:root {
    color-scheme: light;
    --bg: #f6f4f1;
    --text: #1b1b1b;
    --card: #ffffff;
    --accent: #3a7d44;
    --accent-contrast: #ffffff;
    --button-bg: #1b1b1b;
    --button-text: #ffffff;
    --muted: #6a6a6a;
}

:root[data-theme="dark"] {
    color-scheme: dark;
    --bg: #0f1115;
    --text: #f3f3f3;
    --card: #1a1f27;
    --accent: #7fd089;
    --accent-contrast: #0f1115;
    --button-bg: #f3f3f3;
    --button-text: #0f1115;
    --muted: #a3a3a3;
}

* {
    box-sizing: border-box;
}

body {
    font-family: "Trebuchet MS", "Segoe UI", sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    padding: 24px;
    background: radial-gradient(circle at top left, #ffffff 0%, var(--bg) 45%, var(--bg) 100%);
    color: var(--text);
    transition: background-color 200ms ease, color 200ms ease;
}

:root[data-theme="dark"] body {
    background: radial-gradient(circle at top left, #1c2330 0%, var(--bg) 50%, var(--bg) 100%);
}

.container {
    text-align: center;
    background: var(--card);
    padding: 28px 32px 32px;
    border-radius: 16px;
    box-shadow: 0 18px 40px rgba(0, 0, 0, 0.12);
    width: min(520px, 100%);
}

button {
    padding: 12px 20px;
    font-size: 16px;
    cursor: pointer;
    border: none;
    border-radius: 999px;
    background: var(--button-bg);
    color: var(--button-text);
    transition: transform 150ms ease, background-color 200ms ease, color 200ms ease;
}

button:hover {
    transform: translateY(-1px);
}

.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    margin-bottom: 20px;
}

.toolbar h1 {
    margin: 0;
    font-size: 24px;
}

.theme-toggle {
    font-size: 14px;
    padding: 10px 16px;
    background: transparent;
    color: var(--text);
    border: 1px solid var(--muted);
}

.numbers-container {
    display: flex;
    justify-content: center;
    margin-top: 20px;
    gap: 8px;
    flex-wrap: wrap;
}

.number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background-color: var(--accent);
    color: var(--accent-contrast);
    font-size: 24px;
}