/* ============================================================================
 * 🎓 البوابة الأكاديمية الذكية — Smart Academic Portal Stylesheet
 * Deep Slate Glassmorphism (Dark Default) + Alabaster Clean (Light Mode)
 * Mobile-First RTL Arabic Design System
 * ============================================================================ */

:root,
[data-theme="dark"] {
  --bg-base: #0b0f19;
  --bg-elevated: #111827;
  --bg-card: rgba(17, 24, 39, 0.78);
  --bg-card-hover: rgba(30, 41, 59, 0.88);
  --bg-glass: rgba(11, 15, 25, 0.82);
  --bg-pill: rgba(30, 41, 59, 0.7);
  --bg-input: rgba(15, 23, 42, 0.85);

  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;

  --border-subtle: rgba(148, 163, 184, 0.14);
  --border-strong: rgba(148, 163, 184, 0.26);
  --border-interactive: rgba(6, 182, 212, 0.45);

  --accent-primary: #6366f1;
  --accent-primary-hover: #4f46e5;
  --accent-cyan: #06b6d4;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-crimson: #ef4444;
  --accent-purple: #a855f7;

  --grad-primary: linear-gradient(135deg, #6366f1 0%, #06b6d4 100%);
  --grad-interactive: linear-gradient(135deg, #059669 0%, #06b6d4 100%);
  --grad-translated: linear-gradient(135deg, #7c3aed 0%, #ec4899 100%);
  --grad-surface-glow: radial-gradient(circle at 85% 10%, rgba(99, 102, 241, 0.16), transparent 45%),
                       radial-gradient(circle at 15% 85%, rgba(6, 182, 212, 0.12), transparent 50%);

  --shadow-sm: 0 4px 14px -2px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 12px 32px -4px rgba(0, 0, 0, 0.5);
  --shadow-glow-cyan: 0 0 24px rgba(6, 182, 212, 0.22);
  --shadow-glow-indigo: 0 0 24px rgba(99, 102, 241, 0.25);

  --shimmer-base: rgba(30, 41, 59, 0.65);
  --shimmer-highlight: rgba(51, 65, 85, 0.85);
}

[data-theme="light"] {
  --bg-base: #f8fafc;
  --bg-elevated: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.92);
  --bg-card-hover: #ffffff;
  --bg-glass: rgba(248, 250, 252, 0.88);
  --bg-pill: #f1f5f9;
  --bg-input: #ffffff;

  --text-primary: #0f172a;
  --text-secondary: #334155;
  --text-muted: #64748b;

  --border-subtle: rgba(15, 23, 42, 0.08);
  --border-strong: rgba(15, 23, 42, 0.16);
  --border-interactive: rgba(8, 145, 178, 0.45);

  --accent-primary: #4f46e5;
  --accent-primary-hover: #4338ca;
  --accent-cyan: #0891b2;
  --accent-emerald: #059669;
  --accent-amber: #d97706;
  --accent-crimson: #dc2626;
  --accent-purple: #9333ea;

  --grad-primary: linear-gradient(135deg, #4f46e5 0%, #0891b2 100%);
  --grad-interactive: linear-gradient(135deg, #059669 0%, #0891b2 100%);
  --grad-translated: linear-gradient(135deg, #7c3aed 0%, #db2777 100%);
  --grad-surface-glow: radial-gradient(circle at 85% 10%, rgba(79, 70, 229, 0.07), transparent 45%),
                       radial-gradient(circle at 15% 85%, rgba(8, 145, 178, 0.06), transparent 50%);

  --shadow-sm: 0 2px 10px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08);
  --shadow-glow-cyan: 0 6px 20px rgba(8, 145, 178, 0.15);
  --shadow-glow-indigo: 0 6px 20px rgba(79, 70, 229, 0.15);

  --shimmer-base: #e2e8f0;
  --shimmer-highlight: #f1f5f9;
}

/* ================= Reset & Base ================= */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
}

body {
  font-family: "Tajawal", "Cairo", -apple-system, BlinkMacSystemFont, sans-serif;
  background-color: var(--bg-base);
  background-image: var(--grad-surface-glow);
  background-attachment: fixed;
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  padding-bottom: 92px; /* Space for mobile bottom navigation */
  overflow-x: hidden;
  transition: background-color 0.25s ease, color 0.25s ease;
}

