:root {
    --bg-primary: #0a0e27;
    --accent-blue: #5eb3f6;
    --accent-purple: #764ba2;
    --text-primary: #ffffff;
    --text-secondary: rgba(255, 255, 255, 0.7);
    --text-muted: rgba(255, 255, 255, 0.5);
    --card-bg: rgba(255, 255, 255, 0.03);
    --card-border: rgba(255, 255, 255, 0.08);
    --card-hover: rgba(255, 255, 255, 0.06);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Arial, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden;
}

header {
    background: rgba(10, 14, 39, 0.95);
    padding: 1.5rem 3rem;
    border-bottom: 1px solid var(--card-border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1400px;
    margin: 0 auto;
}


.logo-container {
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.brain-logo {
    width: 40px;
    height: 40px;
    border: 2px solid var(--accent-blue);
    border-radius: 50% 50% 0 50%;
    background: rgba(94, 179, 246, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 1rem;
    color: var(--accent-blue);
}

.logo-text {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent-blue);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 2rem;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-links {
    display: flex;
    gap: 2.5rem;
    list-style: none;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 1.1rem;
    transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--accent-blue);
}

@media (max-width: 1100px) {
    header {
        padding: 1.2rem 2rem;
    }

    .nav-links {
        gap: 1.8rem;
    }

    .nav-links a {
        font-size: 1rem;
    }
}

@media (max-width: 950px) {
    header {
        padding: 1rem 1.5rem;
    }

    .nav-links {
        gap: 1.2rem;
    }

    .nav-links a {
        font-size: 0.9rem;
    }

    .logo-text {
        font-size: 1.4rem;
    }

    .brain-logo {
        width: 35px;
        height: 35px;
        font-size: 0.9rem;
    }
}

.hero {
    max-width: 1400px;
    margin: 0 auto;
    padding: 5rem 3rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
}

.hero-content h1 {
    font-size: 4rem;
    line-height: 1.1;
    margin-bottom: 2rem;
}

.hero-content .highlight {
    color: var(--accent-blue);
}

.hero-content .subtitle {
    color: var(--text-secondary);
    font-size: 1.2rem;
    line-height: 1.6;
    margin-bottom: 3rem;
}

.exam-boards {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

.board-badge {
    background: rgba(94, 179, 246, 0.1);
    padding: 0.5rem 1.2rem;
    border-radius: 8px;
    color: var(--accent-blue);
    font-weight: 600;
    border: 1px solid rgba(94, 179, 246, 0.3);
    font-size: 0.9rem;
}

.cta-button {
    display: inline-block;
    background: var(--accent-blue);
    color: var(--bg-primary);
    padding: 1rem 2rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s;
}

.cta-button:hover {
    background: #4a9de0;
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(94, 179, 246, 0.3);
}

.features-box {
    background: var(--card-bg);
    border-radius: 20px;
    padding: 3rem;
    border: 1px solid var(--card-border);
}

.features-box h2 {
    font-size: 2rem;
    margin-bottom: 2rem;
}

.feature {
    margin-bottom: 2.5rem;
}

.feature:last-child {
    margin-bottom: 0;
}

.feature h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.feature-icon {
    font-size: 1.5rem;
}

.feature p {
    color: var(--text-muted);
    line-height: 1.6;
}

.subjects-section {
    max-width: 1400px;
    margin: 4rem auto;
    padding: 0 3rem;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    text-align: center;
}

.subjects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.subject-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2.5rem;
    border: 1px solid var(--card-border);
    transition: all 0.3s;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
    display: block;
}

.subject-card:hover {
    background: var(--card-hover);
    border-color: rgba(94, 179, 246, 0.3);
    transform: translateY(-5px);
}

.subject-card.coming-soon {
    opacity: 0.6;
    cursor: not-allowed;
}

.subject-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.subject-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.8rem;
}

.subject-card p {
    color: var(--text-muted);
    line-height: 1.6;
    margin-bottom: 1rem;
}

