/* ═══════════════════════════════════════════════════════════════
   IT BLOG — Components: Buttons, Cards, Nav, Forms, Badges, etc.
═══════════════════════════════════════════════════════════════ */

/* ─────────────────────────────────────────
   NAVIGATION
───────────────────────────────────────── */
.navbar {
  position: fixed !important;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-h);
  z-index: var(--z-nav);
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  transition: background var(--dur-base) var(--ease),
              border-color var(--dur-base) var(--ease),
              box-shadow var(--dur-base) var(--ease);
  display: flex !important;
  flex-direction: column !important;
  align-items: stretch !important;
  justify-content: flex-start !important;
  padding: 0 !important;
}

.navbar.scrolled {
  background: rgba(10,15,30,0.95);
  box-shadow: var(--shadow-md);
}

[data-theme="light"] .navbar.scrolled {
  background: rgba(255,255,255,0.95);
}

.navbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
  gap: 8px;
}

/* Secondary Navbar styling */
.navbar-secondary {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 36px;
  background: rgba(15, 23, 42, 0.4);
  border-top: 1px solid var(--border, rgba(99,109,143,0.15));
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  transition: all var(--dur-base) var(--ease);
}

[data-theme="light"] .navbar-secondary {
  background: rgba(241, 245, 249, 0.8);
}

.navbar-secondary-inner {
  display: flex;
  align-items: center;
  height: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-pad);
  overflow-x: auto;
  scrollbar-width: none; /* Hide scrollbar Firefox */
  justify-content: space-around !important;
}

.navbar-secondary-inner::-webkit-scrollbar {
  display: none; /* Hide scrollbar Chrome/Safari */
}

.secondary-links {
  display: flex;
  align-items: center;
  gap: var(--space-4, 16px);
  list-style: none;
  margin: 0;
  padding: 0;
  white-space: nowrap;
}

.secondary-links a {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text-secondary);
  font-size: 11px;
  font-weight: 600;
  text-decoration: none;
  transition: all var(--dur-fast) var(--ease);
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.secondary-links a:hover {
  color: var(--primary-light, #818cf8);
  background: rgba(79, 70, 229, 0.08);
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
}

.nav-logo-icon {
  width: 40px;
  height: 40px;
  background: var(--grad-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  box-shadow: var(--shadow-glow);
  flex-shrink: 0;
}

.nav-logo-text {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 800;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2px;
  list-style: none;
  margin: 0;
  padding: 0;
  flex: 1;
  overflow: visible;
  white-space: nowrap;
}

.nav-links a {
  display: flex;
  align-items: center;
  gap: 5px;
  padding: 6px 10px;
  border-radius: var(--radius-md);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  text-decoration: none;
  transition: all var(--dur-fast) var(--ease);
  position: relative;
  white-space: nowrap;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--text-primary);
  background: rgba(79,70,229,0.1);
}

.nav-links a.active::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 50%;
  transform: translateX(-50%);
  width: 16px;
  height: 2px;
  background: var(--grad-primary);
  border-radius: var(--radius-full);
}

/* Dropdown */
.nav-dropdown {
  position: relative;
}

.nav-dropdown-menu {
  position: absolute;
  top: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  min-width: 220px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  padding: var(--space-2);
  opacity: 0;
  visibility: hidden;
  transition: all var(--dur-base) var(--ease);
  z-index: var(--z-popup);
}

.nav-dropdown:hover .nav-dropdown-menu {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

.nav-dropdown-menu a {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  transition: all var(--dur-fast) var(--ease);
  width: 100%;
}

.nav-dropdown-menu a:hover {
  background: rgba(79,70,229,0.1);
  color: var(--text-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.nav-auth-btn {
  border-radius: var(--radius-md);
  padding: 6px 14px;
  font-size: var(--text-sm);
  font-weight: 600;
  white-space: nowrap;
  transition: all var(--dur-fast) var(--ease);
}

/* Theme Toggle */
.theme-toggle {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  transition: all var(--dur-fast) var(--ease);
}

.theme-toggle:hover {
  border-color: var(--border-hover);
  color: var(--text-primary);
  background: var(--bg-card-hover);
}

/* Mobile Nav Toggle */
.nav-hamburger {
  display: none;
  width: 40px;
  height: 40px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  cursor: pointer;
  border: 1px solid var(--border);
  background: var(--bg-card);
  border-radius: var(--radius-md);
}

.nav-hamburger span {
  display: block;
  width: 20px;
  height: 2px;
  background: var(--text-secondary);
  border-radius: 2px;
  transition: all var(--dur-base) var(--ease);
}

.nav-hamburger.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-hamburger.active span:nth-child(2) { opacity: 0; }
.nav-hamburger.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Mobile Nav Drawer */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--header-h);
  left: 0;
  right: 0;
  max-height: calc(100vh - var(--header-h));
  overflow-y: auto;
  -webkit-overflow-scrolling: touch;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  padding: var(--space-4) var(--space-5) var(--space-6);
  z-index: 1050;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
  transform: translateY(-100%);
  opacity: 0;
  pointer-events: none;
  transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.25s ease;
}

.nav-mobile.open {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.nav-mobile-auth-wrapper {
  padding-bottom: 14px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.nav-mobile-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.nav-mobile-links a {
  display: block;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: all var(--dur-fast) var(--ease);
}

.nav-mobile-links a:hover { background: rgba(79,70,229,0.1); color: var(--text-primary); }

@media (max-width: 1024px) {
  .nav-links { display: none; }
  .nav-hamburger { display: flex; }
  .nav-mobile { display: block; }
}

@media (max-width: 576px) {
  .nav-actions .nav-auth-btn { display: none !important; }
}

/* ─────────────────────────────────────────
   BUTTONS
───────────────────────────────────────── */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--dur-base) var(--ease-spring);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn::after {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255,255,255,0);
  transition: background var(--dur-fast) var(--ease);
}

.btn:hover::after { background: rgba(255,255,255,0.06); }
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: var(--grad-primary);
  color: #fff;
  box-shadow: var(--shadow-glow);
}
.btn-primary:hover { box-shadow: 0 0 40px rgba(79,70,229,0.5); color: #fff; transform: translateY(-1px); }

.btn-secondary {
  background: transparent;
  border-color: var(--border);
  color: var(--text-primary);
  background: var(--bg-card);
}
.btn-secondary:hover { border-color: var(--border-hover); background: var(--bg-card-hover); color: var(--text-primary); }

.btn-outline {
  background: transparent;
  border-color: var(--primary);
  color: var(--primary-light);
}
.btn-outline:hover { background: rgba(79,70,229,0.1); color: var(--text-primary); }

.btn-ghost {
  background: transparent;
  border-color: transparent;
  color: var(--text-secondary);
}
.btn-ghost:hover { background: var(--bg-card); color: var(--text-primary); }

.btn-accent {
  background: var(--grad-gold);
  color: #0F172A;
  font-weight: 700;
}
.btn-accent:hover { box-shadow: 0 0 30px rgba(245,158,11,0.4); transform: translateY(-1px); color: #0F172A; }

.btn-success {
  background: var(--grad-success);
  color: #fff;
}

.btn-danger {
  background: var(--error);
  color: #fff;
}
.btn-danger:hover { background: #dc2626; }

