:root {
  --bg: #f4f5f8;
  --panel: #ffffff;
  --ink: #1f2430;
  --muted: #6b7280;
  --line: #e3e6ec;
  --accent: #4f7cf5;
  --accent-soft: #eef2fe;
  --danger: #d0553a;
  --ok: #2f9e6e;
  --warn: #b8860b;
  --radius: 0px;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 14px;
  line-height: 1.6;
}

header {
  background: var(--panel);
  border-bottom: 1px solid var(--line);
  padding: 18px 24px 0;
}

.title {
  font-size: 19px;
  font-weight: 650;
  letter-spacing: 0.2px;
}

.subtitle {
  color: var(--muted);
  font-size: 12.5px;
  margin-top: 2px;
}

.anim-setting {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-top: 10px;
  font-size: 12.5px;
  color: var(--muted);
}

.anim-setting input {
  width: 72px;
  padding: 4px 8px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: inherit;
  font-size: 13px;
  color: var(--ink);
  background: var(--panel);
}

.anim-setting input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

.anim-setting .hint { opacity: 0.75; }

nav.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 2px;
  margin-top: 16px;
}

nav.tabs button {
  appearance: none;
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 13.5px;
  font-family: inherit;
  padding: 9px 14px;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  border-radius: 0;
}

nav.tabs button:hover { color: var(--ink); background: #f7f8fb; }

nav.tabs button.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 600;
}

main {
  max-width: 1180px;
  margin: 0 auto;
  padding: 22px 24px 60px;
}

.panel { display: none; }
.panel.active { display: block; }

.lead {
  color: var(--muted);
  margin: 0 0 16px;
  max-width: 860px;
}

.grid {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(300px, 1fr);
  gap: 16px;
  align-items: start;
}

@media (max-width: 880px) {
  .grid { grid-template-columns: 1fr; }
}

.card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin-bottom: 16px;
}

.card h2 {
  font-size: 13px;
  text-transform: uppercase;
  letter-spacing: 0.7px;
  color: var(--muted);
  margin: 0 0 12px;
  font-weight: 600;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  align-items: flex-end;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.field label {
  font-size: 11.5px;
  color: var(--muted);
}

input[type="number"], input[type="text"], select {
  font-family: inherit;
  font-size: 13.5px;
  padding: 7px 9px;
  border: 1px solid var(--line);
  border-radius: 0;
  background: #fff;
  color: var(--ink);
  min-width: 90px;
}

input:focus, select:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-soft);
}

input[type="range"] { accent-color: var(--accent); }

button.btn {
  appearance: none;
  font-family: inherit;
  font-size: 13.5px;
  padding: 8px 15px;
  border-radius: 0;
  border: 1px solid var(--line);
  background: #fff;
  color: var(--ink);
  cursor: pointer;
}

button.btn:hover { border-color: #cbd2df; background: #fafbff; }
button.btn:disabled { opacity: 0.5; cursor: not-allowed; }

button.btn.primary {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}
button.btn.primary:hover { background: #3f6ae0; }

button.btn.ghost { background: transparent; }

button.btn.accent {
  border-color: var(--accent);
  color: var(--accent);
}

button.btn.accent:hover { background: var(--accent-soft); }

.result-box {
  background: #fbfcfe;
  border: 1px dashed var(--line);
  border-radius: 0;
  padding: 12px 14px;
  min-height: 52px;
  font-family: var(--mono);
  font-size: 13px;
  word-break: break-word;
}

.result-box.big {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 1px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 10px;
}

.stat {
  background: #fbfcfe;
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 9px 11px;
}

.stat .k {
  font-size: 11px;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

.stat .v {
  font-size: 17px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  margin-top: 1px;
}

.stat .v.mono { font-family: var(--mono); font-size: 15px; }
.stat .v.accent { color: var(--accent); }
.stat .v.ok { color: var(--ok); }
.stat .v.danger { color: var(--danger); }

canvas.chart {
  width: 100%;
  height: 260px;
  display: block;
}

canvas.chart.tall { height: 320px; }

.chart-wrap { position: relative; }

table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

table.data th, table.data td {
  text-align: right;
  padding: 6px 8px;
  border-bottom: 1px solid var(--line);
  font-variant-numeric: tabular-nums;
}

table.data th:first-child, table.data td:first-child { text-align: left; }

table.data th {
  color: var(--muted);
  font-weight: 600;
  font-size: 11.5px;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}

table.data tr.hit { background: #f0fbf6; }
table.data td.mono { font-family: var(--mono); }

.progress {
  height: 6px;
  background: #eceef4;
  border-radius: 0;
  overflow: hidden;
  margin-top: 8px;
}

.progress > i {
  display: block;
  height: 100%;
  width: 0%;
  background: var(--accent);
  transition: width 0.08s linear;
}

.progress-note {
  min-height: 15px;
  margin-top: 4px;
  font-size: 11.5px;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.note {
  font-size: 12.5px;
  color: var(--muted);
  margin: 8px 0 0;
}

.formula {
  font-family: var(--mono);
  font-size: 13px;
  background: #f7f8fb;
  border: 1px solid var(--line);
  border-radius: 0;
  padding: 9px 11px;
  margin: 8px 0;
  overflow-x: auto;
  white-space: pre-wrap;
}

.tag {
  display: inline-block;
  font-size: 11.5px;
  padding: 2px 8px;
  border-radius: 0;
  background: var(--accent-soft);
  color: var(--accent);
  margin-right: 6px;
}

.tag.red { background: #fdecea; color: var(--danger); }
.tag.green { background: #e9f7f0; color: var(--ok); }
.tag.amber { background: #fdf6e3; color: var(--warn); }

.legend-inline {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
  font-size: 12px;
  color: var(--muted);
  margin-top: 8px;
}

.legend-inline span::before {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 2px;
  margin-right: 5px;
  vertical-align: -1px;
  background: currentColor;
}

details.theory {
  margin-top: 4px;
}

details.theory > summary {
  cursor: pointer;
  font-size: 12.5px;
  color: var(--accent);
  user-select: none;
}

details.theory[open] > summary { margin-bottom: 6px; }

.badge-row { margin: 6px 0 10px; }

.field label.chk {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12.5px;
  color: var(--ink);
  cursor: pointer;
}

.field label.chk input { accent-color: var(--accent); }