/* =============================================
   AI BOOKS — Landing Page
   Theme: Futuristic Cyan / Neural Dark
   ============================================= */
:root {
  --accent: #06b6d4;
  --accent-dark: #0891b2;
  --accent-darker: #0e7490;
  --accent-light: #a5f3fc;
  --accent-xlight: #ecfeff;
  --secondary: #8b5cf6;
  --text-primary: #0a1628;
  --text-secondary: #334155;
  --text-muted: #64748b;
  --bg: #ffffff;
  --bg-soft: #f8fdff;
  --bg-card: #ffffff;
  --border: #e2e8f0;
  --border-soft: #f0fdff;
  --shadow-sm: 0 1px 3px rgba(6,182,212,0.06);
  --shadow-md: 0 4px 16px rgba(6,182,212,0.12);
  --shadow-lg: 0 12px 40px rgba(6,182,212,0.16);
  --radius: 16px; --radius-lg: 24px;
  --nav-height: 70px;
  --font: 'Segoe UI', system-ui, -apple-system, sans-serif;
}
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
body { font-family: var(--font); background: var(--bg); color: var(--text-primary); overflow-x: hidden; line-height: 1.6; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.container { width: 100%; max-width: 1200px; margin: 0 auto; padding: 0 clamp(1rem,4vw,2rem); }
h1 { font-size: clamp(2rem,4.5vw,3.5rem); font-weight: 800; line-height: 1.1; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.6rem,3vw,2.5rem); font-weight: 700; line-height: 1.2; letter-spacing: -0.01em; }
h3 { font-size: clamp(1rem,1.8vw,1.15rem); font-weight: 600; }
p { color: var(--text-secondary); }
a { text-decoration: none; color: inherit; }
.gradient-text { background: linear-gradient(135deg,#06b6d4,#8b5cf6); -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text; }

.btn-primary { display:inline-flex; align-items:center; gap:.5rem; background:linear-gradient(135deg,#06b6d4,#0891b2); color:white; font-weight:600; font-size:.95rem; padding:.75rem 1.5rem; border-radius:50px; border:none; cursor:pointer; transition:all .25s; box-shadow:0 4px 14px rgba(6,182,212,.35); white-space:nowrap; }
.btn-primary:hover { transform:translateY(-2px); box-shadow:0 6px 20px rgba(6,182,212,.45); }
.btn-primary:focus-visible { outline:3px solid var(--accent); outline-offset:3px; }
.btn-secondary { display:inline-flex; align-items:center; gap:.5rem; background:transparent; color:var(--accent-dark); font-weight:600; font-size:.95rem; padding:.75rem 1.5rem; border-radius:50px; border:2px solid var(--accent); cursor:pointer; transition:all .25s; }
.btn-secondary:hover { background:var(--accent-xlight); transform:translateY(-2px); }
.btn-secondary:focus-visible { outline:3px solid var(--accent); outline-offset:3px; }
.btn-large { padding:1rem 2rem; font-size:1.05rem; }

