:root {
    /* Dark Mode (Default) */
    --bg-color: #0f0f0f;
    --container-bg: #1a1a1a;
    --primary-color: #ffd700; /* Gold */
    --secondary-color: #f1c40f;
    --text-color: #ffffff;
    --sub-text-color: #aaaaaa;
    --shadow-color: rgba(0, 0, 0, 0.7);
    --glow-color: rgba(255, 215, 0, 0.3);
    --ball-border: rgba(255, 255, 255, 0.2);
}

body.light-mode {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --primary-color: #d4af37;
    --secondary-color: #f39c12;
    --text-color: #333333;
    --sub-text-color: #666666;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --glow-color: rgba(212, 175, 55, 0.2);
    --ball-border: rgba(0, 0, 0, 0.05);
}

:root {
    --font-family: 'Poppins', sans-serif;
    --header-font: 'Nanum Pen Script', cursive;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    background-color: var(--bg-color);
    background-image: 
        radial-gradient(var(--container-bg) 0.5px, transparent 0.5px);
    background-size: 30px 30px;
    color: var(--text-color);
    font-family: var(--font-family);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.4s, color 0.4s;
    overflow-x: hidden;
}

.app-container {
    background-color: var(--container-bg);
    width: 90%;
    max-width: 600px;
    padding: 2.5rem;
    border-radius: 30px;
    box-shadow: 0 20px 50px var(--shadow-color);
    text-align: center;
    border: 1px solid rgba(255, 215, 0, 0.1);
    transition: background-color 0.4s;
}

header {
    margin-bottom: 2rem;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    font-family: var(--header-font);
    font-size: 4rem;
    color: var(--primary-color);
    text-shadow: 0 0 15px var(--glow-color);
}

.subtitle {
    color: var(--sub-text-color);
    font-size: 1.1rem;
    margin-top: -0.5rem;
}

.icon-btn {
    background: none;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    font-size: 1.2rem;
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s;
}

.icon-btn:hover {
    background: var(--primary-color);
    color: var(--container-bg);
    transform: rotate(20deg);
}

.lotto-board {
    margin-bottom: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.lotto-row {
    display: flex;
    justify-content: center;
    gap: 0.8rem;
    padding: 1rem;
    background: rgba(128, 128, 128, 0.05);
    border-radius: 50px;
    border: 1px solid var(--ball-border);
    animation: slideUp 0.5s ease-out backwards;
}

.lotto-ball {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1.2rem;
    color: #fff;
    text-shadow: 1px 1px 2px rgba(0, 0, 0, 0.5);
    box-shadow: inset -4px -4px 8px rgba(0, 0, 0, 0.3),
                2px 4px 8px rgba(0, 0, 0, 0.3);
    animation: popIn 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) backwards;
}

/* Ball Colors */
.ball-1 { background: radial-gradient(circle at 30% 30%, #f1c40f, #d4af37); } /* Yellow (1-10) */
.ball-2 { background: radial-gradient(circle at 30% 30%, #3498db, #2980b9); } /* Blue (11-20) */
.ball-3 { background: radial-gradient(circle at 30% 30%, #e74c3c, #c0392b); } /* Red (21-30) */
.ball-4 { background: radial-gradient(circle at 30% 30%, #95a5a6, #7f8c8d); } /* Gray (31-40) */
.ball-5 { background: radial-gradient(circle at 30% 30%, #2ecc71, #27ae60); } /* Green (41-45) */

.actions {
    margin-top: 1rem;
}

.primary-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: #000;
    border: none;
    padding: 1rem 2.5rem;
    font-size: 1.2rem;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

.glow-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 25px var(--glow-color);
}

.glow-btn:active {
    transform: translateY(1px);
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes popIn {
    from { opacity: 0; transform: scale(0.5); }
    to { opacity: 1; transform: scale(1); }
}

@media (max-width: 480px) {
    .app-container { padding: 1.5rem; width: 95%; }
    header h1 { font-size: 3rem; }
    .lotto-ball { width: 35px; height: 35px; font-size: 1rem; }
    .lotto-row { gap: 0.4rem; padding: 0.7rem; }
}