/* Sizes */
.btn-sm { padding: var(--space-2) var(--space-4); font-size: var(--text-xs); border-radius: var(--radius-sm); }
.btn-lg { padding: var(--space-4) var(--space-8); font-size: var(--text-base); border-radius: var(--radius-lg); }
.btn-xl { padding: var(--space-5) var(--space-10); font-size: var(--text-lg); border-radius: var(--radius-lg); }
.btn-block { width: 100%; }
.btn-icon { padding: var(--space-3); width: 42px; height: 42px; }

/* Loading state */
.btn.loading { pointer-events: none; opacity: 0.7; }
.btn.loading::before {
  content: '';
  width: 16px;
  height: 16px;
  border: 2px solid rgba(255,255,255,0.3);
  border-top-color: #fff;
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
  margin-right: var(--space-2);
}

/* ─────────────────────────────────────────
   CARDS
───────────────────────────────────────── */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--dur-base) var(--ease);
  box-shadow: var(--shadow-card);
}

.card:hover {
  border-color: var(--border-hover);
  background: var(--bg-card-hover);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(-4px);
}

.card-glass {
  background: var(--glass-bg);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
}

.card-gradient {
  background: var(--grad-card);
  border: 1px solid var(--border);
}

/* Post Card */
.post-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--dur-base) var(--ease);
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.post-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(-6px);
}

.post-card-thumb {
  position: relative;
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-elevated);
}

.post-card-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--dur-slow) var(--ease);
}

.post-card:hover .post-card-thumb img { transform: scale(1.06); }

.post-card-thumb-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, transparent 50%, rgba(10,15,30,0.7));
}

.post-card-category-badge {
  position: absolute;
  top: var(--space-3);
  left: var(--space-3);
  z-index: 1;
}

.post-card-body {
  padding: var(--space-5);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.post-card-meta {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
  flex-wrap: wrap;
}

.post-card-date {
  font-size: var(--text-xs);
  color: var(--text-muted);
  font-family: var(--font-mono);
}

.post-card-read-time {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

.post-card-title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-3);
  line-height: 1.35;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  transition: color var(--dur-fast) var(--ease);
}

.post-card:hover .post-card-title { color: var(--primary-light); }

.post-card-excerpt {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.7;
  display: -webkit-box;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  overflow: hidden;
  flex: 1;
  margin-bottom: var(--space-4);
}

.post-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: var(--space-4);
  border-top: 1px solid var(--border);
}

.post-author {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.post-author-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: var(--grad-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 700;
  color: #fff;
  flex-shrink: 0;
  overflow: hidden;
}

.post-author-avatar img { width: 100%; height: 100%; object-fit: cover; }

.post-author-name {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-secondary);
}

.post-card-stats {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.post-stat {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* ─────────────────────────────────────────
   BADGES & TAGS
───────────────────────────────────────── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 4px 12px;
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  white-space: nowrap;
}

.badge-primary  { background: rgba(79,70,229,0.15); color: var(--primary-light); border: 1px solid rgba(79,70,229,0.3); }
.badge-cyan     { background: rgba(6,182,212,0.15); color: var(--secondary-light); border: 1px solid rgba(6,182,212,0.3); }
.badge-gold     { background: rgba(245,158,11,0.15); color: var(--accent-light); border: 1px solid rgba(245,158,11,0.3); }
.badge-success  { background: var(--success-bg); color: var(--success); border: 1px solid rgba(16,185,129,0.3); }
.badge-error    { background: var(--error-bg); color: var(--error); border: 1px solid rgba(239,68,68,0.3); }
.badge-warning  { background: var(--warning-bg); color: var(--warning); border: 1px solid rgba(245,158,11,0.3); }
.badge-info     { background: var(--info-bg); color: var(--info); border: 1px solid rgba(59,130,246,0.3); }
.badge-muted    { background: var(--bg-elevated); color: var(--text-muted); border: 1px solid var(--border); }

/* Category Colors */
.badge-ai       { background: rgba(139,92,246,0.15); color: #8258ff; border: 1px solid rgba(139,92,246,0.3); justify-content: center;}
.badge-ml       { background: rgba(6,182,212,0.15); color: #1de2fc; border: 1px solid rgba(6,182,212,0.3); justify-content: center;}
.badge-dl       { background: rgba(99,102,241,0.15); color: #3e51ff; border: 1px solid rgba(99,102,241,0.3); justify-content: center;}
.badge-ds       { background: rgba(16,185,129,0.15); color: #10ee95; border: 1px solid rgba(16,185,129,0.3); justify-content: center;}
.badge-excel    { background: rgba(16,185,129,0.15); color: #09ad71; border: 1px solid rgba(16,185,129,0.3); justify-content: center;}
.badge-tutorial { background: rgba(245,158,11,0.15); color: #a37d00; border: 1px solid rgba(245,158,11,0.3); justify-content: center;}

.tag {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  color: var(--text-muted);
  transition: all var(--dur-fast) var(--ease);
  cursor: pointer;
  text-decoration: none;
}

.tag:hover { border-color: var(--border-hover); color: var(--primary-light); background: rgba(79,70,229,0.08); }

/* ─────────────────────────────────────────
   FORMS
───────────────────────────────────────── */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-5);
}

.form-label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.form-label span { color: var(--error); margin-left: 2px; }

.form-control {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--text-primary);
  transition: all var(--dur-fast) var(--ease);
  outline: none;
}

.form-control::placeholder { color: var(--text-muted); }

.form-control:hover { border-color: var(--border-hover); }

.form-control:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.form-control.error { border-color: var(--error); box-shadow: 0 0 0 3px var(--error-bg); }
.form-control.success { border-color: var(--success); box-shadow: 0 0 0 3px var(--success-bg); }

textarea.form-control { resize: vertical; min-height: 120px; }

select.form-control {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2364748B' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 40px;
}

.form-hint { font-size: var(--text-xs); color: var(--text-muted); }
.form-error { font-size: var(--text-xs); color: var(--error); }

/* Input with icon */
.input-wrapper { position: relative; }
.input-icon-left  { position: absolute; left: 14px; top: 50%; transform: translateY(-50%); color: var(--text-muted); pointer-events: none; }
.input-icon-right { position: absolute; right: 14px; top: 50%; transform: translateY(-50%); color: var(--text-muted); cursor: pointer; }
.input-wrapper .form-control.has-icon-left  { padding-left: 40px; }
.input-wrapper .form-control.has-icon-right { padding-right: 40px; }

/* Checkbox & Radio */
.form-check {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  cursor: pointer;
}

.form-check input[type="checkbox"],
.form-check input[type="radio"] {
  width: 18px;
  height: 18px;
  accent-color: var(--primary);
  cursor: pointer;
}

/* Search Box */
.search-box {
  position: relative;
  max-width: 480px;
}

.search-box input {
  width: 100%;
  padding: var(--space-3) var(--space-5) var(--space-3) 44px;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  color: var(--text-primary);
  transition: all var(--dur-fast) var(--ease);
  outline: none;
}

.search-box input:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--primary-glow);
}

.search-box-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

/* ─────────────────────────────────────────
   ALERTS & TOASTS
───────────────────────────────────────── */
.alert {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  font-size: var(--text-sm);
}

