@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    --warning-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    --glass-bg: rgba(255, 255, 255, 0.25);
    --glass-border: rgba(255, 255, 255, 0.18);
    --shadow-light: 0 8px 32px rgba(31, 38, 135, 0.37);
    --shadow-medium: 0 15px 35px rgba(0, 0, 0, 0.1);
    --shadow-heavy: 0 25px 50px rgba(0, 0, 0, 0.15);
    --border-radius: 16px;
    --border-radius-large: 24px;
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 45%, #f093fb 100%);
    color: #1a1a1a;
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* Animated Background */
.animated-bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.floating-shapes {
    position: absolute;
    width: 100%;
    height: 100%;
}

.shape {
    position: absolute;
    border-radius: 50%;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    animation: float 20s infinite linear;
}

.shape-1 {
    width: 80px;
    height: 80px;
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 120px;
    height: 120px;
    top: 60%;
    right: 10%;
    animation-delay: -5s;
}

.shape-3 {
    width: 60px;
    height: 60px;
    top: 30%;
    right: 20%;
    animation-delay: -10s;
}

.shape-4 {
    width: 100px;
    height: 100px;
    bottom: 20%;
    left: 20%;
    animation-delay: -15s;
}

@keyframes float {
    0% {
        transform: translateY(0px) rotate(0deg);
        opacity: 0.7;
    }
    33% {
        transform: translateY(-20px) rotate(120deg);
        opacity: 0.9;
    }
    66% {
        transform: translateY(10px) rotate(240deg);
        opacity: 0.6;
    }
    100% {
        transform: translateY(0px) rotate(360deg);
        opacity: 0.7;
    }
}

/* Enhanced Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

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

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(0);
    }
    40% {
        transform: translateY(-10px);
    }
    60% {
        transform: translateY(-5px);
    }
}

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

/* Header Enhancements */
header {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    color: #1f2b6f;
    padding: 1rem 1.5rem;
    box-shadow: var(--shadow-light);
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    border-bottom: 1px solid var(--glass-border);
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
}

.hamburger {
    appearance: none;
    border: none;
    background: rgba(102, 126, 234, 0.1);
    width: 48px;
    height: 48px;
    border-radius: var(--border-radius);
    cursor: pointer;
    display: grid;
    place-items: center;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
    z-index: 10;
}

.hamburger-line {
    width: 20px;
    height: 2px;
    background: #667eea;
    position: relative;
    transition: var(--transition-fast);
    border-radius: 1px;
}

.hamburger-line::before,
.hamburger-line::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 2px;
    background: #667eea;
    transition: var(--transition-fast);
    border-radius: 1px;
}

.hamburger-line::before {
    top: -6px;
}

.hamburger-line::after {
    top: 6px;
}

.hamburger:hover {
    background: rgba(102, 126, 234, 0.2);
    transform: scale(1.05);
}

.hamburger:hover .hamburger-line {
    background: #5a67d8;
}

.hamburger:hover .hamburger-line::before,
.hamburger:hover .hamburger-line::after {
    background: #5a67d8;
}

.brand {
    text-decoration: none;
    color: #1f2b6f;
    font-size: 1.5rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition-normal);
}

.brand:hover {
    transform: scale(1.02);
}

.brand-icon {
    font-size: 1.8rem;
    animation: bounce 2s infinite;
}

.top-actions {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex-wrap: wrap;
}

.top-actions .button {
    padding: 0.85rem 1.5rem;
    border-radius: var(--border-radius);
    border: 1px solid rgba(102, 126, 234, 0.2);
    background: rgba(255, 255, 255, 0.9);
    color: #1f2b6f;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
}

.top-actions .button::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: var(--transition-normal);
    z-index: -1;
}

.top-actions .button:hover::before {
    left: 0;
}

.top-actions .button:hover {
    color: white;
    border-color: transparent;
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

.top-actions .button.primary {
    background: var(--primary-gradient);
    color: #fff;
    border-color: transparent;
}

.top-actions .button.primary::before {
    background: var(--secondary-gradient);
}

