/* ==========================================================================
   Unilib — Academic Resource Library
   Theme, Style & Design System: MBKBucket Refined Slate & Deep Teal System
   Mobile-First & Precision Academic UI/UX
   ========================================================================== */

:root {
  /* Brand / Primary Palette (MBKBucket Deep Teal) */
  --primary-color-ml: #0f766e;
  --primary-light-color-ml: #f0fdfa;
  --primary-dark-color-ml: #115e59;
  --secondary-color-ml: #14b8a6;
  --dark-color-ml: #0f172a;
  --light-color-ml: #f8fafc;
  --gray-color-ml: #64748b;
  --gray-light-color-ml: #e2e8f0;
  --danger-color-ml: #ef4444;
  --warning-color-ml: #f59e0b;
  --success-color-ml: #10b981;
  --info-color-ml: #0284c7;

  /* Aliases */
  --primary: var(--primary-color-ml);
  --primary-lt: var(--primary-light-color-ml);
  --primary-dk: var(--primary-dark-color-ml);
  --primary-hover: #115e59;
  --primary-active: #134e4a;
  --primary-ring: rgba(15, 118, 110, 0.16);

  /* Surfaces & Backgrounds */
  --body-bg: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-secondary: #f8fafc;
  --bg-surface-tertiary: #f1f5f9;
  --bg-surface-hover: #f1f5f9;

  /* Borders */
  --border-color: #e2e8f0;
  --border-color-light: #f1f5f9;
  --border-light: #f1f5f9;
  --border-color-focus: #0f766e;

  /* Text */
  --text: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --text-disabled: #94a3b8;

  /* Accent Colors */
  --blue: #2563eb;
  --azure: #0891b2;
  --green: #10b981;
  --yellow: #d97706;
  --orange: #ea580c;
  --red: #ef4444;
  --purple: #7c3aed;
  --cyan: #0f766e;

  /* Light Accent Tints */
  --green-lt: #ecfdf5;
  --red-lt: #fef2f2;
  --yellow-lt: #fffbeb;
  --blue-lt: #eff6ff;
  --azure-lt: #ecfeff;
  --purple-lt: #f5f3ff;
  --cyan-lt: #f0fdfa;

  /* Category Specific Styles */
  --cat-textbook-text: #1d4ed8;
  --cat-textbook-bg: #eff6ff;
  --cat-textbook-border: #bfdbfe;

  --cat-lab-text: #0f766e;
  --cat-lab-bg: #f0fdfa;
  --cat-lab-border: #99f6e4;

  --cat-quiz-text: #b45309;
  --cat-quiz-bg: #fffbeb;
  --cat-quiz-border: #fde68a;

  --cat-solution-text: #6d28d9;
  --cat-solution-bg: #f5f3ff;
  --cat-solution-border: #ddd6fe;

  /* Geometry (Complete token set) */
  --radius-xs: 5px;
  --radius-sm: 7px;
  --radius: 10px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 18px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-xs: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-sm: 0 2px 5px -1px rgba(15, 23, 42, 0.06), 0 1px 3px -1px rgba(15, 23, 42, 0.04);
  --shadow: 0 6px 12px -2px rgba(15, 23, 42, 0.07), 0 3px 6px -3px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 12px 20px -4px rgba(15, 23, 42, 0.08), 0 4px 8px -4px rgba(15, 23, 42, 0.04);

  /* Typography */
  --font: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  --font-headings: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, system-ui, sans-serif;
  --font-mono: "JetBrains Mono", "Cascadia Code", "Segoe UI Mono", Consolas, monospace;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

html {
  font-size: 14.5px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font);
  background-color: var(--body-bg);
  background-image: radial-gradient(ellipse 80% 45% at 50% -15%, rgba(20, 184, 166, 0.07), transparent 70%);
  background-attachment: fixed;
  color: var(--text);
  line-height: 1.5;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-headings);
  color: var(--text);
  font-weight: 700;
  line-height: 1.25;
}

code, kbd, samp, pre, .tabular-nums, .shortcut-key, .file-format-text, .course-code-text, .course-code-badge, .table-course-code {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
}

a {
  color: inherit;
  text-decoration: none;
}

/* Container */
.unilib-container {
  width: 100%;
  max-width: 1180px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.unilib-main {
  flex: 1;
  padding-top: 1.5rem;
  padding-bottom: 4rem;
}

.ui-svg {
  display: inline-block;
  vertical-align: middle;
  flex-shrink: 0;
}

.mobile-only {
  display: none !important;
}

/* Generic Card */
.card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
  transition: border-color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
}

/* ==========================================================================
   Navigation Bar (Glassmorphic Sticky Top-Nav)
   ========================================================================== */
.top-nav, .unilib-nav {
  position: sticky;
  top: 0;
  z-index: 60;
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.85);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.03);
}

.top-nav-inner, .unilib-nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 3.85rem;
  gap: 0.75rem;
}

.logo, .unilib-brand {
  font-family: var(--font-headings);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text);
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  letter-spacing: -0.02em;
  cursor: pointer;
  flex-shrink: 0;
}

.logo-mark, .unilib-brand-mark {
  width: 2.2rem;
  height: 2.2rem;
  border-radius: var(--radius-sm);
  background: linear-gradient(135deg, #0f766e 0%, #0d9488 100%);
  color: #ffffff;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 6px rgba(15, 118, 110, 0.25);
}

.logo-text-group, .unilib-brand-text {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-title, .unilib-brand-name {
  font-size: 1.2rem;
  font-weight: 800;
  color: var(--text);
  letter-spacing: -0.02em;
}

.logo-badge {
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary-dk);
  background: var(--primary-lt);
  border: 1px solid #ccfbf1;
  padding: 2px 7px;
  border-radius: var(--radius-full);
}

.top-nav-actions, .unilib-nav-actions {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  min-width: 0;
}

.nav-shortcut-hint {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--font);
  font-size: 12px;
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.32rem 0.6rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background: var(--bg-surface-secondary);
  cursor: pointer;
  transition: all 0.14s ease;
}

.nav-shortcut-hint:hover {
  border-color: #cbd5e1;
  color: var(--text);
  background: #ffffff;
}

.shortcut-key {
  font-size: 10.5px;
  font-weight: 700;
  padding: 1px 5px;
  background: #ffffff;
  border: 1px solid #cbd5e1;
  border-radius: 4px;
  color: var(--text-secondary);
  box-shadow: 0 1px 0 rgba(15, 23, 42, 0.06);
}