.alert-success { background: var(--success-bg); border-color: rgba(16,185,129,0.3); color: var(--success); }
.alert-error   { background: var(--error-bg);   border-color: rgba(239,68,68,0.3);   color: var(--error); }
.alert-warning { background: var(--warning-bg); border-color: rgba(245,158,11,0.3); color: var(--warning); }
.alert-info    { background: var(--info-bg);    border-color: rgba(59,130,246,0.3);  color: var(--info); }

/* Toast Container */
.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  pointer-events: none;
}

.toast {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
  font-size: var(--text-sm);
  color: var(--text-primary);
  pointer-events: all;
  min-width: 280px;
  max-width: 400px;
  animation: slideInRight var(--dur-base) var(--ease-out) forwards;
}

.toast.removing { animation: slideOutRight var(--dur-base) var(--ease-in) forwards; }

/* ─────────────────────────────────────────
   HERO SECTION
───────────────────────────────────────── */
.hero {
  min-height: 100vh;
  background: var(--grad-hero);
  display: flex;
  align-items: center;
  padding-top: var(--header-h);
  position: relative;
  overflow: hidden;
}

.hero-particles {
  position: absolute;
  inset: 0;
  pointer-events: none;
  overflow: hidden;
}

.hero-particle {
  position: absolute;
  border-radius: 50%;
  animation: float linear infinite;
  opacity: 0.4;
}

.hero-blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
}

.hero-blob-1 {
  width: 500px;
  height: 500px;
  background: rgba(79,70,229,0.2);
  top: -100px;
  right: -100px;
  animation: pulse 8s ease-in-out infinite;
}

.hero-blob-2 {
  width: 400px;
  height: 400px;
  background: rgba(6,182,212,0.15);
  bottom: -100px;
  left: -100px;
  animation: pulse 10s ease-in-out infinite reverse;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
  margin: 0 auto;
  padding: var(--space-20) 0;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: rgba(79,70,229,0.1);
  border: 1px solid rgba(79,70,229,0.3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--primary-light);
  margin-bottom: var(--space-6);
  font-family: var(--font-mono);
  animation: fadeInDown var(--dur-slow) var(--ease-out) both;
}

.hero-title {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1.1;
  color: var(--text-primary);
  margin-bottom: var(--space-6);
  animation: fadeInUp var(--dur-slow) var(--ease-out) 0.1s both;
  letter-spacing: -0.03em;
}

.hero-desc {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: var(--space-8);
  max-width: 650px;
  margin-left: auto;
  margin-right: auto;
  animation: fadeInUp var(--dur-slow) var(--ease-out) 0.2s both;
}

.hero-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  flex-wrap: wrap;
  animation: fadeInUp var(--dur-slow) var(--ease-out) 0.3s both;
}

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-8);
  margin-top: var(--space-12);
  flex-wrap: wrap;
  animation: fadeInUp var(--dur-slow) var(--ease-out) 0.4s both;
}

.hero-stat {
  text-align: center;
}

.hero-stat-num {
  font-family: var(--font-heading);
  font-size: var(--text-3xl);
  font-weight: 800;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: block;
}

.hero-stat-label {
  font-size: var(--text-sm);
  color: var(--text-muted);
}

/* ─────────────────────────────────────────
   AD ZONES
───────────────────────────────────────── */
.ad-zone {
  background: var(--bg-card);
  border: 1px dashed var(--border);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: var(--text-muted);
  font-size: var(--text-xs);
  font-family: var(--font-mono);
  overflow: hidden;
  position: relative;
}

.ad-zone-leaderboard { width: 100%; height: 90px; max-width: 728px; margin: 0 auto; }
.ad-zone-rectangle { width: 300px; height: 250px; }
.ad-zone-responsive { width: 100%; min-height: 90px; }
.ad-zone-in-article { width: 100%; height: 250px; margin: var(--space-8) 0; }

.ad-zone-label {
  position: absolute;
  top: 4px;
  right: 6px;
  font-size: 9px;
  color: var(--text-muted);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  opacity: 0.5;
}

/* ─────────────────────────────────────────
   STAR RATING
───────────────────────────────────────── */
.star-rating {
  display: flex;
  align-items: center;
  gap: 2px;
}

.star {
  font-size: 1.1rem;
  color: var(--text-muted);
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease), transform var(--dur-fast) var(--ease-spring);
}

.star.filled,
.star.hovered { color: var(--accent); transform: scale(1.1); }

.star-rating-input .star:hover ~ .star { color: var(--text-muted) !important; }

/* ─────────────────────────────────────────
   FOOTER
───────────────────────────────────────── */
.footer {
  background: var(--bg-surface);
  border-top: 1px solid var(--border);
  padding: var(--space-20) 0 var(--space-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

.footer-brand p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.75;
  margin: var(--space-4) 0 var(--space-5);
  max-width: 300px;
}

.footer-socials {
  display: flex;
  gap: var(--space-3);
}

.social-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: var(--bg-card);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 1rem;
  transition: all var(--dur-fast) var(--ease);
  text-decoration: none;
}

.social-btn:hover {
  background: rgba(79,70,229,0.1);
  border-color: var(--border-hover);
  color: var(--primary-light);
  transform: translateY(-2px);
}

.footer-col h4 {
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-5);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-links a {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.footer-links a:hover { color: var(--primary-light); }

.footer-bottom {
  padding-top: var(--space-8);
  border-top: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-bottom p { font-size: var(--text-sm); color: var(--text-muted); margin: 0; }

/* ─────────────────────────────────────────
   PAGINATION
───────────────────────────────────────── */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  margin-top: var(--space-12);
}

.page-btn {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-sm);
  font-weight: 500;
  cursor: pointer;
  transition: all var(--dur-fast) var(--ease);
  text-decoration: none;
}

.page-btn:hover { border-color: var(--border-hover); color: var(--text-primary); background: var(--bg-card-hover); }
.page-btn.active { background: var(--grad-primary); border-color: transparent; color: #fff; box-shadow: var(--shadow-glow); }

/* ─────────────────────────────────────────
   TABLE OF CONTENTS
───────────────────────────────────────── */
.toc {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  position: sticky;
  top: calc(var(--header-h) + var(--space-6));
}

.toc-title {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
  margin-bottom: var(--space-4);
}

.toc-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.toc-item a {
  display: block;
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  color: var(--text-secondary);
  border-radius: var(--radius-sm);
  border-left: 2px solid transparent;
  transition: all var(--dur-fast) var(--ease);
}

.toc-item a:hover,
.toc-item.active a {
  color: var(--primary-light);
  border-left-color: var(--primary);
  background: rgba(79,70,229,0.06);
  padding-left: var(--space-4);
}

.toc-item.h3 a { padding-left: var(--space-6); font-size: var(--text-xs); }

/* ─────────────────────────────────────────
   MODAL
───────────────────────────────────────── */
.custom-modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,0.7);
  backdrop-filter: blur(4px);
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  opacity: 0;
  visibility: hidden;
  transition: all var(--dur-base) var(--ease);
}

.custom-modal-overlay.open {
  opacity: 1;
  visibility: visible;
}

.custom-modal {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  width: 100%;
  max-width: 560px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  transform: scale(0.9) translateY(20px);
  transition: transform var(--dur-base) var(--ease-spring);
}