/* Hide logout button by default - shown only when logged in */
#logoutBtn {
    display: none;
}

/* Enhanced Sidebar */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    transform: translateX(-100%);
    width: 300px;
    height: 100vh;
    padding: 2rem 1.5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    box-shadow: var(--shadow-heavy);
    transition: var(--transition-normal);
    z-index: 1001;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    border-right: 1px solid var(--glass-border);
}

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

.sidebar-close {
    border: none;
    background: rgba(102, 126, 234, 0.1);
    color: #1f2b6f;
    cursor: pointer;
    font-size: 1.5rem;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    align-self: flex-end;
    transition: var(--transition-fast);
}

.sidebar-close:hover {
    background: rgba(102, 126, 234, 0.2);
    transform: scale(1.1);
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.nav-item {
    color: #1f2b6f;
    text-decoration: none;
    padding: 1rem 1.2rem;
    border-radius: var(--border-radius);
    transition: var(--transition-normal);
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    position: relative;
    overflow: hidden;
}

.nav-item::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: var(--transition-normal);
    z-index: -1;
}

.nav-item:hover::before,
.nav-item.active::before {
    left: 0;
}

.nav-item:hover,
.nav-item.active {
    color: white;
    transform: translateX(5px);
}

.nav-icon {
    font-size: 1.2rem;
    width: 24px;
    text-align: center;
}

/* Backdrop */
.backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition-normal);
    z-index: 1000;
    backdrop-filter: blur(5px);
}

body.sidebar-open .backdrop {
    opacity: 1;
    visibility: visible;
}

/* Main Content */
main {
    padding: 2rem;
    max-width: 1400px;
    margin: 0 auto;
    position: relative;
    padding-top: 6rem; /* Account for fixed header */
}

/* Enhanced Hero Section */
.hero {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    margin-bottom: 4rem;
    padding: 3rem;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-medium);
    animation: fadeInScale 1s ease-out;
}

.hero-content {
    animation: slideInLeft 1s ease-out 0.3s both;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: 1rem;
    font-weight: 800;
    line-height: 1.1;
}

.hero-text-line {
    display: block;
}

.gradient-text {
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: #666;
    margin-bottom: 2rem;
    line-height: 1.7;
}

.hero-actions {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    margin-left: 120px;
}

.cta-button {
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    border: none;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-normal);
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.cta-button.primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: var(--shadow-medium);
}

.cta-button.primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-heavy);
}

.cta-button.secondary {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 2px solid var(--glass-border);
    color: #1f2b6f;
    text-align: center;
    

}

.cta-button.secondary:hover {
    background: rgba(102, 126, 234, 0.1);
    transform: translateY(-2px);
}

.button-icon {
    font-size: 1.2rem;
    transition: var(--transition-fast);
}

.cta-button:hover .button-icon {
    transform: scale(1.2);
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
    gap: 2rem;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--accent-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: countUp 1s ease-out 1s both;
}

.stat-label {
    font-size: 0.9rem;
    color: #666;
    font-weight: 500;
}

/* Interactive Demo */
.hero-visual {
    animation: slideInRight 1s ease-out 0.6s both;
}

.interactive-demo {
    position: relative;
    max-width: 400px;
    margin: 0 auto;
}

.demo-screen {
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-heavy);
    overflow: hidden;
    border: 1px solid rgba(0,0,0,0.1);
}

.demo-header {
    background: #f8f9fa;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid #e9ecef;
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.demo-dots {
    display: flex;
    gap: 0.5rem;
}

.dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

.dot.red { background: #ff5f57; }
.dot.yellow { background: #ffbd2e; }
.dot.green { background: #28ca42; }

.demo-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: #666;
}

.demo-content {
    padding: 1.5rem;
}

.question-card h4 {
    margin: 0 0 1rem 0;
    color: #1f2b6f;
    font-size: 1.1rem;
}

.options {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.option {
    padding: 0.75rem 1rem;
    border: 2px solid #e9ecef;
    border-radius: var(--border-radius);
    background: white;
    cursor: pointer;
    transition: var(--transition-fast);
    font-weight: 500;
}

