/* -- Color Palette & Fonts -- */
:root {
    --primary-color: #2c3e50;
    --secondary-color: #e74c3c;
    --accent-color: #3498db;
    --light-color: #ecf0f1;
    --dark-color: #2c3e50;
    --success-color: #2ecc71;
    --warning-color: #f39c12;
    --danger-color: #e74c3c;
    --info-color: #3498db;
    --bg-color: #f8f9fa;
    --card-bg: #ffffff;
    --text-color: #333333;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 10px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s ease;
    --font-heading: 'Playfair Display', serif;
    --font-body: 'Lato', sans-serif;
    --font-special: 'Poppins', sans-serif;
}

/* Dark Mode Colors */
.dark-mode {
    --primary-color: #3498db;
    --secondary-color: #e74c3c;
    --accent-color: #f39c12;
    --light-color: #34495e;
    --dark-color: #ecf0f1;
    --bg-color: #1a1a1a;
    --card-bg: #2c2c2c;
    --text-color: #f8f9fa;
    --shadow: 0 4px 6px rgba(0, 0, 0, 0.3);
    --shadow-hover: 0 10px 20px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
    overflow-x: hidden;
}

/* Ensure proper text alignment for LTR/RTL content */
[dir="rtl"] {
    text-align: right;
}

/* -- Header & Navigation -- */
header {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    color: white;
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow);
}

header::before {
    content: "";
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0) 70%);
    z-index: 1;
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 2;
}

header h1 {
    font-family: var(--font-heading);
    font-size: 2.8rem;
    margin-bottom: 0.5rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
    animation: fadeInDown 1s ease;
}

header p {
    font-size: 1.2rem;
    font-style: italic;
    margin-bottom: 1.5rem;
    animation: fadeInUp 1s ease;
}

header .subtitle {
    font-size: 1rem;
    font-style: normal;
    margin-top: 0.5rem;
    opacity: 0.9;
}

/* Theme Toggle Button */
.theme-toggle {
    position: absolute;
    top: 20px;
    right: 20px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: var(--transition);
    z-index: 3;
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: rotate(180deg);
}

/* Cheat Sheet Navigation */
.cheat-sheet-nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
    margin-top: 1.5rem;
    animation: fadeIn 1.5s ease;
}

.cheat-sheet-btn {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 30px;
    padding: 8px 16px;
    cursor: pointer;
    font-family: var(--font-special);
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.cheat-sheet-btn::before {
    content: "";
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: rgba(255, 255, 255, 0.2);
    transition: left 0.3s ease;
}

.cheat-sheet-btn:hover::before {
    left: 0;
}

.cheat-sheet-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.cheat-sheet-btn.active {
    background: rgba(255, 255, 255, 0.3);
    border-color: white;
}

/* -- Main Content & Sidebar -- */
.container {
    display: flex;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem 20px;
    gap: 2rem;
}

/* Sidebar Navigation */
.sidebar {
    width: 250px;
    flex-shrink: 0;
    background: var(--card-bg);
    border-radius: 10px;
    padding: 1.5rem;
    height: fit-content;
    position: sticky;
    top: 20px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    display: none;
}

.sidebar.open {
    display: block;
}

.sidebar h3 {
    font-family: var(--font-special);
    margin-bottom: 1rem;
    color: var(--primary-color);
    font-size: 1.2rem;
}

.sidebar ul {
    list-style: none;
}

.sidebar li {
    margin-bottom: 0.5rem;
}

.sidebar a {
    color: var(--text-color);
    text-decoration: none;
    padding: 0.5rem;
    display: block;
    border-radius: 5px;
    transition: var(--transition);
}

.sidebar a:hover {
    background: var(--light-color);
    color: var(--primary-color);
    padding-left: 1rem;
}

.sidebar a.active {
    background: var(--primary-color);
    color: white;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
    display: none;
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary-color);
    color: white;
    width: 60px;
    height: 60px;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    box-shadow: var(--shadow-hover);
    z-index: 1000;
    font-size: 1.5rem;
    transition: var(--transition);
}

.mobile-menu-toggle:hover {
    transform: scale(1.1);
}

/* Main Content */
main {
    flex: 1;
}

/* -- Progress Bar -- */
.progress-container {
    background: var(--light-color);
    border-radius: 10px;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    padding: 1rem;
    font-family: var(--font-special);
    font-weight: 500;
}

.progress-bar {
    height: 10px;
    background: #ddd;
    border-radius: 5px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--secondary-color), var(--accent-color));
    width: 0%;
    transition: width 0.5s ease;
}

/* -- Chapter Styles -- */
.chapter {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.chapter::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: var(--accent-color);
}

.chapter:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-hover);
}

.chapter h2 {
    font-family: var(--font-heading);
    font-size: 2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    position: relative;
    padding-bottom: 0.5rem;
}