.custom-modal-overlay.open .custom-modal {
  transform: scale(1) translateY(0);
}

.custom-modal-header {
  padding: var(--space-6);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.custom-modal-body { padding: var(--space-6); }
.custom-modal-footer { padding: var(--space-5) var(--space-6); border-top: 1px solid var(--border); display: flex; gap: var(--space-3); justify-content: flex-end; }

/* ─────────────────────────────────────────
   BREADCRUMB
───────────────────────────────────────── */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
  list-style: none;
  padding: 0;
  margin: 0;
}

.breadcrumb li {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--text-muted);
  margin: 0;
}

.breadcrumb li a {
  color: var(--text-muted);
  transition: color var(--dur-fast) var(--ease);
}

.breadcrumb li a:hover { color: var(--primary-light); }
.breadcrumb li:last-child { color: var(--text-secondary); }

/* ─────────────────────────────────────────
   AFFILIATE / COURSE CARD
───────────────────────────────────────── */
.course-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--dur-base) var(--ease);
  box-shadow: var(--shadow-card);
}

.course-card:hover {
  border-color: var(--border-hover);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  transform: translateY(-4px);
}

.course-card-thumb {
  aspect-ratio: 16/9;
  overflow: hidden;
  background: var(--bg-elevated);
  position: relative;
}

.course-card-thumb img { width: 100%; height: 100%; object-fit: cover; transition: transform var(--dur-slow) var(--ease); }
.course-card:hover .course-card-thumb img { transform: scale(1.05); }

.course-card-thumb .course-provider-badge {
  position: absolute;
  bottom: var(--space-3);
  left: var(--space-3);
  background: rgba(10,15,30,0.85);
  color: #fff;
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  font-size: var(--text-xs);
  font-weight: 700;
  backdrop-filter: blur(8px);
}

.course-provider-badge {
  display: inline-block;
  background: rgba(99, 102, 241, 0.15);
  color: var(--primary-light);
  border: 1px solid rgba(99, 102, 241, 0.3);
  border-radius: 100px;
  padding: 2px 8px;
  font-size: 9px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.course-card-body { padding: var(--space-5); }

.course-card-title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.course-rating {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.course-rating-num { font-size: var(--text-sm); font-weight: 700; color: var(--accent); }
.course-rating-count { font-size: var(--text-xs); color: var(--text-muted); }

.course-price-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--border);
}

.course-price { font-family: var(--font-heading); font-size: var(--text-2xl); font-weight: 800; color: var(--text-primary); }
.course-price-original { font-size: var(--text-sm); color: var(--text-muted); text-decoration: line-through; margin-left: var(--space-2); }

/* ─────────────────────────────────────────
   NEWSLETTER
───────────────────────────────────────── */
.newsletter-box {
  background: var(--grad-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--space-12);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.newsletter-form {
  display: flex;
  gap: var(--space-3);
  max-width: 500px;
  margin: var(--space-6) auto 0;
}

.newsletter-form input {
  flex: 1;
  padding: var(--space-3) var(--space-5);
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  color: var(--text-primary);
  outline: none;
  transition: border-color var(--dur-fast) var(--ease);
}

.newsletter-form input:focus { border-color: var(--border-focus); }

@media (max-width: 1024px) {
  .footer-grid { grid-template-columns: 2fr 1fr 1fr; gap: var(--space-8); }
}

@media (max-width: 768px) {
  .footer-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-8); }
}

@media (max-width: 576px) {
  .newsletter-form { flex-direction: column; }
  .footer { padding: var(--space-12) 0 var(--space-6); }
  .footer-grid { grid-template-columns: 1fr; gap: var(--space-6); }
  .footer-bottom { flex-direction: column; gap: var(--space-3); text-align: center; }
}

/* ─────────────────────────────────────────
   PAGE HEADERS (PUBLIC)
   Used across Blog, Courses, About, Contact, Post pages.
───────────────────────────────────────── */
.page-header, .about-hero, .contact-hero, .post-hero {
  position: relative;
  padding-top: calc(var(--header-h) + 30px);
  padding-bottom: 80px;
  background: var(--grad-hero);
  border-bottom: 1px solid var(--border);
  overflow: hidden;
  display: flex;
  align-items: center;
}

.page-header::before, .about-hero::before, .contact-hero::before, .post-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 15% 15%, rgba(79, 70, 229, 0.12) 0%, transparent 60%),
              radial-gradient(circle at 85% 85%, rgba(6, 182, 212, 0.08) 0%, transparent 50%);
  pointer-events: none;
}

/* Floating abstract shapes for high-end look */
.page-header::after, .about-hero::after, .contact-hero::after, .post-hero::after {
  content: '';
  position: absolute;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(79,70,229,0.15) 0%, transparent 70%);
  filter: blur(40px);
  top: -50px;
  right: 10%;
  pointer-events: none;
  animation: float-slow-header 12s ease-in-out infinite alternate;
}

@keyframes float-slow-header {
  0% { transform: translateY(0) scale(1); }
  100% { transform: translateY(20px) scale(1.05); }
}

/* Specific typography enhancements */
.page-title, .about-hero h1, .contact-hero h1, .post-title {
  font-family: var(--font-heading) !important;
  font-size: clamp(2rem, 5vw, 3.5rem) !important;
  font-weight: 800 !important;
  letter-spacing: -0.02em !important;
  line-height: 1.2 !important;
  margin-bottom: var(--space-4) !important;
  background: linear-gradient(135deg, var(--text-primary) 30%, var(--primary-light) 100%) !important;
  -webkit-background-clip: text !important;
  -webkit-text-fill-color: transparent !important;
  background-clip: text !important;
}

.page-subtitle, .about-hero .lead, .contact-hero p {
  font-size: clamp(0.95rem, 1.5vw, 1.15rem) !important;
  color: var(--text-secondary) !important;
  line-height: 1.7 !important;
  max-width: 700px !important;
}

/* Align text properties */
.page-header, .contact-hero {
  text-align: center;
}

.page-header .container, .contact-hero .container {
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

/* Post Hero specific design */
.post-hero {
  padding: 80px 0 60px;
}
.post-hero-bg {
  position: absolute;
  inset: 0;
  background-size: cover;
  background-position: center;
  opacity: 0.12;
  filter: blur(30px);
  z-index: -1;
  transform: scale(1.15);
  transition: background-image var(--dur-slow) var(--ease);
}

/* ─── Navbar Search ─── */
.nav-search {
  position: relative;
  display: flex;
  align-items: center;
  flex-shrink: 1;
}

.nav-search-form {
  position: relative;
  display: flex;
  align-items: center;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  padding: 2px 6px 2px 14px;
  transition: all var(--dur-base) var(--ease);
  width: 160px;
}

.nav-search-form:focus-within {
  width: 220px;
  border-color: var(--primary-light);
  box-shadow: 0 0 10px rgba(79, 70, 229, 0.25);
}

.nav-search-input {
  border: none;
  background: transparent;
  color: var(--text-primary);
  font-size: var(--text-xs);
  outline: none;
  width: 100%;
}

.nav-search-input::placeholder {
  color: var(--text-muted);
}

.nav-search-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 6px;
  font-size: 0.9rem;
  transition: color var(--dur-fast) var(--ease);
  display: flex;
  align-items: center;
  justify-content: center;
}

