/* ============================================================
   ROBOTECH ENTERPRISE MANUAL — PREMIUM STYLESHEET
   ============================================================ */

/* ---------- CSS Variables & Reset ---------- */
:root {
  --bg-deep: #080b14;
  --bg-card: #0e1523;
  --bg-glass: rgba(255, 255, 255, 0.04);
  --bg-glass-hover: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(99, 102, 241, 0.35);

  --accent-indigo: #6366f1;
  --accent-orange: #f97316;
  --accent-teal: #14b8a6;
  --accent-green: #22c55e;

  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #475569;

  --font-fa: 'Vazirmatn', sans-serif;
  --font-en: 'Inter', sans-serif;

  --sidebar-w: 300px;
  --topbar-h: 60px;
  --radius-lg: 16px;
  --radius-md: 10px;
  --radius-sm: 6px;

  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html { scroll-behavior: smooth; }

body {
  background: var(--bg-deep);
  color: var(--text-primary);
  font-family: var(--font-fa);
  min-height: 100vh;
  overflow-x: hidden;
}

/* ---------- Page System ---------- */
.page { display: none; min-height: 100vh; }
.page.active { display: flex; }

/* ============================================================
   LANDING PAGE
   ============================================================ */
#landing-page {
  position: relative;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  overflow: hidden;
}

/* Animated background orbs */
.landing-bg {
  position: absolute; inset: 0;
  pointer-events: none;
  overflow: hidden;
}
.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  animation: drift 8s ease-in-out infinite alternate;
}
.orb-1 {
  width: 500px; height: 500px;
  background: radial-gradient(circle, rgba(99,102,241,0.3), transparent 70%);
  top: -100px; left: -150px;
  animation-delay: 0s;
}
.orb-2 {
  width: 400px; height: 400px;
  background: radial-gradient(circle, rgba(249,115,22,0.2), transparent 70%);
  bottom: -80px; right: -100px;
  animation-delay: -3s;
}
.orb-3 {
  width: 300px; height: 300px;
  background: radial-gradient(circle, rgba(20,184,166,0.2), transparent 70%);
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  animation-delay: -6s;
}

@keyframes drift {
  from { transform: translate(0, 0) scale(1); }
  to { transform: translate(30px, -30px) scale(1.1); }
}

.landing-content {
  position: relative; z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 40px;
  padding: 40px 20px;
  text-align: center;
}

/* Logo */
.logo-wrap {
  display: flex;
  align-items: center;
  gap: 18px;
  text-align: start;
}
.logo-icon svg { width: 72px; height: 72px; filter: drop-shadow(0 0 20px rgba(99,102,241,0.5)); }
.brand-name {
  font-size: clamp(1.6rem, 4vw, 2.4rem);
  font-weight: 800;
  background: linear-gradient(135deg, #a5b4fc, #f97316);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1.1;
  font-family: var(--font-en);
}
.brand-tagline {
  font-size: 0.95rem;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* Language Selection Card */
.lang-card {
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 40px 48px;
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  max-width: 480px;
  width: 100%;
  box-shadow: 0 0 60px rgba(99,102,241,0.08);
}
.lang-prompt {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
}
.lang-prompt-sub {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-family: var(--font-en);
  margin-bottom: 32px;
}

.lang-buttons {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.lang-btn {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 18px 22px;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--text-primary);
  font-family: var(--font-fa);
  text-align: start;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}
.lang-btn::before {
  content: '';
  position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(99,102,241,0.1), transparent);
  opacity: 0;
  transition: opacity var(--transition);
}
.lang-btn:hover {
  border-color: var(--accent-indigo);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(99,102,241,0.2);
}
.lang-btn:hover::before { opacity: 1; }
.lang-btn:active { transform: translateY(0); }

.lang-flag { font-size: 2rem; }
.lang-label { font-size: 1.1rem; font-weight: 600; flex: 1; }
.lang-sub { font-size: 0.8rem; color: var(--text-muted); font-family: var(--font-en); }

.landing-footer {
  font-size: 0.75rem;
  color: var(--text-muted);
  font-family: var(--font-en);
}

/* ============================================================
   MANUAL PAGE
   ============================================================ */
#manual-page {
  flex-direction: row;
  position: relative;
}

/* RTL: sidebar از راست، LTR: sidebar از چپ */
[dir="rtl"] #manual-page {
  flex-direction: row;
}
[dir="ltr"] #manual-page {
  flex-direction: row-reverse;
}

/* ---------- Sidebar ---------- */
.sidebar-overlay {
  display: none;
  position: fixed; inset: 0;
  background: rgba(0,0,0,0.6);
  z-index: 100;
  backdrop-filter: blur(3px);
}
.sidebar-overlay.open { display: block; }

