:root {
    --bg-color: #1a1a1a;
    --container-bg: linear-gradient(145deg, #2a2a2a, #1a1a1a);
    --text-color: #fff;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --secondary-shadow: rgba(0, 0, 0, 0.2);
}

body.light-mode {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --secondary-shadow: rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Helvetica Neue', sans-serif;
    background-color: var(--bg-color);
    background-image: url('https://www.transparenttextures.com/patterns/subtle-zebra-3d.png');
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    background: var(--container-bg);
    padding: 3rem;
    border-radius: 1.5rem;
    box-shadow: 0 2rem 4rem var(--shadow-color), 0 1rem 2rem var(--secondary-shadow);
    text-align: center;
    transition: background 0.3s ease, box-shadow 0.3s ease;
}

h1 {
    font-size: 3rem;
    font-weight: bold;
    background: -webkit-linear-gradient(45deg, #ff8a00, #e52e71);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 2rem;
}

#generate {
    background: linear-gradient(45deg, #ff8a00, #e52e71);
    color: #fff;
    border: none;
    padding: 1.2rem 2.5rem;
    border-radius: 0.8rem;
    font-size: 1.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 0.8rem 1.5rem rgba(229, 46, 113, 0.4);
}

#generate:hover {
    transform: translateY(-3px);
    box-shadow: 0 1.2rem 2rem rgba(229, 46, 113, 0.6);
}

#generate:active {
    transform: translateY(1px);
    box-shadow: 0 0.5rem 1rem rgba(229, 46, 113, 0.3);
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin-top: 3rem;
}

.number {
    width: 4rem;
    height: 4rem;
    display: flex;
    justify-content: center;
    align-items: center;
    border-radius: 50%;
    font-size: 1.8rem;
    font-weight: bold;
    color: #fff;
    box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.3);
}

#theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: transparent;
    border: 2px solid var(--text-color);
    color: var(--text-color);
    padding: 0.5rem 1rem;
    border-radius: 20px;
    cursor: pointer;
    font-weight: bold;
    transition: all 0.3s ease;
}

#theme-toggle:hover {
    background: var(--text-color);
    color: var(--bg-color);
}