/* ==========================================================================
   Buttons (MBKBucket Button System)
   ========================================================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  font-family: var(--font);
  font-weight: 600;
  font-size: 13px;
  line-height: 1;
  padding: 8px 14px;
  min-height: 34px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.14s ease;
  white-space: nowrap;
  user-select: none;
}

.btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 3px var(--primary-ring);
}

.btn-primary, .btn-action {
  background: linear-gradient(180deg, #0d9488 0%, #0f766e 100%);
  color: #ffffff;
  border-color: var(--primary-dark-color-ml);
  box-shadow: 0 1px 2px rgba(15, 118, 110, 0.2);
}

.btn-primary:hover, .btn-action:hover {
  background: var(--primary-hover);
  border-color: var(--primary-hover);
  color: #ffffff;
  box-shadow: 0 3px 6px rgba(15, 118, 110, 0.22);
}

.btn-primary:active, .btn-action:active {
  background: var(--primary-active);
  transform: translateY(0.5px);
}

.btn-outline, .btn-ghost, .btn-subtle {
  background: #ffffff;
  color: var(--text);
  border-color: var(--border-color);
  box-shadow: var(--shadow-xs);
}

.btn-outline:hover, .btn-ghost:hover, .btn-subtle:hover {
  background: #f8fafc;
  color: var(--text);
  border-color: #cbd5e1;
}

.btn-outline:active, .btn-ghost:active, .btn-subtle:active {
  background: #f1f5f9;
}

.btn-danger, .btn-danger-ghost {
  background: var(--danger-color-ml);
  color: #ffffff;
  border-color: var(--danger-color-ml);
  box-shadow: var(--shadow-xs);
}

.btn-danger:hover, .btn-danger-ghost:hover {
  background: #dc2626;
  border-color: #dc2626;
  color: #ffffff;
}

.btn-sm {
  padding: 6px 12px;
  min-height: 32px;
  font-size: 12.5px;
  border-radius: var(--radius-sm);
}

.btn-xs {
  padding: 4px 9px;
  min-height: 27px;
  font-size: 11.5px;
  border-radius: var(--radius-xs);
}

.btn-icon {
  width: 34px;
  height: 34px;
  padding: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* ==========================================================================
   Health Status Badge
   ========================================================================== */
.health-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 4px 9px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
  border: 1px solid transparent;
}

.health-status-badge.healthy {
  background-color: var(--green-lt);
  border-color: #a7f3d0;
  color: #065f46;
}

.health-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--success-color-ml);
  box-shadow: 0 0 0 2px rgba(16, 185, 129, 0.2);
}

/* ==========================================================================
   Homepage Masthead & Metrics
   ========================================================================== */
.archive-masthead, .unilib-compact-hero {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.75rem;
  margin-bottom: 1.5rem;
  padding: 1.5rem 1.75rem;
  background: linear-gradient(135deg, #ffffff 0%, #f0fdfa 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
}

.masthead-main, .compact-hero-left {
  max-width: 640px;
}

.masthead-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--primary-dk);
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid #99f6e4;
  padding: 3px 9px;
  border-radius: var(--radius-full);
  margin-bottom: 0.65rem;
}

.eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--primary);
}

.masthead-title, .unilib-compact-title {
  font-size: 1.85rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-bottom: 0.4rem;
}

.masthead-description, .unilib-compact-subtitle {
  font-size: 0.94rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.masthead-metrics, .compact-hero-stats {
  display: flex;
  align-items: center;
  gap: 1.35rem;
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.85rem 1.35rem;
  box-shadow: var(--shadow-xs);
  flex-shrink: 0;
}

.metric-block, .mini-stat {
  display: flex;
  flex-direction: column;
}

.metric-value, .mini-stat-num {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--primary-dk);
  line-height: 1.1;
}

.metric-label, .mini-stat-label {
  font-size: 10.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.metric-divider, .mini-stat-divider {
  width: 1px;
  height: 2.1rem;
  background-color: var(--border-color);
}

/* ==========================================================================
   Semester Strip (Segmented Filter Bar)
   ========================================================================== */
.semester-strip, .semester-tabs-wrapper {
  margin-bottom: 1.5rem;
}

.semester-strip-track, .semester-tabs {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.35rem;
  overflow-x: auto;
  box-shadow: var(--shadow-xs);
  scrollbar-width: none;
  -ms-overflow-style: none;
  -webkit-overflow-scrolling: touch;
}

.semester-strip-track::-webkit-scrollbar,
.semester-tabs::-webkit-scrollbar {
  display: none;
}

.sem-tab {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 7px 13px;
  min-height: 36px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.14s ease;
  user-select: none;
}

.sem-tab:hover {
  color: var(--text);
  background-color: var(--bg-surface-tertiary);
}

.sem-tab.active {
  color: #ffffff;
  background: linear-gradient(180deg, #0d9488 0%, #0f766e 100%);
  border-color: var(--primary-dk);
  box-shadow: 0 1px 3px rgba(15, 118, 110, 0.25);
}

.sem-tab-count {
  font-size: 11px;
  font-weight: 700;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  background-color: rgba(15, 23, 42, 0.07);
  color: inherit;
}

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

/* ==========================================================================
   Toolbar: Filter & Search
   ========================================================================== */
.materials-toolbar, .materials-filter-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.1rem;
  flex-wrap: wrap;
}

.toolbar-status {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
}

.toolbar-title-row {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.toolbar-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
}

.toolbar-count-pill {
  font-size: 11px;
  font-weight: 700;
  color: var(--primary-dk);
  background: var(--primary-lt);
  border: 1px solid #ccfbf1;
  padding: 2px 8px;
  border-radius: var(--radius-full);
}

.toolbar-subtitle {
  font-size: 12.5px;
  color: var(--text-muted);
}

.toolbar-controls {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  flex-wrap: wrap;
}

.filter-dropdown-wrap {
  position: relative;
  display: inline-flex;
  align-items: center;
}

.dropdown-icon {
  position: absolute;
  left: 0.75rem;
  pointer-events: none;
  color: var(--text-muted);
}

.toolbar-select, .material-category-select {
  appearance: none;
  -webkit-appearance: none;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  background-color: #ffffff;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 0.65rem center;
  background-size: 13px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 7px 2rem 7px 2.1rem;
  min-height: 36px;
  cursor: pointer;
  outline: none;
  box-shadow: var(--shadow-xs);
  transition: border-color 0.14s ease, box-shadow 0.14s ease;
}