.option:hover {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.05);
}

.option.selected {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
}

.option.correct {
    border-color: #4CAF50;
    background: rgba(76, 175, 80, 0.1);
    color: #4CAF50;
}

.option.incorrect {
    border-color: #f44336;
    background: rgba(244, 67, 54, 0.1);
    color: #f44336;
}

.demo-effects {
    position: absolute;
    top: -20px;
    right: -20px;
    width: 100%;
    height: 100%;
    pointer-events: none;
}

.particle {
    position: absolute;
    width: 8px;
    height: 8px;
    background: var(--accent-gradient);
    border-radius: 50%;
    animation: float 3s infinite ease-in-out;
}

.particle-1 {
    top: 20%;
    right: 20%;
    animation-delay: 0s;
}

.particle-2 {
    top: 60%;
    right: 10%;
    animation-delay: -1s;
}

.particle-3 {
    top: 40%;
    right: 30%;
    animation-delay: -2s;
}

/* Features Section */
.features-section {
    margin-bottom: 4rem;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-bottom: 0.5rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    font-size: 1.1rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.feature-grid.visible {
    opacity: 1;
    transform: translateY(0);
}

.interactive-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--glass-border);
    transition: var(--transition-normal);
    position: relative;
    overflow: hidden;
    animation: fadeInUp 0.8s ease-out both;
}

.interactive-card:nth-child(1) { animation-delay: 0.1s; }
.interactive-card:nth-child(2) { animation-delay: 0.2s; }
.interactive-card:nth-child(3) { animation-delay: 0.3s; }
.interactive-card:nth-child(4) { animation-delay: 0.4s; }
.interactive-card:nth-child(5) { animation-delay: 0.5s; }
.interactive-card:nth-child(6) { animation-delay: 0.6s; }

.interactive-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-heavy);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.interactive-card h3 {
    margin: 0 0 1rem 0;
    color: #1f2b6f;
    font-size: 1.3rem;
    font-weight: 700;
}

.interactive-card p {
    color: #666;
    line-height: 1.6;
    margin: 0;
}

.feature-hover-effect {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    opacity: 0;
    transition: var(--transition-normal);
    z-index: -1;
}

.interactive-card:hover .feature-hover-effect {
    opacity: 0.05;
}

/* Game Section */
.game-section {
    margin-bottom: 4rem;
}

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

.game-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--glass-border);
    transition: var(--transition-normal);
    cursor: pointer;
    position: relative;
    overflow: hidden;
    animation: fadeInScale 0.8s ease-out both;
}

.game-card:nth-child(1) { animation-delay: 0.1s; }
.game-card:nth-child(2) { animation-delay: 0.2s; }
.game-card:nth-child(3) { animation-delay: 0.3s; }

.game-card:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: var(--shadow-heavy);
}

.game-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
    display: block;
}

.game-card h3 {
    margin: 0 0 1rem 0;
    color: #1f2b6f;
    font-size: 1.3rem;
    font-weight: 700;
}

.game-card p {
    color: #666;
    line-height: 1.6;
    margin: 0 0 1.5rem 0;
}

.game-progress {
    margin-top: auto;
}

.progress-bar {
    width: 100%;
    height: 8px;
    background: rgba(102, 126, 234, 0.2);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    background: var(--success-gradient);
    border-radius: 4px;
    transition: width 1s ease;
}

.progress-text {
    font-size: 0.9rem;
    color: #666;
    font-weight: 500;
}

/* Enhanced Challenge Arena */
.challenge-arena {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 3rem;
    margin-top: 2rem;
    border: 1px solid var(--glass-border);
    box-shadow: var(--shadow-medium);
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.challenge-arena.visible {
    opacity: 1;
    transform: translateY(0);
}

.challenge-panel {
    display: grid;
    gap: 2rem;
}

.challenge-panel h2 {
    margin: 0;
    color: #1f2b6f;
    font-size: 2rem;
    font-weight: 800;
    text-align: center;
}

.challenge-panel > p {
    text-align: center;
    color: #666;
    font-size: 1.1rem;
    margin: 0;
}

