:root {
    --bg-color: #f0f2f5;
    --container-bg: #ffffff;
    --text-color: #333333;
    --secondary-text: #666666;
    --accent-color: #4CAF50;
    --button-bg: #008CBA;
    --button-hover: #005f7a;
    --shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

[data-theme='dark'] {
    --bg-color: #121212;
    --container-bg: #1e1e1e;
    --text-color: #e0e0e0;
    --secondary-text: #b0b0b0;
    --accent-color: #81c784;
    --button-bg: #2196f3;
    --button-hover: #1976d2;
    --shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    display: flex;
    justify-content: center;
    align-items: flex-start;
    min-height: 100vh;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 40px 20px;
    box-sizing: border-box;
    transition: background-color 0.3s, color 0.3s;
}

.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
}

#theme-btn {
    padding: 8px 16px;
    border-radius: 20px;
    border: 1px solid var(--text-color);
    background: transparent;
    color: var(--text-color);
    cursor: pointer;
    font-weight: bold;
}

.container {
    text-align: center;
    background: var(--container-bg);
    padding: 40px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    max-width: 400px;
    width: 100%;
    transition: background-color 0.3s, box-shadow 0.3s;
}

h1 {
    color: var(--text-color);
    margin-bottom: 10px;
}

p {
    color: var(--secondary-text);
    margin-bottom: 30px;
}

.lotto-numbers {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    background-color: var(--accent-color);
    color: white;
    font-size: 20px;
    font-weight: bold;
    border-radius: 50%;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    animation: pop 0.3s ease-out forwards;
}

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

#generate-btn {
    background-color: var(--button-bg);
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 18px;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s, transform 0.2s;
    width: 100%;
}

#generate-btn:hover {
    background-color: var(--button-hover);
}

#generate-btn:active {
    transform: scale(0.98);
}

.contact-section {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--secondary-text);
    text-align: left;
}

.contact-section h2, .comments-section h2 {
    font-size: 1.5rem;
    color: var(--text-color);
    margin-bottom: 20px;
    text-align: center;
}

.comments-section {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--secondary-text);
    text-align: left;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
    color: var(--text-color);
}

.form-group input, 
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 4px;
    background-color: var(--container-bg);
    color: var(--text-color);
    box-sizing: border-box;
    font-family: inherit;
}

[data-theme='dark'] .form-group input, 
[data-theme='dark'] .form-group textarea {
    border-color: #444;
}

.submit-btn {
    width: 100%;
    padding: 12px;
    background-color: var(--accent-color);
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 1rem;
    font-weight: bold;
    cursor: pointer;
    transition: opacity 0.3s;
}

.submit-btn:hover {
    opacity: 0.9;
}