:root {
    /* Paleta de Cores - Clean & Confiável */
    --primary-color: #2F855A;
    /* Verde sóbrio e ação */
    --primary-hover: #276749;
    --bg-color: #F7FAFC;
    /* Cinza muito suave para o fundo */
    --card-bg: #FFFFFF;
    --text-color: #2D3748;
    /* Cinza escuro para texto principal */
    --text-secondary: #718096;
    --border-color: #E2E8F0;
    --shadow-sm: 0 1px 3px 0 rgba(0, 0, 0, 0.1), 0 1px 2px 0 rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);

    /* Espaçamentos */
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;

    /* Configurações Globais */
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
    --radius-md: 12px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: var(--spacing-md);
}

.quiz-container {
    width: 100%;
    max-width: 600px;
    margin: 0 auto;
}

/* Header & Progress Bar */
.quiz-header {
    margin-bottom: var(--spacing-xl);
}

.progress-container {
    background: transparent;
}

.progress-text {
    display: flex;
    justify-content: space-between;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-sm);
}

.progress-bar-bg {
    width: 100%;
    height: 8px;
    background-color: var(--border-color);
    border-radius: 9999px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background-color: var(--primary-color);
    border-radius: 9999px;
    transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Question Card */
.question-card {
    background: transparent;
    border-radius: var(--radius-lg);
    /* No shadow/bg for the main container initially, maybe add it if requested. 
       Keeping it super clean like an app screen on mobile. */
}

.question-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: var(--spacing-xl);
    line-height: 1.3;
}

/* Options */
.options-container {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.option-btn {
    background-color: var(--card-bg);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    text-align: left;
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-color);
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
    position: relative;
    overflow: hidden;
    font-family: var(--font-family);
}

.option-btn:hover {
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.option-btn:active {
    transform: translateY(0);
    background-color: #f0fff4;
    /* Lightest green hint */
}

/* Animation Classes */
.fade-in {
    opacity: 1;
    transition: opacity 0.5s ease-in;
}

.fade-out {
    opacity: 0;
    transition: opacity 0.3s ease-out;
}

/* Mobile Adjustments */
@media (max-width: 480px) {
    .question-title {
        font-size: 1.25rem;
    }

    .option-btn {
        padding: var(--spacing-md);
        font-size: 0.95rem;
    }

    .main-title {
        font-size: 2rem;
    }
}

/* Start Screen Styles */
.start-screen {
    text-align: center;
    padding: var(--spacing-xl) 0;
}

.hero-container {
    margin-bottom: var(--spacing-lg);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.hero-image {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    max-height: 300px;
    /* Limite de altura para não empurrar muito o conteúdo */
}

.main-title {
    font-size: 2.5rem;
    font-weight: 800;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.subtitle {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 480px;
    margin-left: auto;
    margin-right: auto;
}

.hidden {
    display: none !important;
}

/* Primary Button (CTA) */
.cta-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 2.5rem;
    border: none;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 700;
    font-size: 1.125rem;
    transition: var(--transition);
    box-shadow: 0 4px 6px rgba(47, 133, 90, 0.3);
    cursor: pointer;
}

.cta-button:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 8px rgba(47, 133, 90, 0.4);
}

/* Loading Screen */
.loading-screen {
    text-align: center;
    padding: var(--spacing-xl) 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.loading-text {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-color);
    margin-top: var(--spacing-lg);
}

.spinner {
    width: 60px;
    height: 60px;
    border: 5px solid rgba(47, 133, 90, 0.1);
    border-left-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}