/* ===============================
   CSS VARIABLES & THEMES
   =============================== */

   :root {
    --primary-color: #e12830;
    --secondary-color: #f0f0f0;
    --text-color: #333;
    --background-color: #fff;
    --card-background: #f9f9f9;
    --border-color: #ddd;
    --highlight-color: #ffeb3b;
    --hover-color: #d1242c;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --correct-color: #4caf50;
    --incorrect-color: #f44336;
    
    /* Animation curves */
    --ease-smooth: cubic-bezier(0.175, 0.885, 0.32, 1.275);
    --ease-standard: cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Spacing */
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 30px;
    --spacing-xxl: 40px;
    
    /* Border radius */
    --radius-sm: 4px;
    --radius-md: 6px;
    --radius-lg: 8px;
    --radius-xl: 12px;
}

.dark-mode {
    --primary-color: #e74c3c;
    --secondary-color: #333;
    --text-color: #ffffff;
    --background-color: #292929;
    --card-background: #1a1a1a;
    --border-color: #444;
    --highlight-color: #ffd600;
    --hover-color: #c0392b;
    --shadow-color: rgba(0, 0, 0, 0.3);
    --correct-color: #66bb6a;
    --incorrect-color: #e57373;
}

/* ===============================
   BASE STYLES & RESET
   =============================== */

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

body {
    font-family: 'Arial Unicode MS', 'Kalpurush', 'Preeti', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
    font-size: 1.08em;
    transition: background-color 0.3s var(--ease-standard), color 0.3s var(--ease-standard);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ===============================
   TYPOGRAPHY
   =============================== */

h1, h2, h3, h4, h5, h6 {
    color: var(--primary-color);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

h1 {
    font-size: 24px;
    color: white;
}

h2 {
    font-size: 1.8em;
    margin-top: var(--spacing-xxl);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--primary-color);
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.6s var(--ease-standard) forwards;
}

h3 {
    font-size: 1.4em;
    margin-top: 1.5em;
    padding-bottom: var(--spacing-xs);
    border-bottom: 2px solid var(--primary-color);
}

h4 {
    font-size: 1.4em;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
    transition: color 0.3s var(--ease-standard);
}

p {
    margin-bottom: 1em;
    font-size: 1.08em;
    line-height: 1.8;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.8s var(--ease-standard) forwards;
}

ul, ol {
    margin: 1em 0 1em 2em;
    padding: 0;
}

ul { list-style: disc inside; }
ol { list-style: decimal inside; }

li {
    margin-bottom: 0.5em;
    font-size: 1em;
    line-height: 1.6;
}

/* ===============================
   LAYOUT COMPONENTS
   =============================== */

main {
    padding: var(--spacing-xl) 0;
    min-height: calc(100vh - 180px);
}

section {
    margin-bottom: var(--spacing-xl);
}

/* ===============================
   HEADER & NAVIGATION
   =============================== */

header {
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-md) 0;
    box-shadow: 0 2px 5px var(--shadow-color);
    position: relative;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative; /* Add this */
}

/* Navigation */
nav {
    display: flex;
    align-items: center;
}

nav ul {
    display: flex;
    list-style: none;
    align-items: center;
    margin: 0;
    padding: 0;
}

nav ul li {
    margin-right: var(--spacing-lg);
}

nav ul li:last-child {
    margin-right: 0;
}

nav ul li a {
    color: white;
    text-decoration: none;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    transition: all 0.3s var(--ease-standard);
    display: block;
}

nav ul li a:hover, 
nav ul li a.active {
    background-color: rgba(255, 255, 255, 0.2);
}

nav ul li a:focus {
    outline: 2px solid white;
    outline-offset: 2px;
}

/* Hamburger Menu */
.hamburger {
    display: none;
    width: 32px;
    height: 32px;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    z-index: 1103;
    position: absolute; /* Change from fixed to absolute */
    top: 50%;
    right: 18px;
    transform: translateY(-50%);
    background: none;
    border: none;
    padding: 0;
    transition: all 0.3s var(--ease-standard);
}

