:root {
    --primary: #2563EB;
    --primary-hover: #1D4ED8;
    --bg-color: #F8FAFC;
    --surface: #FFFFFF;
    --text-main: #0F172A;
    --text-muted: #475569;
    --border: #E2E8F0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-main);
    margin: 0;
    padding: 0;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    margin: 0 auto;
    padding: 60px 20px;
}

header {
    text-align: center;
    margin-bottom: 50px;
}

h1 {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 10px;
}

.subtitle {
    color: var(--text-muted);
    font-size: 1.1rem;
}

/* Level Cards (Main Page) */
.level-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
    border-color: var(--primary);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.card h2 {
    margin: 0 0 10px;
    font-size: 1.5rem;
    color: var(--text-main);
}

.card p {
    margin: 0;
    color: var(--text-muted);
    font-size: 0.95rem;
}

/* Questions Area */
.questions-container {
    background: transparent;
    animation: fadeIn 0.4s ease;
}

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

.level-indicator {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    margin-bottom: 30px;
    border-bottom: 1px solid var(--border);
    padding-bottom: 15px;
}

.back-btn {
    background: none;
    border: none;
    color: var(--primary);
    font-weight: 600;
    cursor: pointer;
    padding: 0;
    margin-bottom: 10px;
    font-size: 0.95rem;
    display: flex;
    align-items: center;
}

.back-btn:hover {
    text-decoration: underline;
}

.level-indicator h2 {
    margin: 0;
    font-size: 1.8rem;
    color: var(--text-main);
}

.question-list {
    display: none;
}

.question-list.active {
    display: block;
    animation: fadeIn 0.4s ease;
}

/* Accordion Styles */
.faq-item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 15px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: border-color 0.2s;
}

.faq-item:hover {
    border-color: #CBD5E1;
}

.faq-question {
    width: 100%;
    text-align: left;
    background: transparent;
    border: none;
    padding: 24px 20px;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: background 0.2s;
}

.faq-question:hover {
    background: #F8FAFC;
}

.toggle-icon {
    font-size: 1.5rem;
    color: var(--primary);
    transition: transform 0.3s ease;
    flex-shrink: 0;
    margin-left: 20px;
    font-weight: 400;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s ease-in-out;
    background: #F8FAFC;
}

.answer-content {
    padding: 0 20px 24px 20px;
    color: var(--text-muted);
}

.answer-content p {
    margin-top: 0;
}

.answer-content ul {
    margin-bottom: 0;
}

.faq-item.active .faq-answer {
    max-height: 1000px; /* Arbitrary large max-height for animation */
}

.faq-item.active .toggle-icon {
    transform: rotate(45deg);
}

.faq-item.active .faq-question {
    background: #F8FAFC;
    padding-bottom: 16px;
}

/* Footer Styles */
footer {
    text-align: center;
    padding: 30px 20px;
    margin-top: 40px;
    border-top: 1px solid #CBD5E1;
    color: var(--text-muted);
}

footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

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