.challenge-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
}

.challenge-btn {
    padding: 1.5rem;
    border-radius: var(--border-radius);
    border: 2px solid rgba(102, 126, 234, 0.2);
    background: white;
    color: #1f2b6f;
    font-weight: 600;
    transition: var(--transition-normal);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    position: relative;
    overflow: hidden;
}

.challenge-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: var(--transition-normal);
    z-index: -1;
}

.challenge-btn:hover::before {
    left: 0;
}

.challenge-btn:hover {
    color: white;
    border-color: transparent;
    transform: translateY(-3px);
    box-shadow: var(--shadow-medium);
}

.challenge-btn.completed {
    background: var(--success-gradient);
    color: white;
    border-color: transparent;
}

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

.challenge-text {
    font-size: 1rem;
    font-weight: 600;
}

.challenge-reward {
    font-size: 0.9rem;
    opacity: 0.8;
    font-weight: 500;
}

.challenge-progress {
    display: grid;
    gap: 1rem;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.xp-display, .level-display {
    font-size: 1rem;
    color: #666;
}

.xp-display strong {
    color: #1f2b6f;
    font-weight: 700;
}

.level-display {
    background: var(--warning-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.challenge-track {
    width: 100%;
    height: 20px;
    background: rgba(102, 126, 234, 0.1);
    border-radius: 10px;
    overflow: hidden;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.1);
}

.challenge-fill {
    width: 0;
    height: 100%;
    background: var(--success-gradient);
    transition: width 0.6s ease;
    border-radius: 10px;
}

#challengeStatus {
    text-align: center;
    margin: 0;
    font-weight: 600;
    color: #1f2b6f;
}

/* Testimonials */
.testimonials-section {
    margin-bottom: 4rem;
}

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

.testimonial-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 2rem;
    box-shadow: var(--shadow-medium);
    border: 1px solid var(--glass-border);
    animation: fadeInUp 0.8s ease-out both;
}

.testimonial-card:nth-child(1) { animation-delay: 0.1s; }
.testimonial-card:nth-child(2) { animation-delay: 0.2s; }
.testimonial-card:nth-child(3) { animation-delay: 0.3s; }

.testimonial-content {
    font-style: italic;
    color: #555;
    line-height: 1.6;
    margin-bottom: 1.5rem;
    position: relative;
}

.testimonial-content::before {
    content: '"';
    font-size: 4rem;
    color: rgba(102, 126, 234, 0.2);
    position: absolute;
    top: -20px;
    left: -10px;
    font-family: serif;
}

.testimonial-author {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.author-avatar {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-gradient);
    display: grid;
    place-items: center;
    font-size: 1.5rem;
}

.author-info {
    flex: 1;
}

.author-name {
    font-weight: 700;
    color: #1f2b6f;
    margin-bottom: 0.25rem;
}

.author-title {
    font-size: 0.9rem;
    color: #666;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .hero {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }

    .hero-visual {
        order: -1;
    }

    .sidebar {
        width: 280px;
    }
}

@media (max-width: 768px) {
    main {
        padding: 1rem;
    }

    header {
        padding: 1rem;
    }

    .hero {
        padding: 2rem 1rem;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .hero-actions {
        justify-content: center;
    }

    .feature-grid,
    .game-grid,
    .testimonials-grid {
        grid-template-columns: 1fr;
    }

    .challenge-actions {
        grid-template-columns: 1fr;
    }

    .sidebar {
        width: 100%;
    }

    .top-actions {
        width: 100%;
        justify-content: center;
    }

    .hero-stats {
        grid-template-columns: repeat(3, 1fr);
        gap: 1rem;
    }

    .stat-number {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-stats {
        grid-template-columns: 1fr;
    }

    .hero-actions {
        flex-direction: column;
        align-items: center;
    }

    .cta-button {
        width: 100%;
        justify-content: center;
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus states */
button:focus-visible,
a:focus-visible,
input:focus-visible,
textarea:focus-visible {
    outline: 3px solid rgba(102, 126, 234, 0.6);
    outline-offset: 3px;
}

