/* ===== Reset & Base ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  color: #444934;
  background: #FFFFFF;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; height: auto; display: block; }
a { text-decoration: none; color: inherit; }
button { border: none; background: none; cursor: pointer; font-family: inherit; }

/* ===== Colors (design tokens) ===== */
:root {
  --lime: #AEDB00;
  --lime-dark: #485D00;
  --lime-bg: rgba(174, 219, 0, 0.1);
  --dark: #1A1C1F;
  --body: #444934;
  --muted: #8B8A99;
  --nav-text: #475569;
  --bg-light: #F8FAFC;
  --purple: #5B569C;
  --purple-dark: #282166;
  --btn-text: #161F00;
  --footer-bg: #0F172A;
  --footer-icon-bg: #1E293B;
  --footer-muted: #64748B;
  --border: #E2E8F0;
  --faq-bg: #F8FAFC;
  --shadow: 0px 8px 32px 0px rgba(67, 62, 131, 0.06);
  --shadow-sm: 0px 1px 2px 0px rgba(0, 0, 0, 0.05);
}

/* ===== Navbar ===== */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(255,255,255,0.85);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  box-shadow: var(--shadow-sm);
}

.navbar-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 32px;
  gap: 32px;
}

.navbar-logo img { width: 138px; height: 28px; }

.navbar-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-link {
  font-size: 14px;
  font-weight: 500;
  line-height: 1.43;
  letter-spacing: -0.025em;
  color: var(--nav-text);
  transition: color 0.2s;
}
.nav-link.active {
  font-weight: 700;
  color: var(--lime);
  border-bottom: 2px solid var(--lime);
  padding-bottom: 4px;
}
.nav-link:hover { color: var(--lime-dark); }

.btn-nav {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 24px;
  background: var(--lime);
  border-radius: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--btn-text);
  white-space: nowrap;
  transition: opacity 0.2s;
}
.btn-nav:hover { opacity: 0.9; }

.hamburger { display: none; width: 24px; height: 20px; position: relative; flex-shrink: 0; }
.hamburger span {
  display: block; position: absolute; left: 0; width: 100%; height: 2px;
  background: var(--dark); border-radius: 1px; transition: 0.3s;
}
.hamburger span:nth-child(1) { top: 0; }
.hamburger span:nth-child(2) { top: 9px; }
.hamburger span:nth-child(3) { top: 18px; }
.hamburger.open span:nth-child(1) { top: 9px; transform: rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { top: 9px; transform: rotate(-45deg); }

.mobile-menu {
  display: none;
  position: fixed; top: 60px; left: 0; right: 0; bottom: 0;
  background: #fff; z-index: 99;
  flex-direction: column; padding: 32px;
}
.mobile-menu.open { display: flex; }
.mobile-menu-link {
  font-size: 18px; font-weight: 600; color: var(--dark);
  padding: 16px 0; border-bottom: 1px solid var(--border);
}
.mobile-cta { margin-top: 24px; text-align: center; }

/* ===== CTA Button ===== */
.btn-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 16px 32px;
  background: var(--lime);
  border-radius: 12px;
  font-size: 18px;
  font-weight: 700;
  color: var(--btn-text);
  box-shadow: var(--shadow);
  transition: opacity 0.2s;
  white-space: nowrap;
}
.btn-cta:hover { opacity: 0.9; }

/* ===== Hero ===== */
.hero {
  padding: 80px 0;
}

.hero-text h1 .hero-highlight {
  color: var(--lime);
}

.hero-inner {
  max-width: 1280px;
  margin: 0 auto;
  padding: 84px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 64px;
  position: relative;
}

.hero-text {
  flex: 0 0 544px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.hero-text h1 {
  font-family: 'Manrope', sans-serif;
  font-weight: 800;
  font-size: 72px;
  line-height: 1.14;
  letter-spacing: -0.025em;
  color: var(--dark);
}

.hero-subtitle {
  max-width: 512px;
  font-size: 18px;
  line-height: 1.67;
  color: var(--body);
}

.hero-cta-row {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-top: 16px;
}

.micro-copy {
  font-size: 14px;
  line-height: 1.43;
  color: var(--muted);
  max-width: 260px;
}

.hero-image {
  flex: 0 0 576px;
  width: 576px;
  position: relative;
  z-index: 1;
}
.hero-image::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 514px;
  height: 514px;
  background: rgba(174, 219, 0, 0.2);
  border-radius: 50%;
  filter: blur(100px);
  z-index: -1;
}
.hero-image img {
  width: 100%;
  height: auto;
}

