:root {
    --bg-color: #fdfbfb;
    --text-color: #333;
    --card-bg: rgba(255, 255, 255, 0.95);
    --input-bg: #fff;
    --primary-color: #2563eb;
    --primary-hover: #1d4ed8;
    --border-color: #e5e7eb;
    --shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
}

body.dark-mode {
    --bg-color: #0f172a;
    --text-color: #f8fafc;
    --card-bg: #1e293b;
    --input-bg: #334155;
    --primary-color: #3b82f6;
    --primary-hover: #60a5fa;
    --border-color: #475569;
    --shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.3), 0 8px 10px -6px rgba(0, 0, 0, 0.3);
}

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

body {
    background: var(--bg-color);
    color: var(--text-color);
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 2rem;
    transition: background 0.3s ease, color 0.3s ease;
}

.theme-toggle {
    position: fixed;
    top: 2rem;
    right: 2rem;
    padding: 0.6rem 1.2rem;
    border-radius: 9999px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    color: var(--text-color);
    cursor: pointer;
    font-weight: 600;
    font-size: 0.875rem;
    box-shadow: var(--shadow);
    transition: all 0.2s ease;
}

.theme-toggle:hover {
    transform: translateY(-2px);
    border-color: var(--primary-color);
}

.container {
    width: 100%;
    max-width: 550px;
    background: var(--card-bg);
    padding: 3rem;
    border-radius: 1.5rem;
    box-shadow: var(--shadow);
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.025em;
    margin-bottom: 0.75rem;
    background: linear-gradient(to right, var(--primary-color), #8b5cf6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.sub-title {
    font-size: 1.125rem;
    opacity: 0.7;
    line-height: 1.6;
}

.inquiry-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    opacity: 0.9;
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 0.75rem 1rem;
    border-radius: 0.5rem;
    border: 1px solid var(--border-color);
    background: var(--input-bg);
    color: var(--text-color);
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.2s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.submit-btn {
    margin-top: 1rem;
    padding: 1rem;
    border-radius: 0.5rem;
    background: var(--primary-color);
    color: white;
    border: none;
    font-size: 1.125rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s ease;
}

.submit-btn:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}

footer {
    margin-top: 3rem;
    text-align: center;
    font-size: 0.875rem;
    opacity: 0.5;
}

@media (max-width: 640px) {
    .container {
        padding: 2rem 1.5rem;
    }
    h1 {
        font-size: 2rem;
    }
}