/* Base Styles */
:root {
    --primary-color: #4285F4;
    --secondary-color: #34A853;
    --accent-color: #FBBC05;
    --text-color: #202124;
    --light-bg: #F8F9FA;
    --white: #FFFFFF;
    --highlight: #EA4335;
    --gray: #70757A;
    --light-gray: #DADCE0;
    --dark-gray: #5F6368;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--white);
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1rem;
}

h1 {
    font-size: 2.5rem;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.5rem;
}

p {
    margin-bottom: 1rem;
}

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

a:hover {
    color: var(--secondary-color);
}

ul {
    list-style: none;
}

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

section {
    padding: 5rem 0;
}

section:nth-child(even) {
    background-color: var(--light-bg);
}

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

.section-header h2 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.underline {
    height: 4px;
    width: 70px;
    background-color: var(--secondary-color);
    margin: 0 auto;
}

.btn {
    display: inline-block;
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    font-weight: 500;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
}

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

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

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

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

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

.btn-outline:hover {
    background-color: var(--white);
    color: var(--primary-color);
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background-color: var(--white);
    box-shadow: var(--shadow);
    z-index: 1000;
    padding: 1rem 0;
    transition: var(--transition);
}

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

.logo img {
    height: 40px;
}

.nav-links {
    display: flex;
    align-items: center;
}

.nav-links li {
    margin-left: 1.5rem;
}

.nav-links a {
    color: var(--text-color);
    font-weight: 500;
}

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

.hamburger {
    display: none;
    cursor: pointer;
}

.bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background-color: var(--text-color);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    height: 100vh;
    background: linear-gradient(rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7)), url('images/hero-bg.jpg');
    background-size: cover;
    background-position: center;
    display: flex;
    align-items: center;
    text-align: center;
    color: var(--white);
    padding-top: 80px;
}

.hero-content {
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.tagline {
    font-size: 1.5rem;
    margin-bottom: 2rem;
}

.hero-buttons {
    margin-bottom: 2rem;
}

.hero-buttons .btn {
    margin: 0 0.5rem;
}

.course-meta {
    display: flex;
    justify-content: center;
    gap: 2rem;
}

.meta-item {
    display: flex;
    align-items: center;
}

.meta-item i {
    margin-right: 0.5rem;
    color: var(--accent-color);
}

/* Back to Top Button */
.back-to-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background-color: var(--primary-color);
    color: var(--white);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

.back-to-top.active {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background-color: var(--secondary-color);
    color: var(--white);
}

/* Responsive Styles */
@media screen and (max-width: 768px) {
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .nav-links {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: var(--white);
        width: 100%;
        text-align: center;
        transition: var(--transition);
        box-shadow: 0 10px 10px rgba(0, 0, 0, 0.1);
        padding: 2rem 0;
    }
    
    .nav-links.active {
        left: 0;
    }
    
    .nav-links li {
        margin: 1rem 0;
    }
    
    .hamburger {
        display: block;
    }
    
    .hamburger.active .bar:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }
    
    .hamburger.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .tagline {
        font-size: 1.2rem;
    }
    
    .course-meta {
        flex-direction: column;
        gap: 1rem;
    }
    
    .meta-item {
        justify-content: center;
    }
}

/* Additional section-specific styles will be added in subsequent steps */