:root {
    color-scheme: light;
    --bg: #f0f0f0;
    --bg-pattern: url("data:image/svg+xml,%3Csvg width='6' height='6' viewBox='0 0 6 6' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='%239C92AC' fill-opacity='0.12'%3E%3Cpath d='M5 0h1L0 6V5zM6 5v1H5z'/%3E%3C/g%3E%3C/svg%3E");
    --card: #ffffff;
    --text: #222222;
    --muted: #5a5a5a;
    --shadow: 0 10px 20px rgba(0, 0, 0, 0.12), 0 6px 6px rgba(0, 0, 0, 0.08);
    --accent: #007BFF;
    --accent-hover: #0056b3;
    --accent-shadow: rgba(0, 123, 255, 0.35);
    --number: #4CAF50;
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --bg: #0d1117;
    --bg-pattern: radial-gradient(circle at 1px 1px, rgba(255, 255, 255, 0.06) 1px, transparent 0);
    --card: #161b22;
    --text: #e6edf3;
    --muted: #a2aab4;
    --shadow: 0 12px 24px rgba(0, 0, 0, 0.45), 0 6px 8px rgba(0, 0, 0, 0.35);
    --accent: #66b2ff;
    --accent-hover: #3a8ad6;
    --accent-shadow: rgba(102, 178, 255, 0.25);
    --number: #7ee787;
}

* {
    box-sizing: border-box;
}

body {
    font-family: "Trebuchet MS", "Gill Sans", "Segoe UI", sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--bg);
    background-image: var(--bg-pattern);
    background-size: 12px 12px;
    margin: 0;
    color: var(--text);
}

.container {
    text-align: center;
    padding: 40px;
    background-color: var(--card);
    border-radius: 16px;
    box-shadow: var(--shadow);
    min-width: 320px;
    position: relative;
}

.header {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    flex-wrap: wrap;
}

h1 {
    font-size: 2.4rem;
    color: var(--text);
    margin: 0;
}

.subtitle {
    margin: 6px 0 22px;
    color: var(--muted);
}

.number-display {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 30px;
    flex-wrap: wrap;
}

.number {
    width: 50px;
    height: 50px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: #0f141a;
    border-radius: 50%;
    background-color: var(--number);
    box-shadow: 0 6px 10px rgba(0, 0, 0, 0.15);
}

.actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
}

#generate-btn {
    padding: 15px 30px;
    font-size: 1.1rem;
    color: white;
    background-color: var(--accent);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
    box-shadow: 0 6px 10px var(--accent-shadow);
}

#generate-btn:hover {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 8px 12px var(--accent-shadow);
}

.theme-toggle {
    padding: 12px 16px;
    font-size: 0.95rem;
    border-radius: 999px;
    border: 1px solid transparent;
    background-color: transparent;
    color: var(--text);
    cursor: pointer;
    transition: border-color 0.2s ease, color 0.2s ease, background-color 0.2s ease;
}

.theme-toggle:hover {
    border-color: var(--accent);
    background-color: rgba(0, 123, 255, 0.1);
}

@media (max-width: 600px) {
    .container {
        padding: 24px;
    }

    h1 {
        font-size: 2rem;
    }

    .number {
        width: 42px;
        height: 42px;
        font-size: 1.2rem;
    }

    #generate-btn {
        padding: 12px 24px;
        font-size: 1rem;
    }
}