/* style.css - Playful, child-friendly theme */

:root {
    --primary-color: #FF6B6B;
    --secondary-color: #4ECDC4;
    --accent-color: #FFE66D;
    --text-dark: #2C3E50;
    --text-light: #FFFFFF;
    --bg-color: #F7F9FC;
    --sidebar-bg: #FFFFFF;
    --card-bg: #FFFFFF;
    --success-color: #A8E6CF;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    --border-radius: 12px;
    --font-main: 'Comic Sans MS', 'Chalkboard SE', 'Marker Felt', sans-serif;
    --header-height: 64px; /* Standardized height */
    --header-border-color: rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: var(--font-main);
    background-color: var(--bg-color);
    color: var(--text-dark);
    line-height: 1.6;
    overflow: hidden; /* Prevent full-page scroll */
    margin: 0;
    padding: 0;
    height: 100vh;
}

/* App Layout */
.app-container {
    display: flex;
    height: 100vh;
    overflow: hidden;
}

/* Sidebar Styling */
.sidebar {
    width: 280px;
    min-width: 280px;
    flex-shrink: 0;
    background-color: var(--sidebar-bg);
    box-shadow: var(--shadow);
    display: flex;
    flex-direction: column;
    z-index: 10;
    transition: transform 0.3s ease;
}

.sidebar-header {
    height: var(--header-height);
    min-height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 20px;
    background-color: var(--primary-color);
    color: var(--text-light);
    border-bottom: 2px solid var(--header-border-color);
}

.sidebar-header h2 {
    font-size: 1.5rem;
    margin: 0;
    letter-spacing: 1px;
}

#nav-container {
    padding: 16px;
    overflow-y: auto;
    flex-grow: 1;
}

/* Custom Scrollbar for Sidebar */
#nav-container::-webkit-scrollbar {
    width: 6px;
}
#nav-container::-webkit-scrollbar-track {
    background: transparent;
}
#nav-container::-webkit-scrollbar-thumb {
    background-color: rgba(0,0,0,0.15);
    border-radius: 10px;
}
#nav-container::-webkit-scrollbar-thumb:hover {
    background-color: rgba(0,0,0,0.3);
}

.loading {
    text-align: center;
    padding: 20px;
    color: #888;
    font-style: italic;
}

/* Sidebar Navigation Items */
.nav-group {
    margin-bottom: 12px;
}

.nav-grade {
    font-weight: bold;
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 8px;
    padding-bottom: 4px;
    border-bottom: 2px dashed var(--accent-color);
}

.nav-subject {
    margin-left: 12px;
    margin-bottom: 8px;
    font-weight: bold;
    color: var(--secondary-color);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-right: 8px;
    user-select: none;
    transition: color 0.2s;
}

.nav-subject:hover {
    color: var(--primary-color);
}

.subject-icon {
    font-size: 0.8rem;
    transition: transform 0.3s ease;
}

.nav-subject.collapsed .subject-icon {
    transform: rotate(-90deg);
}

.nav-lesson {
    margin-left: 24px;
    list-style: none;
    overflow: hidden;
    max-height: 1000px;
    transition: max-height 0.3s ease-in-out;
}

.nav-lesson.collapsed {
    max-height: 0;
}

.nav-lesson-item {
    padding: 8px 12px;
    margin-bottom: 4px;
    cursor: pointer;
    border-radius: var(--border-radius);
    transition: background-color 0.2s, transform 0.1s;
    font-size: 0.95rem;
}

.nav-lesson-item:hover {
    background-color: rgba(78, 205, 196, 0.1);
    transform: translateX(4px);
}

.nav-lesson-item.active {
    background-color: var(--secondary-color);
    color: var(--text-light);
    font-weight: bold;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

/* Main Content Area */
.content-area {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    max-width: 100%;
    overflow-y: auto;
    height: 100vh;
}