/* NAV */
.nav-header { position:fixed; top:0; left:0; right:0; z-index:1000; background:rgba(255,255,255,.92); backdrop-filter:blur(16px); border-bottom:1px solid var(--border-soft); height:var(--nav-height); transition:all .3s; }
.nav-header.scrolled { box-shadow:var(--shadow-md); }
.nav-container { max-width:1200px; margin:0 auto; padding:0 clamp(1rem,4vw,2rem); height:100%; display:flex; align-items:center; gap:1.5rem; }
.nav-logo { display:flex; align-items:center; gap:.5rem; font-weight:700; font-size:1rem; flex-shrink:0; }
.nav-logo-icon { font-size:1.4rem; }
.nav-links { display:flex; list-style:none; gap:.1rem; margin-left:auto; }
.nav-links a { color:var(--text-secondary); font-size:.88rem; font-weight:500; padding:.4rem .7rem; border-radius:8px; transition:all .2s; }
.nav-links a:hover { color:var(--accent-dark); background:var(--accent-xlight); }
.nav-links a:focus-visible { outline:2px solid var(--accent); }
.nav-cta { margin-left:.5rem; background:linear-gradient(135deg,#06b6d4,#0891b2); color:white; font-weight:600; font-size:.875rem; padding:.5rem 1.2rem; border-radius:50px; transition:all .25s; white-space:nowrap; box-shadow:0 2px 8px rgba(6,182,212,.3); }
.nav-cta:hover { transform:translateY(-1px); box-shadow:0 4px 12px rgba(6,182,212,.4); }
.nav-cta:focus-visible { outline:3px solid var(--accent); outline-offset:2px; }
.hamburger { display:none; flex-direction:column; gap:5px; background:none; border:none; cursor:pointer; padding:4px; border-radius:8px; margin-left:auto; }
.hamburger span { display:block; width:24px; height:2px; background:var(--text-primary); border-radius:2px; transition:all .3s; }
.hamburger.open span:nth-child(1) { transform:translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity:0; transform:scaleX(0); }
.hamburger.open span:nth-child(3) { transform:translateY(-7px) rotate(-45deg); }
.hamburger:focus-visible { outline:2px solid var(--accent); }
.mobile-menu { position:fixed; top:0; right:0; bottom:0; width:min(320px,85vw); background:white; z-index:2000; padding:2rem 1.5rem; display:flex; flex-direction:column; gap:.5rem; transform:translateX(100%); transition:transform .35s cubic-bezier(.4,0,.2,1); box-shadow:-4px 0 30px rgba(0,0,0,.12); }
.mobile-menu.open { transform:translateX(0); }
.mobile-menu ul { list-style:none; display:flex; flex-direction:column; gap:.25rem; margin-top:1rem; }
.mobile-link { display:block; padding:.75rem 1rem; border-radius:12px; font-weight:500; color:var(--text-secondary); transition:all .2s; }
.mobile-link:hover { background:var(--accent-xlight); color:var(--accent-darker); }
.mobile-menu-close { align-self:flex-end; background:var(--bg-soft); border:none; cursor:pointer; width:36px; height:36px; border-radius:50%; font-size:1rem; color:var(--text-secondary); }
.mobile-cta { margin-top:1.5rem; justify-content:center; }
.mobile-overlay { position:fixed; inset:0; background:rgba(0,0,0,.4); z-index:1999; opacity:0; pointer-events:none; transition:opacity .3s; }
.mobile-overlay.visible { opacity:1; pointer-events:all; }

/* HERO */
.hero { min-height:100svh; padding-top:var(--nav-height); display:flex; align-items:center; position:relative; overflow:hidden; background:linear-gradient(155deg,#ecfeff 0%,#ffffff 50%,#f5f3ff 100%); }
.hero-bg { position:absolute; inset:0; pointer-events:none; }
.neural-grid { position:absolute; inset:0; background-image:linear-gradient(rgba(6,182,212,.06) 1px,transparent 1px),linear-gradient(90deg,rgba(6,182,212,.06) 1px,transparent 1px); background-size:40px 40px; }
.orb { position:absolute; border-radius:50%; }
.orb-1 { width:clamp(350px,45vw,700px); height:clamp(350px,45vw,700px); background:radial-gradient(circle,rgba(6,182,212,.10),transparent 70%); top:-15%; right:-10%; }
.orb-2 { width:clamp(200px,28vw,400px); height:clamp(200px,28vw,400px); background:radial-gradient(circle,rgba(139,92,246,.07),transparent 70%); bottom:5%; left:-5%; }
.node { position:absolute; border-radius:50%; background:var(--accent); animation:pulse 3s ease-in-out infinite; }
.n1 { width:8px; height:8px; top:20%; left:15%; opacity:.4; animation-delay:0s; }
.n2 { width:6px; height:6px; top:35%; right:20%; opacity:.3; animation-delay:.8s; }
.n3 { width:10px; height:10px; bottom:25%; left:10%; opacity:.35; animation-delay:1.6s; }
.n4 { width:5px; height:5px; top:55%; right:8%; opacity:.25; animation-delay:.4s; }
.n5 { width:7px; height:7px; bottom:40%; right:25%; opacity:.3; animation-delay:1.2s; }
@keyframes pulse { 0%,100% { transform:scale(1); opacity:.3; } 50% { transform:scale(1.8); opacity:.6; } }

.hero-inner { display:grid; grid-template-columns:1fr 1fr; gap:clamp(2rem,5vw,5rem); align-items:center; padding:clamp(2rem,5vw,4rem) 0 clamp(3rem,6vw,5rem); }
.hero-badge { display:inline-flex; align-items:center; gap:.4rem; background:var(--accent-xlight); color:var(--accent-darker); font-size:.82rem; font-weight:600; padding:.4rem 1rem; border-radius:50px; border:1px solid var(--accent-light); margin-bottom:1.25rem; }
.hero-content h1 { margin-bottom:1.25rem; }
.hero-desc { font-size:clamp(1rem,1.8vw,1.1rem); margin-bottom:2rem; max-width:480px; line-height:1.7; }
.hero-actions { display:flex; gap:1rem; flex-wrap:wrap; margin-bottom:2rem; }
.hero-tags { display:flex; flex-wrap:wrap; gap:.5rem; }
.tag { background:white; border:1px solid var(--border); color:var(--text-secondary); font-size:.78rem; font-weight:500; padding:.3rem .8rem; border-radius:50px; box-shadow:var(--shadow-sm); }

