:root {
    --primary-color: #4a90e2;
    --secondary-color: #6c757d;
    --background-color: #f8f9fa;
    --text-color: #212529;
    --card-background: #ffffff;
    --card-shadow: 0 4px 12px rgba(0,0,0,0.1);
    --progress-bg: #e0e0e0;
}

body.dark-mode {
    --background-color: #121212;
    --text-color: #f8f9fa;
    --card-background: #1e1e1e;
    --card-shadow: 0 4px 12px rgba(0,0,0,0.5);
    --progress-bg: #333333;
    --primary-color: #64b5f6;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    transition: background-color 0.3s, color 0.3s;
}

#app {
    width: 100%;
    max-width: 600px;
    text-align: center;
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

h1 {
    color: var(--primary-color);
    margin: 0;
    font-size: 1.5rem;
}

#theme-toggle {
    background: none;
    border: 1px solid var(--secondary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    font-size: 1.2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    color: var(--text-color);
    transition: transform 0.2s;
}

#theme-toggle:hover {
    transform: scale(1.1);
}

#progress-container {
    width: 100%;
    height: 8px;
    background-color: var(--progress-bg);
    border-radius: 4px;
    margin-bottom: 30px;
    overflow: hidden;
}

#progress-bar {
    width: 0%;
    height: 100%;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

.question-card {
    background-color: var(--card-background);
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    padding: 25px;
    margin-bottom: 20px;
    text-align: left;
    animation: fadeIn 0.5s ease-out;
}

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

.question-card p {
    font-size: 1.1rem;
    line-height: 1.5;
    margin-bottom: 20px;
}

.options {
    display: grid;
    gap: 10px;
}

.options button {
    background-color: transparent;
    border: 1px solid var(--primary-color);
    color: var(--primary-color);
    padding: 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s;
}

.options button:hover {
    background-color: var(--primary-color);
    color: white;
}

.options button.selected {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

#submit-btn {
    width: 100%;
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 15px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 600;
    margin-top: 10px;
    transition: opacity 0.2s;
}

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

#result-container {
    margin-top: 30px;
    padding: 30px;
    background-color: var(--card-background);
    border-radius: 12px;
    box-shadow: var(--card-shadow);
    display: none;
}

#result-container.show {
    display: block;
    animation: fadeIn 0.5s ease-out;
}

#result-container h2 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.restart-btn {
    margin-top: 20px;
    background-color: var(--secondary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 6px;
    cursor: pointer;
}