.hamburger span {
    display: block;
    width: 28px;
    height: 4px;
    margin: 3px 0;
    background: white;
    border-radius: 2px;
    transition: all 0.3s var(--ease-standard);
    position: relative;
}

.hamburger.active {
    background: #fff;
    border-radius: 50%;
    padding: 4px;
}

.hamburger.active span {
    background: var(--primary-color);
}

.hamburger.active span:nth-child(1) {
    transform: rotate(45deg) translate(0px, 0px);
    position: absolute;
}

.hamburger.active span:nth-child(2) {
    opacity: 0;
}

.hamburger.active span:nth-child(3) {
    transform: rotate(-45deg) translate(0px, 0px);
    position: absolute;
}

/* Mobile Navigation Overlay */
.nav-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1100;
}

.nav-overlay.active {
    display: block;
}

/* ===============================
   COMPONENTS
   =============================== */

/* Mode Toggle Button */
#mode-toggle-btn {
    background-color: var(--primary-color);
    color: var(--background-color);
    border-radius: 50%;
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    transition: background 0.2s var(--ease-standard), color 0.2s var(--ease-standard);
    cursor: pointer;
}

#mode-toggle-btn:hover,
#mode-toggle-btn:active {
    background: var(--primary-color);
    color: #fff !important;
}

#mode-toggle-btn:focus {
    outline: none;
    box-shadow: none;
}

#mode-toggle-btn i {
    font-size: 20px;
    transition: all 0.4s var(--ease-standard);
    transform-origin: center;
}

#mode-toggle-btn i.fa-moon {
    opacity: 1;
    transform: rotate(0deg);
}

#mode-toggle-btn i.fa-sun {
    opacity: 0;
    transform: rotate(-180deg);
    position: absolute;
}

#mode-toggle-btn.active i.fa-moon {
    opacity: 0;
    transform: rotate(180deg);
}

#mode-toggle-btn.active i.fa-sun {
    opacity: 1;
    transform: rotate(0deg);
}

/* Topic Selector */
.topic-selector {
    margin: var(--spacing-lg) 0;
    position: relative;
}

#grammar-topic {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-md);
    font-size: 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-lg);
    background-color: var(--card-background);
    color: var(--text-color);
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23333' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14L2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 15px center;
    transition: all 0.3s var(--ease-standard);
}

#grammar-topic:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
    border-color: var(--primary-color);
}

/* Lesson Links */
.lesson-list {
    margin: var(--spacing-lg) 0;
    padding: 0;
}

.lesson-list ul {
    list-style-type: none;
    padding: 0;
    margin: 0;
}

.lesson-list li {
    margin: var(--spacing-sm) 0;
    list-style: none;
}

.lesson-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--card-background);
    border-radius: var(--radius-sm);
    color: var(--text-color);
    text-decoration: none;
    transition: all 0.3s var(--ease-standard);
    border: 1px solid var(--border-color);
}

.lesson-link:hover {
    background-color: var(--secondary-color);
    transform: translateX(5px);
    box-shadow: 0 2px 5px var(--shadow-color);
}

.lesson-link:focus {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

.lesson-link.active-lesson {
    background-color: #007bff;
    color: white;
    border-color: #007bff;
}

/* ===============================
   TABLES
   =============================== */

table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--spacing-lg) 0;
    background-color: var(--card-background);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: 0 2px 10px var(--shadow-color);
}

table th, 
table td {
    padding: var(--spacing-md) var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
}

table th {
    background-color: var(--primary-color);
    color: white;
    font-weight: bold;
    text-transform: uppercase;
}

table tr:last-child td {
    border-bottom: none;
}

table tr:nth-child(even) {
    background-color: var(--secondary-color);
}

/* ===============================
   HOME PAGE CARDS
   =============================== */

.cards-section {
    margin: var(--spacing-xxl) 0;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.8s var(--ease-standard) forwards;
    animation-delay: 0.2s;
}

.cards-section h3 {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    color: var(--primary-color);
    font-size: 1.6em;
    font-weight: 600;
}

.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.card {
    background-color: var(--card-background);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: 0 4px 15px var(--shadow-color);
    border: 1px solid var(--border-color);
    transition: all 0.4s var(--ease-smooth);
    text-align: center;
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, transparent 0%, rgba(225, 40, 48, 0.05) 100%);
    opacity: 0;
    transition: opacity 0.3s var(--ease-standard);
    pointer-events: none;
}

