/* --- Global Styles & Variables --- */
:root {
    --primary-color: #00aaff; /* A vibrant blue */
    --secondary-color: #0077b6;
    --dark-bg: #121212;
    --card-bg: #1e1e1e;
    --light-text: #f4f4f4;
    --dark-text: #a9a9a9;
    --header-height: 70px;
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 20px;
}

h1, h2, h3 {
    font-weight: 600;
    line-height: 1.2;
}

h1 { font-size: 3rem; }
h2 { font-size: 2.5rem; margin-bottom: 1rem; }
h3 { font-size: 1.5rem; }

p {
    margin-bottom: 1rem;
    color: var(--dark-text);
}

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

.section-title {
    text-align: center;
    margin-bottom: 4rem;
    font-weight: 700;
}

/* --- Buttons --- */
.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 50px;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
}

.btn-primary {
    background: var(--primary-color);
    color: #fff;
}

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-3px);
}

.btn-secondary {
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: #fff;
}


/* --- Header --- */
#main-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    height: var(--header-height);
    transition: background-color 0.4s ease;
}

#main-header.scrolled {
    background-color: rgba(20, 20, 20, 0.8);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

#main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

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

.main-nav ul {
    display: flex;
    list-style: none;
}

.main-nav ul li {
    margin-left: 30px;
}

.main-nav ul li a {
    color: var(--light-text);
    font-weight: 400;
    position: relative;
    padding: 5px 0;
}

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

.main-nav ul li a:hover::after {
    width: 100%;
}


/* --- Hero Section --- */
#hero {
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    position: relative;
    overflow: hidden;
    color: #fff;
}

.hero-slider {
    position: absolute;
    top: 0;
    left: 0;
    width: 300%; /* 3 images */
    height: 100%;
    display: flex;
    animation: slide 15s infinite ease-in-out;
}

.hero-slider .slide {
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
}

@keyframes slide {
    0% { transform: translateX(0); }
    30% { transform: translateX(0); }
    33% { transform: translateX(-33.33%); }
    63% { transform: translateX(-33.33%); }
    66% { transform: translateX(-66.66%); }
    97% { transform: translateX(-66.66%); }
    100% { transform: translateX(0); }
}


#hero::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.6);
    z-index: 1;
}

.hero-content {
    z-index: 2;
    position: relative;
    max-width: 800px;
}

.hero-content p {
    font-size: 1.2rem;
    max-width: 600px;
    margin: 1rem auto 2rem;
    color: #e0e0e0;
}

/* --- Sections General Styling --- */
section {
    padding: 6rem 0;
}

.section-bg {
    background-color: var(--card-bg);
}

/* --- About Section / Features --- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    text-align: center;
}

.feature-item i {
    font-size: 3rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* --- Courses Section --- */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.course-card {
    background-color: var(--card-bg);
    border-radius: 15px;
    padding: 2rem;
    text-align: center;
    border: 1px solid #2a2a2a;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.course-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 10px 30px rgba(0, 170, 255, 0.1);
}

.course-logo {
    height: 80px;
    margin-bottom: 1.5rem;
    object-fit: contain;
}

.course-price {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 1.5rem 0;
}

/* --- Footer --- */
footer {
    background-color: var(--card-bg);
    text-align: center;
    padding: 4rem 0 2rem;
}

.footer-content h3 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.social-links {
    margin: 2rem 0;
}

.social-links a {
    font-size: 1.5rem;
    color: var(--dark-text);
    margin: 0 15px;
    transition: color 0.3s ease;
}

.social-links a:hover {
    color: var(--primary-color);
}

.footer-bottom p {
    font-size: 0.9rem;
    color: #666;
    margin: 0;
}
.footer-bottom .fa-heart {
    color: var(--primary-color);
}


/* --- Animations on Scroll --- */
.animate-on-scroll, .animate-on-load {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.is-visible, .animate-on-load.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* Add delays for staggered effect */
.animate-on-load:nth-child(1) { transition-delay: 0.2s; }
.animate-on-load:nth-child(2) { transition-delay: 0.4s; }
.animate-on-load:nth-child(3) { transition-delay: 0.6s; }

.feature-item.animate-on-scroll:nth-child(1) { transition-delay: 0.1s; }
.feature-item.animate-on-scroll:nth-child(2) { transition-delay: 0.2s; }
.feature-item.animate-on-scroll:nth-child(3) { transition-delay: 0.3s; }

.course-card.animate-on-scroll:nth-child(1) { transition-delay: 0.1s; }
.course-card.animate-on-scroll:nth-child(2) { transition-delay: 0.2s; }
.course-card.animate-on-scroll:nth-child(3) { transition-delay: 0.3s; }

/* --- Responsive Design --- */
@media (max-width: 768px) {
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }

    .main-nav, .btn {
        display: none; /* Simplification for this example. A real site would use a hamburger menu. */
    }

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

@media (max-width: 500px) {
    .hero-content {
        padding: 0 10px;
    }
    
    h1 { font-size: 2rem; }
}