/* Front page styles for Enterprise Developer landing */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0047AB;
    --primary-dark: #001a3d;
    --primary-light: #3366cc;
    --accent-color: #00d4ff;
    --text-primary: #0a0a0a;
    --text-secondary: #2d3748;
    --bg-light: #fafbfc;
    --bg-glass: rgba(255, 255, 255, 0.95);
    --shadow-xl: 0 20px 40px rgba(0, 71, 171, 0.15);
    --shadow-glow: 0 0 60px rgba(0, 212, 255, 0.3);
}

@font-face {
    font-family: 'System';
    src: local('Atkinson Hyperlegible Next'), local('Inter'), local('system-ui'), sans-serif;
}

body {
    font-family: "Atkinson Hyperlegible Next", -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.6;
    color: var(--text-primary);
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    position: relative;
    overflow-x: hidden;
    font-size: 18px;
}

/* Accessibility skip link */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-dark);
    color: white;
    padding: 8px;
    text-decoration: none;
    z-index: 2000;
    font-weight: 700;
}
.skip-link:focus { top: 0; }

body::before {
    content: '';
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background:
        radial-gradient(circle at 20% 50%, rgba(0, 212, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(0, 71, 171, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 40% 20%, rgba(118, 75, 162, 0.1) 0%, transparent 50%);
    pointer-events: none;
    z-index: 1;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 2;
}

/* Navigation */
nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    background: var(--bg-glass);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.3);
    z-index: 1000;
    animation: slideDown 0.6s ease-out;
}
@keyframes slideDown {
    from { transform: translateY(-100%); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}
.nav-container {
    display: flex; justify-content: space-between; align-items: center;
    padding: 1rem 2rem;
}
.logo {
    font-size: 1.5rem; font-weight: bold;
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: glow 3s ease-in-out infinite;
}
@keyframes glow { 0%,100%{ filter: brightness(1);} 50%{ filter: brightness(1.2);} }
.nav-links { display: flex; gap: 2rem; list-style: none; }
.nav-links a {
    color: var(--text-primary);
    text-decoration: none;
    transition: all 0.3s ease;
    position: relative;
    font-weight: 500;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
}
.nav-links a:focus { outline: 2px solid var(--primary-dark); outline-offset: 2px; }
.nav-links a::after {
    content: '';
    position: absolute; bottom: -5px; left: 0.5rem; right: 0.5rem; height: 3px;
    background: linear-gradient(90deg, var(--primary-dark), var(--primary-color));
    transition: transform 0.3s ease; transform: scaleX(0);
}
.nav-links a:hover::after { transform: scaleX(1); }

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex; align-items: center; justify-content: center;
    padding: 120px 0 80px; position: relative;
}
.hero-content { text-align: center; animation: fadeInUp 1s ease-out; }
@keyframes fadeInUp { from { opacity:0; transform: translateY(30px);} to { opacity:1; transform: translateY(0);} }

h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800; line-height: 1.2; margin-bottom: 1.5rem;
    background: linear-gradient(135deg, #ffffff 0%, #e0e7ff 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 4px 20px rgba(0, 0, 0, 0.1));
}
.subtitle {
    font-size: 1.35rem; color: white; margin-bottom: 3rem;
    max-width: 700px; margin-left: auto; margin-right: auto; font-weight: 500;
    text-shadow: 1px 1px 2px rgba(0,0,0,0.3);
}