.card:hover::before {
    opacity: 1;
}

.card:hover {
    box-shadow: 0 8px 25px var(--shadow-color);
    border-color: var(--primary-color);
}

.card:hover .card-icon {
    transform: scale(1.1) rotate(5deg);
}

.card:hover h4 {
    color: var(--hover-color);
}

.card-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, var(--primary-color), var(--hover-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto var(--spacing-lg);
    transition: all 0.4s var(--ease-smooth);
    position: relative;
    overflow: hidden;
}

.card-icon::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3), transparent);
    transition: left 0.5s var(--ease-standard);
}

.card:hover .card-icon::before {
    left: 100%;
}

.card-icon i {
    font-size: 28px;
    color: white;
}

.card p {
    color: var(--text-color);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
    font-size: 0.95em;
}

/* Class Buttons */
.class-buttons {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    flex-wrap: wrap;
    margin-top: var(--spacing-lg);
}

.class-btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-md);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9em;
    transition: all 0.3s var(--ease-smooth);
    border: 2px solid var(--primary-color);
    min-width: 80px;
    text-align: center;
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.class-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.3s var(--ease-standard), height 0.3s var(--ease-standard);
}

.class-btn:hover::before {
    width: 300px;
    height: 300px;
}

.class-btn:hover {
    background-color: transparent;
    color: var(--primary-color);
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 6px 12px var(--shadow-color);
    border-color: var(--hover-color);
}

.class-btn:active {
    transform: translateY(-1px) scale(1.02);
    box-shadow: 0 3px 6px var(--shadow-color);
}

/* Subject Cards */
.subject-card {
    border-left: 4px solid var(--primary-color);
}

.subject-card:hover {
    border-left-color: var(--hover-color);
}

/* ===============================
   CONTACT SECTION
   =============================== */

#contact {
    padding: 70px 0;
    text-align: center;
    background-color: var(--background-color);
    transition: all 0.3s var(--ease-standard);
}

#contact h2 {
    text-align: center;
    margin-bottom: var(--spacing-xl);
    color: var(--primary-color);
}

.contact-form {
    background-color: var(--card-background);
    border-radius: var(--radius-xl);
    padding: 35px;
    box-shadow: 0 8px 20px var(--shadow-color);
    max-width: 800px;
    width: 100%;
    margin: 0 auto;
    border: 1px solid var(--border-color);
    transition: all 0.3s var(--ease-standard);
}

.contact-form:hover {
    box-shadow: 0 12px 30px var(--shadow-color);
}

.form-row {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    font-family: 'Inter', sans-serif;
    font-size: 1rem;
    color: var(--text-color);
    background-color: var(--background-color);
    transition: all 0.3s var(--ease-standard);
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(225, 40, 48, 0.1);
    background-color: var(--card-background);
}

.form-row input {
    flex: 1;
    margin-bottom: 0;
}

.send-message-btn {
    background-color: var(--primary-color);
    color: white;
    padding: var(--spacing-md) 28px;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s var(--ease-standard);
    letter-spacing: 0.3px;
}

.send-message-btn:hover {
    background-color: var(--hover-color);
    transform: translateY(-3px);
    box-shadow: 0 5px 15px var(--shadow-color);
}

.button-container {
    text-align: center;
    margin-top: var(--spacing-lg);
    display: flex;
    justify-content: center;
    align-items: center;
}

/* ===============================
   FOOTER
   =============================== */

footer {
    background-color: var(--secondary-color);
    color: var(--text-color);
    padding: var(--spacing-lg) 0;
    text-align: center;
    margin-top: var(--spacing-xxl);
}

/* ===============================
   ANIMATIONS
   =============================== */

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

/* ===============================
   DARK MODE OVERRIDES
   =============================== */

.dark-mode .class-10-text,
.dark-mode .class-11-text,
.dark-mode .class-12-text,
.dark-mode .unit-name,
.dark-mode .unit-label,
.dark-mode .unit-btn,
.dark-mode .class-btn {
    color: #fff;
}

