:root {
    --primary: #059669;
    /* Emerald 600 */
    --primary-light: #ecfdf5;
    /* Emerald 50 */
    --accent: #10b981;
    /* Emerald 500 */
    --bg-main: #f8fafc;
    --text-dark: #0f172a;
    --text-muted: #64748b;
    --card-bg: #ffffff;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-dark);
    line-height: 1.6;
}

.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: 300px;
    background: white;
    border-right: 1px solid var(--border-color);
    padding: 2rem 1.5rem;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.main-content {
    flex: 1;
    margin-left: 300px;
    padding: 3rem 4rem;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-bottom: 2.5rem;
}

.brand-icon {
    font-size: 1.5rem;
    background: var(--primary-light);
    padding: 0.5rem;
    border-radius: 12px;
}

.brand-name {
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--primary);
}

.nav-group {
    margin-bottom: 2rem;
}

.nav-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    font-weight: 700;
    color: var(--text-muted);
    letter-spacing: 1px;
    margin-bottom: 1rem;
    display: block;
}

.nav-item {
    padding: 0.75rem 1rem;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
    margin-bottom: 0.5rem;
}

.nav-item:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.nav-item.active {
    background: var(--primary);
    color: white;
}

header {
    margin-bottom: 3rem;
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 0.5rem;
}

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

.reasoning-card {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

.reasoning-card:hover {
    transform: translateY(-5px);
}

.question {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 1rem;
    display: flex;
    gap: 0.5rem;
}

.question::before {
    content: 'Q:';
    color: var(--primary);
}

.answer {
    padding: 1rem;
    background: var(--primary-light);
    border-radius: 12px;
    border-left: 4px solid var(--primary);
}

.answer-text {
    font-weight: 500;
}

.keyword {
    color: var(--primary);
    font-weight: 700;
    text-decoration: underline;
}

.chapter-view {
    display: none;
}

.chapter-view.active {
    display: block;
    animation: fadeIn 0.4s ease-out;
}

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

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

.bonus-tag {
    background: #fef3c7;
    color: #b45309;
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    font-size: 0.8rem;
    font-weight: 700;
    float: right;
}

@media (max-width: 1024px) {
    .sidebar {
        width: 80px;
        padding: 1rem;
    }

    .brand-name,
    .nav-label,
    .nav-item span:not(.icon) {
        display: none;
    }

    .main-content {
        margin-left: 80px;
        padding: 2rem;
    }
}