.toolbar-select:focus, .material-category-select:focus {
  border-color: var(--border-color-focus);
  box-shadow: 0 0 0 3px var(--primary-ring);
}

.live-search-box, .live-filter-box {
  position: relative;
  display: inline-flex;
  align-items: center;
}

.search-icon {
  position: absolute;
  left: 0.75rem;
  pointer-events: none;
  color: var(--text-muted);
}

.live-search-input, .live-filter-input {
  font-family: var(--font);
  font-size: 13px;
  color: var(--text);
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 7px 2.25rem 7px 2.15rem;
  min-height: 36px;
  width: 270px;
  outline: none;
  box-shadow: var(--shadow-xs);
  transition: all 0.15s ease;
}

/* Remove native search cancel button in WebKit since we provide a custom button */
.live-search-input::-webkit-search-cancel-button {
  -webkit-appearance: none;
  appearance: none;
}

.live-search-input:focus, .live-filter-input:focus {
  border-color: var(--border-color-focus);
  width: 315px;
  box-shadow: 0 0 0 3px var(--primary-ring);
}

.search-kbd-pill {
  position: absolute;
  right: 0.6rem;
  font-size: 11px;
  font-weight: 700;
  padding: 1px 5px;
  background: var(--bg-surface-secondary);
  border: 1px solid var(--border-color);
  border-radius: 4px;
  color: var(--text-muted);
  pointer-events: none;
}

.search-clear-btn {
  position: absolute;
  right: 0.45rem;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  border: none;
  background: var(--bg-surface-tertiary);
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background-color 0.12s ease, color 0.12s ease;
}

.search-clear-btn:hover {
  background: #e2e8f0;
  color: var(--text);
}

/* ==========================================================================
   Material Card (Refined Academic Storage Card)
   ========================================================================== */
.materials-stack, .resource-list {
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
  margin-bottom: 3rem;
}

.material-card, .resource-card {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  box-shadow: var(--shadow-xs);
  transition: border-color 0.16s ease, box-shadow 0.16s ease, transform 0.16s ease;
  overflow: hidden;
}

.material-card:hover, .resource-card:hover {
  border-color: #cbd5e1;
  box-shadow: var(--shadow-sm);
}

.material-card-body, .resource-main-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.95rem 1.2rem;
  gap: 1.15rem;
}

.material-lead {
  display: flex;
  align-items: flex-start;
  gap: 0.95rem;
  flex: 1;
  min-width: 0;
}

/* File Format Badge Stamp */
.file-icon-badge, .material-format-badge, .resource-file-icon {
  width: 2.75rem;
  height: 2.75rem;
  border-radius: var(--radius-sm);
  background-color: var(--bg-surface-secondary);
  border: 1px solid var(--border-color);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  margin-top: 0.1rem;
}

.file-format-text, .format-ext, .file-ext-label {
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

/* Format Color Variants */
.format-PDF, .file-badge-PDF {
  background-color: var(--red-lt);
  border-color: #fecaca;
  color: var(--danger-color-ml);
}

.format-DOC, .format-DOCX, .file-badge-DOC {
  background-color: var(--blue-lt);
  border-color: #bfdbfe;
  color: var(--blue);
}

.format-IMG, .format-PNG, .format-JPG, .file-badge-IMG {
  background-color: var(--green-lt);
  border-color: #a7f3d0;
  color: var(--success-color-ml);
}

.format-ZIP, .file-badge-ZIP {
  background-color: var(--yellow-lt);
  border-color: #fde68a;
  color: var(--yellow);
}

/* Material Content */
.material-content, .resource-details {
  flex: 1;
  min-width: 0;
}

.material-meta-row, .resource-meta-row {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-wrap: wrap;
  margin-bottom: 0.3rem;
}

.course-code-badge, .material-course-pill, .course-tag-clean {
  font-size: 11px;
  font-weight: 700;
  color: var(--primary-dk);
  background-color: var(--primary-lt);
  border: 1px solid #99f6e4;
  border-radius: var(--radius-xs);
  padding: 1px 6px;
  transition: all 0.12s ease;
}

.course-code-badge:hover, .material-course-pill:hover, .course-tag-clean:hover {
  background-color: #ccfbf1;
}

/* Category Badges */
.category-pill, .material-type-pill, .res-badge-compact {
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.01em;
  padding: 1px 7px;
  border-radius: var(--radius-xs);
  border: 1px solid transparent;
}

.cat-textbook, .pill-textbook, .badge-textbook {
  background-color: var(--cat-textbook-bg);
  color: var(--cat-textbook-text);
  border-color: var(--cat-textbook-border);
}

.cat-lab_manual, .pill-lab_manual, .badge-lab_manual {
  background-color: var(--cat-lab-bg);
  color: var(--cat-lab-text);
  border-color: var(--cat-lab-border);
}

.cat-quiz_assignment, .pill-quiz_assignment, .badge-quiz_assignment {
  background-color: var(--cat-quiz-bg);
  color: var(--cat-quiz-text);
  border-color: var(--cat-quiz-border);
}

.cat-solution, .pill-solution, .badge-solution {
  background-color: var(--cat-solution-bg);
  color: var(--cat-solution-text);
  border-color: var(--cat-solution-border);
}

.has-solution-pill, .material-has-sol-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 11px;
  font-weight: 600;
  color: #065f46;
  background-color: #ecfdf5;
  border: 1px solid #a7f3d0;
  border-radius: var(--radius-xs);
  padding: 1px 6px;
}

.file-meta-item, .material-meta-item, .resource-meta-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 11.5px;
  color: var(--text-muted);
}

.material-title, .resource-title {
  font-size: 14.5px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.35;
  margin: 0;
  word-break: break-word;
}

.material-desc, .resource-desc {
  font-size: 12.5px;
  color: var(--text-secondary);
  margin-top: 0.25rem;
  line-height: 1.45;
}

.material-actions, .resource-actions {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-shrink: 0;
}

/* ==========================================================================
   Attached Linked Solutions (Tree View style)
   ========================================================================== */
.attached-solutions-list, .linked-solutions-drawer, .linked-solutions-box {
  background-color: #fafaff;
  border-top: 1px dashed #ddd6fe;
  padding: 0.7rem 1.2rem 0.7rem 2.25rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.attached-solution-item, .linked-solution-row, .linked-solution-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.85rem;
  font-size: 13px;
}

.solution-lead {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  flex: 1;
  min-width: 0;
}

.solution-tree-guide, .linked-tree-arrow {
  color: var(--cat-solution-text);
  flex-shrink: 0;
  display: flex;
  align-items: center;
}