/* ===== Features Section ===== */
.features {
  padding: 0 0 80px;
}

.features-header {
  text-align: center;
  max-width: 768px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
  margin-bottom: 64px;
}

.features-header h2 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.21;
  color: var(--dark);
}

.features-intro {
  font-size: 18px;
  line-height: 1.67;
  color: var(--muted);
}

.features-slider {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 32px;
}

.features-track {
  display: flex;
  gap: 24px;
  overflow-x: auto;
  scroll-behavior: smooth;
  scroll-snap-type: x mandatory;
  -ms-overflow-style: none; /* IE and Edge */
  scrollbar-width: none; /* Firefox */
}
.features-track::-webkit-scrollbar {
  display: none;
}

.feature-card {
  flex: 0 0 auto;
  width: calc(100% - 24px);
  max-width: 900px;
  border-radius: 32px;
  display: flex;
  align-items: center;
  gap: 100px;
  padding: 50px 42px;
  min-height: 360px;
  scroll-snap-align: center;
}

.feature-card-text {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 400px;
}

.feature-card-text h3 {
  font-size: 26px;
  font-weight: 700;
  line-height: 1.23;
  color: var(--dark);
}

.feature-card-text p {
  font-size: 16px;
  line-height: 1.63;
  color: var(--body);
}

.feature-card-image {
  flex: 0 0 280px;
  width: 280px;
  height: auto;
  display: flex;
  align-items: center;
  justify-content: center;
}
.feature-card-image img {
  width: 100%;
  height: auto;
  object-fit: contain;
}

.slider-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 32px;
}

.slider-arrow {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--nav-text);
  transition: 0.2s;
}
.slider-arrow:hover { background: var(--bg-light); }

.slider-dots {
  display: flex;
  gap: 8px;
}
.slider-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border);
  cursor: pointer;
  transition: 0.2s;
}
.slider-dot.active {
  background: var(--lime);
  width: 28px;
  border-radius: 5px;
}

/* ===== Previews / Excerpts ===== */
.previews {
  padding: 40px 96px 80px;
  max-width: 1280px;
  margin: 0 auto;
}

.previews-header {
  display: flex;
  flex-direction: column;
  gap: 16px;
  margin-bottom: 32px;
  text-align: center;
  align-items: center;
}

.previews-header h2 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.21;
  color: var(--dark);
  text-align: center;
}

.previews-header p {
  font-size: 18px;
  line-height: 1.67;
  color: var(--body);
  text-align: center;
}

.category-tabs {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.tab-btn {
  padding: 12px 16px;
  border-radius: 9999px;
  font-family: 'Inter', sans-serif;
  font-size: 14px;
  font-weight: 600;
  line-height: 1.43;
  color: var(--body);
  background: #fff;
  border: 1px solid var(--border);
  cursor: pointer;
  transition: 0.2s;
}
.tab-btn.active {
  background: var(--lime);
  border-color: var(--lime);
  color: var(--lime-dark);
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  box-shadow: var(--shadow);
}
.tab-btn:hover:not(.active) {
  border-color: var(--lime);
}

.preview-card {
  display: flex;
  background: #fff;
  border-radius: 32px;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.preview-cover {
  flex: 0 0 252px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding-left: 32px;
}
.preview-cover img {
  width: 220px;
  height: 328px;
  object-fit: cover;
}

.preview-content {
  flex: 1;
  padding: 64px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.preview-player-row {
  display: flex;
  align-items: center;
  gap: 24px;
  padding-bottom: 32px;
}

.play-btn {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: var(--lime);
  box-shadow: var(--shadow);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: 0.2s;
}
.play-btn:hover { opacity: 0.9; }
.play-btn svg { margin-left: 3px; }
.play-btn.playing svg {
  display: none;
}
.play-btn.playing::after {
  content: '';
  width: 14px;
  height: 18px;
  border-left: 4px solid var(--btn-text);
  border-right: 4px solid var(--btn-text);
}

.preview-title-area {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.preview-title-area h3 {
  font-family: 'Manrope', sans-serif;
  font-weight: 700;
  font-size: 30px;
  line-height: 1.2;
  color: var(--dark);
}

.book-author {
  font-size: 16px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--purple);
}

