:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --text: #1d2330;
  --muted: #5d6677;
  --border: #d7dbe3;
  --accent: #2458d6;
  --accent-hover: #1b47b3;
  --given: #1f4fbf;
  --computed: #1c7a45;
  --unknown: #b0570f;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

main {
  max-width: 1100px;
  margin: 0 auto;
  padding: 24px 16px 48px;
}

h1 { font-size: 1.5rem; margin: 0 0 16px; }
h2 { font-size: 1.15rem; margin: 0 0 8px; }
h3 { font-size: 1rem; margin: 20px 0 6px; }

.config {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 16px;
  align-items: flex-end;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
}

.config label {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 0.85rem;
  color: var(--muted);
}

.config input {
  width: 150px;
  padding: 6px 8px;
  font: inherit;
  font-size: 0.95rem;
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 5px;
}

.config input:focus { outline: 2px solid var(--accent); outline-offset: -1px; }

.buttons { display: flex; gap: 8px; margin-left: auto; }

button {
  padding: 7px 14px;
  font: inherit;
  font-weight: 600;
  color: #fff;
  background: var(--accent);
  border: 0;
  border-radius: 5px;
  cursor: pointer;
}

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

#btnCalc { background: #fff; color: var(--accent); border: 1px solid var(--accent); }
#btnCalc:hover { background: #eef3ff; }

.info { color: var(--muted); font-size: 0.9rem; margin: 12px 0 8px; }

.canvas-wrap {
  position: relative;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px;
  overflow: hidden;
}

canvas { display: block; margin: 0 auto; }

.hint { color: var(--muted); font-size: 0.85rem; margin: 6px 0 20px; }

.popup {
  position: absolute;
  z-index: 2;
  min-width: 170px;
  padding: 8px 12px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 6px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  font-size: 0.9rem;
  pointer-events: none;
}

.popup strong { display: block; margin-bottom: 4px; }
.popup table { border-collapse: collapse; }
.popup td { padding: 1px 6px 1px 0; }
.popup td:first-child { color: var(--muted); }

.values, .calculation {
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 14px 16px;
  margin-top: 16px;
}

.legend { font-size: 0.85rem; color: var(--muted); margin: 0 0 8px; }

.table-scroll { overflow-x: auto; }

#valueTable { border-collapse: collapse; min-width: 480px; }

#valueTable th, #valueTable td {
  padding: 5px 14px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  white-space: nowrap;
}

#valueTable th { font-size: 0.85rem; color: var(--muted); font-weight: 600; }
#valueTable tr.total td { border-top: 2px solid var(--text); font-weight: 600; }

.given { color: var(--given); font-weight: 700; }
.computed { color: var(--computed); }
.unknown { color: var(--unknown); }

.calculation .math-list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 24px;
}

.calculation .step {
  margin: 10px 0;
  overflow-x: auto;
}

.calculation .caption { font-size: 0.9rem; color: var(--muted); }
.calculation .eq { margin: 6px 0 6px 12px; }
.calculation math { font-size: 1.1rem; math-style: normal; }