.sidebar {
  width: var(--sidebar-w);
  height: 100vh;
  background: rgba(10, 14, 26, 0.95);
  border-inline-end: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  flex-shrink: 0;
  overflow: hidden;
  transition: transform var(--transition);
  backdrop-filter: blur(20px);
}

.sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 20px;
  border-bottom: 1px solid var(--border);
}
.sidebar-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.1rem;
  font-weight: 700;
  font-family: var(--font-en);
  background: linear-gradient(135deg, #a5b4fc, #fb923c);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}
.sidebar-close {
  display: none;
  background: none; border: none;
  color: var(--text-muted);
  font-size: 1.2rem;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}
.sidebar-close:hover { color: var(--text-primary); background: var(--bg-glass-hover); }

.sidebar-lang-switch {
  display: flex;
  gap: 6px;
  padding: 14px 16px;
  border-bottom: 1px solid var(--border);
}
.lang-pill {
  flex: 1;
  padding: 7px 4px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: none;
  color: var(--text-secondary);
  font-family: var(--font-fa);
  font-size: 0.8rem;
  cursor: pointer;
  transition: var(--transition);
}
.lang-pill.active {
  background: var(--accent-indigo);
  border-color: var(--accent-indigo);
  color: #fff;
  font-weight: 600;
}
.lang-pill:hover:not(.active) {
  border-color: var(--accent-indigo);
  color: var(--text-primary);
}

.chapters-nav {
  flex: 1;
  overflow-y: auto;
  padding: 10px 10px;
}
.chapters-nav::-webkit-scrollbar { width: 4px; }
.chapters-nav::-webkit-scrollbar-track { background: transparent; }
.chapters-nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

.chapter-nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 14px;
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--text-secondary);
  transition: var(--transition);
  margin-bottom: 3px;
  border: 1px solid transparent;
}
.chapter-nav-item:hover {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
}
.chapter-nav-item.active {
  background: rgba(99, 102, 241, 0.12);
  border-color: var(--border-accent);
  color: #a5b4fc;
}
.nav-num {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px; height: 28px;
  border-radius: 50%;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  font-size: 0.72rem;
  font-weight: 600;
  flex-shrink: 0;
  font-family: var(--font-en);
}
.chapter-nav-item.active .nav-num {
  background: var(--accent-indigo);
  border-color: var(--accent-indigo);
  color: #fff;
}
.nav-title {
  font-size: 0.85rem;
  line-height: 1.4;
  font-weight: 500;
  overflow: hidden;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
}

.sidebar-footer {
  padding: 14px 16px;
  border-top: 1px solid var(--border);
}
.back-to-home {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-family: var(--font-fa);
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.9rem;
}
.back-to-home:hover {
  background: var(--bg-glass-hover);
  color: var(--text-primary);
  border-color: var(--border-accent);
}

/* ---------- Main Content Area ---------- */
.manual-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  height: 100vh;
  overflow: hidden;
}

/* Top Bar */
.topbar {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 0 20px;
  height: var(--topbar-h);
  background: rgba(10, 14, 26, 0.9);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(20px);
  flex-shrink: 0;
  z-index: 10;
}
.topbar-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 38px; height: 38px;
  background: var(--bg-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  cursor: pointer;
  font-size: 1.2rem;
  transition: var(--transition);
  flex-shrink: 0;
}
.topbar-btn:hover {
  background: var(--bg-glass-hover);
  border-color: var(--border-accent);
}
.topbar-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.hamburger {
  width: 18px; height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  margin: 2px 0;
  transition: var(--transition);
}

.topbar-title {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 10px;
  overflow: hidden;
}
.chapter-badge {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 28px; height: 28px;
  background: linear-gradient(135deg, var(--accent-indigo), #818cf8);
  border-radius: var(--radius-sm);
  font-size: 0.78rem;
  font-weight: 700;
  font-family: var(--font-en);
  flex-shrink: 0;
}
.topbar-chapter-title {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.topbar-actions { display: flex; gap: 8px; }

/* Progress Bar */
.progress-track {
  height: 3px;
  background: var(--border);
  flex-shrink: 0;
}
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-indigo), var(--accent-orange));
  transition: width 0.4s ease;
}

/* Chapter Content */
.chapter-content {
  flex: 1;
  overflow-y: auto;
  padding: 36px clamp(20px, 5vw, 72px) 120px;
  line-height: 1.9;
  font-size: 1rem;
}
.chapter-content::-webkit-scrollbar { width: 5px; }
.chapter-content::-webkit-scrollbar-track { background: transparent; }
.chapter-content::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