.subject-card .boards {
    font-size: 0.85rem;
    color: var(--accent-blue);
    font-weight: 600;
}

.breadcrumb {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1.5rem 3rem 0;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.breadcrumb a {
    color: var(--accent-blue);
    text-decoration: none;
}

.page-header {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem 3rem 3rem;
    display: flex;
    align-items: center;
    gap: 2rem;
}

.subject-icon-large {
    font-size: 5rem;
}

.header-content h1 {
    font-size: 3rem;
    margin-bottom: 0.5rem;
}

.header-description {
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.header-meta {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.exam-board-badge {
    background: rgba(94, 179, 246, 0.15);
    padding: 0.5rem 1rem;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent-blue);
}

.topic-count {
    color: var(--text-muted);
}

footer {
    background: rgba(0, 0, 0, 0.3);
    text-align: center;
    padding: 2.5rem;
    margin-top: 6rem;
    border-top: 1px solid var(--card-border);
}

footer p {
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

@media (max-width: 1024px) {
    .hero {
        grid-template-columns: 1fr;
        padding: 3rem 2rem;
    }

    .hero-content h1 {
        font-size: 3rem;
    }
}

@media (max-width: 768px) {
    body.menu-open {
        overflow: hidden;
    }

    .subject-icon-large {
        font-size: 3rem;
    }

    .header-description {
        font-size: 1rem;
        line-height: 1.5;
    }

    .header-meta {
        flex-wrap: wrap;
        gap: 1rem;
    }

    .mobile-menu-btn {
        display: block;
        background: none;
        border: none;
        color: white;
        font-size: 2rem;
        cursor: pointer;
        padding: 0.5rem;
        transition: transform 0.3s ease;
    }

    .mobile-menu-btn.active {
        transform: rotate(90deg);
    }

    .nav-links {
        position: fixed;
        top: 80px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: rgba(10, 14, 39, 0.98);
        backdrop-filter: blur(20px);
        width: 100%;
        max-height: calc(100vh - 80px);
        overflow-y: auto;
        padding: 2rem;
        gap: 1.5rem;
        transition: transform 0.5s cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 0.3s ease;
        border-top: 1px solid var(--card-border);
        transform: translateX(-100%) scale(0.95);
        opacity: 0;
        pointer-events: none;
    }

    .nav-links.active {
        transform: translateX(0) scale(1);
        opacity: 1;
        pointer-events: auto;
    }

    .nav-links li {
        transform: translateX(-30px);
        opacity: 0;
        transition: all 0.4s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }

    .nav-links.active li:nth-child(1) {
        transition-delay: 0.1s;
    }

    .nav-links.active li:nth-child(2) {
        transition-delay: 0.15s;
    }

    .nav-links.active li:nth-child(3) {
        transition-delay: 0.2s;
    }

    .nav-links.active li:nth-child(4) {
        transition-delay: 0.25s;
    }

    .nav-links.active li:nth-child(5) {
        transition-delay: 0.3s;
    }

    .nav-links.active li {
        transform: translateX(0);
        opacity: 1;
    }

    header {
        padding: 1rem 1.5rem;
    }

    .logo-text {
        font-size: 1.3rem;
    }

    .hero {
        padding: 2rem 1.5rem;
    }

    .hero-content h1 {
        font-size: 2.2rem;
    }

    .hero-content .subtitle {
        font-size: 1rem;
    }

    .subjects-section {
        padding: 0 1.5rem;
    }

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

    .page-header {
        padding: 2rem 1.5rem;
        flex-direction: column;
        align-items: flex-start;
    }

    .page-header h1 {
        font-size: 2rem;
    }

    .page-header-center {
        padding: 2rem 1.5rem;
    }

    .page-header-center h1 {
        font-size: 2rem;
    }

    .filter-section {
        padding: 0 1.5rem;
    }

    .subjects-container {
        padding: 0 1.5rem 4rem;
    }

    .subject-card-detailed {
        padding: 2rem;
    }

    .subject-header {
        flex-direction: column;
        gap: 1.5rem;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 1.8rem;
    }

