:root {
    --background-color: #121212;
    --text-color: #ffffff;
    --container-bg-color: #1e1e1e;
    --primary-color: #4CAF50;
    --primary-hover-color: #45a049;
    --secondary-color: #008CBA;
    --secondary-hover-color: #007B9E;
    --danger-color: #f44336;
    --danger-hover-color: #d32f2f;
    --number-bg-color: #333;
    --shadow-color: rgba(0, 0, 0, 0.5);
    --primary-shadow-color: rgba(76, 175, 80, 0.4);
    --primary-hover-shadow-color: rgba(76, 175, 80, 0.6);
    --secondary-shadow-color: rgba(0, 140, 186, 0.4);
    --secondary-hover-shadow-color: rgba(0, 140, 186, 0.6);
    --danger-shadow-color: rgba(244, 67, 54, 0.4);
    --danger-hover-shadow-color: rgba(244, 67, 54, 0.6);
}

body.light-theme {
    --background-color: #f0f0f0;
    --text-color: #333333;
    --container-bg-color: #ffffff;
    --number-bg-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --primary-shadow-color: rgba(76, 175, 80, 0.2);
    --primary-hover-shadow-color: rgba(76, 175, 80, 0.4);
    --secondary-shadow-color: rgba(0, 140, 186, 0.2);
    --secondary-hover-shadow-color: rgba(0, 140, 186, 0.4);
    --danger-shadow-color: rgba(244, 67, 54, 0.2);
    --danger-hover-shadow-color: rgba(244, 67, 54, 0.4);
}

body {
    background-color: var(--background-color);
    color: var(--text-color);
    font-family: 'Arial', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background-image: url('data:image/svg+xml,%3Csvg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"%3E%3Cfilter id="noise"%3E%3CfeTurbulence type="fractalNoise" baseFrequency="0.65" numOctaves="3" stitchTiles="stitch"/%3E%3C/filter%3E%3Crect width="100%25" height="100%25" filter="url(%23noise)" opacity="0.05"/%3E%3C/svg%3E');
    transition: background-color 0.3s, color 0.3s;
}

.container {
    text-align: center;
    padding: 40px;
    border-radius: 20px;
    background-color: var(--container-bg-color);
    box-shadow: 0 10px 30px var(--shadow-color);
    transition: background-color 0.3s, box-shadow 0.3s;
}

h1 {
    font-size: 3em;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.numbers-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 30px;
}

@keyframes pop-in {
    0% {
        transform: scale(0);
    }
    60% {
        transform: scale(1.1);
    }
    100% {
        transform: scale(1);
    }
}

.number {
    width: 60px;
    height: 60px;
    background-color: var(--number-bg-color);
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em;
    font-weight: bold;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    animation: pop-in 0.5s ease-out forwards;
    transition: background-color 0.3s;
}

.number:hover {
    transform: translateY(-5px);
}

#generate-btn {
    background-color: var(--primary-color);
    color: #ffffff;
    border: none;
    padding: 15px 30px;
    font-size: 1.2em;
    border-radius: 50px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
    box-shadow: 0 5px 15px var(--primary-shadow-color);
    margin-bottom: 10px;
}

#generate-btn:hover {
    background-color: var(--primary-hover-color);
    box-shadow: 0 8px 25px var(--primary-hover-shadow-color);
}

#copy-btn {
    background-color: var(--danger-color);
    color: white;
    padding: 15px 30px;
    font-size: 1.2em;
    border: none;
    border-radius: 50px;
    cursor: pointer;
    transition: background-color 0.3s, box-shadow 0.3s;
    box-shadow: 0 5px 15px var(--danger-shadow-color);
    margin-bottom: 10px;
}

#copy-btn:hover {
    background-color: var(--danger-hover-color);
    box-shadow: 0 8px 25px var(--danger-hover-shadow-color);
}

.theme-switch-wrapper {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    align-items: center;
}

.theme-switch {
    display: inline-block;
    height: 34px;
    position: relative;
    width: 60px;
}

.theme-switch input {
    display:none;
}

.slider {
    background-color: #ccc;
    bottom: 0;
    cursor: pointer;
    left: 0;
    position: absolute;
    right: 0;
    top: 0;
    transition: .4s;
}

.slider:before {
    background-color: #fff;
    bottom: 4px;
    content: "";
    height: 26px;
    left: 4px;
    position: absolute;
    transition: .4s;
    width: 26px;
}

input:checked + .slider {
    background-color: var(--primary-color);
}

input:checked + .slider:before {
    transform: translateX(26px);
}

.slider.round {
    border-radius: 34px;
}

.slider.round:before {
    border-radius: 50%;
}