:root {
  color-scheme: dark;
  --bg: #14161a;
  --panel: #1e2127;
  --border: #2e323a;
  --text: #e8e8ea;
  --muted: #8b8f98;
  --accent: #4da3ff;
  --hit: #3ecf8e;
  --fail: #e5534b;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 1.5rem 1rem 3rem;
}

header {
  width: 100%;
  max-width: 480px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 1rem;
  gap: 0.75rem;
}

.header-actions {
  display: flex;
  gap: 0.5rem;
}

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

button {
  font: inherit;
  background: var(--panel);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 0.6rem 1.2rem;
  cursor: pointer;
}

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

#settings-panel {
  width: 100%;
  max-width: 480px;
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 1rem;
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.setting-row {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.setting-row-inline label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.setting-label {
  color: var(--muted);
  font-size: 0.85rem;
}

.setting-row input[type="number"],
.setting-row select {
  font: inherit;
  background: var(--bg);
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 0.4rem 0.6rem;
}

.checkbox-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1rem;
}

.checkbox-grid label {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.9rem;
}

main {
  width: 100%;
  max-width: 480px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

#start-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  padding: 3rem 0;
}

.hint {
  color: var(--muted);
}

#start-button {
  background: var(--accent);
  border-color: var(--accent);
  color: #0a0a0c;
  font-weight: 600;
}

#start-button.running {
  background: var(--fail);
  border-color: var(--fail);
  color: #fff;
}

.error {
  color: var(--fail);
  text-align: center;
  max-width: 360px;
}

#game-screen {
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
}

.timer {
  font-size: 1.5rem;
  font-variant-numeric: tabular-nums;
  color: var(--muted);
}

.timer.urgent {
  color: var(--fail);
}

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

.chord-symbol {
  font-size: clamp(2.5rem, 12vw, 4rem);
  font-weight: 700;
  letter-spacing: 0.02em;
  text-align: center;
}

.tone-indicators {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
}

.tone-indicator {
  width: 3.75rem;
  height: 3.75rem;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  color: var(--muted);
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.tone-indicator.hit {
  background: var(--hit);
  border-color: var(--hit);
  color: #0a0a0c;
  font-weight: 600;
}

.result-banner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  padding: 1rem;
  border-radius: 10px;
  width: 100%;
}

.result-banner.pass {
  background: rgba(62, 207, 142, 0.12);
}

.result-banner.fail {
  background: rgba(229, 83, 75, 0.12);
}

#result-text {
  font-size: 1.4rem;
  font-weight: 700;
  margin: 0;
}

.result-banner.pass #result-text {
  color: var(--hit);
}

.result-banner.fail #result-text {
  color: var(--fail);
}

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