:root {
  --navy: #0d1b2a;
  --royal: #1a3a6b;
  --blue: #1e5fa8;
  --accent: #4fc3f7;
  --gold: #f0b429;
  --white: #f5f7fa;
  --muted: #8aa0bb;
  --surface: #132236;
  --surface2: #1a2f47;
  --border: rgba(79, 195, 247, 0.18);
  --glow: 0 0 32px rgba(79, 195, 247, 0.15);
  --banner-bg: linear-gradient(90deg, #f0b429, #ffd166);
  --banner-text: #0d1b2a;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Outfit', sans-serif;
  background: var(--navy);
  color: var(--white);
  line-height: 1.7;
  overflow-x: hidden;
}

body::before {
  content: '';
  position: fixed;
  inset: 0;
  background:
    radial-gradient(ellipse 70% 50% at 80% 10%, rgba(30, 95, 168, 0.25) 0%, transparent 60%),
    radial-gradient(ellipse 50% 40% at 10% 80%, rgba(79, 195, 247, 0.12) 0%, transparent 55%);
  pointer-events: none;
  z-index: 0;
}

img {
  max-width: 100%;
  display: block;
}

a {
  color: var(--accent);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Upgrade banner */
.vb-upgrade-banner {
  position: sticky;
  top: 0;
  z-index: 300;
  background: var(--banner-bg);
  color: var(--banner-text);
  text-align: center;
  padding: 0.7rem 1rem;
  font-size: 0.92rem;
  font-weight: 700;
  border-bottom: 1px solid rgba(13, 27, 42, 0.12);
}

.vb-upgrade-banner a {
  color: #0b3d91;
  text-decoration: underline;
  font-weight: 800;
}

/* NAV */
nav {
  position: sticky;
  top: 44px;
  z-index: 250;
  background: rgba(13, 27, 42, 0.92);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border);
  padding: 0 2rem;
}

.nav-inner {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 2rem;
  min-height: 56px;
  flex-wrap: wrap;
}

.nav-brand {
  font-family: 'DM Serif Display', serif;
  font-size: 1.1rem;
  color: var(--accent);
  text-decoration: none;
  white-space: nowrap;
}

nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.85rem;
  font-weight: 500;
  transition: color 0.2s;
  white-space: nowrap;
}

nav a:hover {
  color: var(--accent);
}

/* Hamburger */
.sidebar-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  background: rgba(79, 195, 247, 0.1);
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  margin-left: auto;
  flex-shrink: 0;
  transition: background 0.2s;
}

.sidebar-toggle:hover {
  background: rgba(79, 195, 247, 0.2);
}

.sidebar-toggle svg {
  display: block;
}

.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  z-index: 199;
}

.sidebar-overlay.active {
  display: block;
}

/* PAGE LAYOUT */
.page-layout {
  display: flex;
  max-width: 1200px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.sidebar {
  width: 240px;
  flex-shrink: 0;
  padding: 2rem 0 2rem 2rem;
  position: sticky;
  top: 100px;
  height: calc(100vh - 100px);
  overflow-y: auto;
  border-right: 1px solid var(--border);
}

.sidebar-close {
  display: none;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  background: rgba(79, 195, 247, 0.1);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  margin-left: auto;
  margin-bottom: 1rem;
  transition: background 0.2s;
}

.sidebar-close:hover {
  background: rgba(79, 195, 247, 0.22);
}

.sidebar-close svg {
  display: block;
}

.sidebar h5 {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.8rem;
  margin-top: 1.2rem;
  padding-left: 0.5rem;
}

.sidebar a {
  display: block;
  padding: 0.35rem 0.5rem;
  font-size: 0.82rem;
  color: var(--muted);
  text-decoration: none;
  border-radius: 6px;
  transition: all 0.15s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.sidebar a:hover,
.sidebar a.active {
  background: rgba(79, 195, 247, 0.08);
  color: var(--accent);
}

.sidebar .mini-book {
  background: rgba(79, 195, 247, 0.08);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 0.9rem;
  margin: 1rem 0 0.8rem;
  text-align: center;
}

.sidebar .mini-book h6 {
  font-size: 0.82rem;
  margin-bottom: 0.7rem;
  color: var(--white);
}

