:root {
  --bg: #f6f7f9;
  --card: #ffffff;
  --text: #14181f;
  --muted: #667085;
  --line: #e4e7ec;
  --accent: #2563eb;
  --up: #16a34a;
  --down: #dc2626;
  --radius: 12px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1116;
    --card: #171b22;
    --text: #e8ebf0;
    --muted: #8b95a5;
    --line: #272d37;
    --accent: #5b8def;
    --up: #34d399;
    --down: #f87171;
  }
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Noto Sans SC", sans-serif;
}
main { max-width: 880px; margin: 0 auto; padding: 24px 16px 48px; }
h1 { margin: 0; font-size: 24px; }
h2 { margin: 0; font-size: 16px; }
header { margin-bottom: 16px; }
.muted { color: var(--muted); font-size: 13px; }
header .muted { margin: 4px 0 0; }
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 16px;
}

.converter {
  display: grid;
  grid-template-columns: 1fr 1.4fr auto 1.4fr;
  gap: 8px;
  align-items: center;
}
.converter output {
  grid-column: 1 / -1;
  font-size: 22px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
}
input, select, button {
  font: inherit;
  color: inherit;
  background: var(--bg);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  min-width: 0;
}
button { cursor: pointer; }
button:hover { border-color: var(--accent); }
#swap { width: 40px; padding: 8px 0; }

.chart-head { display: flex; justify-content: space-between; align-items: center; gap: 8px; flex-wrap: wrap; }
#ranges { display: flex; gap: 4px; }
#ranges button { padding: 4px 10px; font-size: 13px; }
#ranges button.on { background: var(--accent); border-color: var(--accent); color: #fff; }
.stats { margin: 6px 0 8px; font-variant-numeric: tabular-nums; }
.chart-wrap { position: relative; height: 260px; }
canvas { width: 100%; height: 100%; display: block; }
#tip {
  position: absolute;
  pointer-events: none;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 4px 8px;
  font-size: 12px;
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
  box-shadow: 0 2px 8px rgb(0 0 0 / .12);
}

.table-wrap { overflow-x: auto; margin-top: 8px; }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 8px 6px; border-bottom: 1px solid var(--line); text-align: left; white-space: nowrap; }
th { font-size: 12px; font-weight: 500; color: var(--muted); }
.num { text-align: right; font-variant-numeric: tabular-nums; }
tbody tr { cursor: pointer; }
tbody tr:hover { background: var(--bg); }
tbody tr.sel { background: color-mix(in srgb, var(--accent) 10%, transparent); }
td small { color: var(--muted); margin-left: 6px; }
.up { color: var(--up); }
.down { color: var(--down); }
td svg { display: block; width: 100px; height: 24px; }
footer { margin-top: 8px; line-height: 1.7; }
footer a { color: var(--accent); }

@media (max-width: 560px) {
  .converter { grid-template-columns: 1fr 1fr; }
  #swap { grid-column: 1 / -1; width: 100%; order: 3; }
  #target { order: 4; grid-column: 1 / -1; }
  .converter output { order: 5; }
  .chart-wrap { height: 220px; }
}