:root {
  --primary-50: #eef4ff;
  --primary-100: #dfeaff;
  --primary-500: #2563eb;
  --primary-600: #1d4ed8;
  --primary-700: #1e3a8a;
  --secondary-500: #0ea5e9;
  --secondary-600: #0284c7;
  --accent-500: #f59e0b;
  --success-500: #22c55e;
  --error-500: #ef4444;
  --warning-500: #f59e0b;
  --neutral-900: #111827;
  --neutral-800: #1f2937;
  --neutral-700: #374151;
  --neutral-600: #4b5563;
  --neutral-500: #6b7280;
  --neutral-300: #d1d5db;
  --neutral-200: #e5e7eb;
  --neutral-100: #f3f4f6;
  --neutral-50: #f9fafb;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.12);
  --shadow-lg: 0 18px 40px rgba(15, 23, 42, 0.16);
  --radius-xs: 0.5rem;
  --radius-sm: 0.75rem;
  --radius-md: 1rem;
  --radius-lg: 1.5rem;
  --radius-xl: 2rem;
  --transition-fast: 180ms ease;
  --transition-base: 260ms ease;
  --transition-slow: 360ms ease;
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 0.75rem;
  --spacing-lg: 1rem;
  --spacing-xl: 1.5rem;
  --spacing-2xl: 2rem;
  --spacing-3xl: 3rem;
  --container-max: 1200px;
  --font-sans: "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  --heading-1: clamp(2rem, 4vw, 3.5rem);
  --heading-2: clamp(1.55rem, 2.5vw, 2.4rem);
  --heading-3: clamp(1.25rem, 2vw, 1.75rem);
  --body: clamp(1rem, 1.4vw, 1.125rem);
  --body-sm: 0.96rem;
  --nav-height: 74px;
}

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

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

body {
  font-family: var(--font-sans);
  line-height: 1.7;
  color: var(--neutral-800);
  background: linear-gradient(180deg, #f8fbff 0%, #f8fafc 100%);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img,
svg,
video {
  max-width: 100%;
  display: block;
}

a {
  color: var(--primary-600);
  text-decoration: none;
  transition: color var(--transition-base), background-color var(--transition-base), transform var(--transition-base);
}

a:hover {
  color: var(--primary-700);
}

button,
input,
select,
textarea {
  font: inherit;
}

button {
  cursor: pointer;
}

input,
select,
textarea {
  width: 100%;
  min-height: 44px;
  padding: 0.8rem 0.9rem;
  border: 1px solid var(--neutral-300);
  border-radius: var(--radius-sm);
  background: #fff;
  color: var(--neutral-800);
  font-size: 16px;
  transition: border-color var(--transition-base), box-shadow var(--transition-base), transform var(--transition-base);
}

input:focus,
select:focus,
textarea:focus,
button:focus-visible,
a:focus-visible {
  outline: none;
  border-color: var(--primary-500);
  box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.14);
}

.container,
.container-fluid {
  width: min(var(--container-max), calc(100% - 2rem));
  margin-inline: auto;
}

main {
  display: block;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  color: var(--neutral-900);
  line-height: 1.2;
  margin-bottom: var(--spacing-lg);
  letter-spacing: -0.02em;
}

h1 { font-size: var(--heading-1); }
h2 { font-size: var(--heading-2); }
h3 { font-size: var(--heading-3); }
h4 { font-size: clamp(1.1rem, 1.5vw, 1.35rem); }

p {
  margin-bottom: var(--spacing-lg);
  color: var(--neutral-700);
}

.site-header,
.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(229, 231, 235, 0.9);
  box-shadow: var(--shadow-sm);
}

.navbar-container,
.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--spacing-xl);
  min-height: var(--nav-height);
  width: min(var(--container-max), calc(100% - 2rem));
  margin-inline: auto;
}

.navbar-brand,
.logo {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 800;
  color: var(--neutral-900);
  letter-spacing: -0.03em;
}

.logo-icon,
.navbar-brand .logo-icon {
  width: 2.65rem;
  height: 2.65rem;
  border-radius: 0.9rem;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--primary-500), #7c3aed);
  color: #fff;
  box-shadow: var(--shadow-md);
}

