/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #6366f1;
    --secondary-color: #4f46e5;
    --accent-color: #818cf8;
    --text-color: #1f2937;
    --light-text: #6b7280;
    --background: #ffffff;
    --card-bg: #f9fafb;
    --gradient: linear-gradient(135deg, #6366f1 0%, #4f46e5 100%);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-hover: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Modern Navigation */
.navbar {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    padding: 0.5rem 2rem;
    background: rgba(255, 255, 255, 0.98);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.nav-links {
    display: flex;
    gap: 2rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    position: relative;
    padding: 0.5rem 0;
    transition: color 0.3s ease;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: width 0.3s ease;
}

.nav-links a:hover::after {
    width: 100%;
}

/* Modern Hero Section */
.grade-hero {
    height: 60vh;
    background: var(--gradient);
    position: relative;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    margin-top: 4rem;
}

.grade-hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('https://images.unsplash.com/photo-1554224155-6726b3ff858f?ixlib=rb-1.2.1&auto=format&fit=crop&w=1950&q=80') center/cover;
    opacity: 0.2;
    z-index: 1;
}

.grade-hero .container {
    position: relative;
    z-index: 2;
    max-width: 800px;
    padding: 2rem;
}

.grade-hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.grade-hero p {
    font-size: 1.25rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s;
}

/* Modern Content Section */
.grade-content {
    padding: 4rem 2rem;
    background: var(--background);
}

.grade-intro {
    text-align: center;
    max-width: 800px;
    margin: 0 auto 4rem;
    animation: fadeIn 1s ease;
}

.grade-intro h2 {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.grade-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

/* Modern Cards */
.grade-card {
    background: var(--card-bg);
    border-radius: 1rem;
    padding: 2rem;
    box-shadow: var(--shadow);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.5s ease;
}

.grade-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient);
    transform: scaleX(0);
    transform-origin: left;
    transition: transform 0.3s ease;
}

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

.grade-card:hover::before {
    transform: scaleX(1);
}

.grade-card i {
    font-size: 2rem;
    margin-bottom: 1rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.grade-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.grade-card p {
    color: var(--light-text);
    font-size: 0.95rem;
}

/* Modern Dropdown */
.dropdown {
    position: relative;
}

.dropdown-content {
    position: absolute;
    top: 100%;
    left: 0;
    background: white;
    min-width: 200px;
    box-shadow: var(--shadow);
    border-radius: 0.5rem;
    padding: 0.5rem 0;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all 0.3s ease;
}

.dropdown:hover .dropdown-content {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-content a {
    display: block;
    padding: 0.75rem 1.5rem;
    color: var(--text-color);
    transition: all 0.2s ease;
}

.dropdown-content a:hover {
    background: var(--card-bg);
    color: var(--primary-color);
}

/* Modern Footer */
footer {
    background: var(--card-bg);
    padding: 2rem;
    text-align: center;
    color: var(--light-text);
    margin-top: 4rem;
}

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

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

/* Responsive Design */
@media (max-width: 768px) {
    .navbar {
        padding: 1rem;
    }

    .nav-links {
        position: fixed;
        top: 0;
        right: -100%;
        height: 100vh;
        width: 70%;
        background: white;
        flex-direction: column;
        align-items: center;
        justify-content: center;
        transition: right 0.3s ease;
        box-shadow: var(--shadow);
    }

    .nav-links.active {
        right: 0;
    }

    .grade-hero h1 {
        font-size: 2.5rem;
    }

    .grade-grid {
        grid-template-columns: 1fr;
    }

    .grade-card {
        margin: 0 1rem;
    }
}

/* Hamburger Menu */
.hamburger {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background: var(--text-color);
    transition: all 0.3s ease;
}

@media (max-width: 768px) {
    .hamburger {
        display: block;
    }

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

    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }
}

/* Hero Section */
.hero {
    height: 100vh;
    background: linear-gradient(rgba(31, 41, 55, 0.8), rgba(31, 41, 55, 0.8)),
                url('https://images.unsplash.com/photo-1554224155-6726b3ff858f?ixlib=rb-4.0.3&ixid=M3wxMjA3fDB8MHxwaG90by1wYWdlfHx8fGVufDB8fHx8fA%3D%3D&auto=format&fit=crop&w=1920&q=80') center/cover;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: white;
    padding-top: 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gradient);
    opacity: 0.1;
    z-index: 1;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
    0% { opacity: 0.1; }
    50% { opacity: 0.2; }
    100% { opacity: 0.1; }
}

.hero-content {
    max-width: 800px;
    padding: 2rem;
    position: relative;
    z-index: 2;
    animation: fadeInUp 1s ease;
}

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

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
    font-weight: 700;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
    animation: slideInLeft 1s ease;
}

@keyframes slideInLeft {
    from {
        opacity: 0;
        transform: translateX(-50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.hero p {
    font-size: 1.3rem;
    margin-bottom: 2.5rem;
    opacity: 0.9;
    animation: slideInRight 1s ease;
}