.dark-mode #contact {
    background-color: var(--background-color);
}

.dark-mode .contact-form {
    background-color: var(--card-background);
    border-color: var(--border-color);
    box-shadow: 0 8px 20px var(--shadow-color);
}

.dark-mode .contact-form:hover {
    box-shadow: 0 12px 30px var(--shadow-color);
}

.dark-mode .contact-form input,
.dark-mode .contact-form textarea {
    background-color: var(--background-color);
    color: var(--text-color);
    border-color: var(--border-color);
}

.dark-mode .contact-form input:focus,
.dark-mode .contact-form textarea:focus {
    background-color: var(--card-background);
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(231, 76, 60, 0.1);
}

.dark-mode .contact-form input::placeholder,
.dark-mode .contact-form textarea::placeholder {
    color: var(--text-color);
    opacity: 0.7;
}

.dark-mode .card {
    background-color: var(--card-background);
    border-color: var(--border-color);
    box-shadow: 0 4px 15px var(--shadow-color);
}

.dark-mode .card:hover {
    box-shadow: 0 8px 25px var(--shadow-color);
}

.dark-mode .card h4 {
    color: var(--primary-color);
}

.dark-mode .card p {
    color: var(--text-color);
}

.dark-mode .class-btn {
    background-color: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.dark-mode .class-btn:hover {
    background-color: transparent;
    color: var(--primary-color);
}

/* ===============================
   RESPONSIVE DESIGN
   =============================== */

/* Tablet Styles */
@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    
    header .container {
        flex-direction: column;
        position: relative;
    }
    
    nav.main-nav {
        position: fixed;
        top: 0;
        right: -100%;
        width: 70vw;
        max-width: 320px;
        height: 100vh;
        background: var(--background-color);
        padding: 80px var(--spacing-lg) var(--spacing-lg);
        transition: right 0.3s var(--ease-standard), opacity 0.3s var(--ease-standard);
        box-shadow: -2px 0 10px var(--shadow-color);
        z-index: 1102;
        visibility: hidden;
        opacity: 0;
        display: flex;
        flex-direction: column;
    }
    
    nav.main-nav.active {
        right: 0;
        visibility: visible;
        opacity: 1;
    }
    
    nav.main-nav ul {
        flex-direction: column;
        align-items: flex-start;
        width: 100%;
    }
    
    nav.main-nav ul li {
        margin: 0 0 var(--spacing-md) 0;
        width: 100%;
    }
    
    nav.main-nav ul li a {
        font-size: 1.1rem;
        width: 100%;
        padding: var(--spacing-md) 0;
        color: var(--text-color);
        border-bottom: 1px solid var(--border-color);
    }
    
    #mode-toggle-btn {
        position: absolute;
        top: 16px;
        right: 60px;
        z-index: 1201;
        width: 36px;
        height: 36px;
    }
    
    #mode-toggle-btn i {
        font-size: 18px;
    }
    
    /* Cards Responsive for Tablet */
    .cards-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-lg);
    }
    
    .card {
        padding: var(--spacing-xl);
    }
    
    .cards-section h3 {
        font-size: 1.4em;
    }
    
    /* Contact Responsive */
    #contact {
        padding: 50px 0;
    }
    
    .contact-form {
        padding: 25px;
        margin: 0 var(--spacing-md);
    }
    
    .form-row {
        flex-direction: column;
        gap: var(--spacing-md);
        margin-bottom: var(--spacing-md);
    }
    
    .form-row input {
        margin-bottom: var(--spacing-md);
    }
    
    .contact-form input,
    .contact-form textarea {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.95rem;
    }
    
    .send-message-btn {
        padding: var(--spacing-sm) 24px;
        font-size: 0.95rem;
        width: 100%;
        max-width: 200px;
    }
}