.logo-text {
  font-size: clamp(1.1rem, 1.8vw, 1.5rem);
  color: var(--neutral-900);
}

.navbar-menu {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  flex: 1;
  gap: var(--spacing-xl);
}

.navbar-nav,
.nav-list {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  list-style: none;
  flex-wrap: wrap;
}

.nav-item,
.nav-list li {
  list-style: none;
}

.nav-link,
.nav-list a {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  border-radius: 0.8rem;
  padding: 0.7rem 0.95rem;
  color: var(--neutral-600);
  font-weight: 600;
  transition: background-color var(--transition-base), color var(--transition-base), transform var(--transition-base);
}

.nav-link:hover,
.nav-list a:hover,
.nav-link.active {
  color: var(--primary-600);
  background: rgba(37, 99, 235, 0.06);
}

.nav-link::after,
.nav-list a::after {
  content: "";
  position: absolute;
  left: 0.9rem;
  right: 0.9rem;
  bottom: 0.45rem;
  height: 2px;
  background: var(--primary-500);
  transform: scaleX(0);
  transform-origin: center;
  transition: transform var(--transition-base);
}

.nav-link:hover::after,
.nav-list a:hover::after,
.nav-link.active::after {
  transform: scaleX(1);
}

.auth-buttons {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-left: var(--spacing-sm);
}

.btn,
.btn-primary,
.btn-secondary,
.btn-outline {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  min-height: 44px;
  padding: 0.8rem 1.2rem;
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  font-weight: 700;
  transition: transform var(--transition-base), box-shadow var(--transition-base), background-color var(--transition-base), border-color var(--transition-base);
}

.btn:hover,
.btn-primary:hover,
.btn-secondary:hover,
.btn-outline:hover {
  transform: translateY(-1px);
}

.btn-primary,
.btn {
  background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
  color: #fff;
  box-shadow: 0 12px 24px rgba(37, 99, 235, 0.18);
}

.btn-secondary {
  background: linear-gradient(135deg, var(--success-500), #16a34a);
  color: #fff;
}

.btn-outline {
  background: transparent;
  border-color: var(--primary-500);
  color: var(--primary-600);
}

.navbar-toggle {
  display: none;
  min-width: 44px;
  min-height: 44px;
  border: 1px solid var(--neutral-200);
  border-radius: 0.8rem;
  background: rgba(255, 255, 255, 0.9);
  color: var(--primary-600);
}

.user-dropdown {
  position: relative;
}

.user-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.8rem;
  min-height: 44px;
  padding: 0.4rem 0.7rem 0.4rem 0.45rem;
  border-radius: 999px;
  border: 1px solid var(--neutral-200);
  background: var(--neutral-50);
  color: var(--neutral-800);
}

.user-avatar {
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: linear-gradient(135deg, var(--primary-500), #8b5cf6);
  color: #fff;
  font-weight: 700;
  overflow: hidden;
}

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

.user-info {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
}

.user-name {
  font-size: 0.78rem;
  font-weight: 700;
  line-height: 1.2;
}

.user-role {
  font-size: 0.68rem;
  color: var(--neutral-500);
  line-height: 1.2;
}

.dropdown-menu {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  min-width: min(250px, 82vw);
  padding: 0.6rem;
  border: 1px solid var(--neutral-200);
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
}

.dropdown-menu.show {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: 0.7rem;
  min-height: 44px;
  padding: 0.75rem 0.8rem;
  border-radius: 0.7rem;
  color: var(--neutral-700);
}

.dropdown-item:hover {
  background: var(--neutral-100);
  color: var(--primary-600);
}

.dropdown-divider {
  height: 1px;
  background: var(--neutral-200);
  margin: 0.4rem 0;
}

.hero-section {
  position: relative;
  background: linear-gradient(135deg, var(--primary-600) 0%, #7c3aed 100%);
  color: #fff;
  padding: clamp(3.5rem, 6vw, 6rem) 0;
  overflow: hidden;
}

