:root {
  --manual-bg: #0b1120;
  --manual-surface: rgba(17, 25, 40, 0.75);
  --manual-surface-solid: #111928;
  --manual-border: rgba(255, 255, 255, 0.08);
  --manual-text: #e2e8f0;
  --manual-muted: #94a3b8;
  --manual-accent: #10b981;
  --manual-accent-2: #3b82f6;
  --manual-radius: 20px;
  --manual-shadow: 0 24px 80px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: 'Nunito', sans-serif;
  background: var(--manual-bg);
  color: var(--manual-text);
  overflow-x: hidden;
  min-height: 100vh;
}

/* Particles */
.manual-particles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  opacity: 0.45;
}

/* Progress top */
.progress-top {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 4px;
  z-index: 1030;
  background: rgba(255, 255, 255, 0.05);
}
.progress-top-bar {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--manual-accent), var(--manual-accent-2));
  box-shadow: 0 0 12px rgba(16, 185, 129, 0.45);
  transition: width 0.1s linear;
}

/* Floating buttons */
.manual-fab {
  position: fixed;
  right: 22px;
  bottom: 28px;
  z-index: 1020;
}
.manual-fab-btn {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  border: none;
  background: linear-gradient(135deg, var(--manual-accent), var(--manual-accent-2));
  color: #fff;
  font-size: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 24px rgba(16, 185, 129, 0.35);
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
}
.manual-fab-btn:hover {
  transform: translateY(-3px) scale(1.05);
  box-shadow: 0 12px 32px rgba(59, 130, 246, 0.45);
}
#btnScrollTop {
  background: var(--manual-surface-solid);
  border: 1px solid var(--manual-border);
  color: var(--manual-text);
}

/* Hero */
.manual-hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 100px 20px 120px;
  background: radial-gradient(circle at 50% 30%, rgba(16,185,129,0.12), transparent 45%),
              radial-gradient(circle at 80% 80%, rgba(59,130,246,0.10), transparent 45%);
}
.manual-hero-content { max-width: 860px; }
.manual-badge {
  display: inline-flex;
  align-items: center;
  padding: 8px 18px;
  border-radius: 50px;
  background: rgba(16, 185, 129, 0.12);
  border: 1px solid rgba(16, 185, 129, 0.25);
  color: var(--manual-accent);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.5px;
  text-transform: uppercase;
}
.manual-title {
  font-family: 'Poppins', sans-serif;
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 800;
  line-height: 1.08;
  margin: 18px 0 24px;
}
.text-gradient {
  background: linear-gradient(90deg, var(--manual-accent), var(--manual-accent-2), #a78bfa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.manual-lead {
  font-size: clamp(18px, 2.4vw, 22px);
  color: var(--manual-muted);
  max-width: 680px;
  margin: 0 auto 36px;
  line-height: 1.6;
}
.manual-hero-actions { margin-top: 10px; }
.manual-btn {
  border-radius: 50px;
  padding: 14px 30px;
  font-weight: 700;
  transition: transform 0.2s, box-shadow 0.2s;
}
.manual-btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: linear-gradient(135deg, var(--manual-accent), #059669);
  border: none;
  box-shadow: 0 8px 24px rgba(16, 185, 129, 0.35);
}
.btn-outline-light {
  border-color: rgba(255,255,255,0.25);
  color: var(--manual-text);
}
.btn-outline-light:hover {
  background: rgba(255,255,255,0.08);
  color: #fff;
}

.manual-stats {
  display: flex;
  justify-content: center;
  gap: 42px;
  flex-wrap: wrap;
}
.manual-stat {
  text-align: center;
}
.manual-stat-number {
  display: block;
  font-family: 'Poppins', sans-serif;
  font-size: 38px;
  font-weight: 800;
  color: #fff;
}
.manual-stat-label {
  font-size: 13px;
  color: var(--manual-muted);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.scroll-indicator {
  display: inline-block;
  width: 26px;
  height: 44px;
  border: 2px solid rgba(255,255,255,0.3);
  border-radius: 14px;
  position: relative;
  margin-top: 40px;
}
.scroll-indicator span {
  position: absolute;
  top: 7px;
  left: 50%;
  width: 6px;
  height: 6px;
  background: #fff;
  border-radius: 50%;
  transform: translateX(-50%);
  animation: scrollBounce 1.6s infinite;
}
@keyframes scrollBounce {
  0% { top: 7px; opacity: 1; }
  100% { top: 24px; opacity: 0; }
}

/* Layout */
.manual-layout {
  position: relative;
  z-index: 1;
  padding-bottom: 80px;
}