@media (min-width: 768px) {
  body {
    padding-bottom: 48px;
  }
}

button,
input {
  font-family: inherit;
  color: inherit;
  border: none;
  outline: none;
  background: none;
}

button {
  cursor: pointer;
  user-select: none;
}

/* ================= Sticky Glass Header ================= */
.portal-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: var(--bg-glass);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--border-subtle);
  transition: background-color 0.25s ease, border-color 0.25s ease;
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

@media (min-width: 768px) {
  .header-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    gap: 20px;
  }
}

.brand-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.brand-identity {
  display: flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
}

.brand-logo {
  width: 42px;
  height: 42px;
  border-radius: 13px;
  background: var(--grad-primary);
  display: grid;
  place-items: center;
  font-size: 1.35rem;
  box-shadow: var(--shadow-glow-indigo);
  flex-shrink: 0;
}

.brand-titles {
  min-width: 0;
}

.brand-subtitle {
  font-size: 0.74rem;
  font-weight: 700;
  color: var(--accent-cyan);
  letter-spacing: 0.02em;
  display: flex;
  align-items: center;
  gap: 6px;
}

.live-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--accent-emerald);
  box-shadow: 0 0 8px var(--accent-emerald);
  display: inline-block;
}

.brand-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

@media (min-width: 768px) {
  .brand-title {
    font-size: 1.28rem;
  }
}

.header-controls {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  max-width: 680px;
  justify-content: flex-end;
}

/* Search Box */
.search-wrapper {
  position: relative;
  flex: 1;
  display: flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  right: 14px;
  font-size: 0.95rem;
  color: var(--text-muted);
  pointer-events: none;
}

.search-input {
  width: 100%;
  background: var(--bg-input);
  border: 1px solid var(--border-subtle);
  border-radius: 14px;
  padding: 10px 40px 10px 38px;
  font-size: 0.92rem;
  font-weight: 500;
  color: var(--text-primary);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.2s ease;
}

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

.search-input:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.18);
}

.search-clear-btn {
  position: absolute;
  left: 10px;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--bg-pill);
  color: var(--text-muted);
  font-size: 0.75rem;
  display: grid;
  place-items: center;
  transition: all 0.15s ease;
}

.search-clear-btn:hover {
  color: var(--text-primary);
  background: var(--border-strong);
}

/* Desktop View Switcher inside Header */
.desktop-view-switcher {
  display: none;
  background: var(--bg-pill);
  padding: 4px;
  border-radius: 14px;
  border: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

@media (min-width: 768px) {
  .desktop-view-switcher {
    display: inline-flex;
    align-items: center;
    gap: 4px;
  }
}

.view-tab-btn {
  padding: 8px 14px;
  border-radius: 10px;
  font-size: 0.88rem;
  font-weight: 700;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.2s ease;
}

.view-tab-btn.active {
  background: var(--grad-primary);
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

.tab-count-badge {
  font-size: 0.73rem;
  padding: 1px 7px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.2);
  font-weight: 800;
}

.view-tab-btn:not(.active) .tab-count-badge {
  background: var(--border-subtle);
  color: var(--text-muted);
}

/* Icon Buttons (Theme & Refresh) */
.icon-action-btn {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: var(--bg-pill);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
  display: grid;
  place-items: center;
  font-size: 1.05rem;
  flex-shrink: 0;
  transition: all 0.2s ease;
}

.icon-action-btn:hover {
  border-color: var(--border-strong);
  transform: translateY(-1px);
}

.icon-action-btn:active {
  transform: translateY(0);
}

.icon-action-btn.spinning svg,
.icon-action-btn.spinning span {
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

/* ================= Main Container ================= */
.portal-main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 18px 16px;
}

@media (min-width: 768px) {
  .portal-main {
    padding: 26px 24px;
  }
}

/* ================= Filter Bars (Subjects & Subcategories) ================= */
.filters-section {
  display: flex;
  flex-direction: column;
  gap: 14px;
  margin-bottom: 22px;
}

.section-micro-label {
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--text-muted);
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.horizontal-scroll-strip {
  display: flex;
  align-items: center;
  gap: 10px;
  overflow-x: auto;
  padding: 4px 2px 8px 2px;
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.horizontal-scroll-strip::-webkit-scrollbar {
  display: none;
}

/* Subject Bento Pills */
.subject-pill {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  border-radius: 14px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.92rem;
  font-weight: 700;
  white-space: nowrap;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.subject-pill:hover {
  border-color: var(--border-strong);
  color: var(--text-primary);
  transform: translateY(-2px);
}

