:root {
    /* Color Palette - Premium Documentation Theme */
    --color-bg: #f9fafb;
    /* Lighter, cleaner gray */
    --color-sidebar: #ffffff;
    --color-text-primary: #111827;
    /* Gray 900 */
    --color-text-secondary: #4b5563;
    /* Gray 600 */
    --color-text-tertiary: #9ca3af;
    /* Gray 400 */

    /* Brand Colors */
    --color-accent: #2563eb;
    /* Blue 600 */
    --color-accent-light: #eff6ff;
    /* Blue 50 */
    --color-accent-hover: #1d4ed8;
    /* Blue 700 */

    --color-border: #e5e7eb;
    /* Gray 200 */
    --color-card-bg: #ffffff;

    /* Typography */
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2.5rem;

    /* Layout */
    --sidebar-width: 300px;
    --header-height: 64px;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
}

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

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: #d1d5db;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #9ca3af;
}

/* Layout Container */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--color-sidebar);
    border-right: 1px solid var(--color-border);
    position: fixed;
    top: 0;
    bottom: 0;
    left: 0;
    display: flex;
    flex-direction: column;
    z-index: 20;
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.sidebar-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    padding: 0 var(--spacing-lg);
    border-bottom: 1px solid var(--color-border);
    background: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(8px);
    position: sticky;
    top: 0;
}

.sidebar-header h2 {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: -0.01em;
    color: var(--color-text-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.module-nav {
    flex: 1;
    overflow-y: auto;
    padding: var(--spacing-md) 0;
}

/* Links */
.nav-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-lg);
    text-decoration: none;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    border-right: 3px solid transparent;
    /* Right border for active indicator */
    transition: all 0.2s;
    line-height: 1.4;
}

.nav-link:hover {
    color: var(--color-text-primary);
    background-color: var(--color-bg);
}

.nav-link.active {
    color: var(--color-accent);
    background-color: var(--color-accent-light);
    border-right-color: var(--color-accent);
}

/* Helper for separating sections in sidebar if we want */
.nav-section-title {
    padding: var(--spacing-md) var(--spacing-lg) var(--spacing-xs);
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--color-text-tertiary);
    font-weight: 700;
    letter-spacing: 0.05em;
    margin-top: var(--spacing-sm);
}

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    display: flex;
    flex-direction: column;
    width: calc(100% - var(--sidebar-width));
}

.top-bar {
    display: none;
    /* Hide on desktop, show only on mobile */
    height: var(--header-height);
    background-color: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
    align-items: center;
    padding: 0 var(--spacing-md);
    position: sticky;
    top: 0;
    z-index: 10;
}

.content-container {
    padding: var(--spacing-xl) var(--spacing-xl) 100px;
    /* Extra bottom padding */
    max-width: 900px;
    /* Optimal reading width */
    margin: 0 auto;
    width: 100%;
}

/* Mobile Responsiveness */
@media (max-width: 1024px) {

    /* Tablet/Mobile Adjustments */
    .sidebar {
        transform: translateX(-100%);
        box-shadow: 10px 0 20px rgba(0, 0, 0, 0.05);
    }

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

    .main-content {
        margin-left: 0;
        width: 100%;
    }

    .top-bar {
        display: flex;
        justify-content: flex-start;
    }

    .content-container {
        padding: var(--spacing-lg);
    }
}

.menu-toggle {
    background: none;
    border: none;
    cursor: pointer;
    margin-right: var(--spacing-md);
    color: var(--color-text-primary);
    padding: 4px;
    border-radius: 4px;
}

.menu-toggle:hover {
    background-color: var(--color-bg);
}


/* --- Full Website Styles --- */

/* Reset for Landing Wrapper to allow full width sections */
.landing-view {
    display: block;
    padding: 0;
    overflow-x: hidden;
    width: 100%;
    min-height: 100vh;
    background: linear-gradient(135deg, #0f172a 0%, #1e1e2e 100%);
    color: white;
}

.landing-page-wrapper {
    width: 100%;
}

/* Navbar */
.main-navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background: rgba(15, 23, 42, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    z-index: 1000;
    display: flex;
    justify-content: center;
}

.nav-container {
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(to right, #60a5fa, #c084fc);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-decoration: none;
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: #cbd5e1;
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: white;
}

/* Mobile Nav */
.mobile-nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-nav-toggle .bar {
    width: 24px;
    height: 2px;
    background: white;
}

.mobile-nav-menu {
    position: fixed;
    top: 70px;
    left: 0;
    width: 100%;
    background: #0f172a;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    z-index: 999;
}

.mobile-nav-menu.active {
    transform: translateY(0);
}

.mobile-nav-menu a {
    color: white;
    text-decoration: none;
    font-size: 1.2rem;
    font-weight: 600;
    text-align: center;
}

/* Hero Section Refinements */
.landing-header {
    margin-bottom: 0;
    padding: 8rem 1rem 6rem;
    text-align: center;
}

