:root {
    --bg-color: #ffffff;
    --text-color: #000000;
    --button-bg: #007bff;
    --button-text: #ffffff;
    --progress-bg: #e0e0e0;
    --progress-fill: #4caf50;
}

body.dark {
    --bg-color: #121212;
    --text-color: #ffffff;
    --button-bg: #0056b3;
    --button-text: #ffffff;
    --progress-bg: #333333;
    --progress-fill: #388e3c;
}

body {
    font-family: Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container {
    text-align: center;
    padding: 20px;
    border: 1px solid #ccc;
    border-radius: 10px;
    max-width: 400px;
    width: 100%;
}

h1 {
    margin-bottom: 20px;
}

#theme-toggle, .preset, button {
    background-color: var(--button-bg);
    color: var(--button-text);
    border: none;
    padding: 10px 20px;
    margin: 5px;
    cursor: pointer;
    border-radius: 5px;
}

#theme-toggle:hover, .preset:hover, button:hover {
    opacity: 0.9;
}

#time-input {
    padding: 10px;
    margin: 10px 0;
    width: 100px;
}

#display {
    font-size: 48px;
    margin: 20px 0;
}

.progress-bar {
    background-color: var(--progress-bg);
    border-radius: 5px;
    height: 10px;
    margin-bottom: 20px;
}

#progress {
    background-color: var(--progress-fill);
    height: 100%;
    width: 0%;
    border-radius: 5px;
}

.presets {
    margin-bottom: 10px;
}