.content-header {
    height: var(--header-height);
    min-height: var(--header-height);
    background-color: var(--card-bg);
    padding: 0 24px;
    border-bottom: 2px solid var(--header-border-color);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 5;
}

.menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--primary-color);
    cursor: pointer;
    margin-right: 16px;
}

.breadcrumbs {
    font-size: 0.9rem;
    color: #666;
    font-weight: bold;
}

.breadcrumbs span {
    margin: 0 4px;
}

.breadcrumbs .current {
    color: var(--primary-color);
}

/* Topic Display Area */
.topic-container {
    flex-grow: 1;
    padding: 24px 40px;
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
}

.welcome-screen {
    text-align: center;
    margin-top: 5vh;
}

.welcome-screen .avatar {
    font-size: 5rem;
    margin-bottom: 16px;
}

.welcome-screen h1 {
    color: var(--primary-color);
    margin-bottom: 16px;
}

.welcome-screen p {
    font-size: 1.2rem;
    color: #666;
}

/* Topic Content Styling */
.topic-card {
    background-color: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 16px 24px;
    box-shadow: var(--shadow);
    border-top: 6px solid var(--secondary-color);
    animation: fadeIn 0.4s ease-out;
    display: flex;
    flex-direction: column;
    height: 100%;
}

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

.topic-title {
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-bottom: 12px;
    text-align: center;
}

.topic-layout-row {
    display: flex;
    gap: 20px;
    align-items: center; /* Center image vertically next to text */
}

.topic-image-column {
    flex: 0 0 38%; /* Image takes 38% of width */
    max-width: 380px;
    display: flex;
    justify-content: center;
}

.topic-image-column img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.12);
    max-height: 300px;
}

.topic-text-column {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 12px; /* Tighter gaps between sections */
}

.topic-section {
    padding: 12px 16px;
    background-color: #fcfcfc;
    border-radius: 8px;
    border-left: 5px solid #ccc;
}

.section-explanation { border-left-color: var(--secondary-color); background-color: rgba(78, 205, 196, 0.05); }
.section-example { border-left-color: var(--accent-color); background-color: rgba(255, 230, 109, 0.1); }
.section-activity { border-left-color: var(--primary-color); background-color: rgba(255, 107, 107, 0.05); }

.section-header {
    display: flex;
    align-items: center;
    font-size: 1.1rem;
    font-weight: bold;
    margin-bottom: 8px;
    color: var(--text-dark);
}

.section-icon {
    margin-right: 12px;
    font-size: 1.4rem;
}

.section-content {
    font-size: 0.95rem;
    line-height: 1.4;
}

/* Footer Navigation Buttons */
.content-footer {
    background-color: var(--card-bg);
    padding: 10px 24px;
    box-shadow: 0 -4px 6px rgba(0, 0, 0, 0.02);
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    bottom: 0;
    z-index: 5;
}

.nav-btn {
    padding: 8px 20px;
    border: none;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: bold;
    font-family: inherit;
    cursor: pointer;
    display: flex;
    align-items: center;
    transition: all 0.2s;
    background-color: #E2E8F0;
    color: #4A5568;
}

.nav-btn:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

.nav-btn:active:not(:disabled) {
    transform: translateY(0);
}

.nav-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.nav-btn .icon {
    font-size: 0.9rem;
}

.prev-btn .icon { margin-right: 8px; }
.next-btn .icon { margin-left: 8px; }

.prev-btn:not(:disabled) {
    background-color: var(--accent-color);
    color: var(--text-dark);
}

.next-btn:not(:disabled) {
    background-color: var(--secondary-color);
    color: var(--text-light);
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        bottom: 0;
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .menu-btn {
        display: block;
    }

    .topic-container {
        padding: 12px;
    }

    .topic-layout-row {
        flex-direction: column; /* Stack image on top of text on tight screens */
    }
    
