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

.container {
    background-color: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    text-align: center;
}

h1 {
    margin-bottom: 1rem;
}

.timer-display {
    font-size: 4rem;
    font-weight: bold;
    margin-bottom: 1rem;
}

.timer-controls {
    margin-bottom: 1rem;
}

.timer-mode {
    margin-bottom: 0.5rem;
}

.custom-time input {
    width: 60px;
}

.buttons button {
    font-size: 1rem;
    padding: 0.5rem 1rem;
    margin: 0 0.5rem;
    border: none;
    border-radius: 5px;
    cursor: pointer;
}

#start-btn {
    background-color: #4CAF50;
    color: white;
}

#pause-btn {
    background-color: #ff9800;
    color: white;
}

#finish-btn {
    background-color: #2196F3;
    color: white;
}

#reset-btn {
    background-color: #f44336;
    color: white;
}

#pip-btn {
    background-color: #607d8b;
    color: white;
}

.category-section {
    margin-top: 2rem;
}

.category-input {
    display: flex;
    margin-bottom: 1rem;
}

.category-input input {
    flex-grow: 1;
    padding: 0.5rem;
    border: 1px solid #ccc;
    border-radius: 5px;
}

.category-input button {
    margin-left: 0.5rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 5px;
    background-color: #2196F3;
    color: white;
    cursor: pointer;
}

.category-list ul, #records-list {
    list-style: none;
    padding: 0;
}

.category-list li, #records-list li {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0.5rem;
    border-bottom: 1px solid #eee;
}

.delete-btn {
    background-color: #f44336;
    color: white;
    border: none;
    border-radius: 3px;
    padding: 0.2rem 0.5rem;
    cursor: pointer;
}

.category-select {
    margin-top: 1rem;
}

#records-section {
    margin-top: 2rem;
}

.records-filter {
    margin-bottom: 1rem;
}

.total-time p {
    margin: 0.5rem 0;
    font-weight: bold;
}