:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #333333;
    --btn-bg: #007bff;
    --btn-hover: #0056b3;
    --shadow: rgba(0, 0, 0, 0.1);
}

body.dark-mode {
    --bg-color: #1a1a1a;
    --card-bg: #2d2d2d;
    --text-color: #f0f2f5;
    --btn-bg: #375a7f;
    --btn-hover: #4b7eb3;
    --shadow: rgba(0, 0, 0, 0.4);
}

body {
    font-family: 'Poppins', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

.container {
    position: relative;
    text-align: center;
    padding: 40px;
}

.card {
    background-color: var(--card-bg);
    padding: 40px;
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow);
    transition: background-color 0.3s, box-shadow 0.3s;
}

h1 {
    color: var(--text-color);
    margin-bottom: 30px;
}

.lotto-display {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 40px;
    min-height: 60px;
}

.lotto-ball {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 24px;
    font-weight: 600;
    color: #fff;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
    transform: scale(0);
    animation: pop-in 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
}

.generate-btn {
    padding: 15px 30px;
    border: none;
    border-radius: 10px;
    background-color: var(--btn-bg);
    color: #fff;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.3);
}

.generate-btn:hover {
    background-color: var(--btn-hover);
    transform: translateY(-2px);
}

.generate-btn:active {
    transform: translateY(0);
}

.theme-toggle {
    position: absolute;
    top: -40px;
    right: 0;
    background-color: var(--card-bg);
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px var(--shadow);
}

.theme-toggle:hover {
    background-color: var(--text-color);
    color: var(--card-bg);
    transform: translateY(-2px);
}

@keyframes pop-in {
    to {
        transform: scale(1);
    }
}