    .topic-image-column {
        max-width: 100%;
    }
}

/* =========================================
   SIDEBAR TITLE AS HOME BUTTON
   ========================================= */
.sidebar-title-btn {
    display: block;
    width: 100%;
    background: none;
    border: none;
    color: white;
    font-family: 'Nunito', var(--font-main);
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: 1px;
    cursor: pointer;
    text-align: center;
    padding: 0;
    margin: 0;
    transition: transform 0.2s ease, opacity 0.2s ease;
    line-height: 1;
}
.sidebar-title-btn:hover {
    transform: scale(1.06);
    opacity: 0.88;
}

/* =========================================
   HOME PAGE — Full Layout
   ========================================= */
.home-page {
    padding: 20px 24px 40px;
    animation: fadeInUp 0.4s ease;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
}

.home-banner {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    margin-bottom: 16px;
    background: linear-gradient(90deg, rgba(78,205,196,0.12), rgba(78,205,196,0.04));
    border-radius: 12px;
    border-left: 4px solid var(--secondary-color);
}

.home-banner-emoji {
    font-size: 1.6rem;
    line-height: 1;
}

.home-banner-text {
    font-family: 'Nunito', var(--font-main);
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-dark);
}

/* =========================================
   SUBJECT CARDS GRID
   ========================================= */
.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 20px;
    margin-top: 8px;
}

.subject-card {
    background: white;
    border-radius: 16px;
    padding: 24px 20px 20px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
    border-top: 5px solid var(--card-accent);
    cursor: pointer;
    transition: transform 0.22s ease, box-shadow 0.22s ease;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.subject-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 28px rgba(0,0,0,0.14);
}

.subject-card-emoji {
    font-size: 40px;
    line-height: 1;
}

.subject-card-title {
    font-family: 'Nunito', var(--font-main);
    font-size: 1.25rem;
    font-weight: 800;
    color: var(--text-dark);
    margin: 0;
}

.subject-card-desc {
    font-size: 0.9rem;
    color: #555;
    line-height: 1.55;
    flex-grow: 1;
}

.subject-card-meta {
    font-size: 0.8rem;
    font-weight: 700;
    color: #999;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.subject-card-btn {
    margin-top: 6px;
    padding: 10px 18px;
    color: white;
    border: none;
    border-radius: 24px;
    font-family: 'Nunito', var(--font-main);
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    transition: opacity 0.2s ease, transform 0.2s ease;
    align-self: flex-start;
}

.subject-card-btn:hover {
    opacity: 0.88;
    transform: scale(1.05);
}

/* =========================================
   GLOBAL FONT UPGRADE (Nunito)
   ========================================= */
body {
    font-family: 'Nunito', 'Comic Sans MS', 'Chalkboard SE', sans-serif;
}

/* =========================================
   TAKE QUIZ BUTTON (in topic card)
   ========================================= */
.take-quiz-btn {
    display: block;
    width: 100%;
    margin-top: 20px;
    padding: 14px 24px;
    background: linear-gradient(135deg, #4ECDC4, #26A69A);
    color: white;
    border: none;
    border-radius: 30px;
    font-family: 'Nunito', var(--font-main);
    font-size: 1.1rem;
    font-weight: 800;
    cursor: pointer;
    letter-spacing: 0.5px;
    box-shadow: 0 4px 12px rgba(78,205,196,0.35);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.take-quiz-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(78,205,196,0.45); }
.take-quiz-disabled { background: linear-gradient(135deg,#b0bec5,#90a4ae); box-shadow:none; cursor:not-allowed; opacity:0.7; }
.take-quiz-disabled:hover { transform: none; }

/* =========================================
   QUIZ PANEL
   ========================================= */
.quiz-panel {
    background: white;
    border-radius: 16px;
    padding: 28px 32px;
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
    animation: fadeIn 0.3s ease;
    display: flex;
    flex-direction: column;
    gap: 18px;
}
.quiz-header { display:flex; justify-content:space-between; align-items:center; }
.quiz-subject-label { font-size:1rem; font-weight:800; color:var(--secondary-color); }
.quiz-progress-label { font-size:0.9rem; color:#888; font-weight:600; }