/* Book Carousel */
.book-carousel { position: relative; height: 400px; margin: 3rem 0; perspective: 1200px; }
.carousel-track {
    position: absolute; width: 100%; height: 100%;
    transform-style: preserve-3d; animation: rotate 20s linear infinite;
}
@keyframes rotate { from { transform: rotateY(0deg);} to { transform: rotateY(360deg);} }
.book-cover {
    position: absolute; width: 200px; height: 300px; left: 50%; top: 50%;
    margin-left: -100px; margin-top: -150px;
    background: linear-gradient(135deg, #1a1a2e, #0f0f1e);
    border-radius: 10px; box-shadow: 0 20px 60px rgba(0,0,0,0.3);
    display: flex; align-items: center; justify-content: center;
    color: white; font-weight: bold; transform-style: preserve-3d; transition: transform 0.5s ease;
}
.book-cover:nth-child(1) { transform: rotateY(0deg) translateZ(300px); }
.book-cover:nth-child(2) { transform: rotateY(72deg) translateZ(300px); }
.book-cover:nth-child(3) { transform: rotateY(144deg) translateZ(300px); }
.book-cover:nth-child(4) { transform: rotateY(216deg) translateZ(300px); }
.book-cover:nth-child(5) { transform: rotateY(288deg) translateZ(300px); }
.carousel-track:hover { animation-play-state: paused; }
.book-cover:hover { transform: scale(1.1) rotateY(var(--rotation)) translateZ(350px); }

/* CTA Buttons */
.cta-group { display: flex; gap: 1.5rem; justify-content: center; flex-wrap: wrap; margin-top: 2rem; }
.btn {
    padding: 1rem 2.5rem; border-radius: 50px; font-weight: 700;
    text-decoration: none; transition: all 0.3s ease; position: relative; overflow: hidden;
    display: inline-block; font-size: 1.1rem;
}
.btn:focus { outline: 3px solid #fff; outline-offset: 3px; }
.btn-primary { background: linear-gradient(135deg, var(--primary-dark), var(--primary-color)); color: white; box-shadow: 0 10px 30px rgba(0,71,171,0.3); }
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 15px 40px rgba(0,71,171,0.4); }
.btn-secondary { background: white; color: var(--primary-dark); backdrop-filter: blur(10px); border: 2px solid rgba(255,255,255,0.9); }
.btn-secondary:hover { background: rgba(255,255,255,0.95); transform: translateY(-3px); box-shadow: 0 10px 30px rgba(255,255,255,0.3); }
.btn::before {
    content: ''; position: absolute; top: 50%; left: 50%; width: 0; height: 0;
    border-radius: 50%; background: rgba(255,255,255,0.3); transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}
.btn:hover::before { width: 300px; height: 300px; }

/* About Section */
.about-section { padding: 100px 0; background: white; position: relative; overflow: hidden; }
.about-section::before {
    content: ''; position: absolute; top: -100px; left: 0; right: 0; height: 200px;
    background: linear-gradient(180deg, transparent, white);
}
.section-header { text-align: center; margin-bottom: 4rem; }
.section-title {
    font-size: 3rem; font-weight: 900; margin-bottom: 1rem;
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-color));
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
}
.section-description { font-size: 1.35rem; color: var(--text-primary); max-width: 800px; margin: 0 auto; font-weight: 400; line-height: 1.7; }

/* Value Props */
.value-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 2rem; margin-top: 3rem; }
.value-card {
    background: white; backdrop-filter: blur(10px); border-radius: 20px; padding: 2rem;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08); transition: all 0.3s ease; border: 2px solid rgba(0, 71, 171, 0.1);
}
.value-card:hover { transform: translateY(-10px); box-shadow: var(--shadow-xl); border-color: var(--primary-light); }
.value-card h3 { color: var(--text-primary); font-size: 1.35rem; margin-top: 0.5rem; margin-bottom: 1rem; }
.value-card p { color: var(--text-primary); line-height: 1.7; }
.value-icon {
    background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
    border-radius: 15px; display: flex; align-items: center; justify-content: center; margin-bottom: 1rem; font-size: 1.5rem; color: white; padding: .5rem;
}

/* Book Grid */
.books-section { padding: 100px 0; background: var(--bg-light); }
.filter-tabs { display: flex; justify-content: center; gap: 1rem; margin-bottom: 3rem; flex-wrap: wrap; }
.filter-tab {
    padding: 0.75rem 1.5rem; background: white; border: 2px solid var(--primary-dark);
    border-radius: 25px; cursor: pointer; transition: all 0.3s ease; color: var(--primary-dark);
    font-weight: 700; font-size: 1rem;
}
.filter-tab:hover, .filter-tab.active { background: var(--primary-dark); color: white; transform: scale(1.05); }
.filter-tab:focus-visible { outline: 3px solid var(--primary-dark); outline-offset: 3px; }

