:root {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333333;
    --button-bg: #4CAF50;
    --button-hover: #45a049;
    --number-bg: #f8f8f8;
    --number-border: #dddddd;
    --transition-speed: 0.3s;
}

body.dark-mode {
    --bg-color: #18191a;
    --container-bg: #242526;
    --text-color: #e4e6eb;
    --number-bg: #3a3b3c;
    --number-border: #4e4f50;
}

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

.container {
    text-align: center;
    background-color: var(--container-bg);
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
    transition: background-color var(--transition-speed);
}

h1 {
    margin-bottom: 20px;
}

#theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--text-color);
    border: 1px solid var(--number-border);
    padding: 10px 15px;
    border-radius: 5px;
    cursor: pointer;
    color: var(--container-bg);
    font-size: 14px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: background-color var(--transition-speed), color var(--transition-speed);
    z-index: 1000;
}

#generator-btn {
    background-color: var(--button-bg);
    color: white;
    padding: 15px 32px;
    text-align: center;
    text-decoration: none;
    display: inline-block;
    font-size: 16px;
    margin: 4px 2px;
    cursor: pointer;
    border: none;
    border-radius: 5px;
    transition: background-color 0.3s;
}

#generator-btn:hover {
    background-color: var(--button-hover);
}

.lotto-numbers-container {
    margin-top: 30px;
    display: flex;
    justify-content: center;
    gap: 10px;
    min-height: 54px; /* Prevent layout jump */
}

.lotto-number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--number-bg);
    border: 2px solid var(--number-border);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 20px;
    font-weight: bold;
    color: var(--text-color);
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.lotto-number.show {
    opacity: 1;
    transform: translateY(0);
}