@keyframes slideInRight {
    from {
        opacity: 0;
        transform: translateX(50px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.cta-button {
    display: inline-block;
    padding: 1.2rem 2.5rem;
    background: var(--gradient);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    transition: all 0.3s ease;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
    animation: fadeIn 1.5s ease;
}

.cta-button:hover {
    transform: translateY(-3px);
    background: var(--gradient-hover);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}

/* Introduction Section */
.intro-section {
    padding: 8rem 0;
    background-color: var(--white);
    position: relative;
}

.intro-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('data:image/svg+xml,<svg width="100" height="100" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="40" fill="%236366f1" fill-opacity="0.05"/></svg>') repeat;
    opacity: 0.5;
    animation: float 20s linear infinite;
}

@keyframes float {
    0% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
    100% { transform: translateY(0); }
}

.intro-content {
    display: flex;
    align-items: center;
    gap: 4rem;
    margin-top: 3rem;
    position: relative;
    z-index: 1;
}

.intro-text {
    flex: 1;
    animation: fadeInLeft 1s ease;
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.intro-text h2 {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.intro-text p {
    font-size: 1.1rem;
    margin-bottom: 1.5rem;
    color: #666;
}

.intro-text ul {
    margin-top: 1.5rem;
    padding-left: 1.5rem;
}

.intro-text li {
    margin-bottom: 0.8rem;
    position: relative;
    padding-left: 1.5rem;
}

.intro-text li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.intro-image {
    flex: 1;
    position: relative;
    animation: fadeInRight 1s ease;
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.intro-image img {
    width: 100%;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
    transform: perspective(1000px) rotateY(-5deg);
    transition: all 0.5s ease;
}

.intro-image:hover img {
    transform: perspective(1000px) rotateY(0deg) scale(1.02);
}

/* Chapters Section */
.chapters-section {
    padding: 8rem 0;
    background-color: var(--light-bg);
    position: relative;
}

.chapters-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    margin-top: 3rem;
}

.chapter-card {
    background-color: var(--white);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    text-align: center;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.5s ease;
}

.chapter-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 5px;
    background: var(--gradient);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.chapter-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.chapter-card:hover::before {
    transform: scaleX(1);
}

.chapter-card i {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
}

.chapter-card:hover i {
    transform: scale(1.1);
}

.chapter-card h3 {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.chapter-card p {
    color: #666;
    line-height: 1.6;
}

/* Syllabus Section */
.syllabus-section {
    padding: 8rem 0;
    background-color: var(--white);
    position: relative;
}

.syllabus-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2.5rem;
    margin-top: 3rem;
}

.syllabus-item {
    background-color: var(--white);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    animation: fadeInUp 0.5s ease;
}

.syllabus-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
}

.syllabus-item h3 {
    color: var(--text-color);
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
    position: relative;
    padding-bottom: 1rem;
}

.syllabus-item h3::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--gradient);
    transition: width 0.3s ease;
}

.syllabus-item:hover h3::after {
    width: 100px;
}

.syllabus-item ul {
    list-style: none;
}

.syllabus-item li {
    padding: 1rem 0;
    border-bottom: 1px solid #eee;
    transition: all 0.3s ease;
}

.syllabus-item li:hover {
    color: var(--primary-color);
    transform: translateX(5px);
}

.syllabus-item li:last-child {
    border-bottom: none;
}

/* Grade Section Styles */
.grade-section {
    padding: 4rem 0;
    background: var(--light-bg);
}

.grade-section h2 {
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-color);
    font-size: 2.5rem;
}

.grade-menu {
    max-width: 1000px;
    margin: 0 auto;
}

.grade-menu-item {
    background: white;
    border-radius: 10px;
    margin-bottom: 1rem;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: all 0.3s ease;
}

.grade-menu-header {
    padding: 1.5rem;
    display: flex;
    align-items: center;
    cursor: pointer;
    transition: all 0.3s ease;
}

.grade-menu-header:hover {
    background: var(--light-bg);
}

.grade-menu-header i {
    font-size: 1.5rem;
    margin-right: 1rem;
    color: var(--primary-color);
}

.grade-menu-header h3 {
    flex: 1;
    margin: 0;
    font-size: 1.2rem;
    color: var(--text-color);
}

.toggle-icon {
    transition: transform 0.3s ease;
}

.grade-menu-content {
    padding: 0 1.5rem;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
}

.grade-menu-item.active .grade-menu-content {
    padding: 1.5rem;
    max-height: 500px;
}

.grade-menu-item.active .toggle-icon {
    transform: rotate(180deg);
}

.grade-menu-content p {
    margin: 0;
    color: var(--text-color);
    line-height: 1.6;
}

/* Responsive Styles */
@media (max-width: 768px) {
    .grade-section h2 {
        font-size: 2rem;
    }

    .grade-menu-header {
        padding: 1rem;
    }

    .grade-menu-header h3 {
        font-size: 1rem;
    }

    .grade-menu-content {
        padding: 0 1rem;
    }

    .grade-menu-item.active .grade-menu-content {
        padding: 1rem;
    }
}