.landing-title {
    font-size: 4rem;
    line-height: 1.1;
    font-weight: 800;
    margin-bottom: var(--spacing-md);
    background: linear-gradient(to right, #60a5fa, #c084fc);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.landing-subtitle {
    font-size: 1.25rem;
    color: #94a3b8;
    font-weight: 300;
}

.brand-highlight {
    color: white;
    /* Fallback */
    background: linear-gradient(to right, #3b82f6, #a855f7);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-cta {
    margin-top: 2.5rem;
    display: flex;
    gap: 1rem;
    justify-content: center;
}

.btn-primary,
.btn-secondary {
    padding: 0.8rem 1.8rem;
    border-radius: 100px;
    font-weight: 600;
    text-decoration: none;
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
    font-size: 1rem;
}

.btn-primary {
    background: #2563eb;
    color: white;
    border: none;
}

.btn-primary:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.15);
}

/* Full Width for Contact Button */
.full-width {
    width: 100%;
}

/* Sections */
.section-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 5rem 1rem;
}

.section-container.alt-bg {
    background: rgba(255, 255, 255, 0.02);
    margin: 0;
    max-width: none;
    border-top: 1px solid rgba(255, 255, 255, 0.05);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.section-container.alt-bg>* {
    max-width: 1200px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    text-align: center;
    color: white;
}

/* Course Grid (Existing styles refined) */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
    text-align: left;
    padding: 0 var(--spacing-md);
}

.course-card {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 2rem;
    transition: all 0.3s ease;
    cursor: default;
    position: relative;
    overflow: hidden;
}

.course-card.clickable:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.08);
    border-color: rgba(96, 165, 250, 0.5);
    cursor: pointer;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.course-card.clickable:active {
    transform: translateY(-2px);
}

.course-card.disabled {
    opacity: 0.6;
}

.course-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.course-name {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: white;
}

.course-desc {
    color: #cbd5e1;
    line-height: 1.6;
    margin-bottom: 1.5rem;
    min-height: 3.2em;
}

.course-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.tag {
    background: rgba(255, 255, 255, 0.1);
    padding: 0.25rem 0.75rem;
    border-radius: 100px;
    font-size: 0.75rem;
    color: #94a3b8;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.course-footer {
    display: flex;
    justify-content: flex-end;
}

.course-status {
    font-size: 0.9rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.course-status.available {
    color: #60a5fa;
}

.course-status.coming-soon {
    color: #94a3b8;
    font-size: 0.8rem;
}

/* About Stats */
.about-content {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 4rem;
    justify-content: center;
    text-align: left;
}

.about-text {
    flex: 1;
    min-width: 300px;
    color: #cbd5e1;
    font-size: 1.1rem;
}

.about-text p {
    margin-bottom: 1.5rem;
}

.about-stats {
    display: flex;
    gap: 2rem;
}

.stat-card {
    background: rgba(255, 255, 255, 0.05);
    padding: 1.5rem 2rem;
    border-radius: 12px;
    text-align: center;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 800;
    color: #60a5fa;
}

.stat-label {
    font-size: 0.9rem;
    color: #94a3b8;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

.testimonial-card {
    background: #1e293b;
    padding: 2rem;
    border-radius: 16px;
    position: relative;
    border: 1px solid rgba(255, 255, 255, 0.05);
}

.quote {
    color: #e2e8f0;
    font-style: italic;
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
}

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

.avatar {
    width: 48px;
    height: 48px;
    background: #334155;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    color: #94a3b8;
}

.info .name {
    display: block;
    font-weight: 600;
    color: white;
}

.info .role {
    font-size: 0.85rem;
    color: #94a3b8;
}

/* Contact Form */
.contact-wrapper {
    max-width: 600px;
    margin: 0 auto;
    background: rgba(30, 41, 59, 0.5);
    padding: 2.5rem;
    border-radius: 16px;
    border: 1px solid rgba(255, 255, 255, 0.1);
}

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: #cbd5e1;
    font-size: 0.9rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.8rem 1rem;
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: white;
    font-family: inherit;
    font-size: 1rem;
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #60a5fa;
    background: rgba(0, 0, 0, 0.4);
}

/* Footer */
.main-footer {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding: 3rem 1rem;
    margin-top: 4rem;
    text-align: center;
    color: #64748b;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.social-links {
    display: flex;
    gap: 1.5rem;
}

.social-links a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.2s;
}

.social-links a:hover {
    color: white;
}

/* Utilities for visibility */
.hidden {
    display: none !important;
}

/* Responsive Overrides */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }

    .mobile-nav-toggle {
        display: flex;
    }

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

    .landing-view {
        align-items: flex-start;
        padding-top: 0;
    }

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

    .about-content {
        flex-direction: column;
        gap: 2rem;
    }

    .main-navbar {
        height: 60px;
    }

    .mobile-nav-menu {
        top: 60px;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }
}