:root {
    --bg-color: #f0f2f5;
    --text-color: #333;
    --card-bg: #ffffff;
    --card-shadow: rgba(0, 0, 0, 0.1);
    --btn-bg: #4CAF50;
    --btn-hover: #45a049;
    --theme-btn-bg: #333;
    --theme-btn-text: #fff;
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #f0f0f0;
    --card-bg: #2d2d2d;
    --card-shadow: rgba(0, 0, 0, 0.5);
    --theme-btn-bg: #f0f0f0;
    --theme-btn-text: #333;
}

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

h1 { color: var(--text-color); }

.controls {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
}

button {
    padding: 12px 24px;
    font-size: 18px;
    cursor: pointer;
    background-color: var(--btn-bg);
    color: white;
    border: none;
    border-radius: 8px;
    transition: background 0.3s;
}

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

#theme-toggle {
    background-color: var(--theme-btn-bg);
    color: var(--theme-btn-text);
}

#result {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.lotto-row {
    display: flex;
    gap: 10px;
    background: var(--card-bg);
    padding: 15px;
    border-radius: 50px;
    box-shadow: 0 4px 6px var(--card-shadow);
    transition: background 0.3s, box-shadow 0.3s;
}

.ball {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: bold;
    font-size: 16px;
    text-shadow: 1px 1px 1px rgba(0,0,0,0.2);
}