:root {
    --bg-color: #f0f0f0;
    --container-bg: white;
    --text-color: #333;
    --button-bg: #4CAF50;
    --button-hover: #45a049;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

body.dark-mode {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --shadow-color: rgba(0, 0, 0, 0.5);
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    background-color: var(--container-bg);
    padding: 3rem;
    border-radius: 20px;
    box-shadow: 0 10px 25px var(--shadow-color);
    text-align: center;
    position: relative;
    transition: background-color 0.3s, box-shadow 0.3s;
    max-width: 90%;
    width: 400px;
}

h1 {
    margin-bottom: 2.5rem;
    margin-top: 0.5rem;
    font-weight: 700;
    letter-spacing: 1px;
    background: linear-gradient(45deg, #FF6B6B, #4ECDC4);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 2rem;
}

.lotto-numbers-container {
    display: flex;
    justify-content: center;
    margin-bottom: 2.5rem;
    perspective: 1000px;
}

.lotto-set {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
}

.lotto-number {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: 900;
    font-size: 1.2rem;
    color: white;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
    box-shadow: inset -5px -5px 10px rgba(0,0,0,0.2), 3px 3px 5px rgba(0,0,0,0.2);
    animation: popIn 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275) forwards;
    opacity: 0;
    transform: scale(0.5);
}

/* Staggered animation delay */
.lotto-number:nth-child(1) { animation-delay: 0.1s; }
.lotto-number:nth-child(2) { animation-delay: 0.2s; }
.lotto-number:nth-child(3) { animation-delay: 0.3s; }
.lotto-number:nth-child(4) { animation-delay: 0.4s; }
.lotto-number:nth-child(5) { animation-delay: 0.5s; }
.lotto-number:nth-child(6) { animation-delay: 0.6s; }

@keyframes popIn {
    to {
        opacity: 1;
        transform: scale(1);
    }
}

/* Color ranges */
.ball-1-10 { background: radial-gradient(circle at 30% 30%, #fbc400, #cfa000); }
.ball-11-20 { background: radial-gradient(circle at 30% 30%, #69c8f2, #4da8d2); }
.ball-21-30 { background: radial-gradient(circle at 30% 30%, #ff7272, #d65050); }
.ball-31-40 { background: radial-gradient(circle at 30% 30%, #aaaaaa, #888888); }
.ball-41-45 { background: radial-gradient(circle at 30% 30%, #b0d840, #90b820); }

#generate-btn {
    padding: 1rem 2rem;
    font-size: 1.1rem;
    border: none;
    border-radius: 50px;
    background: linear-gradient(45deg, #4CAF50, #45a049);
    color: white;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
}

#generate-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(76, 175, 80, 0.4);
}

#generate-btn:active {
    transform: translateY(1px);
}

#theme-toggle {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0.7;
    transition: opacity 0.3s, transform 0.3s;
}

#theme-toggle:hover {
    opacity: 1;
    transform: rotate(15deg);
}