.subject-pill.active {
  background: var(--grad-primary);
  border-color: transparent;
  color: #ffffff;
  box-shadow: var(--shadow-glow-indigo);
}

.subject-pill-count {
  font-size: 0.76rem;
  font-weight: 800;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(148, 163, 184, 0.16);
  color: var(--text-secondary);
}

.subject-pill.active .subject-pill-count {
  background: rgba(255, 255, 255, 0.24);
  color: #ffffff;
}

/* Subcategory Filter Bar */
.subcat-pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: 11px;
  background: var(--bg-pill);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 700;
  white-space: nowrap;
  flex-shrink: 0;
  transition: all 0.18s ease;
}

.subcat-pill:hover {
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.subcat-pill.active {
  background: var(--text-primary);
  color: var(--bg-base);
  border-color: transparent;
}

.subcat-pill.special-html {
  border-color: rgba(16, 185, 129, 0.35);
  color: var(--accent-emerald);
}

.subcat-pill.special-html.active {
  background: var(--grad-interactive);
  color: #ffffff;
  border-color: transparent;
  box-shadow: var(--shadow-glow-cyan);
}

.subcat-pill.special-tr {
  border-color: rgba(168, 85, 247, 0.35);
  color: var(--accent-purple);
}

.subcat-pill.special-tr.active {
  background: var(--grad-translated);
  color: #ffffff;
  border-color: transparent;
}

/* Results Summary Bar */
.results-summary-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 14px;
  font-size: 0.86rem;
  color: var(--text-muted);
  font-weight: 600;
}

.reset-filters-link {
  color: var(--accent-cyan);
  font-weight: 700;
  font-size: 0.84rem;
  text-decoration: underline;
  text-underline-offset: 4px;
}

/* ================= Lecture Cards Grid ================= */
.lectures-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 640px) {
  .lectures-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .lectures-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }
}

.lecture-card {
  position: relative;
  background: var(--bg-card);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 16px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.22s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.22s ease,
              box-shadow 0.22s ease;
  overflow: hidden;
}

.lecture-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

/* Interactive HTML Lecture Highlight Card */
.lecture-card.is-interactive-html {
  border-color: var(--border-interactive);
  background: linear-gradient(
      160deg,
      rgba(16, 185, 129, 0.08) 0%,
      rgba(6, 182, 212, 0.06) 45%,
      transparent 100%
    ),
    var(--bg-card);
}

.lecture-card.is-interactive-html:hover {
  box-shadow: var(--shadow-glow-cyan);
}

.interactive-ribbon {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  padding: 5px 11px;
  border-radius: 999px;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.38);
  color: var(--accent-emerald);
  font-size: 0.76rem;
  font-weight: 800;
}

.card-top-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
}

.badge-group {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-wrap: wrap;
}

.subject-badge {
  font-size: 0.76rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 8px;
  background: rgba(99, 102, 241, 0.14);
  color: var(--accent-primary);
}

[data-theme="dark"] .subject-badge {
  color: #818cf8;
}

.subcat-badge {
  font-size: 0.75rem;
  font-weight: 700;
  padding: 4px 9px;
  border-radius: 8px;
  background: var(--bg-pill);
  color: var(--text-secondary);
}

.file-ext-badge {
  font-size: 0.7rem;
  font-weight: 800;
  padding: 2px 7px;
  border-radius: 6px;
  background: var(--bg-pill);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.lecture-title {
  font-size: 1.06rem;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.45;
  margin-top: 4px;
  word-break: break-word;
}

.lecture-meta-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.79rem;
  color: var(--text-muted);
  padding-top: 10px;
  border-top: 1px solid var(--border-subtle);
}

.meta-stat {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-weight: 600;
}

/* Card Action Buttons */
.card-actions {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.action-row-primary {
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 11px 14px;
  border-radius: 12px;
  font-size: 0.88rem;
  font-weight: 800;
  text-align: center;
  transition: all 0.2s ease;
  text-decoration: none;
  line-height: 1.2;
}

.btn:disabled,
.btn.loading {
  opacity: 0.65;
  pointer-events: none;
}

.btn-interactive-launch {
  width: 100%;
  padding: 13px 16px;
  background: var(--grad-interactive);
  color: #ffffff;
  font-size: 0.94rem;
  box-shadow: var(--shadow-glow-cyan);
}

.btn-interactive-launch:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
}

.btn-primary-dl {
  flex: 1;
  background: var(--grad-primary);
  color: #ffffff;
}