.nav-search-btn:hover {
  color: var(--primary-light);
}

.nav-mobile-search {
  padding: 0 var(--space-4) var(--space-4);
  margin-bottom: var(--space-4);
  border-bottom: 1px solid var(--border);
}

.mobile-search-form {
  display: flex;
  background: var(--bg-input);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 8px 14px;
  align-items: center;
}

.mobile-search-input {
  border: none;
  background: transparent;
  color: var(--text-primary);
  outline: none;
  width: 100%;
  font-size: var(--text-sm);
}

.mobile-search-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 2px;
}

@media (max-width: 1200px) {
  /* Hide lower-priority nav links at mid widths */
  #nav-about, #nav-contact { display: none; }
}

@media (max-width: 1100px) {
  /* Shrink search at tighter widths */
  .nav-search-form { width: 120px; }
  .nav-search-form:focus-within { width: 160px; }
}

@media (max-width: 991px) {
  .nav-search {
    display: none;
  }
}

/* ─── Recommended Card & Popular Search Tags ─── */
.card-recommended {
  flex-direction: row;
}

@media (max-width: 991px) {
  .card-recommended {
    flex-direction: column !important;
  }
  .card-recommended img {
    position: static !important;
    aspect-ratio: 16/9;
  }
}

.btn-search-tag {
  transition: all var(--dur-fast) var(--ease) !important;
}

.btn-search-tag:hover {
  background: rgba(79, 70, 229, 0.2) !important;
  border-color: var(--primary-light) !important;
  transform: translateY(-1px);
}

/* Responsive overrides for topbar actions: collapse on mobile screens (<576px) */
@media (max-width: 576px) {
  .navbar-inner .nav-actions #btn-login,
  .navbar-inner .nav-actions #btn-register {
    display: none !important;
  }
}

/* ─────────────────────────────────────────
   INTERACTIVE WIDGETS
───────────────────────────────────────── */
.diagram {
  background: var(--bg-surface, #fff);
  border: 1px solid var(--border, #E2E5EA);
  border-radius: var(--radius-xl, 14px);
  padding: 14px;
  margin: 18px 0 22px;
  max-width: 820px;
}
.diagram svg { width: 100%; height: auto; display: block; }

/* Notebook Cells */
.cell {
  display: flex;
  align-items: stretch;
  background: var(--bg-surface, #fff);
  border: 1px solid var(--border, #E2E5EA);
  border-radius: var(--radius-xl, 14px);
  overflow: hidden;
  margin-bottom: 10px;
  box-shadow: var(--shadow-sm);
}
.cell-gutter {
  flex-shrink: 0;
  width: 78px;
  padding: 16px 10px 16px 16px;
  font-family: var(--font-mono, monospace);
  font-size: 12px;
  color: var(--text-muted);
  background: var(--bg-elevated);
  border-right: 1px solid var(--border);
}
.out-gutter { color: #10b981; }
.cell-body { flex: 1; padding: 14px 18px; display: flex; align-items: center; gap: 14px; flex-wrap: wrap; }
.cell-code { font-family: var(--font-mono, monospace); font-size: 15px; color: var(--text-primary); }
.inline-input {
  font-family: var(--font-mono, monospace);
  font-size: 15px;
  color: #9333a8;
  border: 1px solid #9333a8;
  background: rgba(147, 51, 168, 0.08);
  border-radius: 6px;
  padding: 3px 8px;
  width: 260px;
  max-width: 60vw;
}
.run-btn {
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 13px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  padding: 9px 16px;
  cursor: pointer;
  transition: all 0.15s;
}
.run-btn:hover { opacity: 0.9; }
.run-btn:active { transform: scale(0.97); }
.output-cell .cell-body { font-family: var(--font-mono, monospace); font-size: 15px; color: #10b981; }

/* Interactive Quizzes */
.quiz {
  background: var(--bg-surface, #fff);
  border: 1px solid var(--border, #E2E5EA);
  border-radius: var(--radius-xl, 14px);
  padding: 18px 20px;
  /* max-width: 680px; */
  margin: 18px 0;
}
.quiz-q { font-family: var(--font-heading); font-weight: 600; font-size: 15px; margin-bottom: 12px; color: var(--text-primary); }
.quiz-q code { background: rgba(79, 70, 229, 0.08); color: var(--primary-light); padding: 2px 6px; border-radius: 5px; }
.quiz-options { 
  display: flex; 
  flex-direction: row;
  justify-content: space-evenly;
  gap: 8px; 
}

.quiz-opt {
  font-family: var(--font-mono, monospace);
  font-size: 14px;
  text-align: left;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 40px;
  cursor: pointer;
  color: var(--text-secondary);
  transition: all 0.15s;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--primary); color: var(--text-primary); }
.quiz-opt.correct { border-color: #10b981; background: rgba(16, 185, 129, 0.08); color: #10b981; }
.quiz-opt.incorrect { border-color: #ef4444; background: rgba(239, 68, 68, 0.08); color: #ef4444; }
.quiz-opt:disabled { cursor: default; }
.quiz-feedback {
  margin-top: 12px;
  font-size: 14.5px;
  padding: 10px 14px;
  border-radius: 8px;
}
.quiz-feedback.feedback-correct { background: rgba(16, 185, 129, 0.08); color: #10b981; }
.quiz-feedback.feedback-incorrect { background: rgba(245, 158, 11, 0.08); color: #f59e0b; }

/* Interactive Cast Playground */
.playground {
  background: var(--bg-surface, #fff);
  border: 1px solid var(--border, #E2E5EA);
  border-radius: var(--radius-xl, 14px);
  padding: 22px 24px;
  margin: 20px 0 26px;
  /* max-width: 720px; */
}
.playground-head { font-family: var(--font-heading); font-weight: 700; font-size: 15px; color: var(--text-primary); margin-bottom: 16px; }
.playground-row { margin-bottom: 14px; gap: 5px; }
.playground-row label { font-family: var(--font-heading); font-size: 13px; font-weight: 600; display: block; margin-bottom: 6px; color: var(--text-secondary); }
.playground-row .hint { font-weight: 400; color: var(--text-muted); font-size: 12px; }
.text-input {
  font-family: var(--font-mono, monospace);
  font-size: 15px;
  padding: 9px 12px;
  border: 1px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-primary);
  border-radius: 8px;
  width: 100%;
  max-width: 320px;
}
.text-input:focus { border-color: var(--primary); outline: none; }
.type-picker { display: flex; gap: 8px; flex-wrap: wrap; }
.type-btn {
  font-family: var(--font-mono, monospace);
  font-size: 14px;
  font-weight: 600;
  padding: 8px 16px;
  border-radius: 8px;
  border: 1.5px solid var(--border);
  background: var(--bg-elevated);
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s;
}
.type-btn:hover { border-color: var(--primary); color: var(--text-secondary); }
.type-btn.active[data-type="int"] { background: rgba(79, 70, 229, 0.08); border-color: var(--primary); color: var(--primary-light); }
.type-btn.active[data-type="float"] { background: rgba(16, 185, 129, 0.08); border-color: #10b981; color: #10b981; }
.type-btn.active[data-type="str"] { background: rgba(147, 51, 168, 0.08); border-color: #a21caf; color: #a21caf; }
.type-btn.active[data-type="bool"] { background: rgba(239, 68, 68, 0.08); border-color: #ef4444; color: #ef4444; }
.playground-cell { margin-top: 16px; }
#cast-result { font-family: var(--font-mono, monospace); font-size: 16px; font-weight: 600; }
#cast-result.is-error { color: #ef4444; }
#cast-result.is-ok { color: #10b981; }
.playground-note { font-size: 13.5px; color: var(--text-muted); margin-top: 6px; /*max-width: 560px;*/ }