/* Loading states */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border: 2px solid #667eea;
    border-top: 2px solid transparent;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Notification Styles */
.xp-notification, .level-up-notification, .demo-success {
    position: fixed;
    top: 100px;
    right: 20px;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    padding: 1rem 1.5rem;
    box-shadow: var(--shadow-heavy);
    z-index: 10000;
    animation: slideInRight 0.5s ease-out, fadeOut 0.5s ease-out 2.5s;
    font-weight: 600;
    color: #1f2b6f;
}

.level-up-notification {
    background: var(--warning-gradient);
    color: white;
    font-size: 1.2rem;
}

.demo-success {
    background: var(--success-gradient);
    color: white;
}

@keyframes fadeOut {
    to {
        opacity: 0;
        transform: translateX(100%);
    }
}

/* Particle Effects */
.particle-effect {
    position: absolute;
    width: 4px;
    height: 4px;
    background: var(--accent-gradient);
    border-radius: 50%;
    pointer-events: none;
    animation: particleFloat 2s ease-out forwards;
}

@keyframes particleFloat {
    0% {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
    100% {
        opacity: 0;
        transform: translateY(-50px) scale(0);
    }
}

/* AI Quest Page Styles */
.quest-header {
    text-align: center;
    margin-bottom: 2rem;
}

.quest-header h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    margin-bottom: 1rem;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.quest-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.stat-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: var(--transition-normal);
}

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

.stat-icon {
    font-size: 2rem;
    width: 60px;
    height: 60px;
    display: grid;
    place-items: center;
    background: var(--primary-gradient);
    border-radius: 50%;
    color: white;
}

.stat-info {
    flex: 1;
}

.stat-value {
    font-size: 2rem;
    font-weight: 800;
    color: #1f2b6f;
}

.stat-label {
    font-size: 0.9rem;
    color: #666;
    margin-top: 0.25rem;
}

/* Quest Modes */
.quest-modes {
    margin-bottom: 3rem;
}

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

.mode-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 2rem;
    border: 1px solid var(--glass-border);
    transition: var(--transition-normal);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.mode-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: var(--primary-gradient);
    transition: var(--transition-normal);
    z-index: -1;
}

.mode-card:hover::before {
    left: 0;
}

.mode-card:hover {
    transform: translateY(-10px) scale(1.02);
    box-shadow: var(--shadow-heavy);
    color: white;
}

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

.mode-card h3 {
    margin: 0 0 1rem 0;
    font-size: 1.4rem;
    font-weight: 700;
}

.mode-card p {
    margin: 0 0 1.5rem 0;
    line-height: 1.6;
}

.mode-difficulty {
    margin-bottom: 1rem;
}

.difficulty-badge {
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 600;
    text-transform: uppercase;
}

.difficulty-badge.easy {
    background: var(--success-gradient);
    color: white;
}

.difficulty-badge.medium {
    background: var(--warning-gradient);
    color: white;
}

.difficulty-badge.hard {
    background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
    color: white;
}

.mode-reward {
    font-weight: 600;
    color: #4CAF50;
}

/* Quiz Section */
.quiz-section {
    margin-bottom: 3rem;
}

.quiz-container {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 2rem;
    border: 1px solid var(--glass-border);
    max-width: 800px;
    margin: 0 auto;
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(102, 126, 234, 0.2);
}

.question-counter {
    font-size: 1.2rem;
    font-weight: 600;
    color: #1f2b6f;
}

.timer {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(102, 126, 234, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 20px;
}

.timer-icon {
    font-size: 1.2rem;
}

.timer-text {
    font-weight: 700;
    color: #1f2b6f;
    font-size: 1.1rem;
}

.question-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-light);
    border: 1px solid rgba(0,0,0,0.1);
}

.question-category {
    display: inline-block;
    background: var(--primary-gradient);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.question-card h2 {
    margin: 0 0 1rem 0;
    color: #1f2b6f;
    font-size: 1.4rem;
    line-height: 1.4;
}

.question-hint {
    background: rgba(102, 126, 234, 0.1);
    padding: 1rem;
    border-radius: var(--border-radius);
    border-left: 4px solid #667eea;
    font-style: italic;
    color: #666;
}

