:root {
    --bg-color: #f0f2f5;
    --container-bg: #fff;
    --text-color: #333;
    --number-bg: #4CAF50;
    --number-text: #fff;
    --btn-bg: #007bff;
    --btn-hover: #0056b3;
    --shadow: rgba(0, 0, 0, 0.1);
    --input-bg: #fff;
    --input-border: #ddd;
}

.dark-mode {
    --bg-color: #1a1a1a;
    --container-bg: #2d2d2d;
    --text-color: #f0f2f5;
    --number-bg: #66bb6a;
    --number-text: #1a1a1a;
    --btn-bg: #3f51b5;
    --btn-hover: #303f9f;
    --shadow: rgba(0, 0, 0, 0.5);
    --input-bg: #3d3d3d;
    --input-border: #444;
}

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

body {
    font-family: 'Pretendard', 'Malgun Gothic', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: background-color 0.3s, color 0.3s;
    padding: 40px 20px;
}

.main-layout {
    display: flex;
    flex-direction: column;
    gap: 30px;
    width: 100%;
    max-width: 500px;
}

.container {
    background-color: var(--container-bg);
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 10px 30px var(--shadow);
    text-align: center;
    transition: background-color 0.3s, box-shadow 0.3s;
}

h1, h2 {
    margin-bottom: 25px;
    color: var(--text-color);
    font-size: 1.5rem;
}

#lotto-numbers {
    display: flex;
    justify-content: center;
    margin-bottom: 25px;
    flex-wrap: wrap;
    gap: 12px;
}

.lotto-number {
    width: 45px;
    height: 45px;
    border-radius: 50%;
    background-color: var(--number-bg);
    color: var(--number-text);
    font-size: 18px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-weight: bold;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

#generate-btn, .submit-btn {
    background-color: var(--btn-bg);
    color: #fff;
    border: none;
    padding: 14px 24px;
    font-size: 16px;
    font-weight: bold;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
    width: 100%;
}

#generate-btn:hover, .submit-btn:hover {
    background-color: var(--btn-hover);
    transform: translateY(-2px);
}

#theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    background-color: var(--btn-bg);
    color: #fff;
    border: none;
    padding: 10px 20px;
    border-radius: 30px;
    cursor: pointer;
    font-size: 14px;
    font-weight: bold;
    transition: all 0.3s;
    z-index: 1000;
    box-shadow: 0 4px 10px var(--shadow);
}

#theme-toggle:hover {
    background-color: var(--btn-hover);
}

/* 폼 스타일 */
.contact-section form {
    text-align: left;
}

.form-group {
    margin-bottom: 18px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: bold;
    font-size: 14px;
}

.form-group input, .form-group textarea {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--input-border);
    border-radius: 6px;
    background-color: var(--input-bg);
    color: var(--text-color);
    font-size: 15px;
    transition: border-color 0.3s;
}

.form-group input:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--btn-bg);
}

.form-group textarea {
    height: 120px;
    resize: vertical;
}

@media (max-width: 480px) {
    .container {
        padding: 20px;
    }
    .lotto-number {
        width: 40px;
        height: 40px;
        font-size: 16px;
    }
}