.quiz-progress-bar { height:8px; background:#e0f7fa; border-radius:8px; overflow:hidden; }
.quiz-progress-fill { height:100%; background:linear-gradient(90deg,#4ECDC4,#26A69A); border-radius:8px; transition:width 0.4s ease; }

.quiz-question {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-dark);
    line-height: 1.5;
    padding: 16px 20px;
    background: #f8f9fa;
    border-radius: 12px;
    border-left: 5px solid var(--secondary-color);
}

.quiz-options { display:grid; grid-template-columns:1fr 1fr; gap:12px; }

.quiz-option-btn {
    padding: 14px 16px;
    background: white;
    border: 2px solid #e0e0e0;
    border-radius: 12px;
    font-family: 'Nunito', var(--font-main);
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-dark);
    cursor: pointer;
    text-align: left;
    line-height: 1.4;
    transition: border-color 0.15s, background 0.15s, transform 0.1s;
}
.quiz-option-btn:hover:not(:disabled) { border-color:var(--secondary-color); background:rgba(78,205,196,0.08); transform:translateY(-1px); }
.quiz-option-btn.quiz-correct { background:#e8f5e9; border-color:#43A047; color:#2e7d32; font-weight:800; }
.quiz-option-btn.quiz-wrong   { background:#ffebee; border-color:#e53935; color:#c62828; }

.quiz-feedback { padding:14px 18px; border-radius:12px; font-size:0.95rem; line-height:1.5; animation:fadeIn 0.3s ease; }
.quiz-feedback-right { background:#e8f5e9; border-left:5px solid #43A047; color:#2e7d32; }
.quiz-feedback-wrong { background:#ffebee; border-left:5px solid #e53935; color:#c62828; }

.quiz-actions { display:flex; justify-content:flex-end; }
.quiz-next-btn {
    padding: 12px 28px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 24px;
    font-family: 'Nunito', var(--font-main);
    font-size: 1rem;
    font-weight: 800;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s;
    box-shadow: 0 4px 10px rgba(255,107,107,0.3);
}
.quiz-next-btn:hover { transform:translateY(-2px); box-shadow:0 6px 16px rgba(255,107,107,0.4); }

.quiz-back-link { background:none; border:none; color:#888; font-family:'Nunito',var(--font-main); font-size:0.9rem; cursor:pointer; text-decoration:underline; padding:0; align-self:flex-start; }
.quiz-back-link:hover { color:var(--primary-color); }

/* =========================================
   QUIZ RESULT SCREEN
   ========================================= */
.quiz-result-panel { text-align:center; gap:14px; padding:48px 32px; }
.quiz-result-emoji { font-size:4rem; }
.quiz-result-title { font-size:1.8rem; font-weight:800; color:var(--text-dark); }
.quiz-result-score { font-size:3rem; font-weight:900; color:var(--secondary-color); }
.quiz-result-stars { font-size:2rem; letter-spacing:4px; }
.quiz-result-msg   { font-size:1.1rem; color:#555; font-weight:600; }
.quiz-result-actions { display:flex; justify-content:center; gap:16px; margin-top:8px; }
.quiz-retry-btn, .quiz-back-btn {
    padding: 12px 28px;
    border: none;
    border-radius: 24px;
    font-family: 'Nunito', var(--font-main);
    font-size: 1rem;
    font-weight: 800;
    cursor: pointer;
    transition: transform 0.15s;
}
.quiz-retry-btn { background:var(--primary-color); color:white; box-shadow:0 4px 10px rgba(255,107,107,0.3); }
.quiz-back-btn  { background:#f0f0f0; color:var(--text-dark); }
.quiz-continue-btn { background:linear-gradient(135deg,#4ECDC4,#26A69A); color:white; box-shadow:0 4px 10px rgba(78,205,196,0.3); }
.quiz-retry-btn:hover, .quiz-back-btn:hover, .quiz-continue-btn:hover { transform:translateY(-2px); }