.solution-details, .linked-solution-lead {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex: 1;
  min-width: 0;
  flex-wrap: wrap;
}

.solution-badges-inline {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

.solution-flag-badge, .linked-sol-badge {
  font-size: 11px;
  font-weight: 600;
  color: var(--cat-solution-text);
  background-color: var(--cat-solution-bg);
  border: 1px solid var(--cat-solution-border);
  border-radius: var(--radius-xs);
  padding: 1px 6px;
  white-space: nowrap;
}

.solution-format-pill {
  padding: 1px 5px;
  border-radius: 4px;
  font-size: 10px;
}

.solution-title, .linked-sol-title {
  font-weight: 600;
  color: var(--text);
  word-break: break-word;
}

.solution-meta, .linked-sol-size {
  font-size: 11px;
  color: var(--text-muted);
}

.solution-actions, .linked-solution-actions {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

/* ==========================================================================
   Courses Section & Grid
   ========================================================================== */
.course-directory-section {
  border-top: 1px solid var(--border-color);
  padding-top: 2.25rem;
  margin-bottom: 3rem;
}

.section-heading-row {
  margin-bottom: 1.25rem;
}

.section-title {
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--text);
}

.section-subtitle {
  font-size: 12.5px;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.courses-grid, .course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(275px, 1fr));
  gap: 0.9rem;
}

.course-card {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1.1rem 1.2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  text-decoration: none;
  box-shadow: var(--shadow-xs);
  transition: all 0.16s ease;
  position: relative;
}

.course-card:hover {
  border-color: #99f6e4;
  box-shadow: var(--shadow);
  transform: translateY(-2px);
}

.course-card-header, .course-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  margin-bottom: 0.55rem;
}

.semester-tag, .course-semester-pill {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-surface-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xs);
  padding: 2px 7px;
}

.course-title {
  font-size: 14.5px;
  font-weight: 700;
  color: var(--text);
  line-height: 1.38;
  margin-bottom: 0.95rem;
}

.course-card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-color-light);
  padding-top: 0.7rem;
  font-size: 12px;
}

.course-materials-count, .resource-badge-count {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-muted);
  font-weight: 500;
}

.course-arrow {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-weight: 700;
  color: var(--primary);
  transition: transform 0.14s ease;
}

.course-card:hover .course-arrow {
  transform: translateX(2px);
}

/* ==========================================================================
   Course Detail Page
   ========================================================================== */
.course-breadcrumbs {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 12.5px;
  color: var(--text-muted);
  margin-bottom: 1.15rem;
  flex-wrap: wrap;
}

.breadcrumb-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  color: var(--text-secondary);
  font-weight: 500;
}

.breadcrumb-link:hover {
  color: var(--primary);
}

.breadcrumb-separator {
  color: #cbd5e1;
}

.breadcrumb-current {
  color: var(--text);
  font-weight: 600;
}

.course-detail-header, .course-header {
  background: linear-gradient(135deg, #ffffff 0%, #f8fafc 100%);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  margin-bottom: 1.35rem;
  box-shadow: var(--shadow-xs);
}

.course-detail-header-inner {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.course-detail-main {
  flex: 1;
  min-width: 240px;
}

.course-code-tag {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  color: var(--primary-dk);
  background: var(--primary-lt);
  border: 1px solid #99f6e4;
  border-radius: var(--radius-xs);
  padding: 2px 8px;
}

.course-badge-row, .course-header-top {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  flex-wrap: wrap;
  margin-bottom: 0.65rem;
}

.course-materials-indicator {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
}

.course-detail-title, .course-header-title {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text);
}

.course-admin-actions {
  flex-shrink: 0;
}

.course-tab-bar, .resource-nav-tabs {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.35rem;
  margin-bottom: 1.25rem;
  overflow-x: auto;
  box-shadow: var(--shadow-xs);
  scrollbar-width: none;
  -ms-overflow-style: none;
  -webkit-overflow-scrolling: touch;
}

.course-tab-bar::-webkit-scrollbar,
.resource-nav-tabs::-webkit-scrollbar {
  display: none;
}

.course-filter-tab, .res-tab-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  padding: 7px 13px;
  min-height: 36px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.14s ease;
  user-select: none;
}

.course-filter-tab:hover, .res-tab-btn:hover {
  background-color: var(--bg-surface-tertiary);
  color: var(--text);
}

.course-filter-tab.active, .res-tab-btn.active {
  background: linear-gradient(180deg, #0d9488 0%, #0f766e 100%);
  color: #ffffff;
  border-color: var(--primary-dk);
  box-shadow: 0 1px 3px rgba(15, 118, 110, 0.25);
}

.tab-count-pill {
  font-size: 11px;
  font-weight: 700;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  background-color: rgba(15, 23, 42, 0.08);
}

.course-filter-tab.active .tab-count-pill {
  background-color: rgba(255, 255, 255, 0.25);
  color: #ffffff;
}

/* ==========================================================================
   Admin Console (MBKBucket style)
   ========================================================================== */
.admin-layout {
  padding-top: 0.75rem;
}

.admin-page-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.25rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
}

.admin-kicker, .course-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--primary-dk);
  background: var(--primary-lt);
  padding: 2px 8px;
  border-radius: var(--radius-xs);
  border: 1px solid #ccfbf1;
}

.admin-page-title {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  color: var(--text);
  margin-top: 0.3rem;
}

.admin-page-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 0.2rem;
}

.admin-actions-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.admin-nav-tabs {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 0.35rem;
  margin-bottom: 1.5rem;
  overflow-x: auto;
  box-shadow: var(--shadow-xs);
  scrollbar-width: none;
  -ms-overflow-style: none;
}

.admin-nav-tabs::-webkit-scrollbar {
  display: none;
}

.admin-nav-tab {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  padding: 7px 13px;
  min-height: 36px;
  border-radius: var(--radius-sm);
  white-space: nowrap;
  transition: all 0.14s ease;
}

.admin-nav-tab:hover {
  background-color: var(--bg-surface-tertiary);
  color: var(--text);
}

.admin-nav-tab.active {
  background: linear-gradient(180deg, #0d9488 0%, #0f766e 100%);
  color: #ffffff;
  box-shadow: var(--shadow-xs);
}

.tab-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  background-color: rgba(15, 23, 42, 0.08);
}

.admin-nav-tab.active .tab-badge {
  background-color: rgba(255, 255, 255, 0.25);
  color: #ffffff;
}

