:root {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333333;
    --ball-default: #dddddd;
    --btn-bg: #4a90e2;
    --btn-hover: #357abd;
    --shadow: rgba(0,0,0,0.1);
}

[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --container-bg: #2d2d2d;
    --text-color: #f0f2f5;
    --ball-default: #444444;
    --btn-bg: #357abd;
    --btn-hover: #4a90e2;
    --shadow: rgba(0,0,0,0.4);
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, 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 {
    text-align: center;
    background: var(--container-bg);
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 10px 25px var(--shadow);
    transition: background-color 0.3s, box-shadow 0.3s;
    position: relative;
}

.theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: 1px solid var(--text-color);
    color: var(--text-color);
    padding: 5px 10px;
    border-radius: 15px;
    cursor: pointer;
    font-size: 0.8rem;
}

h1 {
    margin-bottom: 2rem;
}

.numbers-container {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-bottom: 2rem;
}

.ball {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--ball-default);
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1.2rem;
    color: white;
    transition: transform 0.3s ease;
    box-shadow: 0 4px 6px var(--shadow);
}

.ball:hover {
    transform: scale(1.1);
}

/* Lotto ball colors - keeping these consistent across themes for recognition */
.n1-10 { background-color: #fbc400; }
.n11-20 { background-color: #69c8f2; }
.n21-30 { background-color: #ff7272; }
.n31-40 { background-color: #aaaaaa; }
.n41-45 { background-color: #b0d840; }

button#generate-btn {
    padding: 12px 24px;
    font-size: 1.1rem;
    background-color: var(--btn-bg);
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: background-color 0.2s, transform 0.1s;
}

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

button#generate-btn:active {
    transform: translateY(2px);
}