/* Dark Mode (default) */
[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --bg-pattern: #2a2a2a;
    --text-color: #ffffff;
    --primary-color: #ff6b6b;
    --secondary-color: #f0e68c;
    --container-bg: rgba(0, 0, 0, 0.7);
    --container-shadow: rgba(0, 0, 0, 0.5);
    --btn-hover: #ff8b8b;
    --theme-btn-bg: #333;
    --theme-btn-color: #fff;
    --theme-btn-active: #ff6b6b;
}

/* White Mode */
[data-theme="white"] {
    --bg-color: #f0f0f0;
    --bg-pattern: #e0e0e0;
    --text-color: #222222;
    --primary-color: #e74c3c;
    --secondary-color: #f39c12;
    --container-bg: rgba(255, 255, 255, 0.85);
    --container-shadow: rgba(0, 0, 0, 0.15);
    --btn-hover: #c0392b;
    --theme-btn-bg: #ddd;
    --theme-btn-color: #222;
    --theme-btn-active: #e74c3c;
}

/* Green Mode */
[data-theme="green"] {
    --bg-color: #1b3a2d;
    --bg-pattern: #24503d;
    --text-color: #d4f5e2;
    --primary-color: #2ecc71;
    --secondary-color: #a8e6cf;
    --container-bg: rgba(0, 60, 30, 0.75);
    --container-shadow: rgba(0, 0, 0, 0.4);
    --btn-hover: #27ae60;
    --theme-btn-bg: #24503d;
    --theme-btn-color: #d4f5e2;
    --theme-btn-active: #2ecc71;
}

body {
    font-family: 'Roboto', sans-serif;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background-color: var(--bg-color);
    background-image: linear-gradient(45deg, var(--bg-pattern) 25%, transparent 25%),
                      linear-gradient(-45deg, var(--bg-pattern) 25%, transparent 25%),
                      linear-gradient(45deg, transparent 75%, var(--bg-pattern) 75%),
                      linear-gradient(-45deg, transparent 75%, var(--bg-pattern) 75%);
    background-size: 20px 20px;
    color: var(--text-color);
    transition: background-color 0.4s ease, color 0.4s ease;
}

.theme-buttons {
    position: fixed;
    top: 20px;
    right: 20px;
    display: flex;
    gap: 8px;
    z-index: 100;
}

.theme-btn {
    padding: 8px 16px;
    font-size: 0.85em;
    font-weight: bold;
    cursor: pointer;
    background-color: var(--theme-btn-bg);
    color: var(--theme-btn-color);
    border: 2px solid transparent;
    border-radius: 20px;
    transition: all 0.3s ease;
}

.theme-btn:hover {
    border-color: var(--primary-color);
    transform: scale(1.05);
}

.theme-btn.active {
    background-color: var(--theme-btn-active);
    color: #fff;
    border-color: var(--theme-btn-active);
}

.container {
    text-align: center;
    background: var(--container-bg);
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0 10px 30px var(--container-shadow);
    transition: background 0.4s ease, box-shadow 0.4s ease;
}

h1 {
    font-size: 3em;
    color: var(--primary-color);
    text-shadow: 0 0 10px var(--primary-color), 0 0 20px var(--primary-color);
    margin-bottom: 30px;
    transition: color 0.4s ease, text-shadow 0.4s ease;
}

.lotto-numbers {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    margin: 30px 0;
}

.lotto-number {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.5em;
    font-weight: bold;
    color: #fff;
    position: relative;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.lotto-number:before {
    content: '';
    position: absolute;
    top: 5%;
    left: 10%;
    width: 80%;
    height: 80%;
    border-radius: 50%;
    background: radial-gradient(circle at 30% 30%, #fff, #ddd);
    opacity: 0.8;
    z-index: -1;
}

#generate-button {
    padding: 15px 30px;
    font-size: 1.2em;
    cursor: pointer;
    background-color: var(--primary-color);
    color: #fff;
    border: none;
    border-radius: 10px;
    box-shadow: 0 0 15px var(--primary-color);
    transition: background-color 0.3s ease, box-shadow 0.3s ease, transform 0.3s ease;
}

#generate-button:hover {
    background-color: var(--btn-hover);
    box-shadow: 0 0 25px var(--primary-color);
    transform: scale(1.05);
}