/* Admin Metrics Ribbon */
.admin-stats-ribbon, .stats-ribbon {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 0.75rem;
  margin-bottom: 1.75rem;
}

.admin-stat-card, .stat-item {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  box-shadow: var(--shadow-xs);
}

.admin-stat-num, .stat-num {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--primary-dk);
  line-height: 1.1;
}

.admin-stat-val {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text);
}

.admin-stat-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* Admin Panel Card */
.admin-panel-card, .admin-card {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.35rem 1.5rem;
  box-shadow: var(--shadow-sm);
  margin-bottom: 2rem;
}

.admin-toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 1.25rem;
  flex-wrap: wrap;
}

.admin-panel-heading, .admin-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text);
}

.admin-count-badge {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
}

.admin-filter-form {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.admin-input, .form-control {
  font-family: var(--font);
  font-size: 13.5px;
  color: var(--text);
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  outline: none;
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
  box-sizing: border-box;
}

.form-control {
  width: 100%;
  display: block;
  min-height: 40px;
  line-height: 1.5;
}

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

.form-control-sm {
  min-height: 34px;
  height: 34px;
  padding: 4px 8px;
  font-size: 12.5px;
  border-radius: var(--radius-xs);
}

textarea.form-control {
  min-height: 88px;
  height: auto;
  resize: vertical;
  line-height: 1.5;
}

select.form-control {
  cursor: pointer;
  height: 40px;
  background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
  background-repeat: no-repeat;
  background-position: right 10px center;
  background-size: 14px;
  padding-right: 32px;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
}

.admin-input-search {
  width: 185px;
  min-height: 34px;
}

.admin-select {
  font-family: var(--font);
  font-size: 13px;
  color: var(--text);
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 6px 10px;
  min-height: 34px;
  outline: none;
  cursor: pointer;
}

.admin-select:focus {
  border-color: var(--border-color-focus);
  box-shadow: 0 0 0 3px var(--primary-ring);
}

/* Admin Tables */
.table-responsive {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  border-radius: var(--radius-sm);
}

.admin-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 13px;
}

.admin-table th {
  text-align: left;
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  padding: 10px 12px;
  border-bottom: 1px solid var(--border-color);
  background-color: #f8fafc;
  white-space: nowrap;
}

.admin-table td {
  padding: 11px 12px;
  border-bottom: 1px solid var(--border-color-light);
  vertical-align: middle;
}

.admin-table tbody tr:hover {
  background-color: #f8fafc;
}

.table-course-code {
  font-weight: 700;
  color: var(--primary-dk);
}

.table-course-code:hover {
  text-decoration: underline;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 11px;
  font-weight: 600;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  letter-spacing: 0.02em;
}

.status-visible {
  background-color: #ecfdf5;
  color: #047857;
  border: 1px solid #a7f3d0;
}

.status-hidden {
  background-color: #fef2f2;
  color: #b91c1c;
  border: 1px solid #fecaca;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: currentColor;
}

.table-subtext {
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 0.15rem;
}

.table-title {
  font-weight: 600;
  color: var(--text);
}

.table-file-meta {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.table-ext-tag {
  font-size: 10px;
  font-weight: 800;
  padding: 1px 4px;
  border-radius: 4px;
}

.table-filename {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  max-width: 250px;
}

.table-linked-parent {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 11px;
  color: var(--cat-solution-text);
  margin-top: 0.2rem;
}

.table-muted {
  color: var(--text-secondary);
}

.table-total-count {
  font-weight: 700;
  color: var(--primary-dk);
}

.table-action-row {
  display: inline-flex;
  gap: 0.35rem;
}

.nowrap {
  white-space: nowrap;
}

.text-right {
  text-align: right;
}

/* ==========================================================================
   Forms & Upload Controls
   ========================================================================== */
.admin-form-container {
  max-width: 880px;
  margin-left: auto;
  margin-right: auto;
  padding-top: 0.75rem;
  padding-bottom: 4rem;
}

.admin-form-card {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem 2.25rem;
  box-shadow: var(--shadow-sm);
}

.form-header {
  margin-bottom: 1.75rem;
  padding-bottom: 1.25rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.form-header-main {
  min-width: 0;
  flex: 1;
}

.form-header-quick-links {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-shrink: 0;
}

.form-header-title {
  font-size: 1.45rem;
  font-weight: 800;
  color: var(--text);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  margin-top: 0.3rem;
}

.form-header-subtitle {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 0.35rem;
}

.form-group {
  margin-bottom: 1.35rem;
}

.form-label {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  flex-wrap: wrap;
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.45rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.form-hint {
  font-size: 12px;
  color: var(--text-muted);
  margin-top: 0.3rem;
}

.form-help {
  font-size: 11.5px;
  color: var(--text-muted);
  margin-top: 0.35rem;
  display: block;
  line-height: 1.45;
}

/* Dynamic Solution Group Highlight */
.linked-quiz-panel {
  background: #f0fdfa;
  border: 1.5px dashed var(--primary);
  border-radius: var(--radius-sm);
  padding: 1.15rem 1.25rem;
  margin-bottom: 1.35rem;
  transition: all 0.15s ease;
}

.linked-quiz-title {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-size: 13px;
  font-weight: 700;
  color: var(--primary-dk);
  margin-bottom: 0.5rem;
}

/* Current Attached File in Edit Mode */
.current-file-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.85rem 1.15rem;
  margin-bottom: 0.75rem;
  transition: border-color 0.15s ease;
  flex-wrap: wrap;
}

.current-file-card:hover {
  border-color: #cbd5e1;
}

.current-file-main {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  min-width: 0;
  flex: 1;
}

.current-file-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-xs);
  display: flex;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  border: 1px solid var(--border-color);
  flex-shrink: 0;
  box-shadow: var(--shadow-xs);
}

.current-file-meta {
  min-width: 0;
  flex: 1;
}

.current-file-name {
  font-size: 13.5px;
  font-weight: 700;
  color: var(--text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: block;
}

.current-file-sub {
  font-size: 11.5px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 0.15rem;
  flex-wrap: wrap;
}

.current-file-actions {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  flex-shrink: 0;
}

/* Visibility Toggle Card */
.visibility-toggle-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem 1.25rem;
  background: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  margin-bottom: 1.5rem;
  transition: all 0.15s ease;
  cursor: pointer;
}

.visibility-toggle-card:hover {
  background: #f1f5f9;
  border-color: #cbd5e1;
}

.visibility-toggle-left {
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
}

