body {
  margin: 0;
  font-family: Arial, sans-serif;
  background-color: #f0f4f8;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
}

.container {
  background: #ffffff;
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 0 12px rgba(0, 0, 0, 0.1);
  width: 100%;
  max-width: 480px;
}

tabs, .tabs {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1rem;
}

.tabs button {
  flex: 1;
  padding: 0.75rem;
  border: none;
  background: #e0e0e0;
  cursor: pointer;
  border-radius: 6px;
  font-weight: bold;
}

.tabs button.active {
  background: #0288d1;
  color: #fff;
}

.hidden {
  display: none;
}

.config {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.config label {
  flex: 1;
  display: flex;
  flex-direction: column;
  font-size: 0.9rem;
}

.config input {
  padding: 0.25rem;
  margin-top: 0.25rem;
}

.timer-display {
  text-align: center;
  margin-bottom: 1rem;
}

#timer {
  font-size: 3rem;
  margin: 0.5rem 0;
}

.buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
}

.buttons button {
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: none;
  border-radius: 6px;
  background: #0288d1;
  color: #fff;
  cursor: pointer;
}

.tip {
  margin-top: 0.5rem;
  padding: 0.75rem;
  background: #e0f7fa;
  border-left: 4px solid #00796b;
  border-radius: 4px;
  font-size: 0.9rem;
}

.calendar-form {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 1rem;
}

.calendar-form label {
  flex: 1;
  font-size: 0.9rem;
  display: flex;
  flex-direction: column;
}

.calendar-form input {
  margin-top: 0.25rem;
  padding: 0.25rem;
}

.calendar-list {
  list-style: none;
  padding: 0;
  max-height: 200px;
  overflow-y: auto;
}

.calendar-list li {
  padding: 0.5rem 0;
  border-bottom: 1px solid #e0e0e0;
}