:root {
    --bg-color: #f0f2f5;
    --card-bg: #ffffff;
    --text-color: #1c1e21;
    --number-bg: #e4e6eb;
    --btn-bg: #007bff;
    --btn-hover: #0056b3;
    --border-color: #ddd;
}

.dark-mode {
    --bg-color: #18191a;
    --card-bg: #242526;
    --text-color: #e4e6eb;
    --number-bg: #3a3b3c;
    --btn-bg: #2d88ff;
    --btn-hover: #4b97ff;
    --border-color: #444;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    transition: background-color 0.3s, color 0.3s;
    background-color: var(--bg-color);
    color: var(--text-color);
}

.container {
    text-align: center;
    background-color: var(--card-bg);
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
    width: 90%;
    max-width: 400px;
    position: relative;
    transition: background-color 0.3s, box-shadow 0.3s;
    border: 1px solid var(--border-color);
}

h1 {
    margin-bottom: 2rem;
    font-size: 1.8rem;
}

.theme-toggle {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: var(--number-bg);
    border: 1px solid var(--border-color);
    font-size: 1.2rem;
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
}

.theme-toggle:hover {
    transform: rotate(15deg) scale(1.1);
}

.numbers-container {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 0.8rem;
    margin-bottom: 2rem;
    min-height: 60px;
}

.number {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    background-color: var(--number-bg);
    border-radius: 50%;
    font-size: 1.3rem;
    font-weight: bold;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.2s;
    color: var(--text-color);
}

.number:hover {
    transform: scale(1.1);
}

#generate-btn {
    width: 100%;
    padding: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
    background-color: var(--btn-bg);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s;
}

#generate-btn:hover {
    background-color: var(--btn-hover);
    box-shadow: 0 4px 12px rgba(0, 123, 255, 0.3);
}

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

.divider {
    margin: 2rem 0;
    border: 0;
    border-top: 1px solid var(--border-color);
}

.inquiry-form {
    text-align: left;
}

.inquiry-form h2 {
    font-size: 1.4rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.form-group {
    margin-bottom: 1.2rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    font-weight: 500;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: var(--bg-color);
    color: var(--text-color);
    font-size: 0.95rem;
    box-sizing: border-box;
}

.form-group textarea {
    height: 100px;
    resize: vertical;
}

.submit-btn {
    width: 100%;
    padding: 0.9rem;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    background-color: #28a745;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.submit-btn:hover {
    background-color: #218838;
}