@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@400;700&display=swap');

:root {
    --background-color: #f0f2f5;
    --container-bg: #ffffff;
    --primary-color: #4a90e2;
    --secondary-color: #50e3c2;
    --text-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --font-family: 'Noto Sans KR', sans-serif;
    --button-text: #ffffff;
}

[data-theme="dark"] {
    --background-color: #1a1a2e;
    --container-bg: #16213e;
    --primary-color: #0f3460;
    --secondary-color: #e94560;
    --text-color: #f1f1f1;
    --shadow-color: rgba(0, 0, 0, 0.5);
    --number-bg: #0f3460;
}

body {
    margin: 0;
    padding: 0;
    background-color: var(--background-color);
    font-family: var(--font-family);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s ease;
}

body:not([data-theme="dark"]) {
    background-image: linear-gradient(to top, #a18cd1 0%, #fbc2eb 100%);
}

[data-theme="dark"] body {
    background-image: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
}

.container {
    width: 90%;
    max-width: 600px;
    background-color: var(--container-bg);
    border-radius: 20px;
    box-shadow: 0 10px 30px var(--shadow-color);
    padding: 40px;
    text-align: center;
    transition: transform 0.3s ease, background-color 0.3s ease, box-shadow 0.3s ease;
    position: relative;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 5px 10px;
    border-radius: 20px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 700;
    transition: all 0.3s ease;
}

.theme-toggle:hover {
    background-color: var(--primary-color);
    color: white;
}

.container:hover {
    transform: translateY(-5px);
}

header h1 {
    color: var(--primary-color);
    font-size: 2.5rem;
    margin-bottom: 30px;
    font-weight: 700;
    background: -webkit-linear-gradient(45deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: color 0.3s ease;
}

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

.number {
    width: 60px;
    height: 60px;
    background-color: var(--container-bg);
    border: 2px solid var(--primary-color);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-color);
    transition: all 0.3s ease;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
}

.number:empty {
    background-color: #eee;
    border-color: #ddd;
}

[data-theme="dark"] .number:empty {
    background-color: #2c2c54;
    border-color: #444;
}

#generate-btn {
    background-image: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1.2rem;
    font-weight: 700;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(74, 144, 226, 0.4);
}

#generate-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(74, 144, 226, 0.6);
}

#generate-btn:active {
    transform: translateY(1px);
    box-shadow: 0 3px 10px rgba(74, 144, 226, 0.4);
}

@media (max-width: 480px) {
    .container {
        padding: 20px;
    }

    header h1 {
        font-size: 2rem;
    }

    .number {
        width: 50px;
        height: 50px;
        font-size: 1.5rem;
    }

    #generate-btn {
        padding: 12px 25px;
        font-size: 1rem;
    }

    .theme-toggle {
        top: 10px;
        right: 10px;
        font-size: 0.8rem;
    }
}