/* Mobile Styles */
@media (max-width: 600px) {
    .container {
        padding: var(--spacing-md) 4vw;
        max-width: 100vw;
    }
    
    body {
        font-size: 1rem;
    }
    
    h1 {
        font-size: 1.4em;
    }
    
    h2 {
        font-size: 1.3em;
        margin-top: var(--spacing-xl);
    }
    
    h3 {
        font-size: 1.2em;
    }
    
    p, li {
        font-size: 1rem;
    }
    
    main {
        padding: var(--spacing-lg) 0;
    }
    
    section {
        margin-bottom: var(--spacing-lg);
    }
    
    /* Mobile table styles */
    table, thead, tbody, th, td, tr {
        display: block;
        width: 100%;
        font-size: 0.9em;
    }
    
    table {
        border-radius: 0;
    }
    
    th, td {
        padding: var(--spacing-sm) var(--spacing-md);
        text-align: left;
        border-bottom: 1px solid var(--border-color);
    }
    
    th {
        background-color: var(--primary-color);
        color: white;
        font-weight: bold;
        text-align: center;
    }
    
    ul, ol {
        margin-left: 1em;
    }
    
    .lesson-link {
        padding: var(--spacing-md);
        font-size: 1rem;
    }
    
    nav.main-nav {
        width: 85vw;
        max-width: 100vw;
    }
    
    /* Contact Responsive */
    #contact {
        padding: var(--spacing-xxl) 0;
    }
    
    #contact h2 {
        font-size: 1.4em;
        margin-bottom: var(--spacing-xl);
    }
    
    .contact-form {
        padding: var(--spacing-lg);
        margin: 0 var(--spacing-sm);
        border-radius: var(--radius-lg);
    }
    
    .form-row {
        gap: var(--spacing-md);
        margin-bottom: var(--spacing-md);
    }
    
    .contact-form input,
    .contact-form textarea {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.9rem;
        margin-bottom: var(--spacing-md);
    }
    
    .send-message-btn {
        padding: var(--spacing-xs) var(--spacing-lg);
        font-size: 0.9rem;
    }
}

/* Small Mobile Styles */
@media (max-width: 480px) {
    .container {
        padding: var(--spacing-sm) 3vw;
    }
    
    header {
        padding: var(--spacing-md) 0;
    }
    
    h1 {
        font-size: 1.2em;
    }
    
    h2 {
        font-size: 1.2em;
        margin-top: 25px;
    }
    
    h3 {
        font-size: 1.1em;
    }
    
    main {
        padding: var(--spacing-md) 0;
    }
    
    #grammar-topic {
        font-size: 14px;
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    table th, table td {
        padding: var(--spacing-xs) var(--spacing-xs);
        font-size: 0.85em;
    }
    
    /* Cards Responsive */
    .cards-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-lg);
    }
    
    .card {
        padding: var(--spacing-lg);
    }
    
    .card-icon {
        width: 60px;
        height: 60px;
    }
    
    .card-icon i {
        font-size: 24px;
    }
    
    .card h4 {
        font-size: 1.2em;
    }
    
    .card p {
        font-size: 0.9em;
    }
    
    .class-buttons {
        gap: var(--spacing-xs);
    }
    
    .class-btn {
        padding: var(--spacing-xs) var(--spacing-md);
        font-size: 0.85em;
        min-width: 70px;
    }
    
    /* Contact Responsive */
    #contact {
        padding: var(--spacing-xl) 0;
    }
    
    #contact h2 {
        font-size: 1.3em;
        margin-bottom: var(--spacing-lg);
    }
    
    .contact-form {
        padding: var(--spacing-md);
        margin: 0 var(--spacing-xs);
        border-radius: var(--radius-md);
    }
    
    .form-row {
        gap: var(--spacing-sm);
        margin-bottom: var(--spacing-sm);
    }
    
    .contact-form input,
    .contact-form textarea {
        padding: var(--spacing-xs) var(--spacing-xs);
        font-size: 0.85rem;
        margin-bottom: var(--spacing-md);
        border-radius: var(--radius-md);
    }
    
    .send-message-btn {
        padding: var(--spacing-xs) var(--spacing-md);
        font-size: 0.85rem;
        border-radius: var(--radius-md);
    }
    
    .button-container {
        margin-top: var(--spacing-md);
    }
}

/* Close Menu Button */
.close-menu {
    display: none;
    position: absolute;
    top: 18px;
    right: 18px;
    background: none;
    border: none;
    font-size: 2.2em;
    color: var(--primary-color);
    cursor: pointer;
    z-index: 1200;
}