/* Callouts & Key Takeaways */
.callout {
  border-left: 3px solid #f59e0b;
  background: rgba(245, 158, 11, 0.08);
  padding: 12px 16px;
  border-radius: 0 10px 10px 0;
  /* max-width: 660px; */
  font-size: 15px;
  color: #f59e0b;
  margin: 16px 0;
}
.takeaways {
  background: rgba(79, 70, 229, 0.08);
  border-radius: var(--radius-xl, 14px);
  padding: 22px 26px;
  /* max-width: 680px; */
  margin: 30px 0;
}
.takeaways h4 { margin: 0 0 10px; font-size: 15px; color: var(--primary-light); }
.takeaways ul { margin: 0; padding-left: 20px; font-size: 15px; color: var(--text-secondary); }
.takeaways li { margin-bottom: 6px; }

/* Exercises Checklist */
.exercises { 
  /* max-width: 680px;  */
  margin: 26px 0; 
}

.exercises h4 { font-size: 15px; margin-bottom: 12px; color: var(--text-primary); }
.ex-item {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: 15px;
  padding: 9px 4px;
  border-bottom: 1px solid var(--border);
  cursor: pointer;
  color: var(--text-secondary);
}
.ex-item input { margin-top: 4px; flex-shrink: 0; width: 16px; height: 16px; accent-color: #10b981; }
.ex-item.done span { color: var(--text-muted); text-decoration: line-through; }

/* ─────────────────────────────────────────
   PREMIUM LOADER & DYNAMIC OVERLAY
───────────────────────────────────────── */
.premium-loader-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: radial-gradient(circle at center, rgba(15, 23, 42, 0.95) 0%, var(--bg-base) 100%);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 99999;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: opacity 0.4s ease, visibility 0.4s ease;
}

.premium-loader {
  position: relative;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.premium-loader-ring {
  position: absolute;
  border-radius: 50%;
  box-sizing: border-box;
}

.premium-loader-ring.outer {
  width: 80px;
  height: 80px;
  border: 3px solid transparent;
  border-top: 3px solid var(--primary-light);
  border-right: 3px solid var(--secondary);
  border-bottom: 3px solid transparent;
  animation: spin 1.5s cubic-bezier(0.53, 0.21, 0.29, 0.67) infinite;
  filter: drop-shadow(0 0 12px var(--primary-glow));
}

.premium-loader-ring.inner {
  width: 60px;
  height: 60px;
  border: 2px dashed transparent;
  border-top: 2px dashed var(--secondary-light);
  border-left: 2px dashed var(--primary);
  border-bottom: 2px dashed transparent;
  animation: spin 1s linear infinite reverse;
  filter: drop-shadow(0 0 8px rgba(6, 182, 212, 0.2));
}

.premium-loader-center {
  position: absolute;
  width: 40px;
  height: 40px;
  background: linear-gradient(135deg, rgba(30, 41, 59, 0.9) 0%, rgba(15, 23, 42, 0.9) 100%);
  border: 1px solid var(--border);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 15px rgba(0,0,0,0.5), inset 0 1px 0 rgba(255,255,255,0.05);
}

.premium-loader-icon {
  font-size: 1.25rem;
  color: var(--accent-light);
  text-shadow: 0 0 10px var(--accent);
  animation: pulse 1.5s ease-in-out infinite alternate;
}

.premium-loader-text {
  margin-top: 24px;
  font-family: var(--font-heading);
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  color: var(--text-primary);
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--text-primary) 30%, var(--primary-light) 70%, var(--secondary-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: pulse 2s ease-in-out infinite;
}

/* Drop-in upgraded class spinner (seamlessly updates existing spinners) */
.spinner {
  position: relative;
  display: inline-block;
  box-sizing: border-box;
}

.spinner::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  border: 3px solid transparent;
  border-top-color: var(--primary-light);
  border-right-color: var(--secondary);
  animation: spin 1.2s cubic-bezier(0.53, 0.21, 0.29, 0.67) infinite;
  filter: drop-shadow(0 0 8px var(--primary-glow));
}

.spinner::after {
  content: '';
  position: absolute;
  top: 5px;
  left: 5px;
  right: 5px;
  bottom: 5px;
  border-radius: 50%;
  border: 2px dashed transparent;
  border-top-color: var(--secondary-light);
  border-left-color: var(--primary);
  animation: spin 0.8s linear infinite reverse;
  opacity: 0.8;
}

/* Dynamic Theme Table Styling (Dark & Light Mode Adaptable) */
.theme-table, .tag-table, .demo-table, table.table-bordered, .table:not(.table-dark) {
  width: 100%;
  border-collapse: separate;
  border-spacing: 0;
  background: var(--bg-surface, #1e293b) !important;
  border: 1px solid var(--border, rgba(99, 109, 143, 0.2)) !important;
  border-radius: 12px;
  overflow: hidden;
  margin: 20px 0;
  color: var(--text-primary, #f8fafc) !important;
}
.theme-table th, .tag-table th, .demo-table th, table.table-bordered th, .table:not(.table-dark) th {
  background: var(--bg-elevated, #0f172a) !important;
  color: var(--primary-light, #818cf8) !important;
  font-weight: 700;
  padding: 14px 18px;
  text-align: left;
  border-bottom: 2px solid var(--border, rgba(99, 109, 143, 0.2)) !important;
}
.theme-table td, .tag-table td, .demo-table td, table.table-bordered td, .table:not(.table-dark) td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--border, rgba(99, 109, 143, 0.15)) !important;
  color: var(--text-primary, #e2e8f0) !important;
  background: var(--bg-surface, #1e293b) !important;
  vertical-align: middle;
}
.theme-table td strong, .tag-table td strong, .demo-table td strong, table.table-bordered td strong {
  color: var(--text-primary, #f8fafc) !important;
}
.theme-table tr:last-child td, .tag-table tr:last-child td, .demo-table tr:last-child td, table.table-bordered tr:last-child td {
  border-bottom: none !important;
}
.theme-table tr:hover td, .tag-table tr:hover td, .demo-table tr:hover td, table.table-bordered tr:hover td {
  background: rgba(99, 102, 241, 0.08) !important;
}