    .features-box {
        padding: 2rem;
    }
}

.page-header-center {
    max-width: 1400px;
    margin: 0 auto;
    padding: 3rem 3rem 4rem;
    display: block;
    text-align: center;
}

.page-header-center h1 {
    font-size: 3.5rem;
    margin-bottom: 1rem;
    color: #ffffff;
}

.page-header-center p {
    font-size: 1.2rem;
    color: rgba(255, 255, 255, 0.7);
    max-width: 700px;
    margin: 0 auto;
    line-height: 1.6;
}

.about-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 3rem 4rem;
}

.about-section {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 20px;
    padding: 3rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 2rem;
}

.about-section h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    color: #5eb3f6;
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.about-section h3 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    color: #ffffff;
}

.about-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    margin-bottom: 1.2rem;
    font-size: 1.05rem;
}

.about-section ul {
    list-style: none;
    margin: 1.5rem 0;
}

.about-section li {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    margin-bottom: 1rem;
    padding-left: 2rem;
    position: relative;
    font-size: 1.05rem;
}

.about-section li::before {
    content: "→";
    color: #5eb3f6;
    position: absolute;
    left: 0;
    font-weight: bold;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
}

.stat-card {
    background: rgba(94, 179, 246, 0.1);
    border: 1px solid rgba(94, 179, 246, 0.3);
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
}

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    color: #5eb3f6;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: rgba(255, 255, 255, 0.8);
    font-size: 1.1rem;
}

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

.feature-card {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.feature-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.feature-card h4 {
    font-size: 1.3rem;
    margin-bottom: 0.8rem;
    color: #ffffff;
}

.feature-card p {
    color: rgba(255, 255, 255, 0.6);
    line-height: 1.6;
    font-size: 1rem;
}

.team-section {
    background: rgba(94, 179, 246, 0.05);
    border-radius: 20px;
    padding: 3rem;
    border: 1px solid rgba(94, 179, 246, 0.2);
    text-align: center;
}

.team-section h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
    color: #5eb3f6;
}

.team-section p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    max-width: 800px;
    margin: 0 auto 2rem;
    font-size: 1.05rem;
}

.contact-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: #5eb3f6;
    color: #0a0e27;
    padding: 1rem 2rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    transition: all 0.3s;
}

.contact-cta:hover {
    background: #4a9de0;
    transform: translateY(-2px);
    box-shadow: 0 10px 30px rgba(94, 179, 246, 0.3);
}

footer {
    background: rgba(0, 0, 0, 0.3);
    text-align: center;
    padding: 2.5rem;
    margin-top: 4rem;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
}

footer p {
    color: rgba(255, 255, 255, 0.5);
    margin-bottom: 0.5rem;
}

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

    .nav-links {
        position: fixed;
        top: 80px;
        right: -100%;
        flex-direction: column;
        background: rgba(10, 14, 39, 0.98);
        width: 100%;
        padding: 2rem;
        gap: 1.5rem;
        transition: right 0.3s ease;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

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

    header {
        padding: 1rem 1.5rem;
    }

    .logo {
        font-size: 1.5rem;
    }

    .page-header {
        padding: 3rem 1.5rem 2rem;
    }

    .page-header h1 {
        font-size: 2.2rem;
    }

    .about-content {
        padding: 0 1.5rem 3rem;
    }

    .about-section {
        padding: 2rem;
    }

    .about-section h2 {
        font-size: 1.6rem;
    }

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

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

.journey-title {
    margin-bottom: 2rem;
    margin-top: 2rem;
    text-align: center;
}

.section-journey {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 20px;
    padding: 2.5rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 2rem;

    text-align: center;
}

h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: #5eb3f6;
}

p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
    margin-bottom: 1.2rem;
    font-size: 1.1rem;
}

.card h2 {
    text-align: center;
}

.results-image {
    margin-top: 20px;
    text-align: center;
}

.results-image img {
    width: 100%;
    max-width: 1000px;
    border-radius: 10px;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
}