@media (max-width: 768px) {
    .main-nav.active .close-menu {
        display: block;
    }
}

/* Mode Toggle Button Colors */
#mode-toggle-btn,
#mode-toggle-btn i {
    color: #fff !important;
}

#lesson {
    text-align : center;
    font-family: 'Courier New', Courier, monospace;
}

/* ===============================
   SAMAJIK UNIT DROPDOWN STYLES
   =============================== */

   .unit-list {
    margin: var(--spacing-xl) 0;
    padding: 0;
    opacity: 0;
    transform: translateY(20px);
    animation: fadeInUp 0.6s var(--ease-standard) forwards;
    animation-delay: 0.2s;
}

/* Remove list-style dots from unit list and items */
.unit-list > ul,
.unit-list > ul > li {
    list-style: none;
    margin: 0;
    padding: 0;
}

/* Unified style for dropdown button and lesson links */
.unit-toggle,
.lesson-link {
    display: block;
    width: 100%;
    text-align: left;
    background: var(--background-color);
    color: var(--text-color);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 1.08em;
    font-family: inherit;
    font-weight: 500;
    margin-bottom: var(--spacing-xs);
    cursor: pointer;
    transition: all 0.3s var(--ease-standard);
    position: relative;
    outline: none;
    box-shadow: none;
    text-decoration: none;
}

.unit-toggle i {
    float: right;
    margin-left: var(--spacing-md);
    font-size: 1em;
    transition: transform 0.3s var(--ease-standard);
}

.unit-toggle.open i {
    transform: rotate(180deg);
}

/* Unified hover/focus for dropdown button and lesson links */
.unit-toggle:hover, .unit-toggle:focus,
.lesson-link:hover, .lesson-link:focus {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    border-color: var(--primary-color);
    box-shadow: 0 2px 8px var(--shadow-color);
    transform: translateX(5px);
    outline: none;
}

.unit-toggle:active, .lesson-link:active {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    border-color: var(--primary-color);
    transform: translateX(2px);
}

.unit-toggle:focus-visible, .lesson-link:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* Lesson List Container */
.lesson-list {
    padding: 0;
    background: none;
    border: none;
    animation: none;
    display: none;
}

.lesson-list.open {
    display: block;
}

.lesson-list ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.lesson-list ul li {
    list-style: none;
}

.lesson-list li {
    margin-bottom: var(--spacing-xs);
    opacity: 0;
    transform: translateX(-20px);
    animation: slideInRight 0.3s var(--ease-standard) forwards;
}

.lesson-list li:nth-child(1) { animation-delay: 0.1s; }
.lesson-list li:nth-child(2) { animation-delay: 0.15s; }
.lesson-list li:nth-child(3) { animation-delay: 0.2s; }
.lesson-list li:nth-child(4) { animation-delay: 0.25s; }
.lesson-list li:nth-child(5) { animation-delay: 0.3s; }
.lesson-list li:nth-child(n+6) { animation-delay: 0.35s; }

.lesson-list li:last-child {
    margin-bottom: 0;
}

/* Lesson Links */
.lesson-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--background-color);
    border-radius: var(--radius-sm);
    color: var(--text-color);
    text-decoration: none;
    border: 1px solid var(--border-color);
    transition: all 0.3s var(--ease-smooth);
    position: relative;
    overflow: hidden;
    font-weight: 500;
}

.lesson-link::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(225, 40, 48, 0.1), transparent);
    transition: left 0.4s var(--ease-standard);
}

.lesson-link:hover::before {
    left: 100%;
}

/* Remove any extra hover/active styles from .lesson-link */
.lesson-link::before,
.lesson-link.active-lesson,
.lesson-link.active-lesson:hover {
    background: none !important;
    color: inherit !important;
    border-color: inherit !important;
    box-shadow: none !important;
    transform: none !important;
}

.lesson-link.active-lesson {
    background: linear-gradient(135deg, var(--primary-color), var(--hover-color));
    color: white;
    border-color: var(--primary-color);
    font-weight: 600;
    box-shadow: 0 3px 12px var(--shadow-color);
}