.hero-section::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at top right, rgba(255,255,255,0.14), transparent 32%);
}

.hero-section .container {
  position: relative;
  z-index: 1;
  text-align: center;
}

.hero-section h1,
.hero-section h2,
.hero-section p {
  color: #fff;
}

.hero-section p {
  max-width: 42rem;
  margin-inline: auto;
  opacity: 0.92;
}

.search-wrapper {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  max-width: 38rem;
  margin: 2rem auto 0;
  padding: 0.55rem;
  border-radius: 1rem;
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255,255,255,0.18);
  backdrop-filter: blur(8px);
}

.search-input {
  flex: 1 1 16rem;
  min-width: 0;
  border: none;
  border-radius: 0.8rem;
  background: rgba(255,255,255,0.96);
  color: var(--neutral-800);
}

.search-btn {
  min-height: 44px;
  border: none;
  border-radius: 0.8rem;
  padding: 0.8rem 1.2rem;
  background: var(--accent-500);
  color: #fff;
  font-weight: 700;
}

.classes-section,
.page-shell,
.section-shell {
  padding: clamp(2.5rem, 5vw, 4rem) 0;
}

.classes-grid,
.subjects-grid,
.chapters-grid,
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-2xl);
}

.class-card,
.subject-card,
.chapter-card,
.card {
  position: relative;
  border: 1px solid var(--neutral-200);
  border-radius: var(--radius-lg);
  background: rgba(255,255,255,0.96);
  box-shadow: var(--shadow-sm);
  padding: 1.4rem;
  transition: transform var(--transition-base), box-shadow var(--transition-base), border-color var(--transition-base);
}

.class-card:hover,
.subject-card:hover,
.chapter-card:hover,
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: rgba(37, 99, 235, 0.28);
}

.class-card a,
.subject-card a,
.chapter-card a {
  display: block;
  color: var(--neutral-800);
}

.class-card h2,
.subject-card h3,
.chapter-card h3 {
  margin-bottom: 0.7rem;
}

.page-header {
  margin-bottom: var(--spacing-xl);
  padding-bottom: 0.8rem;
  border-bottom: 1px solid var(--neutral-200);
}

.breadcrumbs {
  overflow-x: auto;
  white-space: nowrap;
  scrollbar-width: thin;
}

.breadcrumbs ol {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  list-style: none;
  flex-wrap: nowrap;
}

.breadcrumbs li {
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
}

.breadcrumbs li:not(:last-child)::after {
  content: "/";
  margin-left: 0.5rem;
  color: var(--neutral-500);
}

.chapter-layout {
  display: grid;
  grid-template-columns: minmax(220px, 280px) minmax(0, 1fr);
  gap: clamp(1.5rem, 2vw, 2rem);
}

.chapter-sidebar {
  position: sticky;
  top: calc(var(--nav-height) + 1rem);
  align-self: start;
}

.toc-wrapper {
  background: var(--neutral-50);
  border: 1px solid var(--neutral-200);
  border-radius: var(--radius-lg);
  padding: 1rem;
}

.toc-list {
  list-style: none;
}

.toc-list li {
  margin-bottom: 0.5rem;
}

.toc-list a {
  display: block;
  padding: 0.7rem 0.8rem;
  border-radius: 0.7rem;
  color: var(--neutral-700);
}

.toc-list a:hover {
  background: rgba(37, 99, 235, 0.05);
  color: var(--primary-600);
}

.chapter-content {
  max-width: 52rem;
}

.chapter-content h2,
.chapter-content h3,
.chapter-content h4 {
  margin-top: clamp(1.5rem, 3vw, 2.5rem);
}

.chapter-content p,
.chapter-content li,
.solution-text,
.note-box {
  font-size: var(--body);
  line-height: 1.8;
}

.chapter-content img,
.solution-visual {
  margin: 1.5rem 0;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.table-responsive,
.code-block,
.math-box,
.solution-box {
  overflow-x: auto;
  border-radius: var(--radius-md);
  margin: 1.5rem 0;
}