/* Phone mockup */
.hero-visual { position:relative; display:flex; justify-content:center; align-items:center; }
.phone-mockup { position:relative; z-index:2; }
.phone-shell { width:clamp(220px,30vw,285px); background:linear-gradient(160deg,#030d1a,#060f20); border-radius:40px; padding:16px; box-shadow:0 30px 80px rgba(0,0,0,.35),0 8px 24px rgba(6,182,212,.2),inset 0 0 0 1px rgba(255,255,255,.06); }
.mock-screen { background:#04111e; border-radius:28px; padding:1rem; }
.mock-header-bar { display:flex; justify-content:space-between; align-items:center; margin-bottom:.75rem; padding-bottom:.75rem; border-bottom:1px solid rgba(6,182,212,.15); }
.mock-header-bar span:first-child { color:white; font-size:.85rem; font-weight:700; }
.mock-level-badge { background:rgba(6,182,212,.2); color:#67e8f9; font-size:.62rem; font-weight:700; padding:.2rem .5rem; border-radius:50px; }
.mock-topic-cards { display:flex; flex-direction:column; gap:.4rem; margin-bottom:.65rem; }
.mtc { display:flex; align-items:center; gap:.5rem; background:rgba(255,255,255,.04); border-radius:10px; padding:.5rem .65rem; border:1px solid rgba(255,255,255,.05); }
.mtc.active { border-color:rgba(6,182,212,.35); background:rgba(6,182,212,.08); }
.mtc-icon { font-size:.85rem; flex-shrink:0; }
.mtc > span:nth-child(2) { flex:1; color:white; font-size:.72rem; font-weight:500; }
.mtc-bar { width:40px; height:3px; background:rgba(255,255,255,.08); border-radius:2px; overflow:hidden; }
.mtc-bar div { height:100%; background:linear-gradient(90deg,#06b6d4,#8b5cf6); border-radius:2px; }
.mock-quiz-card { background:rgba(6,182,212,.1); border:1px solid rgba(6,182,212,.2); border-radius:12px; padding:.65rem; }
.mqc-label { font-size:.62rem; color:#67e8f9; font-weight:700; margin-bottom:.3rem; text-transform:uppercase; letter-spacing:.04em; }
.mqc-q { color:white; font-size:.72rem; font-weight:500; margin-bottom:.4rem; line-height:1.4; }
.mqc-opts { display:flex; flex-direction:column; gap:.25rem; }
.mqc-opt { background:rgba(255,255,255,.05); border-radius:6px; padding:.3rem .5rem; font-size:.65rem; color:rgba(255,255,255,.6); }
.mqc-opt.correct { background:rgba(34,197,94,.15); color:#4ade80; border:1px solid rgba(34,197,94,.25); }

.float-node { position:absolute; background:white; border:1px solid var(--border); border-radius:50px; padding:.45rem .9rem; font-size:.76rem; font-weight:600; color:var(--text-secondary); box-shadow:var(--shadow-md); white-space:nowrap; animation:floatN 4s ease-in-out infinite; }
.fn-1 { top:8%; left:-12%; animation-delay:0s; }
.fn-2 { bottom:28%; left:-14%; animation-delay:1.3s; }
.fn-3 { top:48%; right:-8%; animation-delay:.7s; }
@keyframes floatN { 0%,100% { transform:translateY(0); } 50% { transform:translateY(-8px); } }

/* HIGHLIGHTS */
.highlights { padding:clamp(2.5rem,5vw,4rem) 0; background:var(--bg-soft); border-top:1px solid var(--border-soft); border-bottom:1px solid var(--border-soft); }
.highlights-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(190px,1fr)); gap:1.25rem; }
.hl-item { display:flex; align-items:center; gap:.75rem; background:white; border-radius:var(--radius); padding:1rem 1.2rem; border:1px solid var(--border-soft); box-shadow:var(--shadow-sm); transition:all .25s; }
.hl-item:hover { transform:translateY(-2px); box-shadow:var(--shadow-md); border-color:var(--accent-light); }
.hl-icon { font-size:1.4rem; flex-shrink:0; }
.hl-item div { display:flex; flex-direction:column; gap:.1rem; }
.hl-item strong { font-size:.88rem; color:var(--text-primary); }
.hl-item span { font-size:.76rem; color:var(--text-muted); line-height:1.4; }