.sidebar .mini-book img {
  width: 120px;
  margin: 0 auto;
  border-radius: 6px;
  box-shadow: var(--glow);
}

.main-content {
  flex: 1;
  overflow: hidden;
}

/* Generic sections */
section {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
}

.section-label {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.8rem;
}

h1 {
  font-family: 'DM Serif Display', serif;
  font-size: clamp(2.4rem, 5vw, 3.8rem);
  line-height: 1.1;
  margin-bottom: 1.2rem;
}

h1 span {
  color: var(--accent);
}

h2 {
  font-family: 'DM Serif Display', serif;
  font-size: clamp(1.8rem, 3vw, 2.4rem);
  margin-bottom: 1rem;
}

.section-intro {
  color: var(--muted);
  max-width: 760px;
  margin-bottom: 2rem;
  font-size: 1rem;
}

/* Ad */
.top-ad {
  padding: 1.6rem 2rem 0;
  text-align: center;
}

/* HERO */
.hero {
  max-width: 1200px;
  margin: 0 auto;
  padding: 4.8rem 2rem 3rem;
  display: grid;
  grid-template-columns: 1fr 380px;
  gap: 4rem;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(79, 195, 247, 0.12);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 0.35rem 1rem;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  letter-spacing: 0.06em;
  text-transform: uppercase;
  margin-bottom: 1.5rem;
}

.hero-badge::before {
  content: '';
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--accent);
}

.hero-sub {
  font-size: 1.05rem;
  color: var(--muted);
  max-width: 560px;
  margin-bottom: 2rem;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.6rem;
  border-radius: 8px;
  font-weight: 600;
  font-size: 0.9rem;
  text-decoration: none;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}

.btn-primary {
  background: var(--accent);
  color: var(--navy);
}

.btn-primary:hover {
  background: #81d4fa;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(79, 195, 247, 0.35);
  text-decoration: none;
}

.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--border);
}

.btn-outline:hover {
  background: rgba(79, 195, 247, 0.08);
  transform: translateY(-2px);
  text-decoration: none;
}

/* Version card */
.version-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: var(--glow);
}

.version-card h3 {
  font-family: 'DM Serif Display', serif;
  font-size: 1.1rem;
  color: var(--accent);
  margin-bottom: 1.2rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.version-card h3::before {
  content: '📋';
  font-size: 1.1rem;
}

.version-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.6rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  font-size: 0.88rem;
  gap: 1rem;
}

.version-item:last-child {
  border-bottom: none;
}

.version-item .label {
  color: var(--muted);
}

.version-item .value {
  font-weight: 600;
  color: var(--white);
  font-family: 'DM Mono', monospace;
  font-size: 0.82rem;
  text-align: right;
}

/* Stats */
.stats-row {
  display: flex;
  gap: 3rem;
  flex-wrap: wrap;
  margin: 0 2rem 3rem;
  padding: 2rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
}

.stat {
  text-align: center;
  flex: 1;
  min-width: 120px;
}

.stat-num {
  font-family: 'DM Serif Display', serif;
  font-size: 2.5rem;
  color: var(--accent);
  display: block;
}

.stat-label {
  font-size: 0.82rem;
  color: var(--muted);
  font-weight: 500;
}

/* Divider */
.divider {
  border: none;
  border-top: 1px solid var(--border);
  margin: 0 2rem;
}

/* About + upgrade */
.content-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 2rem;
  box-shadow: var(--glow);
}

.split-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 1.5rem;
}

.quick-points {
  margin: 1rem 0 0;
  padding-left: 1.1rem;
  color: var(--muted);
}

.quick-points li {
  margin-bottom: 0.5rem;
}

.transition-box {
  background: rgba(96, 165, 250, 0.08);
  border: 1px solid rgba(96, 165, 250, 0.3);
  border-radius: 12px;
  padding: 1.4rem;
  margin-top: 1rem;
  text-align: center;
}

.transition-box h3 {
  margin-bottom: 0.7rem;
  color: #60a5fa;
  font-size: 1.2rem;
}

/* Books */
.books-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 2rem;
  margin-top: 2rem;
}