/* Audio progress */
.audio-progress {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-bottom: 24px;
}

.progress-bar-container {
  position: relative;
  cursor: pointer;
  padding: 8px 0;
}

.progress-bar-bg {
  width: 100%;
  height: 6px;
  background: #E2E2E7;
  border-radius: 9999px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  width: 0%;
  background: var(--lime);
  border-radius: 9999px;
  transition: width 0.1s linear;
}

.progress-thumb {
  position: absolute;
  top: 50%;
  left: 0%;
  transform: translate(-50%, -50%);
  width: 20px;
  height: 20px;
  background: #fff;
  border: 4px solid var(--lime);
  border-radius: 50%;
  box-shadow: 0px 2px 4px -2px rgba(0, 0, 0, 0.1), 0px 4px 6px -1px rgba(0, 0, 0, 0.1);
  cursor: grab;
}

.progress-time {
  font-size: 14px;
  font-weight: 700;
  color: var(--purple);
  line-height: 1.43;
}

/* Transcript */
.transcript-area {
  display: flex;
  flex-direction: column;
  gap: 12px;
  overflow-y: auto;
  max-height: 280px;
  padding-right: 16px;
}

.transcript-area::-webkit-scrollbar {
  width: 6px;
}

.transcript-area::-webkit-scrollbar-track {
  background: transparent;
}

.transcript-area::-webkit-scrollbar-thumb {
  background-color: var(--border);
  border-radius: 3px;
}
.transcript-area::-webkit-scrollbar-thumb:hover {
  background-color: var(--muted);
}

.transcript-block p {
  font-size: 18px;
  line-height: 1.63;
  color: var(--body);
}

.transcript-highlight {
  position: relative;
}
.highlight-bar {
  display: none;
}

.highlight-text p {
  font-size: 18px;
  line-height: 1.63;
  color: var(--body);
}
.highlight-text strong {
  font-weight: 700;
  background: var(--lime-bg);
  padding: 0 4px;
  border-radius: 2px;
}

/* ===== Preview Modal ===== */
.preview-modal {
  display: none;
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0,0,0,0.5);
  z-index: 200;
  align-items: center;
  justify-content: center;
}
.preview-modal.open { display: flex; }

.preview-modal-content {
  background: #fff;
  border-radius: 24px;
  padding: 48px;
  max-width: 480px;
  text-align: center;
  position: relative;
}
.preview-modal-content h3 {
  font-size: 28px;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px;
}
.preview-modal-content p {
  font-size: 16px;
  line-height: 1.63;
  color: var(--body);
  margin-bottom: 24px;
}
.modal-close {
  position: absolute;
  top: 16px; right: 16px;
  font-size: 24px;
  color: var(--muted);
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
}

/* ===== Use Cases ===== */
.use-cases {
  max-width: 1152px;
  margin: 0 auto;
  padding: 40px 64px 80px;
}

.use-cases h2 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.21;
  color: var(--dark);
  text-align: center;
  margin-bottom: 64px;
}

.use-cases-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 24px;
  align-items: start;
}

.use-case-card {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.use-case-accent {
  background: #F8FAFC;
  border-radius: 16px;
  height: 300px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.use-case-accent img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 16px;
}

.use-case-card:nth-child(1) {
  margin-top: 0;
}

.use-case-card:nth-child(2) {
  margin-top: 80px;
}

.use-case-card:nth-child(3) {
  margin-top: 0;
}

.use-case-body {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.use-case-body h3 {
  font-size: 24px;
  line-height: 1.5;
  color: var(--purple-dark);
  text-align: center;
  font-weight: 700;
  margin-bottom: -4px;
}

.use-case-body h4 {
  font-size: 24px;
  line-height: 1.5;
  color: var(--purple-dark);
  text-align: center;
  font-weight: 400;
}

.use-case-body p {
  font-size: 16px;
  font-weight: 300;
  line-height: 1.88;
  color: var(--body);
  text-align: center;
}


/* ===== FAQ ===== */
.faq {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 96px 80px;
}

.faq h2 {
  font-size: 48px;
  font-weight: 700;
  line-height: 1.21;
  color: var(--dark);
  text-align: center;
  margin-bottom: 64px;
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.faq-item {
  background: var(--faq-bg);
  border-radius: 16px;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 32px;
  font-size: 18px;
  font-weight: 700;
  color: var(--dark);
  text-align: left;
  line-height: 1.33;
  gap: 24px;
}
.faq-question:hover { opacity: 0.8; }

