* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  background: linear-gradient(45deg, #1a1a2e, #16213e, #0f3460);
  background-size: 400% 400%;
  animation: gradientShift 8s ease infinite;
  font-family: "Arial", sans-serif;
  overflow: hidden;
}

@keyframes gradientShift {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.countdown-container {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.countdown-circle {
  position: relative;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  background: linear-gradient(45deg, #ff6b6b, #4ecdc4, #45b7d1, #96ceb4);
  background-size: 400% 400%;
  animation: gradientRotate 3s ease infinite;
  padding: 8px;
  box-shadow: 0 0 50px rgba(255, 107, 107, 0.3),
    0 0 100px rgba(78, 205, 196, 0.2), inset 0 0 50px rgba(255, 255, 255, 0.1);
}

@keyframes gradientRotate {
  0% {
    background-position: 0% 50%;
  }
  50% {
    background-position: 100% 50%;
  }
  100% {
    background-position: 0% 50%;
  }
}

.countdown-inner {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background: radial-gradient(circle, #1a1a2e, #0f1419);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.countdown-number {
  font-size: 14rem;
  font-weight: bold;
  color: #fff;
  text-shadow: 0 0 20px rgba(255, 255, 255, 0.8),
    0 0 40px rgba(78, 205, 196, 0.6), 0 0 60px rgba(255, 107, 107, 0.4);
  animation: pulse 1s ease-in-out infinite alternate;
  z-index: 10;
  line-height: 1;
}

@keyframes pulse {
  0% {
    transform: scale(1);
    text-shadow: 0 0 30px rgba(255, 255, 255, 0.8),
      0 0 50px rgba(78, 205, 196, 0.6), 0 0 80px rgba(255, 107, 107, 0.4);
  }
  100% {
    transform: scale(1.05);
    text-shadow: 0 0 40px rgba(255, 255, 255, 1),
      0 0 60px rgba(78, 205, 196, 0.8), 0 0 90px rgba(255, 107, 107, 0.6);
  }
}

.progress-ring {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.progress-ring-circle {
  fill: none;
  stroke: url(#gradient);
  stroke-width: 6;
  stroke-linecap: round;
  stroke-dasharray: 942; /* 2 * π * 150 */
  stroke-dashoffset: 942;
  animation: progressAnimation 15s linear forwards;
  filter: drop-shadow(0 0 10px rgba(78, 205, 196, 0.8));
}

@keyframes progressAnimation {
  to {
    stroke-dashoffset: 0;
  }
}

.particles {
  position: absolute;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

.particle {
  position: absolute;
  width: 4px;
  height: 4px;
  background: radial-gradient(circle, #4ecdc4, transparent);
  border-radius: 50%;
  animation: float 3s infinite ease-in-out;
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0) rotate(0deg);
    opacity: 0;
  }
  50% {
    transform: translateY(-100px) rotate(180deg);
    opacity: 1;
  }
}

.countdown-text {
  margin-top: 30px;
  font-size: 1.5rem;
  color: #4ecdc4;
  text-transform: uppercase;
  letter-spacing: 3px;
  text-shadow: 0 0 20px rgba(78, 205, 196, 0.6);
  animation: textGlow 2s ease-in-out infinite alternate;
}

@keyframes textGlow {
  0% {
    text-shadow: 0 0 20px rgba(78, 205, 196, 0.6);
  }
  100% {
    text-shadow: 0 0 30px rgba(78, 205, 196, 1);
  }
}

.finished {
  animation: celebration 1s ease-in-out;
}

@keyframes celebration {
  0%,
  100% {
    transform: scale(1);
  }
  25% {
    transform: scale(1.2) rotate(5deg);
  }
  50% {
    transform: scale(1.1) rotate(-5deg);
  }
  75% {
    transform: scale(1.2) rotate(5deg);
  }
}

.restart-btn {
  margin-top: 30px;
  padding: 12px 30px;
  background: linear-gradient(45deg, #ff6b6b, #4ecdc4);
  border: none;
  border-radius: 25px;
  color: white;
  font-size: 1rem;
  font-weight: bold;
  cursor: pointer;
  text-transform: uppercase;
  letter-spacing: 1px;
  transition: all 0.3s ease;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
  opacity: 0;
  transform: translateY(20px);
}

.restart-btn.show {
  opacity: 1;
  transform: translateY(0);
}

.restart-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
}
/* 更新后的进度条样式 */
.progress-container {
  width: 80%;
  margin: 15px auto;
  position: relative;
}

.progress-label {
  color: #4ecdc4;
  font-size: 0.9rem;
  margin-bottom: 8px;
  display: flex;
  justify-content: space-between;
  text-shadow: 0 0 15px rgba(78, 205, 196, 0.6);
}

.progress-bar {
  height: 12px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 6px;
  overflow: hidden;
  position: relative;
}

.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, #ff6b6b 0%, #4ecdc4 50%, #45b7d1 100%);
  width: 0%;
  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
}

.progress-fill::after {
  content: "";
  position: absolute;
  top: 0;
  left: -200%;
  width: 200%;
  height: 100%;
  background: linear-gradient(
    to right,
    rgba(255, 255, 255, 0) 0%,
    rgba(255, 255, 255, 0.3) 50%,
    rgba(255, 255, 255, 0) 100%
  );
  animation: shine 1.5s infinite;
}

#time-difference {
  position: absolute;
  top: 20px;
  right: 20px;
  color: white;
  font-size: 2rem;
}

#overall_progress {
  position: absolute;
  top: 20px;
  left: 20px;
  color: white;
  font-size: 2rem;
}

.tts-switch-container {
  margin-top: 20px;
  display: flex;
  align-items: center;
  gap: 10px;
  color: white;
}

.tts-checkbox {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  width: 60px;
  height: 30px;
  background-color: #ccc;
  border-radius: 15px;
  position: relative;
  cursor: pointer;
  transition: background-color 0.3s;
}

.tts-checkbox::before {
  content: '';
  position: absolute;
  width: 26px;
  height: 26px;
  background-color: white;
  border-radius: 50%;
  top: 2px;
  left: 2px;
  transition: transform 0.3s;
}

.tts-checkbox:checked {
  background-color: #4ecdc4;
}

.tts-checkbox:checked::before {
  transform: translateX(30px);
}