/* SECTION HEADER */
.section-header { text-align:center; margin-bottom:clamp(2rem,4vw,3.5rem); }
.section-tag { display:inline-block; background:var(--accent-xlight); color:var(--accent-darker); font-size:.78rem; font-weight:700; letter-spacing:.07em; text-transform:uppercase; padding:.3rem .9rem; border-radius:50px; border:1px solid var(--accent-light); margin-bottom:.75rem; }
.section-header h2 { margin-bottom:.75rem; }
.section-header p { color:var(--text-muted); max-width:560px; margin:0 auto; font-size:1rem; }

/* TOPICS */
.topics { padding:clamp(4rem,8vw,7rem) 0; }
.topics-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(220px,1fr)); gap:1.25rem; }
.topic-card { background:var(--bg-card); border:1px solid var(--border); border-radius:var(--radius); padding:clamp(1.25rem,3vw,1.75rem); transition:all .3s; box-shadow:var(--shadow-sm); text-align:center; }
.topic-card:hover { transform:translateY(-4px); box-shadow:var(--shadow-lg); border-color:var(--accent-light); }
.tc-icon { font-size:2.2rem; margin-bottom:.75rem; }
.topic-card h3 { margin-bottom:.5rem; }
.topic-card p { font-size:.85rem; color:var(--text-muted); line-height:1.6; }

/* FEATURES */
.features { padding:clamp(4rem,8vw,7rem) 0; background:var(--bg-soft); }
.features-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(240px,1fr)); gap:1.25rem; }
.feature-card { background:white; border:1px solid var(--border); border-radius:var(--radius); padding:clamp(1.25rem,3vw,1.75rem); transition:all .3s; box-shadow:var(--shadow-sm); }
.feature-card:hover { transform:translateY(-4px); box-shadow:var(--shadow-lg); border-color:var(--accent-light); }
.feat-icon { font-size:1.8rem; margin-bottom:.75rem; }
.feature-card h3 { margin-bottom:.5rem; font-size:.95rem; }
.feature-card p { font-size:.85rem; color:var(--text-muted); line-height:1.6; }

/* SHOWCASE */
.showcase { padding:clamp(3rem,6vw,6rem) 0; }
.showcase-row { display:grid; grid-template-columns:1fr 1fr; gap:clamp(2rem,5vw,4rem); align-items:center; margin-bottom:clamp(3rem,6vw,5rem); }
.showcase-row:last-child { margin-bottom:0; }
.showcase-row.reverse { direction:rtl; }
.showcase-row.reverse > * { direction:ltr; }
.sc-vis-card { background:var(--bg-soft); border:1px solid var(--border); border-radius:var(--radius-lg); padding:1.5rem; box-shadow:var(--shadow-lg); }

/* Roadmap vis */
.rv-title { font-size:.85rem; font-weight:700; color:var(--text-primary); margin-bottom:1rem; }
.rv-step { display:flex; align-items:center; gap:.75rem; padding:.6rem 0; border-bottom:1px solid var(--border-soft); font-size:.85rem; color:var(--text-secondary); }
.rv-step:last-child { border-bottom:none; }
.rv-step.done { color:var(--text-primary); }
.rv-step.active { color:var(--accent-darker); }
.rv-dot { width:12px; height:12px; border-radius:50%; background:var(--border); flex-shrink:0; }
.rv-dot.active { background:var(--accent); box-shadow:0 0 0 3px rgba(6,182,212,.2); }
.rv-dot.locked { background:var(--border); opacity:.5; }
.rv-step.done .rv-dot { background:#22c55e; }
.rv-check { margin-left:auto; color:#22c55e; font-weight:700; }
.rv-badge { margin-left:auto; background:var(--accent-xlight); color:var(--accent-dark); font-size:.68rem; font-weight:700; padding:.15rem .5rem; border-radius:50px; }
.rv-lock { margin-left:auto; font-size:.8rem; opacity:.4; }

/* Quiz vis */
.qv-header { font-size:.82rem; font-weight:700; color:var(--text-primary); margin-bottom:.75rem; }
.qv-q { background:var(--accent-xlight); border-left:3px solid var(--accent); color:var(--accent-darker); font-size:.85rem; font-weight:500; padding:.75rem; border-radius:0 10px 10px 0; margin-bottom:.75rem; line-height:1.5; }
.qv-opts { display:flex; flex-direction:column; gap:.4rem; margin-bottom:.75rem; }
.qv-opt { background:var(--bg-soft); border:1px solid var(--border); border-radius:10px; padding:.5rem .75rem; font-size:.82rem; color:var(--text-secondary); }
.qv-opt.correct { background:#f0fdf4; border-color:#bbf7d0; color:#15803d; }
.qv-score { text-align:center; font-size:.82rem; font-weight:700; color:var(--accent-dark); background:var(--accent-xlight); padding:.4rem; border-radius:8px; }

