/* General Styles */
:root {
    --primary-color: #6366f1; /* Indigo 500 */
    --secondary-color: #8b5cf6; /* Violet 500 */
    --accent-color: #a855f7; /* Purple 500 */
    --text-color-dark: #1f2937; /* Gray 900 */
    --text-color-medium: #4b5563; /* Gray 600 */
    --text-color-light: #6b7280; /* Gray 500 */
    --bg-light: #f9fafb; /* Gray 50 */
    --bg-white: #ffffff;
    --border-color: #e5e7eb; /* Gray 200 */
    --border-light: #f3f4f6; /* Gray 100 */
    --shadow-light: rgba(0, 0, 0, 0.05);
    --shadow-medium: rgba(0, 0, 0, 0.1);
    --shadow-large: rgba(0, 0, 0, 0.2);
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
}

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

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: var(--text-color-medium);
    background-color: var(--bg-white);
    scroll-behavior: smooth;
}

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

h1, h2, h3, h4 {
    color: var(--text-color-dark);
    line-height: 1.2;
}

h1 {
    font-size: 3.5rem;
    font-weight: 700;
}

h2 {
    font-size: 2.5rem;
    font-weight: 700;
}

h3 {
    font-size: 1.75rem;
    font-weight: 700;
}

h4 {
    font-size: 1.25rem;
    font-weight: 700;
}

p {
    font-size: 1.125rem;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 20px;
    font-size: 2.5rem;
}

.section-subtitle {
    text-align: center;
    font-size: 1.25rem;
    color: var(--text-color-medium);
    max-width: 800px;
    margin: 0 auto 60px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 28px;
    border-radius: var(--radius-md);
    font-weight: 700;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.btn-primary {
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: var(--bg-white);
}

.btn-primary:hover {
    background: linear-gradient(to right, #4f46e5, #7c3aed);
}

.btn-outline {
    background-color: transparent;
    border-color: var(--border-color);
    color: var(--text-color-medium);
}

.btn-outline:hover {
    background-color: var(--bg-light);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.btn-secondary {
    background-color: var(--bg-white);
    border-color: var(--border-color);
    color: var(--text-color-medium);
}

.btn-secondary:hover {
    background-color: var(--bg-light);
    border-color: var(--primary-color);
    color: var(--primary-color);
}

/* Icons */
.logo-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    background: linear-gradient(to bottom right, #3b82f6, #9333ea); /* Blue 500 to Purple 600 */
    border-radius: var(--radius-md);
    color: white;
    font-weight: bold;
    font-size: 0.875rem;
}

.feature-icon, .platform-icon, .learning-icon, .marketplace-feature-icon, .card-icon, .upgrade-icon, .mode-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    margin-bottom: 16px;
    font-size: 1.5rem; /* Placeholder for actual icon */
    color: white;
}

.feature-icon.icon-green {
    background: linear-gradient(to right, #22c55e, #16a34a); /* Green 500 to Green 700 */
}
.feature-icon.icon-blue {
    background: linear-gradient(to right, #3b82f6, #2563eb); /* Blue 500 to Blue 700 */
}
.feature-icon.icon-purple {
    background: linear-gradient(to right, #a855f7, #9333ea); /* Purple 500 to Purple 700 */
}
.feature-icon.icon-orange {
    background: linear-gradient(to right, #f97316, #ea580c); /* Orange 500 to Orange 700 */
}
.feature-icon.icon-pink {
    background: linear-gradient(to right, #ec4899, #db2777); /* Pink 500 to Pink 700 */
}
.feature-icon.icon-indigo {
    background: linear-gradient(to right, #6366f1, #4f46e5); /* Indigo 500 to Indigo 700 */
}
.feature-icon.icon-red {
    background: linear-gradient(to right, #ef4444, #dc2626); /* Red 500 to Red 700 */
}
.feature-icon.icon-teal {
    background: linear-gradient(to right, #14b8a6, #0d9488); /* Teal 500 to Teal 700 */
}

.platform-icon.icon-blue-gradient {
    background: linear-gradient(to right, #3b82f6, #2563eb);
}
.platform-icon.icon-purple-gradient {
    background: linear-gradient(to right, #a855f7, #9333ea);
}

.learning-icon.icon-red-gradient {
    background: linear-gradient(to right, #ef4444, #dc2626);
}
.learning-icon.icon-blue-gradient {
    background: linear-gradient(to right, #3b82f6, #2563eb);
}
.learning-icon.icon-green-gradient {
    background: linear-gradient(to right, #22c55e, #16a34a);
}
.learning-icon.icon-purple-gradient {
    background: linear-gradient(to right, #a855f7, #9333ea);
}
.learning-icon.icon-orange-gradient {
    background: linear-gradient(to right, #f97316, #ea580c);
}
.learning-icon.icon-indigo-gradient {
    background: linear-gradient(to right, #6366f1, #4f46e5);
}

