:root {
    --primary-color: #107C41;
    /* Excel Green */
    --secondary-color: #21A366;
    /* Lighter Excel Green */
    --dark-bg: #1e1e1e;
    --light-bg: #f3f3f3;
    --text-color: #333;
    --white: #ffffff;
    --font-main: 'Inter', sans-serif;
}

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

body {
    font-family: var(--font-main);
    color: var(--text-color);
    line-height: 1.6;
    background-color: var(--light-bg);
}

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

/* Navbar */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    background-color: var(--white);
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    margin-left: 20px;
    font-weight: 600;
}

.nav-links .btn-primary {
    color: var(--white);
    padding: 10px 20px;
    margin-left: 20px;
    border-radius: 5px;
}

/* Buttons */
.btn-primary {
    background-color: var(--primary-color);
    color: var(--white);
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    transition: background-color 0.3s;
    display: inline-block;
}

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

.btn-secondary {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    padding: 12px 24px;
    text-decoration: none;
    border-radius: 6px;
    font-weight: 600;
    margin-left: 10px;
    transition: all 0.3s;
    display: inline-block;
}

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

.btn-large {
    background-color: var(--white);
    color: var(--primary-color);
    padding: 15px 30px;
    font-size: 1.2rem;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 700;
    display: inline-block;
    margin-top: 20px;
}

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #107C41 0%, #0b5c30 100%);
    color: var(--white);
    padding: 100px 0;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 5px;
}

.hero h2 {
    font-size: 1.5rem;
    font-weight: 400;
    margin-bottom: 25px;
    opacity: 0.9;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 40px;
    opacity: 0.9;
}

/* About Section */
.about-section {
    padding: 80px 0;
    background-color: var(--white);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 40px;
    flex-wrap: wrap;
}

.author-img {
    width: 300px;
    height: auto;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.about-text h2 {
    color: var(--primary-color);
    margin-bottom: 20px;
    font-size: 2rem;
}

.feature-list {
    list-style: none;
}

.feature-list li {
    margin-bottom: 15px;
    font-size: 1.1rem;
    padding-left: 25px;
    position: relative;
}

.feature-list li::before {
    content: "✓";
    color: var(--primary-color);
    font-weight: bold;
    position: absolute;
    left: 0;
}

/* Testimonials Section */
.testimonials {
    padding: 80px 0;
    background-color: var(--light-bg);
    text-align: center;
}

.testimonials h2 {
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--primary-color);
}

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

.testimonial-card {
    padding: 30px;
    background: var(--white);
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
    text-align: left;
}

.testimonial-card p {
    font-style: italic;
    font-size: 1.1rem;
    color: #444;
    margin-bottom: 20px;
}

.testimonial-card cite {
    font-weight: 600;
    color: var(--primary-color);
    display: block;
    margin-top: 15px;
}

/* PDF Preview Section */
.pdf-preview {
    padding: 80px 0;
    background-color: var(--white);
    text-align: center;
}

.pdf-preview h2 {
    margin-bottom: 40px;
    color: var(--primary-color);
}

.pdf-container {
    background: var(--white);
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    height: 700px;
}

iframe {
    border: none;
    width: 100%;
    height: 100%;
}

/* Download Section */
.download-section {
    background-color: var(--primary-color);
    color: var(--white);
    text-align: center;
    padding: 80px 0;
}

/* Footer */
footer {
    background-color: var(--dark-bg);
    color: #888;
    text-align: center;
    padding: 20px 0;
}

/* Page Specific: Downloads */
.hero-small {
    padding: 60px 0;
    margin-bottom: 0;
}

.active {
    color: var(--primary-color) !important;
}

.downloads-section {
    padding: 60px 0;
    background-color: var(--light-bg);
    min-height: 60vh;
}

.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}

.download-card {
    background: var(--white);
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
    transition: transform 0.2s;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.download-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.download-card .icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.download-card h3 {
    margin-bottom: 10px;
    font-size: 1.2rem;
    color: var(--primary-color);
}

.download-card p {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 20px;
}

.btn-small {
    padding: 8px 16px;
    font-size: 0.9rem;
    margin: auto 0 0 0;
}