.lesson-link.active-lesson:hover {
    background: linear-gradient(135deg, var(--hover-color), var(--primary-color));
    transform: translateX(5px);
}

/* Loading State */
.unit-dropdown.loading .unit-toggle {
    pointer-events: none;
    opacity: 0.7;
}

.unit-dropdown.loading .unit-toggle::after {
    content: '';
    position: absolute;
    right: 40px;
    top: 50%;
    transform: translateY(-50%);
    width: 16px;
    height: 16px;
    border: 2px solid var(--primary-color);
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

/* Custom Animations */
@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
        max-height: 0;
    }
    to {
        opacity: 1;
        transform: translateY(0);
        max-height: 500px;
    }
}

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

@keyframes spin {
    0% { transform: translateY(-50%) rotate(0deg); }
    100% { transform: translateY(-50%) rotate(360deg); }
}

/* ===============================
   DARK MODE OVERRIDES
   =============================== */

.dark-mode .unit-dropdown {
    background: var(--card-background);
    border-color: var(--border-color);
    box-shadow: 0 2px 8px var(--shadow-color);
}

.dark-mode .unit-dropdown:hover {
    box-shadow: 0 4px 16px var(--shadow-color);
    border-color: var(--primary-color);
}

.dark-mode .unit-toggle {
    color: var(--primary-color);
}

.dark-mode .unit-toggle:hover,
.dark-mode .unit-toggle:focus {
    background: var(--secondary-color);
    color: var(--hover-color);
}

.dark-mode .unit-toggle.open {
    background: linear-gradient(135deg, var(--primary-color), var(--hover-color));
    color: white;
}

.dark-mode .lesson-list {
    background: var(--card-background);
    border-top-color: var(--border-color);
}

.dark-mode .lesson-link {
    background-color: var(--background-color);
    color: var(--text-color);
    border-color: var(--border-color);
}

.dark-mode .lesson-link:hover,
.dark-mode .lesson-link:focus {
    background-color: var(--secondary-color);
    color: var(--primary-color);
    border-color: var(--primary-color);
}

.dark-mode .lesson-link.active-lesson {
    background: linear-gradient(135deg, var(--primary-color), var(--hover-color));
    color: white;
    border-color: var(--primary-color);
}

/* ===============================
   RESPONSIVE DESIGN
   =============================== */

/* Tablet Styles */
@media (max-width: 768px) {
    .unit-list {
        margin: var(--spacing-lg) 0;
    }
    
    .unit-dropdown {
        margin-bottom: var(--spacing-md);
        border-radius: var(--radius-md);
    }
    
    .unit-toggle {
        font-size: 1.1em;
        padding: var(--spacing-md) var(--spacing-lg);
    }
    
    .lesson-list ul {
        padding: var(--spacing-md) var(--spacing-lg);
    }
    
    .lesson-link {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.95em;
    }
    
    .lesson-link:hover,
    .lesson-link:focus {
        transform: translateX(6px);
    }
}

/* Mobile Styles */
@media (max-width: 600px) {
    .unit-list {
        margin: var(--spacing-md) 0;
    }
    
    .unit-dropdown {
        margin-bottom: var(--spacing-sm);
        border-radius: var(--radius-sm);
    }
    
    .unit-toggle {
        font-size: 1em;
        padding: var(--spacing-md);
        font-weight: 600;
    }
    
    .unit-toggle i {
        margin-left: var(--spacing-sm);
        font-size: 0.9em;
    }
    
    .lesson-list ul {
        padding: var(--spacing-md);
    }
    
    .lesson-list li {
        margin-bottom: var(--spacing-xs);
    }
    
    .lesson-link {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.9em;
        border-radius: var(--radius-xs);
    }
    
    .lesson-link:hover,
    .lesson-link:focus {
        transform: translateX(4px);
    }
}

/* Small Mobile Styles */
@media (max-width: 480px) {
    .unit-dropdown {
        box-shadow: 0 1px 4px var(--shadow-color);
    }
    
    .unit-dropdown:hover {
        box-shadow: 0 2px 8px var(--shadow-color);
        transform: translateY(-1px);
    }
    
