:root {
    --primary-color: #0d6efd;
    --secondary-color: #198754;
    --background-light: #ffffff;
    --background-alt: #f8f9fa;
    --text-dark: #212529;
    --text-light: #f8f9fa;
    --border-color: #dee2e6;
    --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px; 
}

body {
    font-family: 'Roboto', sans-serif;
    margin: 0;
    padding-top: 75px; 
    color: var(--text-dark);
    background-color: var(--background-light);
    line-height: 1.7;
}

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

h1, h2, h3 {
    font-family: 'Poppins', sans-serif;
    font-weight: 600;
}

/* --- Header & Navigation --- */
.main-header {
    background-color: var(--background-light);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 0;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}
.main-header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.logo {
    font-size: 1.5em;
    font-weight: 700;
    color: var(--text-dark);
    text-decoration: none;
}
.main-nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 25px;
}
.main-nav a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 600;
    font-size: 1em;
    transition: color 0.2s ease;
}
.main-nav a:hover {
    color: var(--primary-color);
}
.nav-button {
    background-color: var(--primary-color);
    color: var(--text-light) !important;
    padding: 10px 20px;
    border-radius: 50px;
    transition: background-color 0.2s ease;
}
.nav-button:hover {
    background-color: #0b5ed7;
    color: var(--text-light) !important;
}

/* --- Hero Section --- */
#hero {
    background: var(--background-light);
    padding: 60px 0;
    text-align: center;
}
#hero h1 {
    font-size: 3em;
    margin-bottom: 15px;
}
#hero .subtitle {
    font-size: 1.2em;
    max-width: 600px;
    margin: 0 auto 30px;
    color: #495057;
}

/* --- Content Sections --- */
.content-section {
    padding: 80px 0;
    text-align: center;
}
.content-section h2 {
    font-size: 2.5em;
    margin-top: 0;
    margin-bottom: 50px;
}
.content-section > .container > p {
    font-size: 1.1em;
    max-width: 750px;
    margin: 0 auto 40px;
    color: #495057;
}
.alt-bg {
    background-color: var(--background-alt);
}

/* --- Features Section --- */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 30px;
    text-align: left;
}
.feature-card {
    background-color: var(--background-light);
    padding: 30px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow);
}
.feature-card h3 {
    font-size: 1.3em;
    margin-top: 0;
    margin-bottom: 10px;
    color: var(--primary-color);
}

/* --- Categories Section --- */
.category-tags {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
}
.category-tags span {
    background-color: #e9ecef;
    padding: 10px 20px;
    border-radius: 50px;
    font-weight: 500;
}

/* --- Download CTA Section --- */
.cta-button {
    display: inline-block;
    background-color: var(--secondary-color);
    color: var(--text-light);
    padding: 15px 35px;
    text-decoration: none;
    font-weight: 600;
    border-radius: 50px;
    transition: transform 0.2s ease, background-color 0.2s ease;
    font-size: 1.1em;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
}
.cta-button:hover {
    background-color: #157347;
    transform: translateY(-3px);
}

/* --- Footer --- */
.main-footer {
    background-color: #212529;
    color: var(--text-light);
    text-align: center;
    padding: 40px 0;
}
.main-footer p {
    margin: 0;
    opacity: 0.8;
}

/* Responsive Nav for smaller screens */
@media (max-width: 768px) {
    .main-nav {
        display: none;
    }
}