color: var(--text-muted); font-size: 0.75rem; line-height: 1.5; }

.chart-tooltip {
  position: fixed;
  z-index: 50;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 10px;
  font-size: 0.78rem;
  color: var(--text-primary);
  pointer-events: none;
  box-shadow: 0 4px 14px rgba(0,0,0,0.15);
}

.yc-axis-label { fill: var(--text-muted); font-size: 11px; }
.yc-value-label { fill: var(--text-primary); font-size: 12px; font-weight: 600; }
.yc-gridline { stroke: var(--gridline); stroke-width: 1px; }
.yc-line { fill: none; stroke: var(--series-1); stroke-width: 2px; }
.yc-point { fill: var(--series-1); stroke: var(--surface-1); stroke-width: 2px; }

/* loading wheel */
@keyframes spin-wheel { to { transform: rotate(360deg); } }
.loading-wheel {
  width: 44px; height: 44px; border-radius: 50%;
  border: 4px solid rgba(123, 63, 242, 0.18); border-top-color: #7B3FF2;
  animation: spin-wheel 0.8s linear infinite;
}
.chart-loading { display: flex; flex-direction: column; align-items: center; gap: 12px; padding: 48px 0; color: #667; font-size: .9rem; }