.marketplace-feature-icon.icon-purple-gradient {
    background: linear-gradient(to right, #a855f7, #9333ea);
}
.marketplace-feature-icon.icon-green-gradient {
    background: linear-gradient(to right, #22c55e, #16a34a);
}
.marketplace-feature-icon.icon-orange-gradient {
    background: linear-gradient(to right, #f97316, #ea580c);
}
.marketplace-feature-icon.icon-blue-gradient {
    background: linear-gradient(to right, #3b82f6, #2563eb);
}

.card-icon.icon-green {
    background: linear-gradient(to right, #22c55e, #16a34a);
}
.card-icon.icon-blue {
    background: linear-gradient(to right, #3b82f6, #2563eb);
}
.card-icon.icon-purple {
    background: linear-gradient(to right, #a855f7, #9333ea);
}

.upgrade-icon.icon-green {
    background: linear-gradient(to right, #22c55e, #16a34a);
}
.upgrade-icon.icon-blue {
    background: linear-gradient(to right, #3b82f6, #2563eb);
}
.upgrade-icon.icon-purple {
    background: linear-gradient(to right, #a855f7, #9333ea);
}

.mode-icon.icon-green {
    background: linear-gradient(to right, #22c55e, #16a34a);
}
.mode-icon.icon-purple {
    background: linear-gradient(to right, #a855f7, #9333ea);
}
.mode-icon.icon-blue {
    background: linear-gradient(to right, #3b82f6, #2563eb);
}

/* Header */
.header {
    background-color: var(--bg-white);
    padding: 16px 0;
    border-bottom: 1px solid var(--border-light);
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-light);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header .logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-color-dark);
}

.nav-menu ul {
    list-style: none;
    display: flex;
    gap: 32px;
}

.nav-menu a {
    color: var(--text-color-medium);
    font-weight: 700;
    transition: color 0.3s ease;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

.header-actions {
    display: flex;
    gap: 16px;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.menu-icon {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-color-dark);
    position: relative;
    transition: background-color 0.3s ease;
}

.menu-icon::before, .menu-icon::after {
    content: '';
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--text-color-dark);
    position: absolute;
    transition: transform 0.3s ease;
}

.menu-icon::before {
    top: -8px;
}

.menu-icon::after {
    top: 8px;
}

.menu-toggle.active .menu-icon {
    background-color: transparent;
}

.menu-toggle.active .menu-icon::before {
    transform: translateY(8px) rotate(45deg);
}

.menu-toggle.active .menu-icon::after {
    transform: translateY(-8px) rotate(-45deg);
}

/* Hero Section */
.hero {
    background: linear-gradient(to bottom right, #e0f2fe, #f3e8ff); /* Light blue to light purple */
    padding: 100px 0;
    text-align: center;
}

.hero .container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 60px;
}

.hero-content {
    max-width: 800px;
}

.hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    color: var(--text-color-dark);
}

.hero h1 .highlight {
    display: block;
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-color-medium);
    margin-bottom: 30px;
}

.hero-features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-bottom: 40px;
}

.hero-features span {
    background-color: var(--bg-white);
    padding: 8px 16px;
    border-radius: var(--radius-full);
    font-size: 0.9rem;
    font-weight: 700;
    color: var(--primary-color);
    border: 1px solid var(--border-color);
}

.hero-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
    margin-bottom: 40px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}

.hero-stats > div {
    text-align: center;
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-color-dark);
}

.stat-text {
    font-size: 0.9rem;
    color: var(--text-color-medium);
}

.hero-image img {
    border-radius: var(--radius-xl);
    box-shadow: 0 20px 25px -5px var(--shadow-medium), 0 8px 10px -6px var(--shadow-light);
}

/* Features Section */
.features-section {
    background-color: var(--bg-white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.feature-item {
    background-color: var(--bg-light);
    padding: 30px;
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid transparent;
}

.feature-item:hover {
    background-color: var(--bg-white);
    box-shadow: 0 10px 15px -3px var(--shadow-medium), 0 4px 6px -2px var(--shadow-light);
    border-color: var(--border-color);
}

.feature-item h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.feature-item p {
    font-size: 1rem;
    color: var(--text-color-light);
}