.faq-chevron {
  flex-shrink: 0;
  transition: transform 0.3s;
}
.faq-item.open .faq-chevron {
  transform: rotate(180deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
}
.faq-item.open .faq-answer {
  max-height: 300px;
}

.faq-answer p {
  padding: 0 32px 24px;
  font-size: 16px;
  line-height: 1.63;
  color: var(--body);
}

/* ===== Footer ===== */
.footer {
  background: var(--footer-bg);
  padding: 60px 64px;
}

.footer-inner {
  max-width: 1280px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 96px;
  gap: 32px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 16px;
}

.footer-brand img {
  width: 138px;
  height: 28px;
  filter: brightness(0) invert(1);
}

.footer-tagline {
  font-size: 12px;
  font-weight: 400;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--footer-muted);
  line-height: 1.33;
}

.footer-social {
  display: flex;
  gap: 16px;
  justify-content: flex-end;
}

.social-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--footer-icon-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: opacity 0.2s;
}
.social-icon:hover { opacity: 0.8; }

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .hero-text h1 { font-size: 52px; }
  .hero-text { flex: 0 0 auto; max-width: 480px; }
  .hero-image { flex: 0 0 420px; width: 420px; }
  .features-header h2, .previews-header h2, .use-cases h2, .faq h2 { font-size: 36px; }
  .feature-card { gap: 48px; padding: 40px 32px; }
  .previews { padding: 40px 48px 80px; }
  .preview-content { padding: 40px; }
  .use-cases { padding: 40px 32px 80px; }
  .faq { padding: 40px 48px 80px; }
  .footer-inner { padding: 0 32px; }
}

@media (max-width: 768px) {
  .navbar-links { display: none; }
  .btn-nav { display: none; }
  .hamburger { display: block; }

  .hero { padding: 80px 0 40px; }
  .hero-inner {
    flex-direction: column;
    gap: 40px;
    padding: 40px 20px;
  }
  .hero-text {
    flex: none;
    max-width: 100%;
  }
  .hero-text h1 { font-size: 40px; }
  .hero-image {
    flex: none;
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
  }
  .hero-cta-row {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .features-header { padding: 0 20px; }
  .features-slider { padding: 0 20px; }
  .feature-card {
    width: calc(100vw - 40px);
    flex-direction: column-reverse;
    gap: 24px;
    padding: 32px 24px;
    min-height: auto;
  }
  .feature-card-text { max-width: 100%; }
  .feature-card-image { flex: 0 0 180px; width: 180px; height: auto; margin: 0 auto; }
  .slider-controls { padding-right: 20px; }

  .previews { padding: 32px 20px 60px; }
  .previews-header h2 { font-size: 32px; }
  .category-tabs { gap: 8px; }
  .tab-btn { padding: 8px 12px; font-size: 13px; }
  .preview-card { flex-direction: column; }
  .preview-cover { 
    flex: none; 
    background: #f7f7f7; 
    padding: 40px 20px;
    display: flex;
    justify-content: center;
  }
  .preview-cover img { 
    width: 180px; 
    height: auto; 
    object-fit: contain;
    border-radius: 8px;
    box-shadow: 0 12px 32px rgba(0,0,0,0.12);
  }
  .preview-content { padding: 24px; }
  .preview-player-row { gap: 16px; }
  .preview-title-area h3 { font-size: 22px; }

  .use-cases { padding: 32px 20px 60px; }
  .use-cases h2 { font-size: 28px; margin-bottom: 32px; }
  .use-cases-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .use-case-card:nth-child(2) { margin-top: 0; }

  .faq { padding: 32px 20px 60px; }
  .faq h2 { font-size: 28px; margin-bottom: 32px; }
  .faq-question { padding: 20px 24px; font-size: 16px; }
  .faq-answer p { padding: 0 24px 20px; font-size: 15px; }

  .footer { padding: 40px 20px; }
  .footer-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
    padding: 0;
  }
  .footer-brand { flex-direction: column; gap: 8px; }
  .footer-social { justify-content: center; }

  .preview-modal-content { margin: 20px; padding: 32px 24px; }
}

@media (max-width: 480px) {
  .hero-text h1 { font-size: 32px; }
  .features-header h2, .previews-header h2 { font-size: 28px; }
  .feature-card-text h3 { font-size: 22px; }
}