:root {
  --bg: #f4f4f5;
  --card-bg: #ffffff;
  --text: #1c1c1e;
  --muted: #6b7280;
  --border: #d4d4d8;
  --accent: #2563eb;
  --accent-text: #ffffff;
  --mono-bg: #f4f4f5;
  --error: #b91c1c;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #18181b;
    --card-bg: #232326;
    --text: #f4f4f5;
    --muted: #9ca3af;
    --border: #3f3f46;
    --accent: #3b82f6;
    --accent-text: #0b1220;
    --mono-bg: #18181b;
    --error: #f87171;
  }
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding: 2rem 1rem;
  background: var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
}

.card {
  width: 100%;
  max-width: 32rem;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1.5rem;
}

h1 {
  margin: 0 0 0.4rem;
  font-size: 1.25rem;
}

.note {
  margin: 0 0 1.25rem;
  color: var(--muted);
  font-size: 0.85rem;
}

.field {
  margin-bottom: 1.25rem;
}

.field-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
}

label {
  font-size: 0.9rem;
}

output {
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

input[type="range"] {
  width: 100%;
  margin-top: 0.4rem;
}

.charsets,
.algorithm {
  border: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

/* .charsets má display: flex, což by jinak přebilo výchozí [hidden] chování
   (autorský styl vyhrává nad UA stylem bez ohledu na specificitu). */
.charsets[hidden] {
  display: none;
}

.charsets legend,
.algorithm legend {
  padding: 0;
  font-size: 0.9rem;
  color: var(--muted);
  margin-bottom: 0.4rem;
}

.charsets label,
.algorithm label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

#algo-info {
  margin-top: -0.75rem;
}

#count {
  width: 5rem;
  padding: 0.3rem 0.5rem;
  border: 1px solid var(--border);
  border-radius: 0.4rem;
  background: var(--card-bg);
  color: var(--text);
}

button#generate {
  width: 100%;
  padding: 0.65rem;
  border: none;
  border-radius: 0.5rem;
  background: var(--accent);
  color: var(--accent-text);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
}

button#generate:hover {
  filter: brightness(1.05);
}

.error {
  color: var(--error);
  font-size: 0.85rem;
  margin: -0.5rem 0 1rem;
}

.results {
  list-style: none;
  margin: 1.25rem 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.results li {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--mono-bg);
  border: 1px solid var(--border);
  border-radius: 0.4rem;
  padding: 0.4rem 0.5rem;
}

.results code {
  flex: 1;
  font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
  font-size: 0.95rem;
  overflow-x: auto;
  white-space: pre;
}

.results button {
  flex-shrink: 0;
  padding: 0.3rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 0.4rem;
  background: var(--card-bg);
  color: var(--text);
  font-size: 0.8rem;
  cursor: pointer;
}

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