.btn-primary-dl:hover {
  filter: brightness(1.08);
}

.btn-preview {
  padding: 11px 14px;
  background: var(--bg-pill);
  border: 1px solid var(--border-subtle);
  color: var(--text-primary);
}

.btn-preview:hover {
  border-color: var(--border-strong);
  background: var(--bg-card-hover);
}

.btn-translated-row {
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-translated {
  flex: 1;
  background: var(--grad-translated);
  color: #ffffff;
  font-size: 0.85rem;
  padding: 10px 14px;
}

.btn-translated:hover {
  filter: brightness(1.08);
}

.btn-translated-preview {
  padding: 10px 12px;
  background: rgba(168, 85, 247, 0.14);
  border: 1px solid rgba(168, 85, 247, 0.32);
  color: var(--accent-purple);
  font-size: 0.84rem;
}

[data-theme="dark"] .btn-translated-preview {
  color: #d8b4fe;
}

/* ================= Schedule & Exam Countdowns View ================= */
.schedule-header-bar {
  display: flex;
   flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 20px;
}

.schedule-filter-group {
  display: inline-flex;
  background: var(--bg-pill);
  padding: 4px;
  border-radius: 12px;
  border: 1px solid var(--border-subtle);
}

.schedule-filter-btn {
  padding: 8px 16px;
  border-radius: 9px;
  font-size: 0.86rem;
  font-weight: 800;
  color: var(--text-secondary);
  transition: all 0.2s ease;
}

.schedule-filter-btn.active {
  background: var(--grad-primary);
  color: #ffffff;
}

.events-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

@media (min-width: 768px) {
  .events-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 18px;
  }
}

.event-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-right-width: 5px;
  border-radius: 16px;
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 12px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease;
}

.event-card:hover {
  transform: translateY(-2px);
}

/* Event Color Coding by Type */
.event-card[data-event-type="exam"] {
  border-right-color: var(--accent-crimson);
}
.event-card[data-event-type="quiz"] {
  border-right-color: var(--accent-amber);
}
.event-card[data-event-type="hw"] {
  border-right-color: var(--accent-primary);
}
.event-card[data-event-type="lab"] {
  border-right-color: var(--accent-emerald);
}

.event-top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  flex-wrap: wrap;
}

.event-type-pill {
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 10px;
  border-radius: 8px;
}

.event-card[data-event-type="exam"] .event-type-pill {
  background: rgba(239, 68, 68, 0.15);
  color: #f87171;
}
[data-theme="light"] .event-card[data-event-type="exam"] .event-type-pill {
  color: #dc2626;
}

.event-card[data-event-type="quiz"] .event-type-pill {
  background: rgba(245, 158, 11, 0.15);
  color: #fbbf24;
}
[data-theme="light"] .event-card[data-event-type="quiz"] .event-type-pill {
  color: #d97706;
}

.event-card[data-event-type="hw"] .event-type-pill {
  background: rgba(99, 102, 241, 0.15);
  color: #818cf8;
}
[data-theme="light"] .event-card[data-event-type="hw"] .event-type-pill {
  color: #4f46e5;
}

.event-card[data-event-type="lab"] .event-type-pill {
  background: rgba(16, 185, 129, 0.15);
  color: #34d399;
}
[data-theme="light"] .event-card[data-event-type="lab"] .event-type-pill {
  color: #059669;
}

.countdown-pill {
  font-size: 0.78rem;
  font-weight: 800;
  padding: 4px 11px;
  border-radius: 999px;
  background: var(--bg-pill);
  color: var(--text-primary);
  border: 1px solid var(--border-subtle);
}

.countdown-pill.urgent {
  background: rgba(239, 68, 68, 0.18);
  border-color: rgba(239, 68, 68, 0.4);
  color: #f87171;
  animation: pulseUrgent 2s infinite;
}

[data-theme="light"] .countdown-pill.urgent {
  color: #dc2626;
}

@keyframes pulseUrgent {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.03);
  }
}

.event-subject-name {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-cyan);
}

.event-title {
  font-size: 1.08rem;
  font-weight: 800;
  color: var(--text-primary);
}

.event-date-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-secondary);
  background: var(--bg-pill);
  padding: 8px 12px;
  border-radius: 10px;
}

/* ================= Empty & Celebratory States ================= */
.empty-state-card {
  background: var(--bg-card);
  border: 1px dashed var(--border-strong);
  border-radius: 20px;
  padding: 44px 20px;
  text-align: center;
  max-width: 520px;
  margin: 24px auto;
}

