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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 20px;
  color: #333;
}

.container {
  max-width: 600px;
  margin: 0 auto;
}

header {
  text-align: center;
  color: white;
  margin-bottom: 30px;
}

header h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

.subtitle {
  font-size: 1.1rem;
  opacity: 0.95;
}

.card {
  background: white;
  border-radius: 16px;
  padding: 30px;
  margin-bottom: 20px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
}

.card h2 {
  color: #667eea;
  margin-bottom: 20px;
  font-size: 1.5rem;
}

.meters-visual {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
  margin-bottom: 20px;
}

.meter-card {
  background: #f8f9ff;
  border-radius: 12px;
  padding: 20px;
  text-align: center;
  border: 2px solid transparent;
  transition: border-color 0.3s;
}

.meter-card.cold {
  border-color: #bbdefb;
}

.meter-card.cold:hover {
  border-color: #2196f3;
}

.meter-card.hot {
  border-color: #ffcdd2;
}

.meter-card.hot:hover {
  border-color: #f44336;
}

.meter-image {
  margin-bottom: 15px;
}

.meter-svg {
  width: 120px;
  height: 120px;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.input-group {
  margin-bottom: 15px;
}

.input-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: #555;
  font-size: 0.9rem;
}

.input-group input {
  width: 100%;
  padding: 12px 16px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.3s;
}

.input-group input:focus {
  outline: none;
  border-color: #667eea;
}

.btn-primary {
  width: 100%;
  padding: 14px;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  margin-bottom: 10px;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
  width: 100%;
  padding: 12px;
  background: #f0f0f0;
  color: #666;
  border: none;
  border-radius: 8px;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background 0.2s;
}

.btn-secondary:hover {
  background: #e0e0e0;
}

.result-grid {
  background: #f8f9ff;
  padding: 20px;
  border-radius: 12px;
  margin-bottom: 20px;
}

.result-item {
  display: flex;
  justify-content: space-between;
  padding: 12px 0;
  border-bottom: 1px solid #e0e0e0;
}

.result-item:last-child {
  border-bottom: none;
}

.result-item.total {
  font-weight: 700;
  font-size: 1.1rem;
  color: #667eea;
  margin-top: 10px;
  padding-top: 15px;
  border-top: 2px solid #667eea;
}

.label {
  color: #666;
}

.value {
  font-weight: 600;
  color: #333;
}

.cost-section {
  margin-top: 20px;
}

.cost-total {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 20px;
  border-radius: 12px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 20px;
}

.cost-label {
  font-size: 1.2rem;
  font-weight: 600;
}

.cost-value {
  font-size: 1.8rem;
  font-weight: 700;
}

#historyList {
  max-height: 300px;
  overflow-y: auto;
}

.history-item {
  background: #f8f9ff;
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 10px;
  border-left: 4px solid #667eea;
}

.history-item .date {
  font-size: 0.85rem;
  color: #888;
  margin-bottom: 8px;
}

.history-item .details {
  display: flex;
  justify-content: space-between;
  font-size: 0.95rem;
}

.empty-msg {
  text-align: center;
  color: #999;
  padding: 30px;
}

.reminder-desc {
  color: #666;
  margin-bottom: 20px;
  line-height: 1.5;
}

.active-reminder {
  background: linear-gradient(135deg, #fff3e0 0%, #ffe0b2 100%);
  border: 2px solid #ff9800;
  border-radius: 12px;
  padding: 20px;
  margin-top: 20px;
  text-align: center;
}

.reminder-status {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-bottom: 15px;
}

.reminder-icon {
  font-size: 2rem;
  animation: shake 1s ease-in-out infinite;
}

@keyframes shake {
  0%, 100% { transform: rotate(0deg); }
  25% { transform: rotate(-10deg); }
  75% { transform: rotate(10deg); }
}

.reminder-text {
  font-weight: 600;
  color: #e65100;
}

.reminder-datetime {
  font-size: 1.2rem;
  font-weight: 700;
  color: #bf360c;
}

footer {
  text-align: center;
  color: white;
  margin-top: 30px;
  opacity: 0.9;
}

@media (max-width: 480px) {
  body {
    padding: 15px;
  }

  header h1 {
    font-size: 2rem;
  }

  .card {
    padding: 20px;
  }

  .meters-visual {
    grid-template-columns: 1fr;
  }

  .cost-value {
    font-size: 1.5rem;
  }
}