/* Light Mode Overrides for Table */
[data-theme="light"] .theme-table,
[data-theme="light"] .tag-table,
[data-theme="light"] .demo-table,
[data-theme="light"] table.table-bordered,
[data-theme="light"] .table:not(.table-dark) {
  background: #ffffff !important;
  border-color: #cbd5e1 !important;
  color: #0f172a !important;
}
[data-theme="light"] .theme-table th,
[data-theme="light"] .tag-table th,
[data-theme="light"] .demo-table th,
[data-theme="light"] table.table-bordered th,
[data-theme="light"] .table:not(.table-dark) th,
[data-theme="light"] .table thead tr {
  background: #f1f5f9 !important;
  color: #4f46e5 !important;
  border-bottom-color: #cbd5e1 !important;
}
[data-theme="light"] .theme-table td,
[data-theme="light"] .tag-table td,
[data-theme="light"] .demo-table td,
[data-theme="light"] table.table-bordered td,
[data-theme="light"] .table:not(.table-dark) td {
  background: #ffffff !important;
  color: #0f172a !important;
  border-bottom-color: #e2e8f0 !important;
}
[data-theme="light"] .theme-table td strong,
[data-theme="light"] .tag-table td strong,
[data-theme="light"] .demo-table td strong,
[data-theme="light"] table.table-bordered td strong,
[data-theme="light"] .table td strong {
  color: #0f172a !important;
}
[data-theme="light"] .theme-table tr:hover td,
[data-theme="light"] .tag-table tr:hover td,
[data-theme="light"] .demo-table tr:hover td,
[data-theme="light"] table.table-bordered tr:hover td,
[data-theme="light"] .table tr:hover td {
  background: #f8fafc !important;
}

/* ═══════════════════════════════════════════════════════════════
   GLOBAL RESPONSIVE DESIGN SYSTEM ENHANCEMENTS
═══════════════════════════════════════════════════════════════ */

/* Ad Zones Mobile Constraints */
.ad-zone, .ad-zone-leaderboard, .ad-zone-responsive {
  max-width: 100% !important;
  overflow: hidden !important;
}
.ad-zone ins.adsbygoogle, .ad-zone-leaderboard ins.adsbygoogle {
  max-width: 100% !important;
}

/* Base Container & Code Blocks */
pre, code, .code-snippet, .demo-box, .diagram, .playground {
  max-width: 100%;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

/* Images & Videos */
img, video, iframe, embed, object {
  max-width: 100%;
  height: auto;
}

/* ─── Tablet Breakpoint (<= 1024px) ─── */
@media (max-width: 1024px) {
  .hero-content {
    padding: var(--space-12) 0;
  }
  .hero-stats {
    gap: var(--space-6);
  }
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ─── Medium Screen Breakpoint (<= 992px) ─── */
@media (max-width: 992px) {
  .hero-title {
    font-size: clamp(2.2rem, 6vw, 3.5rem);
  }
  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }
  .post-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .post-layout aside, .toc-sidebar {
    display: none !important;
  }
  .card-horizontal {
    flex-direction: column;
  }
  .card-horizontal .post-card-thumb,
  .card-horizontal .card-img {
    width: 100% !important;
    max-width: 100% !important;
    aspect-ratio: 16/9;
  }
}

/* ─── Mobile Screen Breakpoint (<= 768px) ─── */
@media (max-width: 768px) {
  .container {
    padding: 0 16px;
  }
  .hero {
    min-height: auto;
    padding-top: calc(var(--header-h) + 16px);
    padding-bottom: 48px;
  }
  .hero-eyebrow {
    font-size: 11px;
    margin-bottom: var(--space-4);
  }
  .hero-title {
    font-size: clamp(1.9rem, 7vw, 2.75rem);
    margin-bottom: var(--space-4);
  }
  .hero-desc {
    font-size: 0.92rem;
    margin-bottom: var(--space-6);
  }
  .hero-stats {
    display: grid !important;
    grid-template-columns: repeat(2, 1fr) !important;
    gap: 16px 12px !important;
    margin-top: var(--space-8);
  }
  .hero-stat-num {
    font-size: 1.7rem;
  }
  .hero-stat-label {
    font-size: 11px;
  }
  .grid-2, .grid-3, .grid-4, .grid-auto {
    grid-template-columns: 1fr !important;
  }
  .page-header, .about-hero, .contact-hero, .post-hero, .tutorials-hero {
    padding-top: calc(var(--header-h) + 20px);
    padding-bottom: 36px;
  }
  .page-title {
    font-size: 1.85rem !important;
  }
  .page-subtitle {
    font-size: 0.95rem !important;
  }

  /* Interactive Quizzes & Notebooks Mobile */
  .quiz-options {
    flex-direction: column !important;
    justify-content: flex-start !important;
    gap: 8px !important;
    width: 100% !important;
  }
  .quiz-opt {
    width: 100% !important;
    padding: 12px 16px !important;
    text-align: left !important;
    box-sizing: border-box !important;
  }
  .cell {
    flex-direction: column !important;
  }
  .cell-gutter {
    width: 100% !important;
    border-right: none !important;
    border-bottom: 1px solid var(--border) !important;
    padding: 6px 12px !important;
  }
  .cell-body {
    padding: 12px !important;
  }
  .inline-input {
    width: 100% !important;
    max-width: 100% !important;
  }
  .diagram, .playground, .quiz {
    padding: 14px 12px !important;
    margin: 14px 0 !important;
    border-radius: var(--radius-lg) !important;
  }

  /* Tables horizontal scroll */
  .theme-table, .tag-table, .demo-table, table.table-bordered, .table:not(.table-dark) {
    display: block !important;
    width: 100% !important;
    overflow-x: auto !important;
    -webkit-overflow-scrolling: touch !important;
    font-size: 0.85rem !important;
  }
  .theme-table th, .theme-table td,
  .tag-table th, .tag-table td,
  .demo-table th, .demo-table td {
    padding: 10px 12px !important;
    white-space: nowrap !important;
  }
}

/* ─── Small Mobile Breakpoint (<= 576px) ─── */
@media (max-width: 576px) {
  .hero-actions {
    flex-direction: column !important;
    width: 100% !important;
    gap: 10px !important;
  }
  .hero-actions .btn {
    width: 100% !important;
  }
  .section-label {
    font-size: 11px;
    padding: 4px 12px;
  }
  .section-title {
    font-size: 1.6rem !important;
  }
  .section-desc {
    font-size: 0.9rem !important;
  }
  .btn-lg, .btn-xl {
    padding: 12px 20px !important;
    font-size: 0.92rem !important;
  }
  .filter-btn {
    padding: 5px 12px !important;
    font-size: 12px !important;
  }
  .toast {
    min-width: calc(100vw - 32px) !important;
    max-width: calc(100vw - 32px) !important;
    margin: 0 16px !important;
  }
  .toast-container {
    left: 0 !important;
    right: 0 !important;
    bottom: 16px !important;
    align-items: center !important;
  }
}

/* ═══════════════════════════════════════════════════════════════
   SVG DIAGRAM FULLSCREEN VIEWER
═══════════════════════════════════════════════════════════════ */
.svg-diagram-card, .diagram-container, .diagram-card, .svg-diagram-wrapper {
  position: relative !important;
}

.svg-diagram-expand-btn {
  position: absolute;
  top: 12px;
  right: 12px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 11px;
  background: rgba(15, 23, 42, 0.85);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.16);
  border-radius: 8px;
  color: #94a3b8;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.3px;
  cursor: pointer;
  z-index: 10;
  transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  text-decoration: none;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

.svg-diagram-expand-btn i {
  font-size: 11px;
  color: #818cf8;
  transition: transform 0.2s ease;
}

