body {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    margin: 0;
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
}

#resetStopwatchBtn:active, #resetTimerBtn:active {
    background-color: #c82333;
}

.developer-credit {
    font-size: 0.8em;
    color: #666;
    margin-top: 20px;
}

#toggleHeaderBtn {
    position: absolute;
    top: 10px;
    left: 10px;
    font-size: 1em;
    padding: 10px 20px;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    background-color: #007bff;
    color: white;
    z-index: 100;
    transition: opacity 0.3s ease;
    opacity: 0.1;
}

#toggleHeaderBtn:hover {
    opacity: 1;
}

header {
    display: flex;
    justify-content: center;
    margin-top: 5px;
    margin-bottom: 5px;
    transition: all 0.3s ease;
}

header button {
    font-size: 1.5em;
    padding: 10px 20px;
    margin: 0 10px;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    background-color: #007bff;
    color: white;
}

header button:active {
    background-color: #0056b3;
}

#content {
    display: flex;
    justify-content: center;
    align-items: center;
    flex-grow: 0.8;
    width: 100%;
    text-align: center;
}

.tab {
    display: none;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.timer {
    background-color: #ffffff;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    width: 80%;
    height: 80%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

#stopwatchDisplay, #timerDisplay, #clockDisplay {
    font-size: 4em;
    margin-bottom: 20px;
    font-weight: bold;
}

#timerInputContainer {
    margin-bottom: 20px;
}

#timerInputContainer input {
    font-size: 2em;
    padding: 10px;
    width: 100px;
    margin: 10px;
    text-align: center;
}

.buttons button {
    font-size: 1.5em;
    padding: 10px 20px;
    margin: 10px;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    background-color: #007bff;
    color: white;
}

.buttons button:active {
    background-color: #0056b3;
}

#resetStopwatchBtn, #resetTimerBtn {
    background-color: #dc3545;
}

#resetStopwatchBtn:active, #resetTimerBtn:active {
    background-color: #c82333;
}