/* Sidebar */
.manual-sidebar-wrapper {
  position: sticky;
  top: 30px;
  height: calc(100vh - 60px);
  padding-top: 10px;
}
.manual-sidebar {
  background: var(--manual-surface);
  backdrop-filter: blur(16px);
  border: 1px solid var(--manual-border);
  border-radius: var(--manual-radius);
  padding: 22px;
  height: 100%;
  display: flex;
  flex-direction: column;
}
.manual-sidebar-header {
  font-family: 'Poppins', sans-serif;
  font-weight: 700;
  font-size: 18px;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--manual-border);
}
.manual-nav {
  flex: 1;
  overflow-y: auto;
  gap: 6px;
}
.manual-nav .nav-link {
  display: flex;
  align-items: center;
  color: var(--manual-muted);
  padding: 12px 14px;
  border-radius: 12px;
  transition: all 0.2s;
  position: relative;
}
.manual-nav .nav-link:hover,
.manual-nav .nav-link.active {
  background: rgba(255,255,255,0.06);
  color: #fff;
}
.manual-nav .nav-link.active {
  box-shadow: inset 3px 0 0 var(--manual-accent);
}
.nav-icon {
  width: 28px;
  display: inline-flex;
  justify-content: center;
  margin-right: 10px;
  font-size: 17px;
}
.nav-text { flex: 1; font-size: 14px; font-weight: 600; }
.nav-check {
  opacity: 0;
  transform: scale(0.6);
  transition: all 0.25s;
  color: var(--manual-accent);
}
.nav-link.read .nav-check {
  opacity: 1;
  transform: scale(1);
}
.manual-sidebar-footer {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--manual-border);
}

/* Content */
.manual-content {
  padding-top: 40px;
  padding-bottom: 60px;
}

/* Chapter card */
.manual-chapter {
  margin-bottom: 60px;
  opacity: 0;
  transform: translateY(40px);
}
.chapter-card {
  background: var(--manual-surface);
  backdrop-filter: blur(16px);
  border: 1px solid var(--manual-border);
  border-radius: var(--manual-radius);
  overflow: hidden;
  box-shadow: var(--manual-shadow);
  transition: border-color 0.3s, box-shadow 0.3s;
}
.chapter-card:hover {
  border-color: rgba(255,255,255,0.14);
  box-shadow: 0 32px 90px rgba(0,0,0,0.42);
}
.chapter-header {
  padding: 42px 36px 32px;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, rgba(255,255,255,0.04), transparent);
}
.chapter-header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 5px;
  background: var(--chapter-color);
  box-shadow: 0 0 24px var(--chapter-color);
}
.chapter-icon {
  width: 72px;
  height: 72px;
  border-radius: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 34px;
  background: linear-gradient(135deg, var(--chapter-color), rgba(255,255,255,0.15));
  color: #fff;
  margin-bottom: 22px;
  box-shadow: 0 12px 28px rgba(0,0,0,0.25);
}
.chapter-number {
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--manual-muted);
  margin-bottom: 8px;
}
.chapter-title {
  font-family: 'Poppins', sans-serif;
  font-size: 30px;
  font-weight: 800;
  margin: 0 0 6px;
}
.chapter-subtitle {
  font-size: 17px;
  color: var(--manual-muted);
  margin: 0 0 14px;
}
.chapter-summary {
  font-size: 15px;
  line-height: 1.6;
  color: #cbd5e1;
  max-width: 700px;
  margin: 0;
}
.chapter-body { padding: 10px 28px 36px; }

/* Accordion */
.chapter-accordion { --bs-accordion-bg: transparent; --bs-accordion-border-color: var(--manual-border); }
.chapter-accordion .accordion-item {
  background: transparent;
  border: none;
  border-bottom: 1px solid var(--manual-border);
}
.chapter-accordion .accordion-button {
  background: transparent;
  color: #fff;
  font-weight: 700;
  padding: 20px 10px;
  box-shadow: none;
}
.chapter-accordion .accordion-button:not(.collapsed) {
  background: transparent;
  color: var(--chapter-color, var(--manual-accent));
}
.chapter-accordion .accordion-button::after {
  filter: invert(1);
}
.section-bullet {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: rgba(255,255,255,0.08);
  color: var(--chapter-color, #fff);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-right: 14px;
  font-size: 14px;
  font-weight: 800;
  flex-shrink: 0;
}
.accordion-button:not(.collapsed) .section-bullet {
  background: var(--chapter-color, var(--manual-accent));
  color: #fff;
}
.section-title-text { font-size: 16px; }
.section-paragraph {
  color: #cbd5e1;
  line-height: 1.7;
  margin-bottom: 14px;
}