.features-cta {
    text-align: center;
    margin-top: 60px;
}

.features-cta span {
    display: inline-block;
    background: linear-gradient(to right, #e0f2fe, #f3e8ff); /* Light blue to light purple */
    padding: 12px 24px;
    border-radius: var(--radius-full);
    font-weight: 700;
    color: var(--primary-color);
    border: 1px solid #bfdbfe;
}

/* Platforms Section */
.platforms-section {
    background: linear-gradient(to bottom right, #f0f9ff, #f5f3ff); /* Blue 50 to Purple 50 */
}

.platform-item {
    display: flex;
    align-items: center;
    gap: 60px;
    margin-bottom: 80px;
}

.platform-item:last-child {
    margin-bottom: 0;
}

.platform-item.mobile {
    flex-direction: row-reverse;
}

.platform-content {
    flex: 1;
}

.platform-content h3 {
    font-size: 2rem;
    margin-bottom: 30px;
}

.detail-item {
    margin-bottom: 20px;
}

.detail-item h4 {
    font-size: 1.125rem;
    margin-bottom: 5px;
}

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

.platform-image {
    flex: 1;
    text-align: center;
}

.platform-image img {
    border-radius: var(--radius-xl);
    box-shadow: 0 20px 25px -5px var(--shadow-medium), 0 8px 10px -6px var(--shadow-light);
}

/* Learning Section */
.learning-section {
    background-color: var(--bg-white);
}

.learning-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 80px;
}

.learning-item {
    background-color: var(--bg-light);
    padding: 40px;
    border-radius: var(--radius-xl);
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.learning-item:hover {
    background: linear-gradient(to bottom right, #e0f2fe, #f3e8ff); /* Light blue to light purple */
    box-shadow: 0 10px 15px -3px var(--shadow-medium), 0 4px 6px -2px var(--shadow-light);
}

.learning-item h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.learning-item p {
    font-size: 1rem;
    color: var(--text-color-light);
}

.learning-modes {
    background: linear-gradient(to right, #e0f2fe, #f3e8ff); /* Light blue to light purple */
    padding: 60px;
    border-radius: var(--radius-xl);
    text-align: center;
}

.learning-modes h3 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.learning-modes p {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto 40px;
}

.modes-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.mode-item {
    background-color: var(--bg-white);
    padding: 30px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
}

.mode-item h4 {
    font-size: 1.25rem;
    margin-bottom: 10px;
}

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

/* Marketplace Section */
.marketplace-section {
    background: linear-gradient(to bottom right, #f5f3ff, #e0f2fe); /* Purple 50 to Blue 50 */
}

.marketplace-content {
    display: flex;
    gap: 60px;
    margin-bottom: 80px;
}

.marketplace-features {
    flex: 2;
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
}

.feature-item-large {
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.feature-item-large h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
}

.feature-item-large p {
    font-size: 1rem;
    color: var(--text-color-light);
}

.marketplace-stats {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.stat-card {
    background-color: var(--bg-white);
    padding: 40px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-medium);
    text-align: center;
}

.stat-card h3 {
    font-size: 1.75rem;
    margin-bottom: 30px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.additional-info div {
    background-color: var(--bg-white);
    padding: 20px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
    margin-bottom: 15px;
    font-size: 1rem;
    color: var(--text-color-medium);
}

.marketplace-cta {
    background-color: var(--bg-white);
    padding: 60px;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-medium);
    text-align: center;
}

.marketplace-cta h3 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.marketplace-cta p {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto 40px;
}

.cta-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
}

/* Pricing Section */
.pricing-section {
    background-color: var(--bg-white);
}

.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    margin-bottom: 80px;
}

.pricing-card {
    background-color: var(--bg-light);
    padding: 40px;
    border-radius: var(--radius-xl);
    text-align: center;
    border: 2px solid transparent;
    transition: all 0.3s ease;
    position: relative;
}

.pricing-card.popular {
    border-color: var(--primary-color);
    box-shadow: 0 20px 25px -5px rgba(99, 102, 241, 0.2), 0 8px 10px -6px rgba(99, 102, 241, 0.1);
    transform: scale(1.03);
}

.pricing-card:hover {
    box-shadow: 0 10px 15px -3px var(--shadow-medium), 0 4px 6px -2px var(--shadow-light);
}

.popular-tag {
    position: absolute;
    top: -15px;
    left: 50%;
    transform: translateX(-50%);
    background: linear-gradient(to right, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 8px 20px;
    border-radius: var(--radius-full);
    font-size: 0.875rem;
    font-weight: 700;
}

.card-header h3 {
    font-size: 2rem;
    margin-bottom: 10px;
}

.price {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-color-dark);
    margin-bottom: 10px;
}

