:root {
  --bg: #f3f4f6;
  --card: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: #d1d5db;
  --accent: #2563eb;
  --accent-text: #ffffff;
  --result-bg: #eef2ff;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f172a;
    --card: #1e293b;
    --text: #f1f5f9;
    --muted: #94a3b8;
    --border: #334155;
    --accent: #60a5fa;
    --accent-text: #0f172a;
    --result-bg: #0b1220;
  }
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: 1rem;
}

.card {
  width: 100%;
  max-width: 420px;
  background: var(--card);
  border-radius: 16px;
  padding: 1.5rem;
  box-shadow: 0 4px 20px rgb(0 0 0 / 0.08);
}

h1 {
  font-size: 1.5rem;
  margin: 0 0 1.25rem;
}

.field {
  margin: 0 0 1.25rem;
  padding: 0;
  border: 0;
  min-width: 0;
}

label,
legend {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  padding: 0;
}

.custom-label {
  margin-top: 0.75rem;
}

input[type="number"] {
  width: 100%;
  min-height: 48px;
  font-size: 1.25rem;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card);
  color: var(--text);
  -moz-appearance: textfield;
}

input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

input:focus-visible,
button:focus-visible {
  outline: 3px solid var(--accent);
  outline-offset: 2px;
}

.money {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.money span {
  font-size: 1.25rem;
  color: var(--muted);
}

.quick-tips {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0.5rem;
}

.quick-tips button {
  min-height: 44px;
  font-size: 1rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 10px;
  background: var(--card);
  color: var(--text);
  cursor: pointer;
}

.quick-tips button[aria-pressed="true"] {
  background: var(--accent);
  color: var(--accent-text);
  border-color: var(--accent);
}

.results {
  background: var(--result-bg);
  border-radius: 12px;
  padding: 1rem 1.25rem;
}

.row {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.4rem 0;
  font-size: 1.1rem;
}

.row output {
  font-variant-numeric: tabular-nums;
  font-weight: 600;
}

.row.big {
  border-top: 1px solid var(--border);
  margin-top: 0.5rem;
  padding-top: 0.75rem;
}

.row.big output {
  font-size: 2rem;
  font-weight: 700;
}

.hint {
  margin: 0.5rem 0 0;
  font-size: 0.9rem;
  color: var(--muted);
}