:root {
    --bg-gradient: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    --text-color: #333;
    --container-bg: rgba(255, 255, 255, 0.9);
    --button-bg: #4e73df;
    --button-text: white;
    --button-hover: #2e59d9;
    --card-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

[data-theme="dark"] {
    --bg-gradient: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    --text-color: #e0e0e0;
    --container-bg: rgba(30, 30, 50, 0.9);
    --button-bg: #f6c23e;
    --button-text: #333;
    --button-hover: #dda20a;
    --card-shadow: 0 4px 15px rgba(0,0,0,0.5);
}

body {
    font-family: 'Arial', sans-serif;
    text-align: center;
    background: var(--bg-gradient);
    background-attachment: fixed;
    margin: 0;
    padding: 0;
    color: var(--text-color);
    transition: background 0.3s, color 0.3s;
    min-height: 100vh;
}

.container {
    margin: 60px auto;
    padding: 40px;
    max-width: 600px;
    background: var(--container-bg);
    border-radius: 20px;
    box-shadow: var(--card-shadow);
    transition: background 0.3s, box-shadow 0.3s;
}

h1 {
    font-size: 36px;
    margin-bottom: 30px;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
}

button {
    padding: 12px 24px;
    font-size: 16px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    background-color: var(--button-bg);
    color: var(--button-text);
    font-weight: bold;
    transition: 0.3s;
    margin: 5px;
}

button:hover {
    background-color: var(--button-hover);
    transform: translateY(-2px);
}

.set {
    margin-top: 30px;
    padding: 15px;
    border-bottom: 1px solid rgba(128,128,128,0.2);
}

.set h3 {
    margin-top: 0;
    color: var(--text-color);
}

.numbers {
    margin-top: 10px;
}

.ball {
    display: inline-block;
    width: 50px;
    height: 50px;
    line-height: 50px;
    margin: 6px;
    border-radius: 50%;
    font-weight: bold;
    color: white;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
    box-shadow: 2px 2px 5px rgba(0,0,0,0.2);
}

/* 로또 공식 색상 */
.yellow { background-color: #fbc400; }
.blue { background-color: #69c8f2; }
.red { background-color: #ff7272; }
.gray { background-color: #aaa; }
.green { background-color: #b0d840; }