/* --- Content Typography --- */
.chapter-content h1 {
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  background: linear-gradient(135deg, #e2e8f0, #a5b4fc);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 6px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border);
}
.chapter-content .chapter-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  font-family: var(--font-en);
}
.chapter-content h2 {
  font-size: 1.25rem;
  font-weight: 700;
  color: #a5b4fc;
  margin: 32px 0 14px;
  display: flex;
  align-items: center;
  gap: 10px;
}
.chapter-content h2::before {
  content: '';
  display: block;
  width: 4px; height: 22px;
  background: linear-gradient(to bottom, var(--accent-indigo), var(--accent-orange));
  border-radius: 2px;
  flex-shrink: 0;
}
.chapter-content h3 {
  font-size: 1.05rem;
  font-weight: 600;
  color: #fb923c;
  margin: 22px 0 10px;
}
.chapter-content p {
  margin-bottom: 14px;
  color: #c5cedd;
}
.chapter-content strong {
  color: var(--text-primary);
  font-weight: 600;
}
.chapter-content em {
  color: var(--text-secondary);
  font-style: normal;
  background: rgba(99,102,241,0.1);
  border: 1px solid var(--border-accent);
  border-radius: 4px;
  padding: 0 6px;
  font-size: 0.9em;
}
.chapter-content ol, .chapter-content ul {
  padding-inline-start: 22px;
  margin-bottom: 16px;
}
.chapter-content li {
  margin-bottom: 8px;
  color: #c5cedd;
}
.chapter-content li::marker {
  color: var(--accent-indigo);
  font-weight: 700;
}
.chapter-content hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 28px 0;
}
.chapter-content blockquote {
  border-inline-start: 3px solid var(--accent-indigo);
  margin: 20px 0;
  padding: 12px 18px;
  background: rgba(99,102,241,0.06);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  color: var(--text-secondary);
  font-style: italic;
}
/* Info box for important notes */
.info-box {
  background: rgba(99,102,241,0.08);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  margin: 20px 0;
  color: #c7d2fe;
  font-size: 0.92rem;
}
.chapter-end-note {
  font-style: italic;
  color: var(--text-muted);
  font-size: 0.88rem;
  text-align: center;
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

/* --- Image placeholders --- */
.chapter-content img {
  max-width: 100%;
  border-radius: var(--radius-md);
  margin: 16px 0;
  border: 1px solid var(--border);
}

/* Bottom Nav */
.bottom-nav-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 20px;
  background: rgba(10, 14, 26, 0.95);
  border-top: 1px solid var(--border);
  flex-shrink: 0;
  backdrop-filter: blur(20px);
}
.bottom-nav-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border: 1px solid var(--border);
  border-radius: 30px;
  background: var(--bg-glass);
  color: var(--text-secondary);
  font-family: var(--font-fa);
  font-size: 0.9rem;
  cursor: pointer;
  transition: var(--transition);
  font-weight: 500;
}
.bottom-nav-btn:hover:not(:disabled) {
  border-color: var(--accent-indigo);
  color: var(--text-primary);
  background: var(--bg-glass-hover);
}
.bottom-nav-btn.primary {
  background: linear-gradient(135deg, var(--accent-indigo), #818cf8);
  border-color: transparent;
  color: #fff;
  font-weight: 600;
}
.bottom-nav-btn.primary:hover:not(:disabled) {
  opacity: 0.9;
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(99,102,241,0.4);
}
.bottom-nav-btn:disabled { opacity: 0.3; cursor: not-allowed; }
.page-indicator {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-family: var(--font-en);
  white-space: nowrap;
}

/* ============================================================
   TRANSITIONS & ANIMATIONS
   ============================================================ */
@keyframes fadeSlideIn {
  from { opacity: 0; transform: translateY(18px); }
  to { opacity: 1; transform: translateY(0); }
}
.chapter-content .animate-in {
  animation: fadeSlideIn 0.4s ease both;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    top: 0; bottom: 0;
    z-index: 110;
  }
  /* RTL: از راست باز می‌شود */
  [dir="rtl"] .sidebar {
    right: 0;
    transform: translateX(100%);
  }
  [dir="rtl"] .sidebar.open {
    transform: translateX(0);
  }
  /* LTR: از چپ باز می‌شود */
  [dir="ltr"] .sidebar {
    left: 0;
    transform: translateX(-100%);
  }
  [dir="ltr"] .sidebar.open {
    transform: translateX(0);
  }
  .sidebar-close { display: flex; }

  .lang-card { padding: 28px 24px; }

  :root { --sidebar-w: 280px; }
}

@media (min-width: 769px) {
  .menu-btn { display: none; }
  .sidebar-overlay { display: none !important; }
}

/* RTL direction switch */
[dir="ltr"] .chapter-content h2::before {
  background: linear-gradient(to bottom, var(--accent-indigo), var(--accent-orange));
}

/* For Russian/Tajik — LTR text in LTR mode */
[dir="ltr"] .chapter-content ol, [dir="ltr"] .chapter-content ul {
  padding-left: 22px;
  padding-right: 0;
}