:root {
    --primary-color: #4a90e2;
    --secondary-color: #f5a623;
    --background-color: #f0f4f8;
    --text-color: #333;
    --surface-color: #fff;
    --muted-surface: #eee;
    --ball-bg: #c8f36a;
    --ball-text: #1f2a12;
    --border-color: rgba(0, 0, 0, 0.08);
}

body[data-theme="dark"] {
    --primary-color: #89b4ff;
    --secondary-color: #f6b55a;
    --background-color: #0e141b;
    --text-color: #e6edf3;
    --surface-color: #151e28;
    --muted-surface: #1d2733;
    --ball-bg: #c8f36a;
    --ball-text: #16210b;
    --border-color: rgba(255, 255, 255, 0.12);
}

body {
    font-family: 'Arial', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

#app {
    background-color: var(--surface-color);
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    text-align: center;
    border: 1px solid var(--border-color);
}

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

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

#numbers-container {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin: 2rem 0;
}

#theme-toggle {
    background-color: transparent;
    color: var(--text-color);
    border: 1px solid var(--border-color);
    padding: 0.5rem 0.9rem;
    font-size: 0.9rem;
    border-radius: 999px;
    cursor: pointer;
    transition: border-color 0.3s ease, color 0.3s ease;
}

#theme-toggle:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

#generate-button {
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

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

#history-container {
    margin-top: 2rem;
}

#history-list {
    list-style: none;
    padding: 0;
    max-height: 200px;
    overflow-y: auto;
}

#history-list li {
    background-color: var(--muted-surface);
    padding: 0.5rem;
    border-radius: 5px;
    margin-bottom: 0.5rem;
}

#partner-section {
    margin-top: 2.5rem;
    text-align: left;
}

#partner-form {
    margin-top: 1rem;
    display: grid;
    gap: 0.9rem;
}

#partner-form label {
    display: grid;
    gap: 0.4rem;
    font-size: 0.95rem;
}

#partner-form input,
#partner-form textarea {
    width: 100%;
    padding: 0.65rem 0.8rem;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--surface-color);
    color: var(--text-color);
    font-size: 0.95rem;
}

#partner-form input:focus,
#partner-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.2);
}

#partner-submit {
    justify-self: start;
    background-color: var(--secondary-color);
    color: #111;
    border: none;
    padding: 0.7rem 1.2rem;
    font-size: 0.95rem;
    border-radius: 8px;
    cursor: pointer;
    transition: filter 0.2s ease;
}

#partner-submit:hover {
    filter: brightness(0.95);
}