:root {
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --primary-color: #4a90e2;
    --secondary-color: #357abd;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    
    /* Lotto Colors */
    --color-1: #fbc400; /* 1-10 */
    --color-11: #69c8f2; /* 11-20 */
    --color-21: #ff7272; /* 21-30 */
    --color-31: #aaaaaa; /* 31-40 */
    --color-41: #b0d840; /* 41-45 */
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    width: 90%;
    max-width: 600px;
    background: white;
    padding: 2rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    text-align: center;
}

header h1 {
    margin: 0;
    font-size: 2rem;
    color: var(--primary-color);
}

header p {
    color: #666;
    margin-top: 0.5rem;
}

.ball-container {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 3rem 0;
    flex-wrap: wrap;
    min-height: 80px;
}

.placeholder {
    color: #ccc;
    font-style: italic;
    font-size: 1.1rem;
}

/* Lotto Ball Style */
.ball {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    font-size: 1.4rem;
    color: white;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2), inset -4px -4px 8px rgba(0,0,0,0.1);
    animation: bounceIn 0.6s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    text-shadow: 1px 1px 2px rgba(0,0,0,0.2);
}

@keyframes bounceIn {
    0% { transform: scale(0) rotate(-180deg); opacity: 0; }
    60% { transform: scale(1.1) rotate(10deg); }
    100% { transform: scale(1) rotate(0); opacity: 1; }
}

.generate-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 1rem 3rem;
    font-size: 1.2rem;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.2s ease;
    box-shadow: 0 4px 15px rgba(74, 144, 226, 0.3);
}

.generate-btn:hover {
    background-color: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(74, 144, 226, 0.4);
}

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

.history-section {
    margin-top: 3rem;
    text-align: left;
    border-top: 1px solid #eee;
    padding-top: 2rem;
}

.history-list {
    list-style: none;
    padding: 0;
}

.history-item {
    background: #fdfdfd;
    padding: 10px 15px;
    border-radius: 10px;
    margin-bottom: 8px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid #f0f0f0;
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from { transform: translateY(-10px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

.history-balls {
    display: flex;
    gap: 5px;
}

.mini-ball {
    width: 25px;
    height: 25px;
    border-radius: 50%;
    font-size: 0.8rem;
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
}

footer {
    margin-top: 2rem;
    color: #aaa;
    font-size: 0.9rem;
}