    .unit-toggle {
        font-size: 0.95em;
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .lesson-list ul {
        padding: var(--spacing-sm) var(--spacing-md);
    }
    
    .lesson-link {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.85em;
    }
    
    .lesson-link:hover,
    .lesson-link:focus {
        transform: translateX(3px);
        box-shadow: 0 2px 8px var(--shadow-color);
    }
}

/* ===============================
   ACCESSIBILITY ENHANCEMENTS
   =============================== */

/* Focus indicators */
.unit-toggle:focus-visible {
    outline: 3px solid var(--primary-color);
    outline-offset: 2px;
}

.lesson-link:focus-visible {
    outline: 2px solid var(--primary-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .unit-dropdown {
        border-width: 2px;
    }
    
    .unit-toggle {
        font-weight: 700;
    }
    
    .lesson-link {
        border-width: 2px;
        font-weight: 600;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    .unit-dropdown,
    .unit-toggle,
    .lesson-list,
    .lesson-link {
        transition: none;
        animation: none;
    }
    
    .unit-toggle i {
        transition: none;
    }
    
    .lesson-list li {
        animation: none;
        opacity: 1;
        transform: none;
    }
    
    .unit-list {
        animation: none;
        opacity: 1;
        transform: none;
    }
}

/* Print styles */
@media print {
    .unit-dropdown {
        box-shadow: none;
        border: 1px solid #000;
    }
    
    .unit-toggle {
        background: none !important;
        color: #000 !important;
    }
    
    .lesson-list {
        display: block !important;
        opacity: 1 !important;
        transform: none !important;
    }
    
    .lesson-link {
        background: none !important;
        color: #000 !important;
        border: 1px solid #000;
    }
}

/* ===============================
   UNIT DROPDOWN WITH INDENTED LESSONS
   =============================== */

/* Lesson List Container - Add padding and background to create indented effect */
.lesson-list {
    padding: var(--spacing-sm) 0 var(--spacing-sm) var(--spacing-xl); /* Left padding creates the indent */
    background: none;
    border: none;
    animation: none;
    display: none;
    position: relative;
}

.lesson-list.open {
    display: block;
    background-color: var(--secondary-color); /* Optional: Add background to emphasize indent */
    border-left: 3px solid var(--primary-color); /* Optional: Add left border for visual hierarchy */
    margin-left: var(--spacing-md); /* Pull the entire lesson list inward */
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0; /* Round only right corners */
}

.lesson-list ul {
    list-style: none;
    margin: 0;
    padding: 0 var(--spacing-md) 0 0; /* Right padding for breathing room */
}

.lesson-list ul li {
    list-style: none;
}

.lesson-list li {
    margin-bottom: var(--spacing-xs);
    opacity: 0;
    transform: translateX(-20px);
    animation: slideInRight 0.3s var(--ease-standard) forwards;
}

/* Lesson Links - Reduce width to emphasize the indent */
.lesson-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    background-color: var(--card-background);
    border-radius: var(--radius-sm);
    color: var(--text-color);
    text-decoration: none;
    border: 1px solid var(--border-color);
    transition: all 0.3s var(--ease-smooth);
    position: relative;
    overflow: hidden;
    font-weight: 500;
    margin-left: var(--spacing-md); /* Additional indent for individual lessons */
    font-size: 0.95em; /* Slightly smaller font to show hierarchy */
}

/* Dark mode adjustments */
.dark-mode .lesson-list.open {
    background-color: var(--card-background);
    border-left-color: var(--primary-color);
}

.dark-mode .lesson-link {
    background-color: var(--background-color);
    color: var(--text-color);
    border-color: var(--border-color);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .lesson-list {
        padding-left: var(--spacing-lg);
    }
    
    .lesson-list.open {
        margin-left: var(--spacing-sm);
    }
    
    .lesson-link {
        margin-left: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    .lesson-list {
        padding-left: var(--spacing-md);
    }
    
    .lesson-list.open {
        margin-left: var(--spacing-xs);
    }
    
    .lesson-link {
        margin-left: var(--spacing-xs);
    }
}