.options-grid {
    display: grid;
    gap: 1rem;
    margin-bottom: 2rem;
}

.quiz-option {
    background: white;
    border: 2px solid #e9ecef;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    cursor: pointer;
    transition: var(--transition-fast);
    font-weight: 500;
    text-align: left;
}

.quiz-option:hover {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.05);
    transform: translateY(-2px);
}

.quiz-option.selected {
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
}

.quiz-option.correct {
    border-color: #4CAF50;
    background: rgba(76, 175, 80, 0.1);
}

.quiz-option.incorrect {
    border-color: #f44336;
    background: rgba(244, 67, 54, 0.1);
}

.quiz-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.action-btn {
    padding: 1rem 2rem;
    border-radius: var(--border-radius);
    border: none;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition-normal);
}

.action-btn.primary {
    background: var(--primary-gradient);
    color: white;
}

.action-btn.secondary {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    color: #1f2b6f;
}

.action-btn.outline {
    background: transparent;
    border: 2px solid #667eea;
    color: #667eea;
}

.action-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-medium);
}

/* Result Section */
.result-section {
    margin-bottom: 3rem;
}

.result-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius-large);
    padding: 3rem;
    border: 1px solid var(--glass-border);
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.result-header h2 {
    margin-bottom: 2rem;
    color: #1f2b6f;
}

.final-score {
    margin-bottom: 2rem;
}

.score-display {
    display: inline-flex;
    align-items: baseline;
    gap: 0.5rem;
    margin-bottom: 0.5rem;
}

.score-number {
    font-size: 4rem;
    font-weight: 800;
    background: var(--success-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.score-total {
    font-size: 2rem;
    color: #666;
}

.score-percentage {
    font-size: 1.5rem;
    font-weight: 600;
    color: #4CAF50;
}

.result-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
}

.result-stats .stat-item {
    background: white;
    border-radius: var(--border-radius);
    padding: 1.5rem;
    box-shadow: var(--shadow-light);
    border: 1px solid rgba(0,0,0,0.1);
}

.result-stats .stat-icon {
    width: 50px;
    height: 50px;
    margin: 0 auto 1rem auto;
}

.result-stats .stat-value {
    font-size: 1.5rem;
    text-align: center;
}

.result-stats .stat-label {
    text-align: center;
    color: #666;
}

.result-feedback {
    margin: 2rem 0;
}

.result-feedback p {
    font-size: 1.1rem;
    color: #666;
    font-style: italic;
}

.result-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

/* Achievements */
.achievements-section h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: #1f2b6f;
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
}

.achievement-card {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    border: 1px solid var(--glass-border);
    display: flex;
    align-items: center;
    gap: 1rem;
    transition: var(--transition-normal);
}

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

.achievement-card.locked {
    opacity: 0.6;
}

.achievement-card.unlocked {
    background: var(--success-gradient);
    color: white;
}

.achievement-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    display: grid;
    place-items: center;
    background: rgba(102, 126, 234, 0.1);
    border-radius: 50%;
}

.achievement-card.unlocked .achievement-icon {
    background: rgba(255, 255, 255, 0.2);
}

.achievement-info h4 {
    margin: 0 0 0.5rem 0;
    font-size: 1.1rem;
}

.achievement-info p {
    margin: 0;
    font-size: 0.9rem;
    color: #666;
}

.achievement-card.unlocked .achievement-info p {
    color: rgba(255, 255, 255, 0.8);
}


.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    transform: translateX(-100%);
    width: 280px;
    height: 100vh;
    padding: 1.5rem 1rem;
    background: rgba(255, 255, 255, 0.98);
    box-shadow: 12px 0 30px rgba(0, 0, 0, 0.14);
    transition: transform 0.35s ease;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    overflow-y: auto;
}

