body {
    font-family: sans-serif;
    background-color: #f0f0f0;
    color: #333;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container {
    background-color: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    width: 350px;
}

h1, h2 {
    text-align: center;
    color: #555;
}

.section {
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
}

.calibration-controls {
    display: flex;
    align-items: center;
    gap: 8px; /* Space between elements */
    margin-bottom: 10px;
}
.input-group {
    display: flex;
    align-items: center;
    margin-bottom: 10px;
}

.input-group label {
    display: flex; /* Added for vertical alignment */
    align-items: center; /* Added for vertical alignment */
    flex: 1;
}

.calibration-controls input, .input-group input[type="number"] {
    width: 60px;
    padding: 5px;
    border: 1px solid #ccc;
    border-radius: 4px;
}

.input-group .unit {
    margin-left: 8px;
    font-size: 0.9em;
    color: #666;
}

button {
    width: 100%;
    padding: 10px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
}

button:hover {
    background-color: #0056b3;
}

#startPause.paused {
    background-color: #28a745;
}

#startPause.paused:hover {
    background-color: #218838;
}


#currentTime {
    text-align: center;
    font-size: 2em;
    font-weight: bold;
    color: #808080; /* Grey for initial/stopped state */
}

#currentTime.running {
    color: #28a745; /* Green */
}

#currentTime.paused {
    color: #808080; /* Grey */
}

.seconds-label {
    margin-left: 15px; /* 在分钟和秒输入框之间创建间距 */
}

.time-adjust-btn {
    padding: 5px 8px;
    font-size: 0.8em;
    width: auto; /* Override full width */
    flex-shrink: 0; /* Prevent button from shrinking */
}

#time-display-wrapper {
    display: flex;
    justify-content: space-between; /* Distribute items */
    align-items: center;
    margin-bottom: 10px;
}

#volume-control label {
    margin-right: 15px; /* 音量选项之间的间距 */
}