.visibility-checkbox {
  width: 1.25rem;
  height: 1.25rem;
  accent-color: var(--primary);
  cursor: pointer;
  margin-top: 0.15rem;
  flex-shrink: 0;
}

.visibility-info-title {
  font-size: 13.5px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 0.2rem;
}

.visibility-info-desc {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.45;
}

.visibility-status-badge {
  font-size: 11px;
  font-weight: 700;
  padding: 3px 9px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
  white-space: nowrap;
}

.visibility-status-badge.live {
  background: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.visibility-status-badge.hidden {
  background: #fef2f2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

/* Drop Zone */
.upload-drop-zone {
  border: 2px dashed #cbd5e1;
  border-radius: var(--radius);
  padding: 2.25rem 1.5rem;
  text-align: center;
  background: #f8fafc;
  cursor: pointer;
  transition: all 0.15s ease;
  position: relative;
}

.upload-drop-zone:hover, .upload-drop-zone.dragover {
  border-color: var(--primary);
  background: var(--primary-light-color-ml);
}

.drop-zone-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.drop-icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: #ffffff;
  color: var(--primary);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 0.75rem;
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-xs);
}

.drop-text {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 0.25rem;
}

.drop-browse-link {
  color: var(--primary);
  text-decoration: underline;
  cursor: pointer;
  font-weight: 700;
}

.drop-hint {
  font-size: 11.5px;
  color: var(--text-muted);
}

.drop-formats-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  margin-top: 0.65rem;
  flex-wrap: wrap;
}

.drop-fmt-pill {
  font-size: 10px;
  font-weight: 700;
  padding: 1px 6px;
  border-radius: var(--radius-xs);
  background: #ffffff;
  border: 1px solid #e2e8f0;
  color: var(--text-muted);
}

/* Selected File Preview Box */
.selected-file-box {
  display: none;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  margin-top: 0.85rem;
  box-shadow: var(--shadow-xs);
}

.selected-file-info {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  min-width: 0;
}

.selected-file-name {
  font-weight: 600;
  color: var(--text);
  font-size: 13px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.selected-file-size {
  font-size: 11.5px;
  color: var(--text-muted);
  white-space: nowrap;
}

.form-footer-actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 0.75rem;
  margin-top: 1.75rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-color);
  flex-wrap: wrap;
}

/* ==========================================================================
   Alerts & Notifications
   ========================================================================== */
.alert {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  padding: 0.8rem 1.05rem;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 1.25rem;
  box-shadow: var(--shadow-xs);
}

.alert-success {
  background-color: var(--green-lt);
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.alert-error, .alert-danger {
  background-color: var(--red-lt);
  color: #991b1b;
  border: 1px solid #fecaca;
}

/* ==========================================================================
   Empty States
   ========================================================================== */
.empty-state-box, .empty-state {
  text-align: center;
  padding: 3.25rem 1.5rem;
  background-color: #ffffff;
  border: 1px dashed #cbd5e1;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xs);
}

.empty-icon-wrap {
  color: var(--text-disabled);
  margin-bottom: 0.75rem;
}

.empty-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.35rem;
}

.empty-description {
  font-size: 13px;
  color: var(--text-secondary);
  max-width: 440px;
  margin: 0 auto 1.25rem;
  line-height: 1.5;
}

.empty-actions {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  flex-wrap: wrap;
}

/* Notice / 404 Page */
.notice-container {
  max-width: 540px;
  padding-top: 4rem;
  padding-bottom: 4rem;
  text-align: center;
}

.notice-card {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2rem;
  box-shadow: var(--shadow-sm);
}

.notice-icon-circle {
  width: 3.25rem;
  height: 3.25rem;
  border-radius: var(--radius-sm);
  background-color: var(--red-lt);
  color: var(--danger-color-ml);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
}

.notice-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.65rem;
}

.notice-text {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.75rem;
}

.notice-actions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.65rem;
  flex-wrap: wrap;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.app-footer, .unilib-footer {
  margin-top: auto;
  background-color: #ffffff;
  border-top: 1px solid var(--border-color);
  padding: 1.75rem 0;
  font-size: 13px;
  color: var(--text-muted);
}

.app-footer-inner, .unilib-footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.footer-col-left {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.footer-brand-line {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  color: var(--text-secondary);
  flex-wrap: wrap;
}

.footer-brand-title {
  font-weight: 800;
  color: var(--primary-dk);
}

.footer-divider {
  color: #cbd5e1;
}

.footer-tagline {
  font-size: 12px;
  color: var(--text-muted);
}

.footer-col-right {
  display: flex;
  align-items: center;
  gap: 1.15rem;
  font-size: 12.5px;
  flex-wrap: wrap;
}

.footer-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--text-secondary);
  font-weight: 500;
  transition: color 0.12s ease;
}

.footer-link:hover {
  color: var(--primary);
}

/* ==========================================================================
   Chapters & Experiments Page Slicing
   ========================================================================== */
.has-sections-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 11px;
  font-weight: 600;
  color: var(--primary-dk);
  background-color: var(--primary-lt);
  border: 1px solid #99f6e4;
  padding: 1px 7px;
  border-radius: var(--radius-xs);
}

.btn-sections-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}

.btn-sections-toggle .chevron-icon {
  transition: transform 0.18s ease;
}

.btn-sections-toggle.active {
  background-color: var(--primary-lt);
  border-color: #99f6e4;
  color: var(--primary-dk);
}

.btn-sections-toggle.active .chevron-icon {
  transform: rotate(180deg);
}

.attached-sections-drawer {
  background-color: #f8fafc;
  border-top: 1px dashed var(--border-color);
  padding: 0.9rem 1.2rem;
  animation: fadeIn 0.16s ease-out;
}

.sections-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.65rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border-color-light);
  flex-wrap: wrap;
}

.sections-drawer-title-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sections-flag-badge {
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  background-color: var(--primary-lt);
  color: var(--primary-dk);
  border: 1px solid #99f6e4;
  padding: 1px 6px;
  border-radius: var(--radius-xs);
}

.sections-drawer-title {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.sections-drawer-count {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
}

.sections-grid-list {
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.section-slice-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.55rem 0.85rem;
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  transition: border-color 0.12s ease, box-shadow 0.12s ease;
}

.section-slice-item:hover {
  border-color: #99f6e4;
  box-shadow: var(--shadow-xs);
}

.section-lead {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex: 1;
  min-width: 0;
}

.section-slice-item .section-tree-guide {
  color: var(--primary);
  opacity: 0.75;
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.section-details {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex: 1;
  min-width: 0;
  flex-wrap: wrap;
}

