:root {
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --success-color: #28a745;
    --success-bg: #d4edda;
    --error-color: #dc3545;
    --error-bg: #f8d7da;
    --bg-color: #f4f7f6;
    --card-bg: #ffffff;
    --text-color: #333333;
    --border-radius: 8px;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

.screen {
    display: none;
    animation: fadeIn 0.3s ease-in-out;
}

.screen.active {
    display: block;
}

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

h1 {
    text-align: center;
    margin-bottom: 20px;
    color: var(--primary-color);
}

.bank-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 25px;
    background: var(--card-bg);
    padding: 20px;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.bank-option {
    display: flex;
    align-items: center;
    cursor: pointer;
    font-size: 1.1rem;
}

.bank-option input {
    margin-right: 10px;
    width: 18px;
    height: 18px;
}

.btn {
    display: block;
    width: 100%;
    padding: 12px;
    font-size: 1.1rem;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: background-color 0.2s;
    text-align: center;
}

.primary-btn {
    background-color: var(--primary-color);
    color: white;
}

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

.primary-btn:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
}

.secondary-btn {
    background-color: #6c757d;
    color: white;
    margin-top: 10px;
}

.secondary-btn:hover {
    background-color: #5a6268;
}

.error-text {
    color: var(--error-color);
    text-align: center;
    margin-top: 10px;
}

.header-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    font-weight: bold;
    font-size: 1.1rem;
}

.card {
    background: var(--card-bg);
    padding: 25px;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 15px;
}

.tag {
    background: #e9ecef;
    color: #495057;
    padding: 4px 8px;
    border-radius: 4px;
    font-size: 0.85rem;
    font-weight: bold;
}

.tag.easy { background: var(--success-bg); color: #155724; }
.tag.medium { background: #fff3cd; color: #856404; }
.tag.hard { background: var(--error-bg); color: #721c24; }

h2 {
    margin-bottom: 20px;
    font-size: 1.3rem;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.option-label {
    display: flex;
    align-items: flex-start;
    padding: 15px;
    border: 2px solid #e9ecef;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.2s;
    background: #f8f9fa;
}

.option-label:hover {
    background: #e2e6ea;
    border-color: #dae0e5;
}

.option-label input {
    margin-top: 4px;
    margin-right: 15px;
    width: 18px;
    height: 18px;
    flex-shrink: 0;
}

.option-text {
    flex-grow: 1;
}

/* Validation styles */
.option-label.selected {
    border-color: var(--primary-color);
    background: #cce5ff;
}

.option-label.correct {
    border-color: var(--success-color);
    background: var(--success-bg);
}

.option-label.incorrect {
    border-color: var(--error-color);
    background: var(--error-bg);
}

.feedback-card {
    padding: 20px;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
    animation: fadeIn 0.3s ease-in-out;
}

.feedback-card.success {
    background-color: var(--success-bg);
    border-left: 5px solid var(--success-color);
    color: #155724;
}

.feedback-card.error {
    background-color: var(--error-bg);
    border-left: 5px solid var(--error-color);
    color: #721c24;
}

.feedback-card h3 {
    margin-bottom: 10px;
}

.score-display {
    text-align: center;
    background: var(--card-bg);
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    margin-bottom: 30px;
}

#score-percentage {
    font-size: 3rem;
    font-weight: bold;
    color: var(--primary-color);
    margin-top: 10px;
}

/* Markdown code styling */
pre {
    background: #272822;
    color: #f8f8f2;
    padding: 15px;
    border-radius: 5px;
    overflow-x: auto;
    margin: 10px 0;
}

code {
    font-family: Consolas, Monaco, 'Andale Mono', 'Ubuntu Mono', monospace;
}

p code {
    background: #e9ecef;
    padding: 2px 4px;
    border-radius: 3px;
    color: #d63384;
}