.book-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 1.8rem;
  display: flex;
  gap: 1.4rem;
  box-shadow: var(--glow);
}

.book-card img {
  width: 100px;
  height: 142px;
  border-radius: 6px;
  object-fit: cover;
  object-position: center top;
  flex-shrink: 0;
  align-self: flex-start;
}

.book-info h4 {
  font-weight: 600;
  font-size: 1rem;
  margin-bottom: 0.3rem;
}

.book-info .author {
  color: var(--muted);
  font-size: 0.82rem;
  margin-bottom: 0.8rem;
}

.book-info p {
  color: var(--muted);
  font-size: 0.84rem;
  line-height: 1.6;
  margin-bottom: 0.7rem;
}

.book-info ul {
  padding-left: 1.1rem;
  color: var(--muted);
  font-size: 0.82rem;
  margin-bottom: 0.9rem;
}

.book-info li {
  margin-bottom: 0.4rem;
}

.book-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 0.6rem;
}

.book-links a {
  display: inline-block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--accent);
  text-decoration: none;
}

/* Testimonials */
.testimonials {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
  margin-top: 2rem;
}

.testimonial {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.5rem;
  box-shadow: var(--glow);
}

.testimonial p {
  font-size: 0.88rem;
  color: var(--muted);
  margin-bottom: 1rem;
  font-style: italic;
}

.testimonial cite {
  font-size: 0.8rem;
  font-style: normal;
  font-weight: 600;
  color: var(--accent);
}

/* Resources */
.resources-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1.2rem;
  margin-top: 2rem;
}

.resource-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 1.4rem;
  text-decoration: none;
  transition: all 0.2s;
}

.resource-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
  text-decoration: none;
}

.resource-card h4 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.4rem;
  color: var(--white);
}

.resource-card p {
  font-size: 0.8rem;
  color: var(--muted);
}

.video-card iframe {
  width: 100%;
  aspect-ratio: 16 / 9;
  border: none;
  border-radius: 8px;
  margin-top: 0.75rem;
}

/* CTA Banner */
.cta-banner {
  position: relative;
  z-index: 1;
  margin: 2rem auto;
  max-width: 1200px;
  padding: 0 2rem 4rem;
}

.cta-inner {
  background: linear-gradient(135deg, var(--royal) 0%, var(--blue) 100%);
  border: 1px solid rgba(79, 195, 247, 0.3);
  border-radius: 20px;
  padding: 3rem;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-inner::after {
  content: '';
  position: absolute;
  top: -40%;
  right: -10%;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(79, 195, 247, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.cta-inner h2 {
  font-size: 1.8rem;
  margin-bottom: 1rem;
}

.cta-inner p {
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 2rem;
  max-width: 520px;
  margin-left: auto;
  margin-right: auto;
}

/* Footer */
footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2rem;
  color: var(--muted);
  font-size: 0.82rem;
  border-top: 1px solid var(--border);
}

footer a {
  color: var(--accent);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

/* Responsive */
@media (max-width: 900px) {
  .hero {
    grid-template-columns: 1fr;
  }

  .split-grid {
    grid-template-columns: 1fr;
  }

  .version-card {
    max-width: 440px;
  }
}

@media (max-width: 768px) {
  nav {
    top: 44px;
  }

  .sidebar-toggle {
    display: flex;
  }

  .sidebar-close {
    display: flex;
  }

  .page-layout {
    position: static;
    z-index: auto;
  }

  .sidebar {
    position: fixed !important;
    top: 0 !important;
    left: 0 !important;
    width: 280px !important;
    height: 100dvh !important;
    padding: 1rem 0.75rem 2rem 1rem !important;
    background: #0d1b2a !important;
    border-right: 1px solid rgba(79, 195, 247, 0.18) !important;
    z-index: 200 !important;
    overflow-y: auto !important;
    transform: translateX(-100%);
    transition: transform 0.28s cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform;
  }

  .sidebar.open {
    transform: translateX(0);
    box-shadow: 4px 0 32px rgba(0, 0, 0, 0.5);
  }

  .sidebar a {
    white-space: normal !important;
    overflow: visible !important;
    text-overflow: unset !important;
    font-size: 0.92rem !important;
    padding: 0.6rem 0.5rem !important;
    line-height: 1.4 !important;
  }