.section-slice-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text);
  word-break: break-word;
}

.section-meta-pill {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  background-color: var(--bg-surface-secondary);
  border: 1px solid var(--border-color);
  padding: 1px 7px;
  border-radius: var(--radius-xs);
  white-space: nowrap;
}

.section-actions {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  flex-shrink: 0;
}

/* Sections Builder (Admin Form) */
.sections-builder-card {
  background-color: #f8fafc;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.05rem 1.2rem;
  margin-top: 1rem;
  margin-bottom: 1.25rem;
}

.sections-builder-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 0.35rem;
}

.sections-builder-heading {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.sections-builder-title {
  font-size: 13px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: -0.01em;
}

.sections-builder-desc {
  font-size: 12px;
  color: var(--text-secondary);
  margin-bottom: 0.85rem;
  line-height: 1.45;
}

.sections-table-wrapper {
  background-color: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: 0.75rem;
  box-shadow: var(--shadow-xs);
}

.sections-table-header {
  display: grid;
  grid-template-columns: 38px 1fr 85px 85px 95px 44px;
  gap: 0.65rem;
  padding: 0.6rem 0.85rem;
  background-color: var(--bg-surface-tertiary);
  border-bottom: 1px solid var(--border-color);
  font-size: 11px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--text-secondary);
  align-items: center;
}

.sections-table-header .col-num,
.sections-table-header .col-page,
.sections-table-header .col-span,
.sections-table-header .col-action {
  text-align: center;
}

.sections-list {
  display: flex;
  flex-direction: column;
}

.section-table-row {
  display: grid;
  grid-template-columns: 38px 1fr 85px 85px 95px 44px;
  gap: 0.65rem;
  padding: 0.55rem 0.85rem;
  align-items: center;
  border-bottom: 1px solid var(--border-color-light);
  background-color: #ffffff;
  transition: background-color 0.1s ease;
}

.section-table-row:hover {
  background-color: #fbfcfd;
}

.section-table-row:last-child {
  border-bottom: none;
}

.section-table-row .col-num,
.section-table-row .col-action {
  display: flex;
  justify-content: center;
  align-items: center;
}

.section-table-row .col-page input {
  text-align: center;
  font-variant-numeric: tabular-nums;
}

.section-table-row .col-span {
  display: flex;
  justify-content: center;
}

.section-row-badge {
  font-size: 11px;
  font-weight: 700;
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 22px;
  height: 22px;
  border-radius: var(--radius-xs);
  background-color: var(--bg-surface-secondary);
}

.sec-span-pill {
  font-size: 11px;
  font-weight: 600;
  color: var(--primary-dk);
  background-color: var(--primary-lt);
  border: 1px solid #ccfbf1;
  padding: 2px 6px;
  border-radius: var(--radius-xs);
  text-align: center;
  display: block;
}

.sections-toolbar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  flex-wrap: wrap;
}

/* ==========================================================================
   Google Drive & MBKBucket Dual Mirror Verification System
   ========================================================================== */
.btn-drive {
  background-color: #ffffff;
  color: #1e293b;
  border: 1px solid #cbd5e1;
  box-shadow: var(--shadow-xs);
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
}

.btn-drive:hover {
  background-color: #f8fafc;
  border-color: #94a3b8;
  color: #0f172a;
}

.btn-drive svg.gdrive-svg {
  flex-shrink: 0;
}

.section-mirror-tag {
  display: inline-flex;
  align-items: center;
  font-size: 10px;
  font-weight: 600;
  padding: 0.1rem 0.4rem;
  border-radius: var(--radius-sm);
  background: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
  margin-left: 0.35rem;
  vertical-align: middle;
}

/* Network Status Indicator in Top Navbar */
.network-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.34rem 0.7rem;
  font-family: var(--font);
  font-size: 11.5px;
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 1px solid var(--border-color);
  background: var(--bg-surface);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all 0.15s ease;
  user-select: none;
  white-space: nowrap;
}

.network-status-pill:hover {
  background: var(--bg-surface-secondary);
  border-color: #cbd5e1;
}

.status-text-short {
  display: none;
}

.status-pulse-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  display: inline-block;
  background-color: #94a3b8;
  flex-shrink: 0;
}

.network-status-pill.checking .status-pulse-dot {
  background-color: #3b82f6;
  animation: pulse-checking 1.2s infinite;
}

.network-status-pill.gdrive-ok {
  border-color: #a7f3d0;
  background: #ecfdf5;
  color: #065f46;
}

.network-status-pill.gdrive-ok .status-pulse-dot {
  background-color: #10b981;
}

.network-status-pill.gdrive-blocked {
  border-color: #fde68a;
  background: #fffbeb;
  color: #92400e;
}

.network-status-pill.gdrive-blocked .status-pulse-dot {
  background-color: #f59e0b;
}

@keyframes pulse-checking {
  0% { transform: scale(0.9); opacity: 0.6; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.9); opacity: 0.6; }
}

/* Campus Network Notice Banner */
.campus-network-notice {
  margin-bottom: 1.15rem;
  padding: 0.8rem 1rem;
  border-radius: var(--radius);
  background: #fffbeb;
  border: 1px solid #fde68a;
  color: #92400e;
  font-size: 12.5px;
  line-height: 1.45;
  display: flex;
  align-items: center;
  justify-content: space-between;
  box-shadow: var(--shadow-xs);
  animation: noticeSlideDown 0.25s ease-out;
}

.campus-network-notice .notice-inner {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
}

.campus-network-notice .notice-icon {
  flex-shrink: 0;
  color: #d97706;
  margin-top: 0.1rem;
}

@keyframes noticeSlideDown {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ==========================================================================
   Mobile & Tablet Responsive Architecture
   ========================================================================== */
@media (max-width: 768px) {
  .desktop-only {
    display: none !important;
  }

  .mobile-only {
    display: inline-flex !important;
  }

  .unilib-container {
    padding-left: 1rem;
    padding-right: 1rem;
  }

  .unilib-main {
    padding-top: 1rem;
    padding-bottom: 3rem;
  }

  /* Compact Navbar on Mobile */
  .top-nav-inner, .unilib-nav-inner {
    height: 3.5rem;
    gap: 0.5rem;
  }