/* Tip box */
.tip-box {
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.18);
  border-radius: 14px;
  padding: 18px 20px;
  margin-top: 18px;
}
.tip-box-title {
  color: var(--manual-accent);
  font-weight: 700;
  margin-bottom: 10px;
  font-size: 14px;
}
.tip-list {
  margin: 0;
  padding-left: 20px;
  color: #e2e8f0;
}
.tip-list li { margin-bottom: 6px; line-height: 1.55; }
.tip-list li::marker { color: var(--manual-accent); }

/* Action button */
.btn-action {
  background: linear-gradient(135deg, var(--chapter-color, var(--manual-accent)), rgba(255,255,255,0.12));
  border: none;
  color: #fff;
  border-radius: 50px;
  padding: 10px 24px;
  font-weight: 700;
  box-shadow: 0 6px 18px rgba(0,0,0,0.2);
  transition: transform 0.2s, box-shadow 0.2s;
}
.btn-action:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 28px rgba(0,0,0,0.3);
  color: #fff;
}

/* Chapter footer */
.chapter-footer {
  padding: 18px 36px;
  background: rgba(255,255,255,0.02);
  border-top: 1px solid var(--manual-border);
  text-align: right;
}
.btn-mark-read {
  background: rgba(255,255,255,0.06);
  border: 1px solid var(--manual-border);
  color: var(--manual-text);
  border-radius: 50px;
  padding: 9px 22px;
  font-weight: 700;
  transition: all 0.2s;
}
.btn-mark-read:hover {
  background: var(--manual-accent);
  border-color: var(--manual-accent);
  color: #fff;
}
.btn-mark-read.read {
  background: rgba(16,185,129,0.15);
  border-color: rgba(16,185,129,0.35);
  color: var(--manual-accent);
}

/* Decorative panel */
.manual-decor { padding-top: 50px; }
.manual-decor-card {
  background: var(--manual-surface);
  border: 1px solid var(--manual-border);
  border-radius: var(--manual-radius);
  padding: 24px;
  text-align: center;
  position: sticky;
  top: 50px;
}
.manual-decor-icon {
  width: 56px;
  height: 56px;
  border-radius: 18px;
  background: linear-gradient(135deg, #8b5cf6, #3b82f6);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  color: #fff;
  margin: 0 auto 16px;
}
.manual-decor-text { font-size: 13px; color: var(--manual-muted); line-height: 1.5; }

/* End footer */
.manual-end { position: relative; z-index: 1; }
.manual-end-card {
  max-width: 520px;
  background: var(--manual-surface);
  border: 1px solid var(--manual-border);
  border-radius: var(--manual-radius);
  padding: 48px 32px;
  box-shadow: var(--manual-shadow);
}
.manual-end-icon {
  font-size: 48px;
  color: #fbbf24;
  margin-bottom: 16px;
  display: inline-block;
  animation: starPulse 2s infinite;
}
@keyframes starPulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.15); }
}
.manual-end-title {
  font-family: 'Poppins', sans-serif;
  font-weight: 800;
  font-size: 26px;
  margin-bottom: 10px;
}

/* Modal */
.manual-modal {
  background: var(--manual-surface-solid);
  border: 1px solid var(--manual-border);
  color: #fff;
  border-radius: var(--manual-radius);
  box-shadow: var(--manual-shadow);
}
.manual-modal-icon {
  width: 90px;
  height: 90px;
  border-radius: 50%;
  background: linear-gradient(135deg, #fbbf24, #f59e0b);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 42px;
  color: #fff;
  margin-bottom: 18px;
  animation: trophyBounce 1s ease-out;
}
@keyframes trophyBounce {
  0% { transform: scale(0); }
  60% { transform: scale(1.2); }
  100% { transform: scale(1); }
}

/* Responsive */
@media (max-width: 991px) {
  .manual-hero { min-height: auto; padding: 80px 20px 90px; }
  .manual-stats { gap: 24px; }
  .manual-content { padding-top: 20px; }
  .chapter-header { padding: 30px 22px 24px; }
  .chapter-body { padding: 10px 18px 26px; }
  .chapter-footer { padding: 16px 22px; }
}
@media (max-width: 575px) {
  .manual-title { font-size: 34px; }
  .chapter-title { font-size: 24px; }
  .chapter-icon { width: 58px; height: 58px; font-size: 26px; }
  .manual-fab { right: 14px; bottom: 18px; }
}