.empty-state-emoji {
  font-size: 2.8rem;
  margin-bottom: 12px;
  display: block;
}

.empty-state-title {
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 6px;
}

.empty-state-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* ================= Shimmer Skeletons ================= */
.skeleton-card {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 18px;
  padding: 18px;
  height: 196px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.shimmer-box {
  background: linear-gradient(
    90deg,
    var(--shimmer-base) 25%,
    var(--shimmer-highlight) 50%,
    var(--shimmer-base) 75%
  );
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
  border-radius: 8px;
}

@keyframes shimmer {
  0% {
    background-position: 200% 0;
  }
  100% {
    background-position: -200% 0;
  }
}

/* ================= Sticky Mobile Bottom Navigation ================= */
.mobile-bottom-nav {
  position: fixed;
  bottom: 0;
  right: 0;
  left: 0;
  z-index: 45;
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-top: 1px solid var(--border-subtle);
  padding: 8px 16px calc(8px + env(safe-area-inset-bottom, 0px));
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}

@media (min-width: 768px) {
  .mobile-bottom-nav {
    display: none;
  }
}

.mobile-nav-btn {
  padding: 10px 12px;
  border-radius: 12px;
  font-size: 0.88rem;
  font-weight: 800;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  transition: all 0.2s ease;
}

.mobile-nav-btn.active {
  background: var(--grad-primary);
  color: #ffffff;
  box-shadow: var(--shadow-sm);
}

/* ================= Fullscreen Interactive Player & PDF Preview Modal ================= */
.fullscreen-modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  background: #070a12;
  display: flex;
  flex-direction: column;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.22s ease;
}

.fullscreen-modal.open {
  opacity: 1;
  pointer-events: auto;
}

.player-topbar {
  background: rgba(15, 23, 42, 0.95);
  border-bottom: 1px solid rgba(148, 163, 184, 0.18);
  padding: 10px 14px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: wrap;
  color: #f8fafc;
}

.player-title-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  min-width: 0;
  flex: 1;
}

.player-badge {
  font-size: 0.72rem;
  font-weight: 800;
  padding: 3px 8px;
  border-radius: 6px;
  background: rgba(16, 185, 129, 0.2);
  color: #34d399;
  white-space: nowrap;
}

.player-title {
  font-size: 0.95rem;
  font-weight: 800;
  color: #f8fafc;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.player-controls {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.player-btn {
  padding: 7px 12px;
  border-radius: 9px;
  font-size: 0.8rem;
  font-weight: 700;
  background: rgba(30, 41, 59, 0.9);
  border: 1px solid rgba(148, 163, 184, 0.24);
  color: #f8fafc;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: all 0.15s ease;
}

.player-btn:hover {
  background: rgba(51, 65, 85, 0.95);
}

.player-btn.highlight {
  background: var(--grad-interactive);
  border-color: transparent;
  color: #ffffff;
}

.player-btn.close-btn {
  background: rgba(239, 68, 68, 0.18);
  border-color: rgba(239, 68, 68, 0.35);
  color: #fca5a5;
}

.player-btn.close-btn:hover {
  background: rgba(239, 68, 68, 0.32);
  color: #ffffff;
}

.player-viewport {
  position: relative;
  flex: 1;
  width: 100%;
  height: 100%;
  background: #ffffff;
}

.player-iframe {
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.player-loading-overlay {
  position: absolute;
  inset: 0;
  background: #0b0f19;
  color: #f8fafc;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 14px;
  z-index: 5;
}

.spinner-ring {
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 3px solid rgba(99, 102, 241, 0.25);
  border-top-color: #06b6d4;
  animation: spin 0.8s linear infinite;
}

/* ================= Toast Notification ================= */
.toast-container {
  position: fixed;
  bottom: 84px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 120;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
  width: max-content;
  max-width: 92vw;
}

@media (min-width: 768px) {
  .toast-container {
    bottom: 28px;
  }
}

.toast-item {
  background: rgba(15, 23, 42, 0.95);
  color: #f8fafc;
  border: 1px solid rgba(148, 163, 184, 0.25);
  padding: 11px 18px;
  border-radius: 12px;
  font-size: 0.88rem;
  font-weight: 700;
  box-shadow: var(--shadow-md);
  display: flex;
  align-items: center;
  gap: 8px;
  animation: toastIn 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes toastIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hidden {
  display: none !important;
}