.sc-tag { display:inline-block; background:var(--accent-xlight); color:var(--accent-darker); font-size:.75rem; font-weight:700; letter-spacing:.05em; text-transform:uppercase; padding:.25rem .75rem; border-radius:50px; margin-bottom:.75rem; }
.showcase-content h3 { font-size:clamp(1.3rem,3vw,1.9rem); margin-bottom:.75rem; }
.showcase-content p { font-size:1rem; margin-bottom:1.25rem; line-height:1.7; }
.sc-list { list-style:none; display:flex; flex-direction:column; gap:.5rem; }
.sc-list li { display:flex; align-items:center; gap:.5rem; font-size:.875rem; color:var(--text-secondary); }
.sc-list li::before { content:'✓'; color:var(--accent); font-weight:700; }

/* SCREENSHOTS */
.screenshots { padding:clamp(4rem,8vw,7rem) 0; background:var(--bg-soft); }
.screenshots-row { display:flex; justify-content:center; align-items:flex-end; gap:clamp(1rem,3vw,2rem); flex-wrap:wrap; }
.screenshot-frame { display:flex; flex-direction:column; align-items:center; gap:1rem; transition:transform .3s; }
.screenshot-frame:hover { transform:translateY(-6px); }
.screenshot-frame p { font-size:.82rem; font-weight:600; color:var(--text-muted); }
.screenshot-frame.featured { transform:scale(1.06); }
.screenshot-frame.featured:hover { transform:scale(1.06) translateY(-6px); }
.phone-frame { width:clamp(140px,19vw,175px); background:#030d1a; border-radius:32px; padding:10px; box-shadow:0 20px 60px rgba(0,0,0,.3),inset 0 0 0 1px rgba(6,182,212,.1); }
.phone-screen-ss { border-radius:24px; overflow:hidden; aspect-ratio:9/18; background:#04111e; }
.ss-inner { padding:.75rem; height:100%; display:flex; flex-direction:column; gap:.4rem; }
.ss-bar { display:flex; justify-content:space-between; font-size:.68rem; font-weight:600; color:rgba(255,255,255,.7); padding-bottom:.4rem; border-bottom:1px solid rgba(255,255,255,.08); }
.ss-tile { padding:.5rem .65rem; border-radius:10px; font-size:.68rem; font-weight:600; color:white; border-left:3px solid; }
.ss-tile.cyan { background:rgba(6,182,212,.15); border-color:#06b6d4; }
.ss-tile.blue { background:rgba(59,130,246,.15); border-color:#3b82f6; }
.ss-tile.violet { background:rgba(139,92,246,.15); border-color:#8b5cf6; }
.ss-tile.pink { background:rgba(236,72,153,.15); border-color:#ec4899; }
.ss-note-block { background:rgba(255,255,255,.06); border-radius:8px; padding:.55rem; font-size:.62rem; color:rgba(255,255,255,.8); line-height:1.5; }
.ss-example-block { background:rgba(6,182,212,.1); border-radius:8px; padding:.45rem; font-size:.62rem; color:#67e8f9; }
.ss-quiz-prompt { background:linear-gradient(135deg,#06b6d4,#8b5cf6); color:white; font-size:.65rem; font-weight:700; padding:.4rem; border-radius:8px; text-align:center; margin-top:auto; }
.ss-prog-row { display:flex; align-items:center; gap:.4rem; }
.ss-prog-row span:first-child { font-size:.6rem; color:rgba(255,255,255,.6); width:60px; flex-shrink:0; }
.ss-pbar { flex:1; height:4px; background:rgba(255,255,255,.1); border-radius:2px; overflow:hidden; }
.ss-pfill { height:100%; background:linear-gradient(90deg,#06b6d4,#8b5cf6); border-radius:2px; }
.ss-pct { font-size:.58rem; color:#67e8f9; font-weight:700; flex-shrink:0; }
.ss-streak { background:rgba(249,115,22,.15); border-radius:8px; padding:.4rem; font-size:.65rem; font-weight:600; color:#fb923c; text-align:center; margin-top:auto; }

/* HOW IT WORKS */
.how-it-works { padding:clamp(4rem,8vw,7rem) 0; }
.steps-grid { display:grid; grid-template-columns:repeat(auto-fit,minmax(200px,1fr)); gap:2rem; }
.step { text-align:center; padding:1.75rem 1rem; background:var(--bg-soft); border-radius:var(--radius-lg); border:1px solid var(--border-soft); transition:all .3s; }
.step:hover { transform:translateY(-4px); box-shadow:var(--shadow-md); border-color:var(--accent-light); }
.step-num { font-size:2.5rem; font-weight:900; color:var(--accent-light); line-height:1; margin-bottom:.25rem; }
.step-icon { font-size:1.8rem; margin-bottom:.75rem; }
.step h3 { margin-bottom:.5rem; }
.step p { font-size:.85rem; color:var(--text-muted); }