.chapter h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--secondary-color);
}

.chapter-description {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
    opacity: 0.8;
}

.chapter-image {
    width: 100%;
    max-width: 500px;
    display: block;
    margin: 1.5rem auto;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.chapter-image:hover {
    transform: scale(1.02);
    box-shadow: var(--shadow-hover);
}

.decorative-image {
    max-width: 200px;
    display: block;
    margin: 1.5rem auto;
    opacity: 0.7;
}

.inline-image {
    max-width: 100%;
    border-radius: 5px;
    margin: 1rem 0;
}

/* -- Card Styles -- */
.card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-left: 4px solid var(--accent-color);
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.card h3 {
    font-family: var(--font-special);
    font-size: 1.5rem;
    color: var(--primary-color);
    margin-top: 0;
    margin-bottom: 1rem;
}

.card h4 {
    font-family: var(--font-special);
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-top: 1.5rem;
    margin-bottom: 0.8rem;
}

.card h4.sub-heading {
    margin-top: 1.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--light-color);
}

.pronunciation {
    font-weight: 600;
    color: var(--secondary-color);
    background: rgba(231, 76, 60, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 5px;
    display: inline-block;
    margin: 0.5rem 0;
    border-left: 3px solid var(--secondary-color);
}

.card .details {
    margin: 1rem 0;
    font-size: 1.05rem;
}

.details-list {
    padding-left: 1.5rem;
    list-style-type: disc;
    margin: 1rem 0;
}

.details-list li {
    margin-bottom: 0.5rem;
}

[dir="rtl"] .details-list {
    padding-left: 0;
    padding-right: 1.5rem;
}

[dir="rtl"] .details-list p,
[dir="rtl"] .details-list .pronunciation {
    text-align: right;
}

/* -- Pro Tip Box -- */
.pro-tip {
    background: rgba(241, 196, 15, 0.1);
    border: 1px solid rgba(241, 196, 15, 0.3);
    border-left: 4px solid var(--warning-color);
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    border-radius: 5px;
    position: relative;
}

[dir="rtl"].pro-tip {
    border-left: none;
    border-right: 4px solid var(--warning-color);
}

.pro-tip::before {
    content: "\f0eb";
    font-family: "Font Awesome 5 Free";
    font-weight: 900;
    position: absolute;
    top: -10px;
    left: 10px;
    background: var(--warning-color);
    color: white;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
}

[dir="rtl"].pro-tip::before {
    left: auto;
    right: 10px;
}

.pro-tip h4 {
    margin-top: 0;
    margin-left: 1.5rem;
    color: var(--warning-color);
}

.pro-tip ul, .pro-tip p {
    margin: 0.5rem 0;
}

.pro-tip ul {
    padding-left: 1.5rem;
}

[dir="rtl"] .pro-tip ul {
    padding-left: 0;
    padding-right: 1.5rem;
}

/* -- Tag -- */
.tag {
    font-size: 0.8rem;
    background: var(--accent-color);
    color: white;
    padding: 0.2rem 0.6rem;
    border-radius: 20px;
    vertical-align: middle;
    margin-left: 0.5rem;
}

/* -- Audio Container -- */
.audio-container {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 1rem;
    margin: 1.5rem 0;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--info-color);
    transition: var(--transition);
}

.audio-container:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.audio-container span {
    display: block;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--primary-color);
}

audio {
    width: 100%;
    margin-top: 0.5rem;
    border-radius: 5px;
}

.audio-container.playing {
    border-left-color: var(--success-color);
}

/* -- Exercise Card -- */
.exercise-card {
    background: linear-gradient(135deg, rgba(52, 152, 219, 0.1), rgba(155, 89, 182, 0.1));
    border: 1px solid rgba(52, 152, 219, 0.2);
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.exercise-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.exercise-card h3 {
    font-family: var(--font-special);
    color: var(--accent-color);
    margin-top: 0;
}

/* -- Verb and Dialogue Styles -- */
.verb-conjugation {
    list-style-type: none;
    padding: 0;
    margin: 1rem 0;
}

.verb-conjugation li {
    padding: 0.8rem 1rem;
    margin-bottom: 0.5rem;
    background: var(--light-color);
    border-radius: 5px;
    border-left: 3px solid var(--secondary-color);
    transition: var(--transition);
}

.verb-conjugation li:hover {
    transform: translateX(5px);
    background: rgba(231, 76, 60, 0.1);
}

[dir="rtl"] .verb-conjugation li {
    border-left: none;
    border-right: 3px solid var(--secondary-color);
}

[dir="rtl"] .verb-conjugation li:hover {
    transform: translateX(-5px);
}

.dialogue {
    background: var(--light-color);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    box-shadow: var(--shadow);
    position: relative;
}