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

.sidebar-close {
    border: none;
    background: transparent;
    color: #1f2b6f;
    cursor: pointer;
    font-size: 1.4rem;
    align-self: flex-end;
    padding: 0.25rem;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.sidebar-nav a {
    color: #1f2b6f;
    text-decoration: none;
    padding: 0.85rem 1rem;
    border-radius: 14px;
    transition: background 0.25s ease, color 0.25s ease;
    font-weight: 700;
}

.sidebar-nav a:hover,
.sidebar-nav a.active {
    background: rgba(99, 78, 155, 0.12);
    color: #5f2ea4;
}

.sidebar-nav a:focus-visible,
.hamburger:focus-visible,
.sidebar-close:focus-visible,
.top-actions .button:focus-visible {
    outline: 3px solid rgba(99, 78, 155, 0.6);
    outline-offset: 3px;
}

.backdrop {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.32);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
    z-index: 100;
    pointer-events: none;
}

.sidebar {
    pointer-events: auto;
    z-index: 1000;
}

.sidebar-nav a {
    cursor: pointer;
    touch-action: manipulation;
}

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

body.sidebar-open .backdrop {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
}

@media (max-width: 1024px) {
    .sidebar {
        width: 240px;
    }
}

@media (max-width: 768px) {
    header {
        padding: 1rem;
    }
    .topbar {
        width: 100%;
    }
    .top-actions {
        width: 100%;
        justify-content: flex-end;
    }
}

nav {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem;
    margin-top: 0.75rem;
}

nav a {
    color: #3f51b5;
    text-decoration: none;
    font-weight: 600;
    transition: color 0.25s ease;
}

nav a:hover {
    color: #9c27b0;
}

main {
    padding: 2rem;
    max-width: 1200px;
    margin: 2rem auto;
    background: rgba(255, 255, 255, 0.94);
    border-radius: 20px;
    box-shadow: 0 10px 35px rgba(0,0,0,0.15);
}

.hero {
    text-align: center;
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease-out;
}

.hero h1 {
    font-size: clamp(2.2rem, 4vw, 3.6rem);
    margin-bottom: 0.5rem;
    animation: fadeInUp 1.2s ease-out 0.3s both;
}

.hero p {
    max-width: 760px;
    margin: 0 auto;
    font-size: 1.05rem;
    line-height: 1.7;
    color: #444;
    animation: fadeInUp 1.2s ease-out 0.6s both;
}

.feature-grid, .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.25rem;
    margin-top: 1.5rem;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.feature-grid.visible, .grid.visible, .challenge-arena.visible {
    opacity: 1;
    transform: translateY(0);
}

.challenge-arena {
    background: linear-gradient(135deg, rgba(95,124,249,0.08), rgba(155,69,216,0.08));
    border-radius: 22px;
    padding: 1.8rem;
    margin-top: 1.5rem;
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease, transform 0.8s ease;
}

.challenge-panel {
    display: grid;
    gap: 1rem;
}

.challenge-panel h2 {
    margin-top: 0;
    color: #3f51b5;
}

.challenge-actions {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.9rem;
}

.challenge-btn {
    padding: 1rem 1.2rem;
    border-radius: 14px;
    border: 1px solid rgba(99, 78, 155, 0.18);
    background: #fff;
    color: #3f51b5;
    font-weight: 700;
    transition: background 0.3s ease, transform 0.2s ease, border-color 0.3s ease;
}

.challenge-btn:hover,
.challenge-btn.completed {
    background: linear-gradient(135deg, #5f7cf9, #9b45d8);
    color: #fff;
    border-color: transparent;
    transform: translateY(-2px);
}

.challenge-progress {
    display: grid;
    gap: 0.5rem;
}

.challenge-track {
    width: 100%;
    height: 16px;
    background: #ececff;
    border-radius: 999px;
    overflow: hidden;
}

.challenge-fill {
    width: 0;
    height: 100%;
    background: linear-gradient(135deg, #5f7cf9 0%, #9b45d8 100%);
    transition: width 0.4s ease;
}

.quiz-meta {
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    gap: 0.75rem;
    margin-bottom: 1rem;
    color: #555;
    font-size: 0.95rem;
}