/* FAQ */
.faq { padding:clamp(4rem,8vw,7rem) 0; background:var(--bg-soft); }
.faq-list { max-width:720px; margin:0 auto; display:flex; flex-direction:column; gap:.75rem; }
.faq-item { background:white; border:1px solid var(--border); border-radius:var(--radius); overflow:hidden; box-shadow:var(--shadow-sm); }
.faq-question { display:flex; justify-content:space-between; align-items:center; width:100%; background:none; border:none; text-align:left; padding:1.2rem 1.5rem; font-size:.92rem; font-weight:600; color:var(--text-primary); cursor:pointer; gap:1rem; transition:background .2s; }
.faq-question:hover { background:var(--bg-soft); }
.faq-question:focus-visible { outline:2px solid var(--accent); outline-offset:-2px; }
.faq-question[aria-expanded="true"] { color:var(--accent-darker); }
.faq-icon { font-size:1.2rem; font-weight:400; color:var(--accent); flex-shrink:0; transition:transform .3s; line-height:1; }
.faq-question[aria-expanded="true"] .faq-icon { transform:rotate(45deg); }
.faq-answer { padding:0 1.5rem 1.2rem; }
.faq-answer p { font-size:.875rem; color:var(--text-muted); line-height:1.7; }

/* CTA */
.final-cta { padding:clamp(4rem,8vw,7rem) 0; }
.cta-box { text-align:center; background:linear-gradient(135deg,#ecfeff,#f5f3ff); border:1px solid var(--accent-light); border-radius:var(--radius-lg); padding:clamp(3rem,6vw,5rem) clamp(1.5rem,4vw,3rem); }
.cta-icon { font-size:3rem; margin-bottom:1rem; }
.cta-box h2 { margin-bottom:.75rem; }
.cta-box p { font-size:1.05rem; color:var(--text-muted); margin-bottom:2rem; max-width:480px; margin-left:auto; margin-right:auto; }

/* FOOTER */
.footer { background:#030d1a; color:rgba(255,255,255,.6); padding:clamp(3rem,6vw,5rem) 0 2rem; }
.footer-inner { display:grid; grid-template-columns:2fr 1fr 1fr; gap:clamp(2rem,4vw,3rem); margin-bottom:3rem; }
.footer-brand { display:flex; flex-direction:column; gap:.75rem; }
.footer-logo { display:flex; align-items:center; gap:.5rem; font-size:1rem; font-weight:700; color:white; }
.footer-brand p { font-size:.875rem; line-height:1.6; max-width:280px; }
.footer-dl { align-self:flex-start; margin-top:.5rem; font-size:.875rem; }
.footer-links h3 { color:white; font-size:.82rem; font-weight:700; text-transform:uppercase; letter-spacing:.05em; margin-bottom:1rem; }
.footer-links ul { list-style:none; display:flex; flex-direction:column; gap:.6rem; }
.footer-links a { font-size:.875rem; color:rgba(255,255,255,.55); transition:color .2s; }
.footer-links a:hover { color:var(--accent-light); }
.footer-links a:focus-visible { outline:2px solid var(--accent); border-radius:2px; }
.footer-bottom { border-top:1px solid rgba(255,255,255,.08); padding-top:1.5rem; display:flex; flex-direction:column; gap:.25rem; }
.footer-bottom p { font-size:.8rem; color:rgba(255,255,255,.35); }

/* BACK TO TOP */
.back-to-top { position:fixed; bottom:1.5rem; right:1.5rem; z-index:900; width:44px; height:44px; border-radius:50%; background:var(--accent); color:white; border:none; cursor:pointer; display:flex; align-items:center; justify-content:center; box-shadow:0 4px 16px rgba(6,182,212,.4); transition:all .3s; opacity:0; transform:translateY(8px); }
.back-to-top:not([hidden]) { opacity:1; transform:translateY(0); }
.back-to-top:hover { background:var(--accent-dark); transform:translateY(-2px); }
.back-to-top:focus-visible { outline:3px solid var(--accent); outline-offset:2px; }

[data-reveal] { opacity:0; transform:translateY(24px); transition:opacity .6s ease,transform .6s ease; }
[data-reveal].revealed { opacity:1; transform:translateY(0); }

