:root {
    --sidebar-bg: #3e2723; /* Marrom Café */
    --main-bg: #fdfaf5;    /* Creme Papel */
    --accent: #8d6e63;      /* Terracota */
    --text-dark: #3c2f2f;
    --white: #ffffff;
    --highlight: #d7ccc8;
    --correct: #6d8c54;
    --wrong: #a65d57;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: 'Segoe UI', Tahoma, sans-serif; background: var(--main-bg); color: var(--text-dark); overflow: hidden; }

#app { display: flex; height: 100vh; }

/* Sidebar 15% */
#sidebar { 
    width: 15%; background: var(--sidebar-bg); color: var(--white); 
    padding: 20px 10px; display: flex; flex-direction: column;
    border-right: 1px solid var(--accent);
}

.logo { font-weight: 800; font-size: 1.1rem; color: var(--highlight); margin-bottom: 30px; text-align: center; border-bottom: 1px solid var(--accent); padding-bottom: 10px; }

#menu-topicos { list-style: none; overflow-y: auto; flex-grow: 1; }
.topico-link { 
    padding: 12px 10px; font-size: 0.8rem; cursor: pointer; border-radius: 6px; margin-bottom: 5px; transition: 0.2s; color: var(--highlight);
}
.topico-link:hover { background: rgba(255,255,255,0.1); }
.topico-link.active { background: var(--accent); color: var(--white); }

/* Área de Conteúdo 85% */
#content { width: 85%; display: flex; flex-direction: column; }

#top-bar { background: var(--white); padding: 15px 40px; border-bottom: 1px solid #d7ccc8; display: flex; justify-content: space-between; align-items: center; font-size: 0.9rem; }

#display-area { flex-grow: 1; padding: 40px; overflow-y: auto; }

/* Cards */
.card-aula { background: var(--white); padding: 30px; border-radius: 12px; border-left: 6px solid var(--accent); line-height: 1.6; margin-bottom: 25px; box-shadow: 0 4px 6px rgba(0,0,0,0.03); }
.card-questao { background: var(--white); padding: 35px; border-radius: 12px; box-shadow: 0 10px 15px -3px rgba(0,0,0,0.05); }
.enunciado { font-size: 1.1rem; font-weight: 600; margin-bottom: 25px; color: var(--text-dark); }

/* Botões de Alternativa */
#q-options { display: flex; flex-direction: column; gap: 12px; }
.btn-modulo { 
    width: 100%; text-align: left; padding: 16px; border: 1px solid #d7ccc8; 
    border-radius: 8px; background: #fafafa; cursor: pointer; font-size: 0.95rem; transition: 0.2s;
}
.btn-modulo:hover { background: var(--highlight); }

/* Feedback */
#q-feedback { margin-top: 20px; padding: 20px; border-radius: 8px; line-height: 1.5; font-size: 0.95rem; }

#nav-footer { background: var(--white); padding: 20px 40px; display: flex; justify-content: space-between; border-top: 1px solid #d7ccc8; }
.nav-btn { padding: 12px 25px; border-radius: 6px; cursor: pointer; border: none; font-weight: 600; background: var(--sidebar-bg); color: var(--white); }