  .logo-mark {
    width: 2rem;
    height: 2rem;
  }

  .logo-title {
    font-size: 1.12rem;
  }

  .status-text-full {
    display: none;
  }

  .status-text-short {
    display: inline;
  }

  .network-status-pill {
    padding: 0.3rem 0.58rem;
    font-size: 11px;
  }

  /* Masthead Hero on Mobile */
  .archive-masthead, .unilib-compact-hero {
    flex-direction: column;
    align-items: stretch;
    gap: 1.1rem;
    padding: 1.15rem 1.1rem;
    margin-bottom: 1.15rem;
  }

  .masthead-title, .unilib-compact-title {
    font-size: 1.45rem;
  }

  .masthead-description, .unilib-compact-subtitle {
    font-size: 0.88rem;
  }

  .masthead-metrics, .compact-hero-stats {
    width: 100%;
    justify-content: space-around;
    padding: 0.75rem 0.65rem;
    gap: 0.5rem;
  }

  .metric-block, .mini-stat {
    align-items: center;
    text-align: center;
    flex: 1;
  }

  .metric-value, .mini-stat-num {
    font-size: 1.25rem;
  }

  /* Semester Strip & Filter Tabs on Mobile */
  .semester-strip, .semester-tabs-wrapper {
    margin-bottom: 1.15rem;
  }

  .sem-tab, .course-filter-tab {
    padding: 7px 11px;
    font-size: 12.5px;
  }

  /* Toolbar & Search on Mobile (16px font prevents iOS Safari auto-zoom on tap) */
  .materials-toolbar, .materials-filter-bar {
    flex-direction: column;
    align-items: stretch;
    gap: 0.75rem;
  }

  .toolbar-controls {
    display: grid;
    grid-template-columns: 1fr;
    gap: 0.55rem;
    width: 100%;
  }

  .filter-dropdown-wrap,
  .live-search-box,
  .live-filter-box {
    width: 100%;
  }

  .toolbar-select,
  .material-category-select,
  .live-search-input,
  .live-filter-input,
  .admin-input,
  .admin-select,
  .form-control {
    width: 100% !important;
    font-size: 16px;
    min-height: 42px;
  }

  /* Material Cards on Mobile: Side-by-Side Icon + Info, Full-Width Touch Action Bar */
  .material-card-body, .resource-main-row {
    flex-direction: column;
    align-items: stretch;
    padding: 0.9rem 0.95rem;
    gap: 0.8rem;
  }

  .material-lead {
    gap: 0.75rem;
  }

  .file-icon-badge {
    width: 2.5rem;
    height: 2.5rem;
  }

  .material-title {
    font-size: 14px;
  }

  .material-actions, .resource-actions {
    width: 100%;
    padding-top: 0.65rem;
    border-top: 1px solid var(--border-color-light);
    display: flex;
    flex-wrap: wrap;
    gap: 0.45rem;
  }

  .material-actions .btn,
  .resource-actions .btn {
    flex: 1 1 auto;
    min-height: 38px;
    justify-content: center;
    font-size: 12.5px;
  }

  /* Attached Chapters & Solutions on Mobile */
  .attached-sections-drawer {
    padding: 0.75rem 0.9rem;
  }

  .section-slice-item {
    flex-direction: column;
    align-items: stretch;
    gap: 0.55rem;
    padding: 0.65rem 0.75rem;
  }

  .section-actions {
    width: 100%;
    display: flex;
    gap: 0.45rem;
  }

  .section-actions .btn {
    flex: 1;
    min-height: 34px;
    justify-content: center;
  }

  .attached-solutions-list, .linked-solutions-drawer {
    padding: 0.7rem 0.95rem;
  }

  .attached-solution-item {
    flex-direction: column;
    align-items: stretch;
    gap: 0.55rem;
  }

  .solution-actions {
    width: 100%;
    display: flex;
    gap: 0.45rem;
  }

  .solution-actions .btn {
    flex: 1;
    min-height: 34px;
    justify-content: center;
  }

  /* Course Grid & Course Detail on Mobile */
  .courses-grid, .course-grid {
    grid-template-columns: 1fr;
    gap: 0.7rem;
  }

  .course-detail-header, .course-header {
    padding: 1.15rem 1.1rem;
  }

  .course-detail-title, .course-header-title {
    font-size: 1.4rem;
  }

  .course-admin-actions,
  .course-admin-actions .btn {
    width: 100%;
  }

  /* Admin Layout & Forms on Mobile */
  .admin-stats-ribbon, .stats-ribbon {
    grid-template-columns: repeat(2, 1fr);
    gap: 0.6rem;
  }

  .admin-panel-card, .admin-card {
    padding: 1rem;
  }

  .admin-filter-form {
    flex-direction: column;
    align-items: stretch;
    width: 100%;
  }

  .admin-filter-form .btn {
    width: 100%;
    min-height: 40px;
  }

  .admin-form-card {
    padding: 1.25rem 1.1rem;
  }

  .form-row {
    grid-template-columns: 1fr;
    gap: 0;
  }

  .form-header {
    flex-direction: column;
    gap: 0.85rem;
  }

  .form-header-quick-links {
    width: 100%;
  }

  .form-header-quick-links .btn {
    flex: 1;
  }

  .current-file-card {
    flex-direction: column;
    align-items: stretch;
  }

  .current-file-actions {
    width: 100%;
  }

  .current-file-actions .btn {
    flex: 1;
    min-height: 36px;
  }

  .visibility-toggle-card {
    flex-direction: column;
    align-items: flex-start;
  }

  .form-footer-actions {
    flex-direction: column-reverse;
    align-items: stretch;
  }

  .form-footer-actions .btn {
    width: 100%;
    min-height: 42px;
  }

  /* Admin Section Builder Rows on Mobile */
  .sections-table-header {
    display: none;
  }

  .section-table-row {
    grid-template-columns: 34px repeat(4, 1fr) 36px;
    gap: 0.45rem;
    padding: 0.75rem;
  }

  .section-table-row .col-num {
    grid-column: 1 / 2;
    grid-row: 1;
  }

  .section-table-row .col-title {
    grid-column: 2 / 6;
    grid-row: 1;
  }

  .section-table-row .col-action {
    grid-column: 6 / 7;
    grid-row: 1;
  }

  .section-table-row > .col-page:nth-child(3) {
    grid-column: 1 / 3;
    grid-row: 2;
  }

  .section-table-row > .col-page:nth-child(4) {
    grid-column: 3 / 5;
    grid-row: 2;
  }

  .section-table-row .col-span {
    grid-column: 5 / 7;
    grid-row: 2;
  }

  /* Footer on Mobile */
  .app-footer-inner, .unilib-footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
  }
}