:root {
    color-scheme: light;
    --bg: #f0f2f5;
    --bg-texture: url('https://www.transparenttextures.com/patterns/subtle-zebra-3d.png');
    --text: #333;
    --muted: #7f8c8d;
    --card: #fff;
    --shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    --title: #2c3e50;
    --btn: #3498db;
    --btn-hover: #2980b9;
    --btn-shadow: 0 4px 15px rgba(52, 152, 219, 0.4);
    --footer: #95a5a6;
    --toggle-bg: #ffffff;
    --toggle-border: #d0d7de;
    --toggle-text: #34495e;
}

html[data-theme="dark"] {
    color-scheme: dark;
    --bg: #0f131a;
    --bg-texture: linear-gradient(135deg, rgba(255,255,255,0.03), rgba(0,0,0,0.2));
    --text: #e6edf3;
    --muted: #a1adba;
    --card: #161b22;
    --shadow: 0 12px 30px rgba(0, 0, 0, 0.45);
    --title: #e6edf3;
    --btn: #4aa3ff;
    --btn-hover: #2f7fe0;
    --btn-shadow: 0 4px 15px rgba(74, 163, 255, 0.35);
    --footer: #8b98a5;
    --toggle-bg: #0b1118;
    --toggle-border: #2b3947;
    --toggle-text: #e6edf3;
}

/* style.css */
body {
    font-family: 'Pretendard', sans-serif;
    background-color: var(--bg);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-image: var(--bg-texture);
}

.container {
    background-color: var(--card);
    padding: 40px;
    border-radius: 20px;
    box-shadow: var(--shadow);
    text-align: center;
    max-width: 500px;
    width: 90%;
}

.header-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.theme-toggle {
    background-color: var(--toggle-bg);
    color: var(--toggle-text);
    border: 1px solid var(--toggle-border);
    padding: 8px 14px;
    font-size: 0.95rem;
    border-radius: 999px;
    cursor: pointer;
    transition: all 0.25s ease;
}

.theme-toggle:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.12);
}

header h1 {
    font-size: 2.5rem;
    color: var(--title);
    margin-bottom: 10px;
}

header p {
    font-size: 1.2rem;
    color: var(--muted);
    margin-bottom: 30px;
}

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

.lotto-number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    background-color: #f39c12;
    color: #fff;
    font-size: 1.8rem;
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(243, 156, 18, 0.4);
}

#generate-btn {
    background-color: var(--btn);
    color: #fff;
    border: none;
    padding: 15px 30px;
    font-size: 1.2rem;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--btn-shadow);
}

#generate-btn:hover {
    background-color: var(--btn-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(52, 152, 219, 0.5);
}

footer {
    margin-top: 40px;
    color: var(--footer);
    font-size: 0.9rem;
}

/* Lotto ball colors */
.color-1 { background-color: #f1c40f; box-shadow: 0 4px 15px rgba(241, 196, 15, 0.4); } /* Yellow */
.color-2 { background-color: #2ecc71; box-shadow: 0 4px 15px rgba(46, 204, 113, 0.4); } /* Green */
.color-3 { background-color: #e74c3c; box-shadow: 0 4px 15px rgba(231, 76, 60, 0.4); } /* Red */
.color-4 { background-color: #9b59b6; box-shadow: 0 4px 15px rgba(155, 89, 182, 0.4); } /* Purple */
.color-5 { background-color: #3498db; box-shadow: 0 4px 15px rgba(52, 152, 219, 0.4); } /* Blue */