:root {
    --bg-color: oklch(0.98 0.02 240);
    --bg-gradient-start: oklch(0.90 0.1 240 / 0.5);
    --bg-gradient-end: oklch(0.90 0.1 280 / 0.5);
    --container-bg: oklch(0.99 0.01 240);
    --text-color: oklch(0.40 0.25 260);
    --button-bg: oklch(0.65 0.25 260);
    --button-hover-bg: oklch(0.70 0.28 260);
    --shadow-color: oklch(0 0 0 / 0.1);
}

body.dark {
    --bg-color: oklch(0.20 0.02 240);
    --bg-gradient-start: oklch(0.15 0.1 240 / 0.5);
    --bg-gradient-end: oklch(0.15 0.1 280 / 0.5);
    --container-bg: oklch(0.25 0.01 240);
    --text-color: oklch(0.80 0.25 260);
    --button-bg: oklch(0.50 0.25 260);
    --button-hover-bg: oklch(0.55 0.28 260);
    --shadow-color: oklch(0 0 0 / 0.4);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: var(--bg-color);
    background-image: linear-gradient(315deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 74%);
    position: relative;
    transition: background-color 0.3s ease;
}

body::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADAAAAADCAYAAAANH/blAAAAEElEQVR42mN8/eJFEwYGAIEnAwA7kAf24rQyYwAAAABJRU5ErkJggg==');
    opacity: 0.2;
    z-index: -1;
}

#theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-color);
}

.container {
    text-align: center;
    background-color: var(--container-bg);
    padding: 2rem 4rem;
    border-radius: 1rem;
    box-shadow: 0 10px 20px var(--shadow-color), 0 6px 6px var(--shadow-color);
    transition: background-color 0.3s ease;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--text-color);
    font-weight: 700;
    transition: color 0.3s ease;
}

lotto-numbers {
    display: block;
    margin-bottom: 2rem;
}

#generate-btn {
    background-color: var(--button-bg);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1.2rem;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px oklch(0% 0 0 / 10%);
}

#generate-btn:hover {
    background-color: var(--button-hover-bg);
    box-shadow: 0 7px 14px oklch(0% 0 0 / 10%), 0 3px 6px oklch(0% 0 0 / 8%);
    transform: translateY(-2px);
}