.svg-diagram-expand-btn:hover {
  background: rgba(99, 102, 241, 0.28);
  border-color: rgba(99, 102, 241, 0.55);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(99, 102, 241, 0.3);
}

.svg-diagram-expand-btn:hover i {
  transform: scale(1.15);
  color: #a5b4fc;
}

.svg-diagram-expand-btn:active {
  transform: translateY(0);
}

.svg-diagram-card svg, .diagram-container svg {
  cursor: zoom-in;
}

/* ═══════════════════════════════════════════════════════════════
   GLOBAL MOBILE OVERFLOW PREVENTION
   Prevents any element from causing horizontal page scroll
═══════════════════════════════════════════════════════════════ */
html, body {
  overflow-x: hidden !important;
  max-width: 100vw;
}

/* Chapter containers */
.container, main.container {
  max-width: 100% !important;
  overflow-x: hidden;
}

/* ═══════════════════════════════════════════════════════════════
   CODE BLOCKS — MOBILE HORIZONTAL SCROLL
   Applies to all chapters (11, 12, 13, 14)
═══════════════════════════════════════════════════════════════ */
pre {
  overflow-x: auto !important;
  -webkit-overflow-scrolling: touch !important;
  max-width: 100% !important;
  white-space: pre !important;     /* keep code formatting */
  word-wrap: normal !important;
  box-sizing: border-box;
}

pre code {
  display: block;
  overflow-x: visible;
  white-space: pre !important;
  word-break: normal !important;
  width: max-content;
  min-width: 100%;
}

/* W3-style example boxes must clip their pre, not overflow */
.w3-example,
.code-example,
.example-box {
  overflow: hidden;
  max-width: 100%;
}

.w3-example pre,
.code-example pre,
.example-box pre {
  overflow-x: auto !important;
  -webkit-overflow-scrolling: touch !important;
  border-radius: 0 0 8px 8px;
}

/* ═══════════════════════════════════════════════════════════════
   CHAPTER RESPONSIVE — 768px BREAKPOINT
═══════════════════════════════════════════════════════════════ */
@media (max-width: 768px) {

  /* ── Body Layout ── */
  body {
    overflow-x: hidden !important;
  }

  main.container,
  .tutorial-post-body,
  .chapter-body {
    padding-left: 12px !important;
    padding-right: 12px !important;
    overflow-x: hidden;
  }

  /* ── Typography Scale ── */
  h1 { font-size: 1.6rem !important; line-height: 1.25 !important; }
  h2 { font-size: 1.25rem !important; }
  h3 { font-size: 1.1rem !important; }

  /* ── Code Blocks ── */
  pre {
    font-size: 12px !important;
    padding: 12px !important;
    border-radius: 8px !important;
    margin: 12px 0 !important;
  }

  code {
    font-size: 12px !important;
  }

  /* ── Chapter glass/info cards ── */
  .glass-card,
  .callout,
  .callout-info,
  .callout-warning,
  .callout-success,
  .callout-danger {
    padding: 14px !important;
    border-radius: 10px !important;
    margin: 14px 0 !important;
  }

  /* ── W3 Example boxes ── */
  .w3-example {
    padding: 14px !important;
    border-radius: 0 10px 10px 0 !important;
    margin: 16px 0 !important;
  }

  /* ── Section spacing ── */
  section.mb-5 {
    margin-bottom: 2rem !important;
  }

  /* ── Bootstrap rows inside chapters ── */
  .row { margin-left: 0 !important; margin-right: 0 !important; }
  .col, [class*="col-"] { padding-left: 8px !important; padding-right: 8px !important; }

  /* ── Comparison tables (chapter-specific class) ── */
  .comparison-table {
    min-width: 520px;
    font-size: 12px !important;
  }
  .comparison-table th,
  .comparison-table td {
    padding: 10px 12px !important;
    font-size: 12px !important;
  }

  /* ── SVG Diagram Cards ── */
  .svg-diagram-card {
    padding: 12px !important;
    overflow-x: auto !important;
    -webkit-overflow-scrolling: touch !important;
    overflow-y: visible !important;
  }

  .svg-diagram-card svg {
    display: block;
    min-width: 520px;
    height: auto;
  }

  /* ── Fullscreen expand button: move below title on mobile ── */
  .svg-diagram-expand-btn {
    position: relative !important;
    top: auto !important;
    right: auto !important;
    display: flex !important;
    width: 100% !important;
    justify-content: center !important;
    margin-top: 8px !important;
    margin-bottom: 8px !important;
    padding: 8px 14px !important;
    font-size: 12px !important;
  }

  .svg-diagram-title {
    padding-right: 0 !important;
    font-size: 12px !important;
  }

  /* ── Interactive labs ── */
  .interactive-lab {
    padding: 14px !important;
    border-radius: 10px !important;
  }

  /* ── Try-it button wrapping ── */
  .try-it-btn {
    font-size: 11px !important;
    padding: 5px 12px !important;
  }
}

/* ═══════════════════════════════════════════════════════════════
   CHAPTER RESPONSIVE — 480px BREAKPOINT
═══════════════════════════════════════════════════════════════ */
@media (max-width: 480px) {
  h1 { font-size: 1.4rem !important; }
  h2 { font-size: 1.15rem !important; }

  .glass-card { padding: 12px !important; }
  .w3-example { padding: 12px !important; }
  pre { font-size: 11px !important; padding: 10px !important; }

  main.container {
    padding-left: 10px !important;
    padding-right: 10px !important;
  }
}

/* ═══════════════════════════════════════════════════════════════
   SVG FULLSCREEN MODAL — MOBILE CONTROLS
   Overrides svg-fullscreen.js injected styles on mobile
═══════════════════════════════════════════════════════════════ */
@media (max-width: 768px) {
  /* Header becomes two rows on mobile */
  .svg-fs-header {
    height: auto !important;
    min-height: 52px !important;
    padding: 8px 10px !important;
    flex-wrap: wrap !important;
    gap: 8px !important;
    row-gap: 6px !important;
  }

  .svg-fs-title-group {
    flex: 1 1 auto;
    min-width: 0;
  }

  .svg-fs-badge {
    display: none !important;
  }

  .svg-fs-title {
    font-size: 12px !important;
    max-width: 180px !important;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  /* Toolbar stays together */
  .svg-fs-toolbar {
    flex: 0 0 auto;
    gap: 4px !important;
  }

  /* All buttons: taller touch targets */
  .svg-fs-btn {
    height: 38px !important;
    padding: 0 10px !important;
    font-size: 13px !important;
  }

  .svg-fs-pill {
    height: 38px !important;
    min-width: 44px !important;
    font-size: 11px !important;
  }

  /* Hide text labels, keep icons */
  .svg-fs-btn span { display: none !important; }

  /* Hide footer hints on mobile */
  .svg-fs-footer { display: none !important; }

  /* SVG uses maximum available space */
  .svg-fs-stage svg {
    max-width: 100vw !important;
    max-height: calc(100dvh - 58px) !important;
    width: 100vw !important;
    height: auto !important;
    border-radius: 0 !important;
    filter: none !important;
  }

  .svg-fs-body {
    background-size: 20px 20px !important;
  }

  /* Close button: always visible, slightly larger */
  .svg-fs-close-btn {
    height: 38px !important;
    padding: 0 12px !important;
    font-size: 13px !important;
  }
}