.books-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 2rem; }
.book-card {
    background: white; border-radius: 20px; overflow: hidden; box-shadow: 0 10px 30px rgba(0,0,0,0.1);
    transition: all 0.3s ease; position: relative; display: flex; flex-direction: column; justify-content: space-between;
}
.book-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 5px;
    background: linear-gradient(90deg, var(--primary-color), var(--accent-color));
    transform: scaleX(0); transition: transform 0.3s ease;
}
.book-card:hover { transform: translateY(-10px); box-shadow: var(--shadow-xl); }
.book-card:hover::before { transform: scaleX(1); }
.book-card-image {
    height: 250px; background: linear-gradient(135deg, #667eea, #764ba2);
    display: flex; align-items: center; justify-content: center; color: white; font-size: 1.5rem; font-weight: bold;
}
.book-card-image img { box-shadow: 0 0 40px rgba(255,255,255,0.6); border-radius: 8px; transition: box-shadow 0.3s ease; }
.book-card:hover .book-card-image img { box-shadow: 0 0 60px rgba(255,255,255,0.85); }
.book-card-content { padding: 1.5rem; display: flex; flex-direction: column; flex: 1; }
.book-title { font-size: 1.25rem; font-weight: bold; margin-bottom: 0.5rem; color: var(--text-primary); }
.book-subtitle { font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 1rem; font-weight: 500; }
.book-description { color: var(--text-primary); margin-bottom: 1.5rem; line-height: 1.6; }
.book-actions { margin-top: auto; display: flex; gap: 0.75rem; }
.book-btn { flex: 1; padding: 0.75rem; text-align: center; border-radius: 10px; text-decoration: none; font-weight: 700; transition: all 0.3s ease; }
.book-btn:focus { outline: 3px solid var(--primary-dark); outline-offset: 2px; }
.book-btn-primary { background: var(--primary-dark); color: white; }
.book-btn-primary:hover { background: #000d1a; transform: scale(1.05); }
.book-btn-secondary { background: transparent; color: var(--primary-dark); border: 2px solid var(--primary-dark); }
.book-btn-secondary:hover { background: var(--primary-dark); color: white; }

/* Testimonials */
.testimonials-section { padding: 100px 0; background: white; position: relative; }
.testimonial-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(350px, 1fr)); gap: 2rem; margin-top: 3rem; }
.testimonial-card {
    display: flex; flex-direction: column; justify-content: space-between;
    background: linear-gradient(135deg, var(--bg-glass), white); backdrop-filter: blur(10px);
    border-radius: 20px; padding: 2rem; box-shadow: 0 10px 30px rgba(0,0,0,0.1); position: relative; border: 1px solid rgba(0, 71, 171, 0.1);
}
.testimonial-quote {
    flex: 1; display: flex; flex-direction: column; font-size: 1.15rem; line-height: 1.8; color: var(--text-primary);
    margin-bottom: 1.5rem; position: relative; padding-left: 2rem; font-weight: 500;
}
.testimonial-quote::before { content: '\"'; position: absolute; left: 0; top: -10px; font-size: 3rem; color: var(--primary-color); opacity: 0.3; }
.testimonial-author { margin-top: auto; display: flex; align-items: center; gap: 1rem; }
.author-avatar { width: 50px; height: 50px; border-radius: 50%; background: linear-gradient(135deg, var(--primary-color), var(--accent-color)); }
.author-info { flex: 1; }
.author-name { font-weight: 700; color: var(--text-primary); font-size: 1.1rem; }
.author-role { font-size: 0.9rem; color: var(--text-secondary); }