.chapter-content table {
  width: 100%;
  min-width: 520px;
  border-collapse: collapse;
  background: #fff;
  border: 1px solid var(--neutral-200);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.chapter-content th,
.chapter-content td {
  padding: 0.8rem 0.9rem;
  border-bottom: 1px solid var(--neutral-200);
  text-align: left;
  vertical-align: top;
}

.chapter-content th {
  background: linear-gradient(135deg, var(--primary-500), var(--primary-600));
  color: #fff;
  font-weight: 700;
}

.chapter-content tr:nth-child(even) td {
  background: rgba(243, 244, 246, 0.65);
}

.solution-box,
.math-box,
.code-block,
.note-box,
.faq-item {
  background: #fff;
  border: 1px solid var(--neutral-200);
  border-radius: var(--radius-md);
  padding: 1.2rem;
  box-shadow: var(--shadow-sm);
}

.code-block,
.math-box {
  padding: 1.1rem;
  background: #0f172a;
  color: #e2e8f0;
  border: 1px solid rgba(148, 163, 184, 0.2);
}

.chapter-pager {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-top: 2rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--neutral-200);
}

.faq-section {
  margin-top: 2rem;
}

.faq-item {
  margin-bottom: 0.75rem;
}

.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  color: var(--neutral-800);
}

.site-footer,
.footer {
  margin-top: clamp(2.5rem, 6vw, 4rem);
  background: linear-gradient(180deg, var(--neutral-900) 0%, #0f172a 100%);
  color: #fff;
  padding: 3rem 0 1.5rem;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: clamp(1.5rem, 3vw, 2rem);
}

.footer-section h4,
.footer-section h3 {
  color: #fff;
  margin-bottom: 1rem;
}

.footer-section ul {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer-section li {
  margin-bottom: 0.6rem;
}

.footer-section a {
  color: rgba(255,255,255,0.8);
}

.footer-section a:hover {
  color: #fff;
}

.footer-bottom {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255,255,255,0.14);
  color: rgba(255,255,255,0.7);
}

.back-to-top {
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  width: 46px;
  height: 46px;
  border: none;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary-500), var(--secondary-600));
  color: #fff;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

@media (max-width: 1024px) {
  .chapter-layout {
    grid-template-columns: 1fr;
  }

  .chapter-sidebar {
    position: static;
  }
}

@media (max-width: 767px) {
  .navbar-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .navbar-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    display: flex;
    flex-direction: column;
    align-items: stretch;
    gap: 1rem;
    padding: 1rem 1rem 1.2rem;
    background: rgba(255,255,255,0.98);
    border-top: 1px solid var(--neutral-200);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
  }

  .navbar-menu.active {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }

  .navbar-nav,
  .nav-list,
  .auth-buttons {
    flex-direction: column;
    width: 100%;
  }

  .nav-link,
  .nav-list a,
  .btn,
  .btn-primary,
  .btn-secondary,
  .btn-outline,
  .user-toggle {
    width: 100%;
    justify-content: center;
  }

  .user-toggle {
    justify-content: space-between;
  }

  .dropdown-menu {
    position: static;
    margin-top: 0.5rem;
    display: none;
    box-shadow: none;
    border-color: var(--neutral-200);
  }

  .dropdown-menu.show {
    display: block;
  }

  .search-wrapper {
    flex-direction: column;
    padding: 0.8rem;
  }

  .search-input,
  .search-btn {
    width: 100%;
  }

  .chapter-pager {
    flex-direction: column;
    align-items: stretch;
  }
}

@media (max-width: 479px) {
  :root {
    --container-max: 100%;
  }

  body {
    line-height: 1.65;
  }

  .container,
  .navbar-container,
  .site-header .container {
    width: min(100% - 1rem, var(--container-max));
  }

  .hero-section {
    padding-top: 3rem;
    padding-bottom: 3rem;
  }

  .class-card,
  .subject-card,
  .chapter-card,
  .card,
  .solution-box,
  .math-box,
  .code-block,
  .note-box,
  .faq-item {
    padding: 1rem;
  }

  .nav-link,
  .nav-list a {
    padding-inline: 0.8rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

