:root {
    --primary-color: #4a90e2;
    --background-color: #f0f4f8;
    --text-color: #333;
    --surface-color: #ffffff;
    --muted-color: #5b6b7a;
    --white: #fff;
    --border-radius: 8px;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --focus-ring: 0 0 0 3px rgba(74, 144, 226, 0.35);
}

[data-theme="dark"] {
    --primary-color: #7db4ff;
    --background-color: #0f1720;
    --text-color: #e4edf6;
    --surface-color: #182433;
    --muted-color: #9bb0c6;
    --white: #0f1720;
    --shadow: 0 6px 14px rgba(0, 0, 0, 0.4);
    --focus-ring: 0 0 0 3px rgba(125, 180, 255, 0.4);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

#app {
    background: var(--surface-color);
    padding: 2rem;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    text-align: center;
}

h1 {
    color: var(--primary-color);
    margin: 0;
}

.app-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.theme-toggle {
    border: 1px solid rgba(0, 0, 0, 0.1);
    background: transparent;
    color: var(--muted-color);
    padding: 8px 12px;
    border-radius: 999px;
    font-size: 0.9rem;
    cursor: pointer;
    transition: color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
}

[data-theme="dark"] .theme-toggle {
    border-color: rgba(255, 255, 255, 0.2);
}

.theme-toggle:hover {
    color: var(--text-color);
    transform: translateY(-1px);
}

.theme-toggle:focus-visible {
    outline: none;
    box-shadow: var(--focus-ring);
}

.lotto-numbers-container {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 1.5rem;
}

.lotto-number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: var(--white);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
}

#generate-btn {
    background-color: var(--primary-color);
    color: var(--white);
    border: none;
    padding: 10px 20px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s ease;
}

#generate-btn:hover {
    background-color: #357abd;
}

[data-theme="dark"] #generate-btn:hover {
    background-color: #5f9be4;
}

@media (max-width: 480px) {
    #app {
        width: min(90vw, 360px);
        padding: 1.5rem;
    }

    .app-header {
        flex-direction: column;
    }
}