.feature-card, .course-card, .quiz-card, .forum-card, .stat-card {
    background: #ffffff;
    border-radius: 18px;
    padding: 1.3rem;
    box-shadow: 0 10px 25px rgba(0,0,0,0.08);
    border: 1px solid rgba(115, 103, 197, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover, .course-card:hover, .quiz-card:hover, .forum-card:hover, .stat-card:hover {
    transform: scale(1.05);
    box-shadow: 0 15px 35px rgba(99, 78, 155, 0.2);
}

.feature-card h3, .course-card h3, .stat-card h3 {
    margin-top: 0;
    color: #4b2fa8;
}

h2, h3 {
    color: #3f51b5;
}

form {
    display: grid;
    gap: 1rem;
    max-width: 450px;
    margin: 0 auto;
}

label {
    font-weight: 600;
}

input, textarea, select, button {
    width: 100%;
    padding: 0.95rem 1rem;
    border-radius: 12px;
    border: 1px solid #d0d7ff;
    font-size: 1rem;
    background: #fafbff;
}

textarea {
    min-height: 120px;
    resize: vertical;
}

input:focus, textarea:focus, select:focus {
    outline: 2px solid rgba(99, 78, 155, 0.3);
}

button {
    background: linear-gradient(135deg, #5f7cf9, #9b45d8);
    color: #fff;
    border: none;
    cursor: pointer;
    font-weight: 700;
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

button:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 25px rgba(99, 78, 155, 0.22);
    animation: bounce 0.6s ease;
}

.quiz-option {
    display: block;
    margin: 0.5rem 0;
    width: 100%;
    padding: 0.75rem;
    text-align: left;
}

.top-actions .button:hover {
    transform: translateY(-3px);
    animation: bounce 0.6s ease;
}

#message {
    color: #d32f2f;
    margin-top: 1rem;
    text-align: center;
    padding: 0.9rem 1.2rem;
    border-radius: 12px;
    background: rgba(211, 47, 47, 0.08);
    border-left: 4px solid #d32f2f;
    font-weight: 500;
    min-height: 20px;
}

.course-card button, .feature-card button {
    margin-top: 1rem;
}

#chat-messages {
    min-height: 260px;
    max-height: 360px;
    overflow-y: auto;
    padding: 1rem;
    border-radius: 16px;
    background: #f2f4ff;
    border: 1px solid #e0e4ff;
}

.chat-ai, .chat-you {
    padding: 0.9rem 1rem;
    margin-bottom: 0.75rem;
    border-radius: 14px;
    width: fit-content;
    max-width: 90%;
}

.chat-ai {
    background: #ffffff;
    border: 1px solid #c6c9ff;
}

.chat-you {
    background: #e4e8ff;
    border: 1px solid #b4b8ff;
    margin-left: auto;
}

#chat-input {
    width: calc(100% - 130px);
    display: inline-block;
}

.chat-row {
    display: flex;
    gap: 0.75rem;
    align-items: center;
    margin-top: 1rem;
}

.progress-bar {
    width: 100%;
    height: 18px;
    background: #ececff;
    border-radius: 999px;
    overflow: hidden;
    margin-top: 0.75rem;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(135deg, #5f7cf9 0%, #9b45d8 100%);
    width: 0;
    transition: width 0.4s ease;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    background: #fff2c1;
    color: #5f3913;
    padding: 0.6rem 1rem;
    border-radius: 999px;
    font-weight: 700;
    box-shadow: 0 8px 20px rgba(155, 69, 216, 0.08);
}

.stat-card {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.heatmap-row {
    display: grid;
    grid-template-columns: 1.1fr 3fr 0.5fr;
    gap: 1rem;
    align-items: center;
    margin-bottom: 1rem;
}

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

.leaderboard li {
    margin-bottom: 0.75rem;
    padding: 0.85rem 1rem;
    background: #f8f8ff;
    border-radius: 14px;
}

.forum-card {
    border: 1px solid #e0e4ff;
    background: #fafbff;
}

@media (max-width: 768px) {
    nav {
        justify-content: center;
    }
    .heatmap-row {
        grid-template-columns: 1fr;
    }
    #chat-input {
        width: 100%;
    }
}