@media print {
  .navbar,
  .site-header,
  .back-to-top,
  .search-wrapper,
  .chapter-sidebar {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
  }
}
/* ============================================================
   ADMIN SHELL - shared layout for all /admin/* pages.
   Extracted verbatim from admin/dashboard.php (the reference
   implementation) so every admin page renders the same
   dark sidebar + content shell without duplicating CSS.
   Public pages never use these class names (verified).
   ============================================================ */
.admin-container {
    display: grid;
    grid-template-columns: 250px 1fr;
    min-height: 100vh;
    transition: all 0.3s ease;
}

.admin-sidebar {
    background: linear-gradient(180deg, #1f2937 0%, #111827 100%);
    color: white;
    padding: 20px 0;
    position: relative;
    z-index: 1000;
    box-shadow: 3px 0 10px rgba(0, 0, 0, 0.1);
}

.admin-sidebar .brand {
    padding: 0 20px 20px;
    border-bottom: 1px solid #374151;
    margin-bottom: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.admin-sidebar .brand h2 {
    color: white;
    margin: 0;
    font-size: 1.2rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 5px;
}

.close-sidebar {
    display: none;
    position: absolute;
    right: 15px;
    top: 15px;
    background: none;
    border: none;
    color: white;
    font-size: 1.5rem;
    cursor: pointer;
    z-index: 1001;
}

.admin-sidebar .nav-links {
    list-style: none;
    padding: 0;
    margin: 0;
}

.admin-sidebar .nav-links a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    color: #d1d5db;
    text-decoration: none;
    transition: all 0.3s;
    border-left: 4px solid transparent;
}

.admin-sidebar .nav-links a:hover,
.admin-sidebar .nav-links a.active {
    background: linear-gradient(90deg, rgba(79, 70, 229, 0.1) 0%, transparent 100%);
    color: white;
    border-left: 4px solid #4f46e5;
}

.admin-sidebar .nav-links i {
    width: 20px;
    text-align: center;
    font-size: 1.1rem;
}

.admin-sidebar .nav-links span {
    font-size: 0.95rem;
}

.admin-content {
    padding: 20px;
    background: #f9fafb;
    min-height: 100vh;
}

.admin-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    background: white;
    padding: 15px 20px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
    position: relative;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    color: #4f46e5;
    cursor: pointer;
    padding: 5px 10px;
    border-radius: 5px;
    transition: background 0.3s;
}

.mobile-menu-btn:hover {
    background: #f3f4f6;
}

.admin-header h1 {
    margin: 0;
    color: #374151;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 15px;
    color: #4b5563;
    font-weight: 500;
}

.user-info i {
    color: #4f46e5;
}

/* Scrollbar Styling */
.admin-sidebar::-webkit-scrollbar {
    width: 5px;
}

.admin-sidebar::-webkit-scrollbar-track {
    background: #374151;
}

.admin-sidebar::-webkit-scrollbar-thumb {
    background: #4f46e5;
    border-radius: 5px;
}

.admin-sidebar::-webkit-scrollbar-thumb:hover {
    background: #4338ca;
}

/* Mobile Responsive (admin shell) */
@media (max-width: 1024px) {
    .admin-container {
        grid-template-columns: 1fr;
    }

    .admin-sidebar {
        position: fixed;
        left: -250px;
        top: 0;
        height: 100vh;
        width: 250px;
        transition: left 0.3s ease;
        z-index: 1000;
        overflow-y: auto;
    }

    .admin-sidebar.active {
        left: 0;
        box-shadow: 5px 0 15px rgba(0, 0, 0, 0.2);
    }

    .mobile-menu-btn {
        display: block;
    }

    .close-sidebar {
        display: block;
    }

    .mobile-toggle {
        display: block;
    }

    .overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
    }

    .overlay.active {
        display: block;
    }
}

@media (max-width: 768px) {
    .admin-content {
        padding: 15px;
    }

    .admin-header {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
        padding: 15px;
    }

    .admin-header h1 {
        font-size: 1.3rem;
    }

    .user-info {
        font-size: 0.9rem;
    }
}