body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: #f4f4f4;
  }
  
  .container {
    width: 100%;
    max-width: 1200px;
    padding: 20px;
    box-sizing: border-box;
  }
  
  select {
    margin: 20px;
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    border: 2px solid #007bff;
    background-color: white;
    color: #007bff;
    border-radius: 5px;
  }
  
  select:hover {
    border-color: #0056b3;
  }
  
  .calendar {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
  }
  
  .month {
    background-color: white;
    border-radius: 5px;
    overflow: hidden;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    width: 100%;
    max-width: 300px;
    margin: 10px;
  }
  
  .month-header {
    background-color: #007bff;
    color: white;
    padding: 10px;
    text-align: center;
    font-weight: bold;
  }
  
  .calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 1px;
  }
  
  .day {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-sizing: border-box;
    cursor: pointer;
    position: relative;
  }
  
  .day.mixed-day {
    background-color: transparent;
  }
  
  .day.mixed-day .work-day-half {
    position: absolute;
    top: 0;
    left: 0;
    width: 50%;
    height: 100%;
    background-color: blue;
    color: white;
    text-align: center;
    line-height: 40px;
  }
  
  .day.mixed-day .highlight-day-half {
    position: absolute;
    top: 0;
    left: 50%;
    width: 50%;
    height: 100%;
    background-color: yellow;
    color: black;
    text-align: center;
    line-height: 40px;
  }
  
  .day.mixed-day .fixed-day-half {
    position: absolute;
    top: 0;
    left: 50%;
    width: 50%;
    height: 100%;
    background-color: red;
    color: white;
    text-align: center;
    line-height: 40px;
  }
  
  .work-day {
    background-color: blue;
    color: white;
  }
  
  .free-day {
    background-color: white;
    color: black;
  }
  
  .fixed-day {
    background-color: red;
    color: white;
  }

  
  
  .highlight-day {
    background-color: yellow;
    color: black;
  }
  
  .current-day {
    background-color: green;
    color: white;
  }
  
  .day-name {
    background-color: #ddd;
    font-weight: bold;
  }
  
  .legend {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    gap: 20px;
  }
  
  .legend div {
    display: flex;
    align-items: center;
    gap: 10px;
  }
  
  .legend div div {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    display: inline-block;
  }
  
  .legend .work-day-color {
    background-color: blue;
  }
  
  .legend .highlight-day-color {
    background-color: yellow;
  }
  
  .legend .fixed-day-color {
    background-color: red;
  }
  
  #fireworks {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    pointer-events: none;
    z-index: 1000;
    overflow: hidden;
    display: none;
  }
  
  .firework {
    position: absolute;
    border-radius: 50%;
    opacity: 0;
    pointer-events: none;
    animation: explode 1s forwards;
  }
  
  @keyframes explode {
    0% {
      transform: scale(0);
      opacity: 1;
    }
    100% {
      transform: scale(1);
      opacity: 0;
    }
  }
  
  #message {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%);
    background-color: #007bff;
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    font-size: 18px;
    z-index: 1001;
    display: block;
  }