.card-header p {
    font-size: 1rem;
    color: var(--text-color-light);
    margin-bottom: 30px;
}

.card-body ul {
    list-style: none;
    text-align: left;
    margin-bottom: 30px;
}

.card-body ul li {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    font-size: 1rem;
    color: var(--text-color-medium);
}

.card-body ul li::before {
    content: '✔';
    color: #22c55e; /* Green 500 */
    font-weight: bold;
}

.limitations {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

.limitations h4 {
    font-size: 1rem;
    color: var(--text-color-medium);
    margin-bottom: 10px;
}

.limitations ul {
    list-style: none;
}

.limitations ul li {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 8px;
    font-size: 0.9rem;
    color: var(--text-color-light);
}

.limitations ul li::before {
    content: '•';
    color: var(--text-color-light);
    font-weight: bold;
}

.card-footer .btn {
    width: 100%;
}

.upgrade-info {
    background: linear-gradient(to right, #f0f9ff, #f5f3ff); /* Blue 50 to Purple 50 */
    padding: 60px;
    border-radius: var(--radius-xl);
    text-align: center;
}

.upgrade-info h3 {
    font-size: 2rem;
    margin-bottom: 20px;
}

.upgrade-info p {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto 40px;
}

.upgrade-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.upgrade-item {
    background-color: var(--bg-white);
    padding: 30px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-light);
}

.upgrade-item h4 {
    font-size: 1.25rem;
    margin-bottom: 10px;
}

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

/* Footer */
.footer {
    background-color: var(--text-color-dark);
    color: var(--bg-white);
    padding: 80px 0 40px;
}

.footer .logo {
    color: var(--bg-white);
}

.footer-columns {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 40px;
    margin-bottom: 60px;
}

.footer-col h3 {
    font-size: 1.25rem;
    color: var(--bg-white);
    margin-bottom: 20px;
}

.footer-col p {
    font-size: 0.95rem;
    color: #d1d5db; /* Gray 300 */
    margin-bottom: 20px;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: #d1d5db; /* Gray 300 */
    transition: color 0.3s ease;
}

.footer-col ul li a:hover {
    color: var(--bg-white);
}

.social-links a {
    display: inline-block;
    width: 40px;
    height: 40px;
    background-color: #374151; /* Gray 700 */
    border-radius: var(--radius-md);
    margin-right: 10px;
    /* Placeholder for icons */
}

.contact-info div {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
    font-size: 0.95rem;
    color: #d1d5db;
}

.footer-bottom {
    border-top: 1px solid #4b5563; /* Gray 600 */
    padding-top: 40px;
    text-align: center;
    font-size: 0.9rem;
    color: #d1d5db;
}

.footer-bottom p {
    margin-bottom: 10px;
}

.heart-icon {
    color: #ef4444; /* Red 500 */
}

/* Responsive Design */
@media (max-width: 1024px) {
    .platform-item {
        flex-direction: column;
        text-align: center;
    }

    .platform-item.mobile {
        flex-direction: column;
    }

    .platform-content h3 {
        margin-top: 30px;
    }

    .marketplace-content {
        flex-direction: column;
    }

    .marketplace-stats {
        order: -1; /* Move stats to top on smaller screens */
    }
}

@media (max-width: 768px) {
    h1 {
        font-size: 2.5rem;
    }

    h2 {
        font-size: 2rem;
    }

    .section-subtitle {
        font-size: 1rem;
    }

    .header .nav-menu,
    .header .header-actions {
        display: none;
    }

    .header .menu-toggle {
        display: block;
    }

    .nav-menu.active {
        display: flex;
        flex-direction: column;
        position: absolute;
        top: 64px;
        left: 0;
        width: 100%;
        background-color: var(--bg-white);
        border-top: 1px solid var(--border-light);
        box-shadow: var(--shadow-medium);
        padding: 20px;
        gap: 15px;
    }

    .nav-menu.active ul {
        flex-direction: column;
        gap: 15px;
    }

    .hero .container {
        flex-direction: column;
    }

    .hero-stats {
        flex-direction: column;
        gap: 30px;
    }

    .features-grid,
    .learning-grid,
    .modes-grid,
    .pricing-grid,
    .upgrade-features,
    .footer-columns {
        grid-template-columns: 1fr;
    }

    .platform-item,
    .platform-item.mobile {
        gap: 30px;
    }

    .marketplace-content {
        gap: 30px;
    }

    .marketplace-cta .cta-buttons {
        flex-direction: column;
    }

    .pricing-card.popular {
        transform: scale(1);
    }
}