:root {
  --ring-bg: #e2e8f0;
  --ring-color: #3b82f6;
}

.tool-main { max-width: 520px; }

h2.section-title { font-size: 1rem; color: var(--text-sub); margin-bottom: 1rem; font-weight: 600; }

.btn-large { padding: 0.75rem 2.5rem; font-size: 1.1rem; }

.timer-card { text-align: center; }
.phase-label {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-sub);
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
}
.svg-wrap { display: flex; justify-content: center; margin-bottom: 1rem; }
.svg-wrap svg { overflow: visible; }

.session-counter {
  font-size: 1.5rem;
  margin-bottom: 1.25rem;
  min-height: 2rem;
  letter-spacing: 0.1em;
}

.timer-btns { display: flex; gap: 0.75rem; justify-content: center; }

.settings-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 1.5rem;
}
@media (max-width: 420px) { .settings-grid { grid-template-columns: 1fr; } }

/* フェーズ別リングカラー */
body.phase-work  { --ring-color: #3b82f6; }
body.phase-short { --ring-color: #22c55e; }
body.phase-long  { --ring-color: #f97316; }

html[data-theme="dark"] { --ring-bg: #334155; }