:root {
    --primary: #4F46E5;
    --primary-hover: #4338CA;
    --secondary: #64748B;
    --bg: #F8FAFC;
    --surface: #FFFFFF;
    --text-main: #0F172A;
    --text-muted: #475569;
    --success: #10B981;
    --success-bg: #D1FAE5;
    --danger: #EF4444;
    --danger-bg: #FEE2E2;
    --radius: 12px;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg);
    color: var(--text-main);
    line-height: 1.5;
}

#app {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem 1rem;
    position: relative;
    min-height: 100vh;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-muted);
}

.screen {
    display: none;
    animation: fadeIn 0.4s ease-in-out;
}

.screen.active {
    display: block;
}

.card-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.card {
    background: var(--surface);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
    text-align: center;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

.card-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.card h2 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
}

.btn {
    display: inline-block;
    background-color: var(--surface);
    color: var(--text-main);
    font-family: 'Inter', sans-serif;
    font-weight: 600;
    font-size: 0.875rem;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius);
    border: 1px solid #E2E8F0;
    cursor: pointer;
    transition: all 0.2s;
}

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

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

.btn-icon {
    border: none;
    background: transparent;
    color: var(--primary);
    padding: 0;
    font-size: 1rem;
}

.btn-icon:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

.mt-3 {
    margin-top: 1rem;
}

.mt-4 {
    margin-top: 1.5rem;
}

/* Quiz layout */
.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.progress-bar {
    width: 50%;
    height: 8px;
    background-color: #E2E8F0;
    border-radius: 4px;
    overflow: hidden;
}

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

.timer {
    font-weight: 600;
    color: var(--text-muted);
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background-color: var(--primary);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 999px;
    margin-bottom: 1rem;
    text-transform: uppercase;
}

.tema-text {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 600;
    margin-bottom: 0.5rem;
}

.pregunta-text {
    font-size: 1.25rem;
    font-weight: 500;
    margin-bottom: 2rem;
}

.options-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.option {
    background: var(--surface);
    border: 2px solid #E2E8F0;
    border-radius: var(--radius);
    padding: 1rem;
    cursor: pointer;
    font-weight: 500;
    transition: all 0.2s;
    display: flex;
    align-items: center;
}

.option:hover:not(.disabled) {
    border-color: var(--primary);
    background-color: #EEF2FF;
}

.option.selected {
    border-color: var(--primary);
    background-color: #EEF2FF;
}

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

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

.option.disabled {
    cursor: default;
    opacity: 0.8;
}

.feedback-container {
    margin-top: 2rem;
    padding: 1.5rem;
    border-radius: var(--radius);
    background-color: var(--surface);
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary);
    animation: slideUp 0.3s ease-out;
}

.feedback-container.hidden {
    display: none;
}

.feedback-container.correct {
    border-left-color: var(--success);
}

.feedback-container.incorrect {
    border-left-color: var(--danger);
}

#feedback-title {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    font-weight: 600;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        transform: translateY(10px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}