:root {
  --bg: #f9fafc;
  --card: #ffffff;
  --text: #1f2933;
  --muted: #64748b;
  --accent: #ffac33;
  --accent-weak: #ffd66b;
  --track: #e2e8f0;
}

* {
  box-sizing: border-box;
  touch-action: manipulation;
}

html, body {
  height: 100%;
  width: 100%;
  margin: 0;
  padding: 0;
}

body {
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Noto Sans JP, Helvetica, Arial, "Apple Color Emoji", "Segoe UI Emoji";
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  gap: clamp(12px, 3vh, 24px);
}

@supports (-webkit-touch-callout: none) {
  body { min-height: -webkit-fill-available; }
}

html {
  background: var(--bg);
  background-attachment: fixed;
}

.app-header, .app-footer {
  text-align: center;
  padding: 8px 16px;
}

.app-header {
  padding-top: 16px;
  padding-top: calc(16px + env(safe-area-inset-top, 0px));
}

.app-footer {
  padding-bottom: 16px;
  padding-bottom: calc(16px + env(safe-area-inset-bottom, 0px));
}

.app-header h1 {
  font-size: clamp(32px, 8vw, 44px);
  margin: 16px 0 0;
  font-weight: 700;
}


.control-actions,
.footer-actions {
  margin-top: 0px;
  display: flex;
  justify-content: center;
  gap: 12px;
}

.copy-btn {
  appearance: none;
  border: 1px solid rgba(255, 172, 51, 0.4);
  background: rgba(255, 255, 255, 0.8);
  color: var(--text);
  font-size: 12px;
  border-radius: 999px;
  padding: 6px 12px;
  box-shadow: 0 6px 20px rgba(255, 172, 51, 0.12);
}

.app-main {
  flex: 1 1 auto; /* flex-grow を 1 に変更 */
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: clamp(10px, 3vh, 12px);
  padding-inline: clamp(16px, 5vw, 40px);
  padding-block: clamp(12px, 4vh, 24px);
}

.app-main {
  padding-top: calc(clamp(12px, 4vh, 24px) + env(safe-area-inset-top, 0px));
  padding-bottom: calc(clamp(12px, 4vh, 24px) + env(safe-area-inset-bottom, 0px));
}

@media (max-height: 760px) {
  body {
    justify-content: flex-start;
    gap: 12px;
  }

  .app-main {
    flex: 1 0 auto;
    justify-content: flex-start;
  }
}

.app-controls {
  width: min(100%, 520px);
  display: grid;
  gap: clamp(10px, 2.5vw, 14px);
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
}

.slider-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 12px 16px;
  border-radius: 16px;
  border: 1px solid rgba(226, 232, 240, 0.9);
  background: rgba(255, 255, 255, 0.85);
  min-width: 0;
  box-shadow: 0 10px 35px rgba(148, 163, 184, 0.18);
}

.slider-label {
  font-size: 13px;
  color: var(--text);
  letter-spacing: 0.03em;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.slider {
  appearance: none;
  width: 100%;
  height: 20px;
  padding-block: 6px;
  border-radius: 999px;
  background: transparent;
  outline: none;
  transition: background 0.2s ease;
}

.slider::-webkit-slider-runnable-track {
  height: 6px;
  border-radius: 999px;
  background: var(--track);
}

.slider:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.slider::-webkit-slider-thumb {
  appearance: none;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), #ff8857);
  box-shadow: 0 8px 16px rgba(255, 138, 76, 0.35);
  border: none;
  cursor: pointer;
  transition: transform 0.12s ease;
  margin-top: -8px;
}

.slider::-webkit-slider-thumb:active {
  transform: scale(1.05);
}

.slider::-moz-range-thumb {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--accent), #ff8857);
  box-shadow: 0 8px 16px rgba(255, 138, 76, 0.35);
  border: none;
  cursor: pointer;
  transition: transform 0.12s ease;
}

.slider::-moz-range-thumb:active {
  transform: scale(1.05);
}

.slider::-moz-range-track {
  background: var(--track);
  height: 6px;
  border-radius: 999px;
}

.timer-card {
  position: relative;
  width: clamp(260px, 72vw, 420px);
  aspect-ratio: 1 / 1;
  border-radius: 50%;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.95), rgba(255, 255, 255, 0.7));
  border: 1px solid rgba(255, 255, 255, 0.9);
  box-shadow: 0 20px 45px rgba(255, 172, 51, 0.25);
  display: grid;
  place-items: center;
  overflow: hidden;
}

.progress-ring {
  position: absolute;
  inset: 0;
  background: conic-gradient(var(--accent) 0deg, var(--track) 0deg);
}

.timer-content {
  position: relative;
  z-index: 1;
  width: 76%;
  height: 76%;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.8);
  display: grid;
  grid-template-rows: auto 1fr auto;
  align-items: center;
  justify-items: center;
  padding: clamp(16px, 5vw, 22px);
  gap: 8px;
}

.phase {
  font-size: clamp(20px, 6vw, 24px);
  color: var(--accent);
  letter-spacing: 0.08em;
}

.countdown {
  font-size: clamp(48px, 16vw, 72px);
  font-weight: 800;
  line-height: 1;
  color: var(--text);
}

.primary-btn {
  margin-top: 4px;
  appearance: none;
  border: none;
  border-radius: 999px;
  padding: clamp(12px, 3.8vw, 16px) clamp(20px, 6vw, 26px);
  background: linear-gradient(135deg, var(--accent), #ff8857);
  color: #1f1300;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.04em;
  box-shadow: 0 12px 28px rgba(255, 138, 76, 0.35);
}

.primary-btn:active { transform: translateY(1px); }

.primary-btn:disabled {
  opacity: 0.7;
  filter: saturate(0.7);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

@media (max-width: 420px) {
  .footer-actions { margin-top: 0px; }
  .app-controls {
    gap: 10px;
    grid-template-columns: 1fr;
  }
  .slider-group {
    padding: 12px 14px;
  }
}