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

:root {
    --primary-color: #f6821f;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --card-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-dark);
    background-color: #fff;
    line-height: 1.5;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 5%;
    background: #fff;
    border-bottom: 1px solid #e5e7eb;
}

.navbar .logo {
    font-size: 1.25rem;
    font-weight: bold;
}

.navbar nav a {
    text-decoration: none;
    color: var(--text-light);
    margin-left: 20px;
    font-size: 0.95rem;
    transition: color 0.2s;
}

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

.hero {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    padding: 60px 5%;
    background: var(--bg-light);
    gap: 40px;
}

.hero-content {
    flex: 1;
    min-width: 300px;
}

.badge {
    background: #ffedd5;
    color: var(--primary-color);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.hero-content h1 {
    font-size: 3rem;
    line-height: 1.2;
    margin: 15px 0;
}

.subtitle {
    color: var(--text-light);
    font-size: 1.15rem;
    margin-bottom: 25px;
}

.price-tag {
    font-size: 1.75rem;
    font-weight: bold;
    margin-bottom: 20px;
}

.btn-primary {
    display: inline-block;
    background: var(--primary-color);
    color: #fff;
    text-decoration: none;
    padding: 14px 28px;
    border-radius: 8px;
    font-weight: 600;
    transition: transform 0.2s, background 0.2s;
}

.btn-primary:hover {
    background: #e06b0f;
    transform: translateY(-2px);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    min-width: 300px;
}

.book-mockup {
    width: 240px;
    height: 340px;
    background: #374151;
    color: #fff;
    border-radius: 4px 12px 12px 4px;
    box-shadow: 10px 10px 20px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 500;
}

.library-container {
    padding: 60px 5%;
}

.section-title {
    font-size: 1.75rem;
    margin-bottom: 40px;
    text-align: center;
}

.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 30px;
}

.book-card {
    border: 1px solid #e5e7eb;
    border-radius: 12px;
    padding: 20px;
    background: #fff;
    box-shadow: var(--card-shadow);
    display: flex;
    flex-direction: column;
}

.book-thumbnail {
    height: 220px;
    background: #e5e7eb;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-light);
    margin-bottom: 15px;
}

.book-card h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.book-desc {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 20px;
    flex-grow: 1;
}

.card-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.price {
    font-weight: bold;
    font-size: 1.1rem;
}

.btn-secondary {
    text-decoration: none;
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
}

footer {
    text-align: center;
    padding: 40px 20px;
    border-top: 1px solid #e5e7eb;
    color: var(--text-light);
    font-size: 0.85rem;
}