.ask-me {
    max-width: 700px;
    margin: 0 auto;
    padding: 4rem 3rem;

    .ask-me-title {
        font-size: 3rem;
        margin-bottom: 1rem;
        text-align: center;
    }

    .subtitle {
        text-align: center;
        color: rgba(255, 255, 255, 0.7);
        font-size: 1.1rem;
        margin-bottom: 3rem;
    }

    .form-container {
        background: rgba(255, 255, 255, 0.03);
        border-radius: 20px;
        padding: 3rem;
        border: 1px solid rgba(255, 255, 255, 0.08);
    }

    .form-group {
        margin-bottom: 1.5rem;
    }

    label {
        display: block;
        color: rgba(255, 255, 255, 0.9);
        margin-bottom: 0.5rem;
        font-weight: 500;
        font-size: 1rem;
    }

    input,
    textarea {
        width: 100%;
        background: rgba(255, 255, 255, 0.05);
        border: 1px solid rgba(255, 255, 255, 0.1);
        border-radius: 10px;
        padding: 1rem;
        color: #ffffff;
        font-size: 1rem;
        font-family: 'Inter', sans-serif;
        transition: all 0.3s;
    }

    input:focus,
    textarea:focus {
        outline: none;
        border-color: #5eb3f6;
        background: rgba(255, 255, 255, 0.08);
    }

    input::placeholder,
    textarea::placeholder {
        color: rgba(255, 255, 255, 0.4);
    }

    textarea {
        resize: vertical;
        min-height: 150px;
    }

    .submit-btn {
        width: 100%;
        background: #5eb3f6;
        color: #0a0e27;
        border: none;
        padding: 1.2rem;
        border-radius: 10px;
        font-size: 1.1rem;
        font-weight: 600;
        cursor: pointer;
        transition: all 0.3s;
        margin-top: 1rem;
    }

    .submit-btn:hover {
        background: #4a9de0;
        transform: translateY(-2px);
        box-shadow: 0 10px 30px rgba(94, 179, 246, 0.3);
    }

    .success-message {
        display: none;
        background: rgba(34, 197, 94, 0.2);
        border: 1px solid rgba(34, 197, 94, 0.5);
        border-radius: 10px;
        padding: 1.5rem;
        margin-top: 1.5rem;
        text-align: center;
        color: #4ade80;
    }

    .success-message.show {
        display: block;
    }
}

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

    .nav-links {
        position: fixed;
        top: 80px;
        right: -100%;
        flex-direction: column;
        background: rgba(10, 14, 39, 0.98);
        width: 100%;
        padding: 2rem;
        gap: 1.5rem;
        transition: right 0.3s ease;
        border-top: 1px solid rgba(255, 255, 255, 0.1);
    }

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

    header {
        padding: 1rem 1.5rem;
    }

    .logo {
        font-size: 1.5rem;
    }

    .content {
        padding: 3rem 1.5rem;
    }

    h1 {
        font-size: 2rem;
    }

    .form-container {
        padding: 2rem;
    }
}

.filter-section {
    max-width: 1400px;
    margin: 0 auto 3rem;
    padding: 0 3rem;
}

.filter-tabs {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.filter-tab {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.7);
    padding: 0.8rem 1.8rem;
    border-radius: 10px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.3s;
    font-size: 1rem;
}

.filter-tab:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(94, 179, 246, 0.3);
}

.filter-tab.active {
    background: #5eb3f6;
    color: #0a0e27;
    border-color: #5eb3f6;
}

.subjects-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 3rem 4rem;
}

.subject-card-detailed {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 20px;
    padding: 2.5rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 2rem;
    transition: all 0.3s;
}

.subject-card-detailed:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(94, 179, 246, 0.3);
}

.subject-header {
    display: flex;
    align-items: center;
    gap: 2rem;
    margin-bottom: 1.5rem;
}