  .sidebar h5 {
    font-size: 0.72rem !important;
    margin-top: 1rem !important;
  }

  .hero {
    padding: 3rem 2rem 2rem;
  }

  .top-ad {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .stats-row {
    margin-left: 1rem;
    margin-right: 1rem;
    gap: 1.5rem;
  }

  section {
    padding: 3rem 1rem;
  }

  .divider {
    margin: 0 1rem;
  }

  .cta-banner {
    padding: 0 1rem 3rem;
  }

  .cta-inner {
    padding: 2rem 1.2rem;
  }

  .book-card {
    flex-direction: column;
  }

  .book-card img {
    width: 120px;
    height: auto;
  }
}

@media (max-width: 560px) {
  .nav-inner {
    gap: 1rem;
  }

  nav a:not(.nav-brand) {
    display: none;
  }

  .hero-buttons {
    flex-direction: column;
    align-items: flex-start;
  }

  .btn {
    width: 100%;
    justify-content: center;
  }

  .version-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .version-item .value {
    text-align: left;
  }
}
/* ===== NEW HEADER OPTIMIZATION ===== */

.authority-banner {
  background: linear-gradient(135deg, #f0b429, #ffd166);
  color: #000;
  text-align: center;
  padding: 8px;
  font-weight: 700;
  font-size: 0.85rem;
}

/* Improve nav spacing */
.nav-links {
  display: flex;
  gap: 10px;
  flex: 1;
}

.nav-links a {
  padding: 6px 10px;
  border-radius: 999px;
  font-weight: 600;
}

.nav-links a:hover {
  background: rgba(79,195,247,0.1);
}

/* Highlight VB.NET 2026 (first item) */
.nav-links a:first-child {
  color: var(--white);
  background: rgba(79,195,247,0.15);
  border: 1px solid rgba(79,195,247,0.2);
}

/* CTA button */
.nav-cta {
  background: linear-gradient(135deg, #f0b429, #ffd166);
  color: #000;
  padding: 6px 12px;
  border-radius: 999px;
  font-weight: 800;
  font-size: 0.82rem;
  text-decoration: none;
  white-space: nowrap;
}

.nav-cta:hover {
  transform: translateY(-1px);
  text-decoration: none;
}

/* ===== FOOTER IMPROVEMENT ===== */

/* ===== FORCE FOOTER VERSION LINKS INTO COLUMNS ===== */

.footer-versions,
.footer-other {
  margin-top: 1.5rem;
  text-align: center;
}

.footer-versions h4,
.footer-other h4 {
  color: var(--accent);
  margin-bottom: 0.6rem;
  font-size: 0.95rem;
}

.footer-version-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px 22px;
  max-width: 720px;
  margin: 0 auto;
}

.footer-other-links {
  display: flex;
  justify-content: center;
  gap: 12px;
  margin: 0 auto;
}

.footer-version-links a,
.footer-other-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.85rem;
  white-space: nowrap;
}

.footer-version-links a:hover,
.footer-other-links a:hover {
  color: var(--white);
}
/* ===== FLOATING BOOKSTORE BUTTON ===== */

.floating-bookstore-cta {
  position: fixed !important;
  left: 18px !important;
  bottom: 18px !important;
  z-index: 99999 !important;
  display: inline-flex !important;
  align-items: center !important;
  justify-content: center !important;
  opacity: 1 !important;
  visibility: visible !important;
  pointer-events: auto !important;
  background: #22c55e !important;
  color: #fff !important;
  padding: 0.85rem 1rem !important;
  border-radius: 999px !important;
  font-weight: 700 !important;
  text-decoration: none !important;
  box-shadow: 0 10px 24px rgba(34, 197, 94, 0.28) !important;
  transition: transform 0.2s ease !important;
}

.floating-bookstore-cta:hover {
  transform: translateY(-2px);
  text-decoration: none !important;
}

@media (max-width: 768px) {
  .floating-bookstore-cta {
    left: 12px !important;
    bottom: 12px !important;
    font-size: 0.9rem !important;
    padding: 0.75rem 0.9rem !important;
  }
}