@media (prefers-reduced-motion:reduce) {
  *,*::before,*::after { animation-duration:.01ms !important; animation-iteration-count:1 !important; scroll-behavior:auto !important; transition-duration:.01ms !important; }
  .float-node,.node { animation:none; }
}
@media (max-width:1024px) { .footer-inner { grid-template-columns:1fr 1fr; } .footer-brand { grid-column:1 / -1; } }
@media (max-width:768px) {
  .nav-links,.nav-cta { display:none; } .hamburger { display:flex; }
  .hero-inner { grid-template-columns:1fr; text-align:center; }
  .hero-desc,.hero-actions,.hero-tags { justify-content:center; margin-left:auto; margin-right:auto; } .hero-desc { max-width:100%; }
  .float-node { display:none; }
  .showcase-row,.showcase-row.reverse { grid-template-columns:1fr; direction:ltr; }
  .footer-inner { grid-template-columns:1fr; } .footer-brand { grid-column:auto; }
}
@media (max-width:480px) {
  .hero-actions { flex-direction:column; align-items:center; }
  .hero-actions > * { width:100%; max-width:280px; justify-content:center; }
  .topics-grid,.features-grid { grid-template-columns:1fr; }
  .steps-grid { grid-template-columns:1fr 1fr; }
  .screenshots-row { flex-direction:column; align-items:center; } .screenshot-frame.featured { transform:scale(1); }
}
@media (max-width:360px) { h1 { font-size:1.9rem; } .steps-grid { grid-template-columns:1fr; } }

/* ============================================================
   AI BOOKS — LOADING SCREEN + ENHANCED UI  (v2 redesign)
   ============================================================ */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Space+Grotesk:wght@600;700;800&display=swap');

:root {
  --font-display: 'Space Grotesk', 'Inter', sans-serif;
  --shadow-xl: 0 20px 60px rgba(6,182,212,.22);
  --radius-xl: 32px;
}

/* ── Scroll progress ── */
#aib-scroll-progress {
  position: fixed; top: 0; left: 0; height: 3px; width: 0%;
  background: linear-gradient(90deg, #06b6d4, #8b5cf6);
  z-index: 9999; pointer-events: none;
  transition: width .1s linear;
  box-shadow: 0 0 8px rgba(6,182,212,.6);
}

/* ── Loader ── */
#aib-loader {
  position: fixed; inset: 0; z-index: 9999;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  background: radial-gradient(ellipse at 40% 50%, #021320 0%, #030d1a 60%, #010810 100%);
  overflow: hidden;
  transition: opacity .65s ease, visibility .65s ease;
}
#aib-loader.aib-out { opacity: 0; visibility: hidden; pointer-events: none; }

/* Neural grid bg */
.aib-grid {
  position: absolute; inset: 0;
  background-image:
    linear-gradient(rgba(6,182,212,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(6,182,212,.06) 1px, transparent 1px);
  background-size: 44px 44px;
  animation: aibGridPulse 4s ease-in-out infinite;
}
@keyframes aibGridPulse { 0%,100%{opacity:.5;} 50%{opacity:1;} }

/* Pulsing neural nodes */
.aib-nodes { position: absolute; inset: 0; pointer-events: none; }
.aib-node {
  position: absolute; border-radius: 50%; background: var(--accent);
  animation: aibNodePulse 2.5s ease-in-out infinite;
}
.aib-node:nth-child(1){width:8px;height:8px;top:20%;left:15%;opacity:.5;animation-delay:0s;}
.aib-node:nth-child(2){width:5px;height:5px;top:60%;right:20%;opacity:.4;animation-delay:.5s;}
.aib-node:nth-child(3){width:10px;height:10px;bottom:25%;left:25%;opacity:.45;animation-delay:1s;}
.aib-node:nth-child(4){width:6px;height:6px;top:35%;right:10%;opacity:.35;animation-delay:1.5s;}
.aib-node:nth-child(5){width:7px;height:7px;bottom:40%;right:30%;opacity:.4;animation-delay:.8s;}
@keyframes aibNodePulse { 0%,100%{transform:scale(1);opacity:.35;} 50%{transform:scale(2);opacity:.7;} }

/* Orbs */
.aib-orb-1 {
  position: absolute; border-radius: 50%; pointer-events: none;
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(6,182,212,.12) 0%, transparent 65%);
  top: -100px; right: -80px;
  animation: aibOrbFloat 6s ease-in-out infinite;
}
.aib-orb-2 {
  position: absolute; border-radius: 50%; pointer-events: none;
  width: 350px; height: 350px;
  background: radial-gradient(circle, rgba(139,92,246,.10) 0%, transparent 65%);
  bottom: -80px; left: -60px;
  animation: aibOrbFloat 8s ease-in-out infinite reverse;
}
@keyframes aibOrbFloat { 0%,100%{transform:translateY(0) scale(1);} 50%{transform:translateY(-18px) scale(1.05);} }