.subject-info h3 {
    font-size: 2rem;
    margin-bottom: 0.5rem;
}

.subject-meta {
    display: flex;
    gap: 1.5rem;
    align-items: center;
    margin-top: 0.5rem;
}

.view-resources-btn {
    background: #5eb3f6;
    color: #0a0e27;
    padding: 1rem 2rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-block;
    margin-top: 1rem;
}

.view-resources-btn:hover {
    background: #4a9de0;
}

.topics-list-section {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 3rem 2rem;
}

.topics-list {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 15px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.topics-list h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #5eb3f6;
}

.topics-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.topic-tag {
    background: rgba(94, 179, 246, 0.1);
    padding: 0.6rem 1rem;
    border-radius: 8px;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(94, 179, 246, 0.2);
}

.main-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 3rem 4rem;
}

.topic-card {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 15px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 1.5rem;
    overflow: hidden;
    transition: all 0.3s;
}

.topic-card:hover {
    border-color: rgba(94, 179, 246, 0.3);
}

.topic-card-header {
    padding: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
}

.topic-info {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    flex: 1;
}

.topic-icon {
    font-size: 2.5rem;
}

.topic-title h3 {
    font-size: 1.5rem;
    margin-bottom: 0.3rem;
}

.topic-description {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.95rem;
}

.view-more-btn {
    background: rgba(94, 179, 246, 0.15);
    color: #5eb3f6;
    padding: 0.7rem 1.5rem;
    border-radius: 8px;
    border: 1px solid rgba(94, 179, 246, 0.3);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.95rem;
}

.view-more-btn:hover {
    background: rgba(94, 179, 246, 0.25);
}

.topic-card-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.topic-card-content.open {
    max-height: 400px;
}

.topic-actions {
    padding: 0 2rem 2rem 2rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.action-btn {
    flex: 1;
    min-width: 200px;
    background: #5eb3f6;
    color: #0a0e27;
    padding: 1rem 2rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.action-btn:hover {
    background: #4a9de0;
    transform: translateY(-2px);
}

.action-btn.secondary {
    background: rgba(94, 179, 246, 0.2);
    color: #5eb3f6;
}

.action-btn.secondary:hover {
    background: rgba(94, 179, 246, 0.3);
}

@media (max-width: 768px) {

    .topics-list-section,
    .main-content {
        padding-left: 1.5rem;
        padding-right: 1.5rem;
    }

    .topic-card-header {
        flex-direction: column;
        gap: 1.5rem;
        align-items: flex-start;
    }

    .topic-info {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

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

    .action-btn {
        min-width: 100%;
    }
}

.topics-list-section {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 3rem 2rem;
}

.topics-list {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 15px;
    padding: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.topics-list h3 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: #5eb3f6;
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 0.8rem;
}

.topic-tag {
    background: rgba(94, 179, 246, 0.1);
    padding: 0.6rem 1rem;
    border-radius: 8px;
    font-size: 0.95rem;
    color: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(94, 179, 246, 0.2);
}

.main-content {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 3rem 4rem;
}

.topic-card {
    background: rgba(255, 255, 255, 0.03);
    border-radius: 15px;
    border: 1px solid rgba(255, 255, 255, 0.08);
    margin-bottom: 1.5rem;
    overflow: hidden;
    transition: all 0.3s;
}

.topic-card:hover {
    border-color: rgba(94, 179, 246, 0.3);
}

.topic-card-header {
    padding: 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
}

.topic-info {
    display: flex;
    align-items: center;
    gap: 1.5rem;
    flex: 1;
}

.topic-icon {
    font-size: 2.5rem;
}

.topic-title h3 {
    font-size: 1.5rem;
    margin-bottom: 0.3rem;
}

.topic-description {
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.95rem;
}

.view-more-btn {
    background: rgba(94, 179, 246, 0.15);
    color: #5eb3f6;
    padding: 0.7rem 1.5rem;
    border-radius: 8px;
    border: 1px solid rgba(94, 179, 246, 0.3);
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    font-size: 0.95rem;
}