/* Newsletter */
.newsletter-section {
    padding: 120px 0; background: #000; color: white; text-align: center; position: relative; overflow: hidden;
    border-top: 2px solid rgba(0, 212, 255, 0.3); border-bottom: 2px solid rgba(0, 212, 255, 0.3);
}
.newsletter-section::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; bottom: 0;
    background: linear-gradient(135deg, rgba(0,71,171,0.15) 0%, transparent 50%, rgba(118,75,162,0.15) 100%);
    z-index: 1;
}
.newsletter-section::after {
    content: ''; position: absolute; top: -50%; left: -50%; width: 200%; height: 200%;
    background: radial-gradient(circle, rgba(0,212,255,0.1) 0%, transparent 70%);
    animation: pulse 4s ease-in-out infinite; z-index: 1;
}
@keyframes pulse { 0%,100%{ transform: scale(1); opacity: 0.5;} 50%{ transform: scale(1.1); opacity: 0.3;} }
.newsletter-section .container { position: relative; z-index: 2; }
.newsletter-title {
    color: #fff; font-size: 4.5rem; font-weight: 900;
    text-shadow: 0 0 40px rgba(0,212,255,0.5), 0 0 20px rgba(0,212,255,0.3), 3px 3px 8px rgba(0,0,0,1);
    margin-bottom: 1rem; letter-spacing: -0.02em; line-height: 1.1;
}
.newsletter-description {
    color: #fff; font-size: 1.6rem; font-weight: 600;
    text-shadow: 0 0 20px rgba(0,212,255,0.3), 2px 2px 6px rgba(0,0,0,1);
    margin-bottom: 3rem; opacity: 0.95;
}
.newsletter-form { max-width: 600px; margin: 3rem auto 0; display: flex; gap: 1rem; flex-wrap: wrap; justify-content: center; }
.btn-newsletter {
    background: linear-gradient(135deg, #fff 0%, #f0f0f0 100%); color: #000; font-weight: 900; font-size: 1.2rem;
    padding: 1.25rem 3rem; box-shadow: 0 10px 40px rgba(255,255,255,0.4), 0 0 60px rgba(0,212,255,0.3);
    border: none; text-transform: uppercase; letter-spacing: 0.05em;
}
.btn-newsletter:hover {
    background: linear-gradient(135deg, #00d4ff 0%, #0099ff 100%); color: white;
    transform: translateY(-3px) scale(1.05);
    box-shadow: 0 15px 50px rgba(0,212,255,0.5), 0 0 80px rgba(0,212,255,0.4);
}
.btn-newsletter:focus { outline: 4px solid #00d4ff; outline-offset: 4px; }
.email-input {
    flex: 1; min-width: 250px; padding: 1.25rem 2rem; border-radius: 50px;
    border: 4px solid rgba(255,255,255,0.9); background: rgba(255,255,255,0.1); color: white;
    font-size: 1.2rem; font-weight: 600; backdrop-filter: blur(10px);
    box-shadow: 0 0 30px rgba(0,212,255,0.2), inset 0 0 20px rgba(255,255,255,0.05);
}
.email-input::placeholder { color: rgba(255,255,255,0.8); font-weight: 500; }
.email-input:focus { outline: none; border-color: #00d4ff; background: rgba(255,255,255,0.15); box-shadow: 0 0 40px rgba(0,212,255,0.4), 0 0 0 6px rgba(0,212,255,0.2), inset 0 0 20px rgba(255,255,255,0.1); }

/* Author Bio */
.author-section { padding: 100px 0; background: var(--bg-light); }
.author-container { display: flex; gap: 3rem; align-items: center; max-width: 1000px; margin: 0 auto; flex-wrap: wrap; }
.author-image { width: 300px; height: 300px; border-radius: 20px; background: linear-gradient(135deg, var(--primary-color), var(--accent-color)); position: relative; overflow: hidden; }
.author-content { flex: 1; min-width: 300px; }
.author-main-name { font-size: 2.5rem; font-weight: 900; margin-bottom: 1rem; color: var(--text-primary); }
.author-bio { font-size: 1.15rem; line-height: 1.8; color: var(--text-primary); margin-bottom: 2rem; }
.social-links { display: flex; gap: 1rem; }
.social-link { width: 50px; height: 50px; background: white; display: flex; align-items: center; justify-content: center; text-decoration: none; color: var(--primary-dark); font-weight: 700; box-shadow: 0 5px 15px rgba(0,0,0,0.1); transition: all 0.3s ease; }
.social-link.rounded { border-radius: 50%; border: 2px solid var(--primary-dark); }
.social-link:hover { transform: translateY(-5px); box-shadow: 0 10px 25px rgba(0,0,0,0.2); background: var(--accent-color); color: white; }

