body {
    font-family: sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f4f4f9;
}

.timer-container {
    background-color: #fff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

h1 {
    color: #333;
    margin-bottom: 20px;
}

.display {
    font-size: 5em;
    font-weight: bold;
    color: #4a90e2;
    margin-bottom: 20px;
    padding: 10px 0;
}

.input-area input {
    width: 80px;
    padding: 10px;
    margin: 0 5px 20px;
    border: 1px solid #ccc;
    border-radius: 6px;
    text-align: center;
    font-size: 1em;
}

.controls button {
    padding: 10px 20px;
    margin: 0 5px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-size: 1em;
    font-weight: bold;
    transition: background-color 0.3s;
}

#startBtn {
    background-color: #5cb85c;
    color: white;
}

#startBtn:hover:not(:disabled) {
    background-color: #4cae4c;
}

#stopBtn {
    background-color: #f0ad4e;
    color: white;
}

#stopBtn:hover:not(:disabled) {
    background-color: #ec971f;
}

#resetBtn {
    background-color: #d9534f;
    color: white;
}

#resetBtn:hover:not(:disabled) {
    background-color: #c9302c;
}

.controls button:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}