.dialogue::before {
    content: "\f075";
    font-family: "Font Awesome 5 Free";
    font-weight: 900;
    position: absolute;
    top: -10px;
    left: 10px;
    background: var(--info-color);
    color: white;
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
}

[dir="rtl"].dialogue::before {
    left: auto;
    right: 10px;
}

.dialogue p {
    margin: 0 0 0.8rem 0;
}

.dialogue p:last-child {
    margin-bottom: 0;
}

/* -- Alphabet & Columns -- */
.alphabet-list, .columns {
    list-style: none;
    padding: 0;
    columns: 2;
    -webkit-columns: 2;
    -moz-columns: 2;
    column-gap: 2rem;
    margin: 1rem 0;
}

.alphabet-list li, .columns li {
    padding: 0.5rem 0;
    break-inside: avoid;
    border-bottom: 1px dashed var(--light-color);
}

/* -- Toggle Button -- */
.toggle-btn {
    display: inline-block;
    margin: 0.5rem 0;
    font-size: 0.9rem;
    padding: 0.5rem 1rem;
    cursor: pointer;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 5px;
    transition: var(--transition);
}

.toggle-btn:hover {
    background: var(--accent-color);
    transform: translateY(-2px);
}

/* -- Interactive Exercise -- */
.interactive-exercise {
    margin: 1.5rem 0;
    padding: 1.5rem;
    background: var(--card-bg);
    border-radius: 8px;
    box-shadow: var(--shadow);
    border: 1px solid var(--light-color);
}

.interactive-exercise label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--primary-color);
}

.interactive-exercise input[type="text"] {
    width: 100%;
    max-width: 300px;
    padding: 0.8rem;
    margin-bottom: 1rem;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-family: var(--font-body);
    font-size: 1rem;
    transition: var(--transition);
}

.interactive-exercise input[type="text"]:focus {
    outline: none;
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

.interactive-exercise button {
    background: var(--secondary-color);
    color: white;
    border: none;
    border-radius: 5px;
    padding: 0.8rem 1.5rem;
    margin-right: 1rem;
    margin-bottom: 0.5rem;
    cursor: pointer;
    font-family: var(--font-special);
    font-weight: 500;
    transition: var(--transition);
}

.interactive-exercise button:hover {
    background: var(--primary-color);
    transform: translateY(-2px);
}

.interactive-exercise #spelling-result {
    margin-top: 1rem;
    font-weight: 600;
    padding: 0.8rem;
    border-radius: 5px;
    background: var(--light-color);
}

/* -- Cheat Sheets -- */
.cheat-sheets-container {
    margin-bottom: 2rem;
}

.cheat-sheet {
    background: var(--card-bg);
    border: 1px solid var(--light-color);
    border-radius: 10px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    animation: fadeIn 0.5s ease;
}

.cheat-sheet h3 {
    font-family: var(--font-heading);
    color: var(--primary-color);
    margin-top: 0;
    margin-bottom: 1rem;
    text-align: center;
    position: relative;
    padding-bottom: 0.5rem;
}

.cheat-sheet h3::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 50px;
    height: 3px;
    background: var(--secondary-color);
}

.cheat-sheet.hidden {
    display: none;
}

/* -- Footer -- */
footer {
    text-align: center;
    margin-top: 3rem;
    padding: 2rem 0;
    border-top: 1px solid var(--light-color);
    font-size: 0.9rem;
    color: var(--text-color);
    opacity: 0.8;
}

/* -- Animations -- */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* -- Responsive Design -- */
@media (min-width: 992px) {
    .sidebar {
        display: block;
    }
    
    .mobile-menu-toggle {
        display: none;
    }
}

@media (max-width: 768px) {
    .container {
        flex-direction: column;
    }
    
    header h1 {
        font-size: 2.2rem;
    }
    
    .chapter h2 {
        font-size: 1.8rem;
    }
    
    .card h3 {
        font-size: 1.3rem;
    }
    
    .card h4 {
        font-size: 1.1rem;
    }
    
    .alphabet-list, .columns {
        columns: 1;
        -webkit-columns: 1;
        -moz-columns: 1;
    }
    
    .chapter-image, .decorative-image, .inline-image {
        max-width: 100%;
        height: auto;
    }
    
    .cheat-sheet-btn {
        font-size: 0.9rem;
        padding: 0.5rem 1rem;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.8rem;
    }
    
    .chapter h2 {
        font-size: 1.5rem;
    }
    
    .card h3 {
        font-size: 1.2rem;
    }
    
    .card h4 {
        font-size: 1rem;
    }
    
    .pronunciation {
        font-size: 0.9rem;
        padding: 0.4rem 0.8rem;
    }
    
    .audio-container {
        padding: 0.8rem;
    }
    
    .cheat-sheet-btn {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
}