/* FAQ */
.faq-section { padding: 100px 0; background: white; }
.faq-container { max-width: 800px; margin: 0 auto; }
.faq-item { background: var(--bg-light); border-radius: 15px; margin-bottom: 1rem; overflow: hidden; transition: all 0.3s ease; }
.faq-question { padding: 1.5rem; cursor: pointer; display: flex; justify-content: space-between; align-items: center; font-weight: 600; color: var(--text-primary); transition: all 0.3s ease; }
.faq-question:hover { background: rgba(0,71,171,0.05); }
.faq-toggle { width: 30px; height: 30px; border-radius: 50%; background: var(--primary-color); color: white; display: flex; align-items: center; justify-content: center; transition: transform 0.3s ease; }
.faq-item.active .faq-toggle { transform: rotate(45deg); }
.faq-answer { max-height: 0; overflow: hidden; transition: max-height 0.3s ease; }
.faq-item.active .faq-answer { max-height: 500px; }
.faq-answer-content { padding: 0 1.5rem 1.5rem; color: var(--text-secondary); line-height: 1.8; }

/* Footer */
footer { padding: 50px 0 30px; background: var(--text-primary); color: white; }
.footer-content { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 3rem; margin-bottom: 3rem; }
.footer-column h4 { margin-bottom: 1rem; color: white; font-size: 1.2rem; }
.footer-column ul { list-style: none; }
.footer-column a {
    color: rgba(255,255,255,0.9); text-decoration: none; transition: color 0.3s ease; font-weight: 400; display: inline-block; padding: 0.25rem 0;
}
.footer-column a:hover { color: var(--accent-color); text-decoration: underline; }
.footer-column a:focus-visible {
    outline: 2px solid white;
    outline-offset: 2px; /* fixed */
    border-radius: 4px;
}
.footer-bottom { text-align: center; padding-top: 2rem; border-top: 1px solid rgba(255,255,255,0.2); color: rgba(255,255,255,0.85); font-size: 0.95rem; }

/* Focus states for accessibility */
*:focus-visible { outline: 3px solid var(--primary-dark); outline-offset: 2px; border-radius: 4px; }
input:focus-visible { outline: 3px solid white; outline-offset: 0; }

/* Mobile Responsive */
@media (max-width: 768px) {
    .nav-links { display: none; }
    h1 { font-size: 2rem; }
    .newsletter-title { font-size: 2.8rem; line-height: 1.2; }
    .newsletter-description { font-size: 1.25rem; padding: 0 1rem; }
    .book-carousel { height: 300px; }
    .book-cover { width: 150px; height: 225px; margin-left: -75px; margin-top: -112px; }
    .author-container { flex-direction: column; text-align: center; }
    .books-grid { grid-template-columns: 1fr; }
    .testimonial-grid { grid-template-columns: 1fr; }
    .btn-newsletter { width: 100%; max-width: 300px; }
}

/* Loading Animation */
.fade-in { opacity: 0; transform: translateY(30px); animation: fadeIn 0.8s ease forwards; }
@keyframes fadeIn { to { opacity: 1; transform: translateY(0); } }
.stagger-1 { animation-delay: 0.1s; }
.stagger-2 { animation-delay: 0.2s; }
.stagger-3 { animation-delay: 0.3s; }
.stagger-4 { animation-delay: 0.4s; }
.stagger-5 { animation-delay: 0.5s; }