/* Content */
.aib-content {
  position: relative; z-index: 2;
  display: flex; flex-direction: column;
  align-items: center; gap: 1.4rem;
}
.aib-icon-wrap {
  position: relative; width: 110px; height: 110px;
}
.aib-icon-wrap::before {
  content: ''; position: absolute; inset: 0; border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: #06b6d4; border-left-color: rgba(6,182,212,.4);
  animation: aibSpin 1.1s linear infinite;
}
.aib-icon-wrap::after {
  content: ''; position: absolute; inset: 10px; border-radius: 50%;
  border: 2px solid transparent;
  border-bottom-color: #8b5cf6; border-right-color: rgba(139,92,246,.4);
  animation: aibSpin 1.7s linear infinite reverse;
}
@keyframes aibSpin { to { transform: rotate(360deg); } }
.aib-icon-inner {
  position: absolute; inset: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 2.8rem;
  animation: aibBounce .65s cubic-bezier(.34,1.56,.64,1) both;
}
@keyframes aibBounce { from{transform:scale(0) rotate(-20deg);opacity:0;} to{transform:scale(1) rotate(0);opacity:1;} }

.aib-name {
  font-family: var(--font-display);
  font-size: 2rem; font-weight: 800; letter-spacing: -.03em;
  background: linear-gradient(135deg, #06b6d4, #8b5cf6);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  animation: aibFadeUp .6s .3s ease both;
}
.aib-tagline {
  font-size: .85rem; font-weight: 600; color: rgba(147,197,253,.6);
  letter-spacing: .1em; text-transform: uppercase;
  animation: aibFadeUp .6s .45s ease both;
}
.aib-topics-row {
  display: flex; gap: .6rem; flex-wrap: wrap; justify-content: center;
  animation: aibFadeUp .6s .55s ease both;
}
.aib-topic-chip {
  background: rgba(6,182,212,.1); border: 1px solid rgba(6,182,212,.2);
  border-radius: 50px; padding: .28rem .75rem;
  font-size: .75rem; font-weight: 600; color: #67e8f9;
  animation: aibChipFloat 2.5s ease-in-out infinite;
}
.aib-topic-chip:nth-child(2){animation-delay:.25s;}
.aib-topic-chip:nth-child(3){animation-delay:.5s;}
.aib-topic-chip:nth-child(4){animation-delay:.75s;}
@keyframes aibChipFloat { 0%,100%{transform:translateY(0);} 50%{transform:translateY(-5px);} }

.aib-progress-wrap {
  width: 210px; height: 4px;
  background: rgba(6,182,212,.1); border-radius: 50px; overflow: hidden;
  animation: aibFadeUp .6s .65s ease both;
}
.aib-progress-bar {
  height: 100%; background: linear-gradient(90deg, #06b6d4, #8b5cf6);
  border-radius: 50px; width: 0%; transition: width .1s linear;
  box-shadow: 0 0 10px rgba(6,182,212,.6);
}
@keyframes aibFadeUp { from{opacity:0;transform:translateY(16px);} to{opacity:1;transform:translateY(0);} }

/* ── Enhanced feature cards ── */
.feature-card { position: relative; overflow: hidden; }
.feature-card::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, var(--accent-xlight), transparent);
  opacity: 0; transition: opacity .3s;
}
.feature-card:hover::before { opacity: 1; }
.feature-card > * { position: relative; }

/* ── Enhanced topic cards ── */
.topic-card { position: relative; overflow: hidden; }
.topic-card::after {
  content: ''; position: absolute; bottom: 0; left: 0; right: 0;
  height: 3px; background: linear-gradient(90deg, #06b6d4, #8b5cf6);
  transform: scaleX(0); transition: transform .3s; transform-origin: left;
}
.topic-card:hover::after { transform: scaleX(1); }

/* ── Enhanced step cards ── */
.step { position: relative; overflow: hidden; }
.step::before {
  content: ''; position: absolute; inset: 0;
  background: linear-gradient(135deg, rgba(6,182,212,.06), transparent);
  opacity: 0; transition: opacity .3s;
}
.step:hover::before { opacity: 1; }
.step > * { position: relative; }
.step-num { font-family: var(--font-display); }

/* ── Zodiac/section tag font ── */
.section-tag, .nav-logo-text { font-family: var(--font-display, 'Segoe UI', system-ui); }

/* ── CTA box decoration ── */
.cta-box { position: relative; overflow: hidden; }
.cta-box::before {
  content: '🤖'; position: absolute;
  font-size: 8rem; opacity: .04;
  top: -1rem; right: 2rem; pointer-events: none;
}

/* ── Footer upgrade ── */
.footer { background: linear-gradient(160deg, #030d1a, #04152a); }