.view-more-btn:hover {
    background: rgba(94, 179, 246, 0.25);
}

.topic-card-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
}

.topic-card-content.open {
    max-height: 400px;
}

.topic-actions {
    padding: 0 2rem 2rem 2rem;
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.action-btn {
    flex: 1;
    min-width: 200px;
    background: #5eb3f6;
    color: #0a0e27;
    padding: 1rem 2rem;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    text-align: center;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.action-btn:hover {
    background: #4a9de0;
    transform: translateY(-2px);
}

.action-btn.secondary {
    background: rgba(94, 179, 246, 0.2);
    color: #5eb3f6;
}

.action-btn.secondary:hover {
    background: rgba(94, 179, 246, 0.3);
}

@media (max-width: 768px) {

    .topics-list-section,
    .main-content {
        padding-left: 1.5rem;
        padding-right: 1.5rem;
    }

    .topic-card-header {
        flex-direction: column;
        gap: 1.5rem;
        align-items: flex-start;
    }

    .topic-info {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

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

    .action-btn {
        min-width: 100%;
    }
}

.useful-videos {
            max-width: 1400px;
            margin: 4rem auto;
            padding: 0 3rem;
        }
        .useful-videos h2 {
            text-align: center;
            font-size: 2rem;
            margin-bottom: 2rem;
            color: #5eb3f6;
        }
        .video-grid {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
            gap: 1.5rem;
        }
        .video-card {
            background: rgba(255, 255, 255, 0.03);
            border-radius: 12px;
            border: 1px solid rgba(94, 179, 246, 0.2);
            overflow: hidden;
            transition: all 0.3s;
        }
        .video-card:hover {
            transform: translateY(-5px);
            border-color: #5eb3f6;
        }
        .video-card iframe {
            width: 100%;
            height: 180px;
            border: none;
        }
        .video-info {
            padding: 1rem;
            text-align: center;
        }
        .video-info h3 {
            font-size: 1.2rem;
            margin: 0.5rem 0;
            color: #fff;
        }
        .video-info p {
            font-size: 0.9rem;
            color: rgba(255, 255, 255, 0.7);
            margin: 0;
        }
        @media (max-width: 768px) {
            .useful-videos { padding: 0 1.5rem; }
            .video-card iframe { height: 160px; }
        }

button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid #5eb3f6;
    outline-offset: 2px;
}

@media (max-width: 768px) {
    button,
    .action-btn,
    .filter-tab,
    a.subject-card,
    a.subject-card-detailed {
        min-height: 48px;
        align-items: center;
        justify-content: center;
    }

    .topics-grid {
        gap: 0.5rem;
    }

    .page-header-center h1 {
        font-size: 1.8rem;
        line-height: 1.3;
    }

