:root {
  --bg: #0f1115;
  --card: #5f6b77;
  --ink: #e8e8e8;
  --brand: #1fd6ff;
  --brand2: #0eb7e0;
}

* {
  box-sizing: border-box
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  padding: 28px
}

h1 {
  margin: 0 0 18px;
  font-size: 44px;
  font-weight: 800;
  letter-spacing: .5px
}

h1::after {
  content: "";
  display: block;
  height: 3px;
  background: #2b3945;
  margin-top: 12px;
  width: 75%
}

.wrap {
  max-width: 980px;
  margin: 0 auto
}

.card {
  background: #6c7a88;
  background: linear-gradient(180deg, #6b7580 0%, #5d6874 100%);
  border-radius: 12px;
  padding: 22px;
  max-width: 520px;
  margin: 18px auto;
  box-shadow: 0 14px 36px rgba(0, 0, 0, .35)
}

.title {
  font-size: 40px;
  font-weight: 900;
  text-align: center;
  margin: 0 0 12px
}

.group {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: 12px 0
}

input,
select,
button {
  border: none;
  border-radius: 10px;
  padding: 14px 16px;
  font-size: 20px;
  outline: none
}

input,
select {
  background: #f5f7fb;
  color: #111
}

button {
  background: linear-gradient(180deg, var(--brand), var(--brand2));
  color: #06222b;
  font-weight: 800;
  cursor: pointer
}

button:disabled {
  opacity: .6;
  cursor: not-allowed
}

.result {
  font-size: 28px;
  font-weight: 800;
  text-align: center;
  margin-top: 12px
}

.error {
  display: none;
  margin: 10px auto 0;
  max-width: 520px;
  background: #2a0000;
  color: #ffd9d9;
  border: 1px solid #5a1b1b;
  padding: 10px 14px;
  border-radius: 10px
}

.status {
  text-align: center;
  opacity: .9;
  min-height: 1.2em;
  margin: 8px 0
}

.chart-card {
  background: #fff;
  border-radius: 16px;
  padding: 16px;
  height: 420px;
  box-shadow: 0 8px 22px rgba(0, 0, 0, .35);
  margin: 22px auto
}

canvas {
  width: 100% !important;
  height: 100% !important
}