:root {
    --primary-color: #0056b3;
    --secondary-color: #004494;
    --accent-color: #e6f2ff;
    --text-color: #333;
    --bg-color: #f0f8ff;
    --card-bg: #ffffff;
    --font-main: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background-color: var(--card-bg);
    padding: 1rem 2rem;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo img {
    height: 50px;
    width: auto;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
    max-width: 800px;
    margin: 0 auto;
    width: 100%;
    box-sizing: border-box;
}

.survey-container {
    background-color: var(--card-bg);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 8px 16px rgba(0,0,0,0.05);
    width: 100%;
    box-sizing: border-box;
}

h1, h2, h3 {
    color: var(--primary-color);
}

p {
    line-height: 1.6;
    color: #4a5568;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    transition: background-color 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 1rem;
}

.btn:hover {
    background-color: var(--secondary-color);
}

.btn-secondary {
    background-color: #e2e8f0;
    color: #4a5568;
}

.btn-secondary:hover {
    background-color: #cbd5e0;
}

.navigation-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 2rem;
}

/* Unique Architecture: Stacked buttons on mobile, specific spacing */
@media (max-width: 600px) {
    .navigation-buttons {
        flex-direction: column-reverse;
        gap: 1rem;
    }
    .btn {
        width: 100%;
        text-align: center;
    }
}

/* Progress Bar */
.progress-container {
    width: 100%;
    background-color: #e2e8f0;
    border-radius: 4px;
    margin-bottom: 2rem;
    height: 8px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background-color: var(--primary-color);
    width: 0%;
    transition: width 0.5s ease;
}

footer {
    background-color: var(--card-bg);
    padding: 2rem;
    text-align: center;
    border-top: 1px solid #e2e8f0;
    font-size: 0.9rem;
}

footer a {
    color: var(--primary-color);
    text-decoration: none;
    margin: 0 10px;
}

footer a:hover {
    text-decoration: underline;
}

.options-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin: 1.5rem 0;
}

.option-label {
    display: flex;
    align-items: center;
    padding: 1rem;
    border: 2px solid #e2e8f0;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s;
}

.option-label:hover {
    border-color: var(--primary-color);
    background-color: var(--accent-color);
}

.option-label input {
    margin-right: 1rem;
}