/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #333;
}

/* Header */
.header {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav__container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav__title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #2563eb;
}

.nav__menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav__link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
}

.nav__link:hover {
    color: #2563eb;
}

/* Hero section */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 6rem 0;
}

.hero__container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.hero__content {
    display: grid;
    grid-template-columns: 1fr 400px;
    gap: 4rem;
    align-items: center;
    min-height: 500px;
}

.hero__text {
    text-align: left;
}

.hero__title {
    font-size: 2.8rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero__subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero__actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.hero__book {
    display: flex;
    justify-content: center;
    align-items: center;
}

.hero__book-cover {
    max-width: 100%;
    height: auto;
    max-height: 450px;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    transition: transform 0.3s ease;
}

.hero__book-cover:hover {
    transform: scale(1.05);
}

/* Buttons */
.btn {
    padding: 0.75rem 2rem;
    border: none;
    border-radius: 0.5rem;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
}

.btn--primary {
    background: #2563eb;
    color: white;
}

.btn--primary:hover {
    background: #1d4ed8;
    transform: translateY(-2px);
}

.btn--secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn--secondary:hover {
    background: white;
    color: #2563eb;
}

/* Context-specific secondary button styling */
.contact .btn--secondary {
    color: #2563eb;
    border-color: #2563eb;
}

.contact .btn--secondary:hover {
    background: #2563eb;
    color: white;
}

/* Sections */
.about,
.authors,
.contact {
    padding: 5rem 0;
}

.about__container,
.authors__container,
.contact__container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
}

.about__title,
.authors__title,
.contact__title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: #1f2937;
}

.about__text,
.contact__text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: #6b7280;
    max-width: 800px;
    margin: 0 auto 2rem;
}

.contact__actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 2rem;
}

.about__highlights {
    max-width: 800px;
    margin: 2rem auto;
}

.about__list {
    list-style: none;
    padding: 0;
    text-align: left;
}

.about__list li {
    font-size: 1.125rem;
    line-height: 1.8;
    color: #374151;
    margin-bottom: 1rem;
    padding-left: 2rem;
    position: relative;
}

.about__list li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #2563eb;
    font-weight: bold;
    font-size: 1.25rem;
}

/* Quote styles */
.about__quotes {
    max-width: 800px;
    margin: 3rem auto;
    display: grid;
    gap: 2rem;
}

.quote {
    background: #f8fafc;
    border-left: 4px solid #2563eb;
    padding: 2rem;
    margin: 0;
    border-radius: 0 0.5rem 0.5rem 0;
    position: relative;
}

.quote p {
    font-size: 1.125rem;
    line-height: 1.7;
    color: #374151;
    font-style: italic;
    margin: 0;
}

.quote:before {
    content: """;
    position: absolute;
    top: -0.5rem;
    left: 1rem;
    font-size: 3rem;
    color: #2563eb;
    font-weight: bold;
}

/* Content highlights section */
.content-highlights {
    padding: 5rem 0;
    background: #f8fafc;
}

.content-highlights__container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.content-highlights__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.content-box {
    background: white;
    border-radius: 1rem;
    padding: 2.5rem;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    border: 1px solid #e5e7eb;
}

.content-box:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.1);
}

.content-box__icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
    display: block;
}

.content-box__title {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1.5rem;
    line-height: 1.3;
}

.content-box__description {
    font-size: 1rem;
    line-height: 1.7;
    color: #6b7280;
    margin: 0;
    text-align: left;
}

.content-box:nth-child(1) {
    border-top: 4px solid #2563eb;
}

.content-box:nth-child(2) {
    border-top: 4px solid #059669;
}

.content-box:nth-child(3) {
    border-top: 4px solid #dc2626;
}

.content-box:nth-child(1):hover {
    border-top-color: #1d4ed8;
}

.content-box:nth-child(2):hover {
    border-top-color: #047857;
}

.content-box:nth-child(3):hover {
    border-top-color: #b91c1c;
}

/* Chapters section */
.chapters {
    padding: 5rem 0;
    background: #ffffff;
}

.chapters__container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.chapters__title {
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: #1f2937;
    text-align: center;
}

.chapters__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.chapter-card {
    background: white;
    border: 1px solid #e5e7eb;
    border-radius: 1rem;
    padding: 2rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.chapter-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    border-color: #2563eb;
}

.chapter-card__number {
    position: absolute;
    top: -10px;
    right: -10px;
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: bold;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.chapter-card__title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #1f2937;
    margin-bottom: 1rem;
    margin-right: 3rem;
    line-height: 1.4;
}

.chapter-card__description {
    font-size: 1rem;
    line-height: 1.6;
    color: #6b7280;
    margin: 0;
}

.chapter-card:nth-child(odd) {
    background: linear-gradient(135deg, #f8fafc 0%, #ffffff 100%);
}

.chapter-card:nth-child(even) .chapter-card__number {
    background: linear-gradient(135deg, #059669, #047857);
}

.chapter-card:nth-child(3n) .chapter-card__number {
    background: linear-gradient(135deg, #dc2626, #b91c1c);
}

.chapter-card:nth-child(4n) .chapter-card__number {
    background: linear-gradient(135deg, #7c3aed, #6d28d9);
}

.chapter-card:nth-child(5n) .chapter-card__number {
    background: linear-gradient(135deg, #ea580c, #c2410c);
}

/* Authors section */
.authors {
    background: #f9fafb;
}

.authors__grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.author-card {
    background: white;
    padding: 2.5rem;
    border-radius: 1rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
    text-align: center;
    height: 100%;
    display: flex;
    flex-direction: column;
}

.author-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.15);
}

.author-card__image {
    width: 150px;
    height: 150px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 1.5rem;
    display: block;
    border: 4px solid #f3f4f6;
}

.author-card__name {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1f2937;
    margin-bottom: 1rem;
}

.author-card__bio {
    font-size: 0.95rem;
    line-height: 1.6;
    color: #6b7280;
    text-align: left;
    flex-grow: 1;
    margin: 0;
}

/* Footer */
.footer {
    background: #1f2937;
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.footer__container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Responsive design */
@media (max-width: 768px) {
    .nav__container {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav__menu {
        gap: 1rem;
    }
    
    .hero__content {
        grid-template-columns: 1fr;
        gap: 2rem;
        text-align: center;
    }
    
    .hero__text {
        text-align: center;
    }
    
    .hero__title {
        font-size: 1.8rem;
        line-height: 1.3;
    }
    
    .hero__actions {
        justify-content: center;
    }
    
    .hero__book-cover {
        max-height: 350px;
    }
    
    .content-highlights__grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .content-box {
        padding: 2rem;
    }
    
    .content-box__icon {
        font-size: 2.5rem;
        margin-bottom: 1rem;
    }
    
    .content-box__title {
        font-size: 1.25rem;
        margin-bottom: 1rem;
    }
    
    .chapters__grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .chapter-card {
        padding: 1.5rem;
    }
    
    .chapter-card__number {
        width: 50px;
        height: 50px;
        font-size: 1.25rem;
        top: -5px;
        right: -5px;
    }
    
    .chapter-card__title {
        font-size: 1.125rem;
        margin-right: 2rem;
    }
    
    .authors__grid {
        grid-template-columns: 1fr;
    }
}