    .header-content h1 {
        font-size: 2rem;
    }

    .subject-card {
        padding: 1.5rem;
    }

    .view-more-btn {
        padding: 0.8rem 1.2rem;
        min-height: 44px;
    }

    .topic-actions {
        gap: 0.8rem;
        flex-direction: column;
    }

    .action-btn {
        width: 100%;
        min-width: auto;
    }
}

@media (max-width: 480px) {
    header {
        padding: 0.8rem 1rem;
    }

    .logo-text {
        font-size: 1.2rem;
    }

    .page-header-center h1 {
        font-size: 1.5rem;
    }

    .topic-title h3 {
        font-size: 1.2rem;
    }

    .topic-description {
        font-size: 0.85rem;
    }

    .nav-links {
        padding: 1rem;
        gap: 1rem;
    }

    .filter-tab {
        padding: 0.6rem 1rem;
        font-size: 0.9rem;
    }

    .exam-boards {
        flex-direction: column;
        width: 100%;
    }

    .board-badge {
        width: 100%;
        text-align: center;
    }

    .hero {
        padding: 1.5rem 1rem;
    }

    .subjects-section {
        padding: 0 1rem;
    }

    .main-content {
        padding: 0 1rem 4rem;
    }

    .topics-list-section {
        padding: 0 1rem 2rem;
    }

    .subjects-container {
        padding: 0 1rem 4rem;
    }

    .breadcrumb {
        padding: 1rem 1rem 0;
    }

    .about-content {
        padding: 0 1rem 4rem;
    }

    .topic-card-header {
        padding: 1.5rem 1rem;
    }

    .topic-actions {
        padding: 0 1rem 1.5rem;
    }

    .page-header {
        padding: 1.5rem 1rem;
    }

    .page-header-center {
        padding: 1.5rem 1rem 2rem;
    }

    .section-title {
        font-size: 2rem;
        margin-bottom: 2rem;
    }

    .subject-card {
        padding: 1.2rem;
    }

    h1, h2, h3, h4, h5, h6 {
        word-wrap: break-word;
        overflow-wrap: break-word;
    }

    p, a, span, li {
        word-wrap: break-word;
        overflow-wrap: break-word;
    }

    .useful-videos {
        padding: 0 1rem;
        margin: 2rem auto;
    }

    .useful-videos h2 {
        font-size: 1.5rem;
    }

    .video-grid {
        gap: 1rem;
    }

    .form-container {
        padding: 1rem;
    }

    .subject-card p {
        display: none;
    }

    .subject-card .boards {
        display: none;
    }

    .subject-card-detailed p {
        display: none;
    }

    .subject-meta {
        display: none;
    }
}

html {
    scroll-behavior: smooth;
}

body {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img, iframe, video {
    max-width: 100%;
    height: auto;
}

@media (hover: hover) and (pointer: fine) {
    .subject-card,
    .subject-card-detailed,
    .topic-card,
    .action-btn {
        transition: all 0.3s cubic-bezier(0.25, 0.46, 0.45, 0.94);
    }
}

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}

 .game{
            touch-action: none; /* Prevent default touch behaviors like zoom/scroll */
            margin: 0;
            padding: 20px;
            color: #fff;
            font-family: Arial, sans-serif;
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            min-height: 90vh;
            overflow: hidden;
        canvas {
            border: 2px solid #333;
            background: #111;
            box-shadow: 0 0 20px rgba(0, 191, 255, 0.5);
            max-width: 90vw;
            max-height: 90vh;
            touch-action: none;
        }
        #score {
            font-size: clamp(20px, 5vw, 28px);
            margin-bottom: 10px;
            text-align: center;
        }
        #gameOver {
            position: fixed;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            background: rgba(0, 0, 0, 0.95);
            padding: clamp(20px, 8vw, 40px);
            border-radius: 15px;
            text-align: center;
            display: none;
            z-index: 100;
            border: 2px solid #00BFFF;
            box-shadow: 0 0 30px rgba(0, 191, 255, 0.5);
        }
        #gameOver h2 {
            margin-top: 0;
            color: #00BFFF;
        }
        button {
            background: linear-gradient(45deg, #00BFFF, #87CEEB);
            color: #000;
            border: none;
            padding: 13px 27px;
            font-size: clamp(16px, 4vw, 20px);
            border-radius: 10px;
            cursor: pointer;
            margin-top: 5px;
            font-weight: bold;
            box-shadow: 0 4px 15px rgba(0, 191, 255, 0.3);
        }
        button:hover, button:active {
            background: linear-gradient(45deg, #87CEEB, #00BFFF);
            transform: scale(1.05);
        }
        .instructions {
            margin-top: 20px;
            text-align: center;
            max-width: 90vw;
            font-size: clamp(14px, 3.5vw, 16px);
            line-height: 1.4;
        }
        .swipe-hint {
            background: rgba(0, 191, 255, 0.2);
            padding: 10px;
            border-radius: 8px;
            margin-top: 10px;
            border: 1px solid rgba(0, 191, 255, 0.4);
        }
        }

        .personal-tips {
        max-width: 800px;
        margin: 40px auto;
        padding: 20px;
        border-radius: 10px;
    }