:root {
  color-scheme: dark;
  --bg: #0f172a;
  --panel: #111827;
  --panel-2: #1f2937;
  --accent: #38bdf8;
  --text: #f8fafc;
  --muted: #94a3b8;
}

* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: "Segoe UI", Meiryo, sans-serif;
  background: linear-gradient(135deg, #020617, var(--bg));
  color: var(--text);
  min-height: 100vh;
  padding: 24px;
}

.shell {
  max-width: 980px;
  margin: 0 auto;
  background: rgba(17, 24, 39, 0.92);
  border: 1px solid rgba(148, 163, 184, 0.2);
  border-radius: 20px;
  padding: 24px;
  box-shadow: 0 24px 60px rgba(0,0,0,.35);
}

h1 { margin: 0 0 8px; font-size: 1.8rem; }
.lead { color: var(--muted); margin-bottom: 20px; line-height: 1.6; }
.badge {
  display: inline-block;
  margin-top: 8px;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(56, 189, 248, 0.15);
  color: #7dd3fc;
  font-size: 0.85rem;
  border: 1px solid rgba(56, 189, 248, 0.25);
}

.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin-bottom: 20px;
}

.volume-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem 1rem;
  margin: -0.35rem 0 1.2rem;
  color: var(--muted);
}

.volume-controls label {
  display: inline-grid;
  grid-template-columns: auto minmax(7rem, 12rem) 3.4rem;
  align-items: center;
  gap: 0.45rem;
  white-space: nowrap;
}

.volume-controls input[type="range"] { width: 100%; }
.volume-controls output { color: var(--text); text-align: right; }
.volume-controls button { padding: 8px 13px; }

button, .file-button {
  border: 0;
  border-radius: 999px;
  padding: 10px 16px;
  font-weight: 600;
  cursor: pointer;
  transition: transform .15s ease, opacity .15s ease;
  background: var(--accent);
  color: #082f49;
}

button:hover, .file-button:hover { transform: translateY(-1px); }
button:disabled { opacity: .45; cursor: not-allowed; transform: none; }

.file-button input { display: none; }

.status {
  background: var(--panel-2);
  border-radius: 14px;
  padding: 14px 16px;
  margin-bottom: 18px;
  color: var(--muted);
  min-height: 56px;
  border: 1px solid rgba(148,163,184,0.15);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 16px;
  margin-bottom: 16px;
}

.card {
  background: var(--panel);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: 14px;
  padding: 14px;
}

.card h2 { font-size: 1rem; margin: 0 0 10px; }
.card p { margin: 4px 0; color: var(--muted); font-size: 0.95rem; }

.track-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  gap: 8px;
}

.start-delay-option {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  white-space: nowrap;
}

.tempo-option {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text);
  white-space: nowrap;
}

.tempo-option select {
  border: 1px solid rgba(148, 163, 184, 0.35);
  border-radius: 7px;
  padding: 0.35rem 0.55rem;
  background: var(--panel-2);
  color: var(--text);
  font: inherit;
}

.playback-monitor,
#channelMonitor {
  text-align: left;
}

.playback-monitor p {
  display: grid;
  grid-template-columns: 7rem 1fr;
  margin: 0.25rem 0;
}

.playback-monitor p > span {
  text-align: right;
  padding-right: 0.5rem;
}

#seekBar {
  width: 100%;
  height: 1.4rem;
}

#channelMonitor .track-item {
  display: grid;
  grid-template-columns: 3.25rem 4.5rem 6rem;
  align-items: center;
  column-gap: 0.6rem;
  padding-right: 1rem;
}

.channel-note {
  display: inline-block;
  box-sizing: border-box;
  width: 4.5rem;
  height: 1.7rem;
  line-height: 1.35rem;
  margin-left: 0;
  padding: 0.1rem 0.4rem;
  border: 1px solid rgba(148, 163, 184, 0.28);
  border-radius: 5px;
  text-align: left;
}

.channel-mute {
  position: static;
  transform: none;
  white-space: nowrap;
}

.raw-card {
  margin-top: 1rem;
  text-align: left;
}

.raw-card pre {
  max-height: 22rem;
  overflow: auto;
  padding: 0.75rem;
  background: #0b1220;
  border-radius: 8px;
  font-size: 0.78rem;
}

.track-item {
  background: var(--panel);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: 12px;
  padding: 10px 12px;
  color: var(--muted);
}

.track-item strong { color: var(--text); }

.score-board {
  display: grid;
  gap: 12px;
  margin-top: 12px;
}

.score-card {
  background: var(--panel-2);
  border: 1px solid rgba(148,163,184,0.15);
  border-radius: 12px;
  padding: 12px;
}

.score-card summary {
  cursor: pointer;
  font-size: 0.98rem;
  color: var(--text);
}

.score-card[open] summary { margin-bottom: 8px; }

.score-card pre {
  margin: 0;
  white-space: pre-wrap;
  word-break: break-word;
  color: var(--muted);
  font-family: Consolas, monospace;
  font-size: 0.9rem;
  line-height: 1.6;
}