/* ================================================
   LMS E-Learning - Design System
   Premium dark/light theme with glassmorphism
   ================================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* ---- CSS Variables (Light Theme) ---- */
:root {
    --primary: #6366f1;
    --primary-hover: #4f46e5;
    --primary-light: rgba(99, 102, 241, 0.1);
    --primary-gradient: linear-gradient(135deg, #6366f1 0%, #8b5cf6 50%, #a78bfa 100%);
    --secondary: #06b6d4;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;

    --bg-body: #f0f2f5;
    --bg-card: #ffffff;
    --bg-sidebar: #ffffff;
    --bg-navbar: rgba(255, 255, 255, 0.85);
    --bg-input: #f8f9fa;
    --bg-hover: #f3f4f6;
    --bg-dropdown: #ffffff;

    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;
    --text-on-primary: #ffffff;

    --border-color: #e2e8f0;
    --border-light: #f1f5f9;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.15);

    --sidebar-width: 270px;
    --sidebar-collapsed-width: 70px;
    --navbar-height: 64px;
    --radius: 12px;
    --radius-sm: 8px;
    --radius-lg: 16px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);

    --glass-bg: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.3);
}

/* ---- Dark Theme ---- */
body.dark-theme {
    --bg-body: #0f172a;
    --bg-card: #1e293b;
    --bg-sidebar: #1e293b;
    --bg-navbar: rgba(30, 41, 59, 0.9);
    --bg-input: #334155;
    --bg-hover: #334155;
    --bg-dropdown: #1e293b;

    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;

    --border-color: #334155;
    --border-light: #1e293b;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.4);
    --shadow-xl: 0 20px 50px rgba(0, 0, 0, 0.5);

    --glass-bg: rgba(30, 41, 59, 0.7);
    --glass-border: rgba(51, 65, 85, 0.5);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-body);
    color: var(--text-primary);
    transition: background 0.3s ease, color 0.3s ease;
    overflow-x: hidden;
    min-height: 100vh;
    font-size: 14px;
    line-height: 1.6;
}

a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-hover); }

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--text-muted); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: var(--text-secondary); }

/* ======== AUTH PAGES ======== */
.auth-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    background: var(--bg-body);
    position: relative;
    overflow: hidden;
}

.auth-container::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    background: var(--primary-gradient);
    opacity: 0.1;
    top: -200px;
    right: -200px;
    animation: float 20s ease-in-out infinite;
}

.auth-container::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    border-radius: 50%;
    background: linear-gradient(135deg, #06b6d4, #8b5cf6);
    opacity: 0.08;
    bottom: -150px;
    left: -100px;
    animation: float 15s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.05); }
    66% { transform: translate(-20px, 20px) scale(0.95); }
}

.auth-card {
    width: 100%;
    max-width: 440px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    box-shadow: var(--shadow-lg);
    position: relative;
    z-index: 1;
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.auth-logo {
    text-align: center;
    margin-bottom: 32px;
}

.auth-logo .logo-icon {
    width: 60px;
    height: 60px;
    background: var(--primary-gradient);
    border-radius: 16px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    color: #fff;
    margin-bottom: 16px;
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.auth-logo h1 {
    font-size: 22px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.auth-logo p {
    color: var(--text-secondary);
    font-size: 14px;
}

.auth-card .form-group {
    margin-bottom: 20px;
}

.auth-card .form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.auth-card .form-control {
    width: 100%;
    padding: 12px 16px;
    background: var(--bg-input);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
}

.auth-card .form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
    background: var(--bg-card);
}

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

.auth-card .btn-primary {
    width: 100%;
    padding: 12px;
    background: var(--primary-gradient);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    font-family: inherit;
}

.auth-card .btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 25px rgba(99, 102, 241, 0.3);
}

.auth-footer {
    text-align: center;
    margin-top: 20px;
    color: var(--text-secondary);
    font-size: 14px;
}

.auth-footer a {
    font-weight: 600;
}

.auth-card .form-check {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 20px;
}

.auth-card .form-check input[type="checkbox"] {
    appearance: none;
    width: 18px;
    height: 18px;
    border: 2px solid var(--border-color);
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.auth-card .form-check input[type="checkbox"]:checked {
    background: var(--primary);
    border-color: var(--primary);
}

.auth-card .form-check input[type="checkbox"]:checked::after {
    content: '✓';
    color: #fff;
    font-size: 12px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* ======== MAIN LAYOUT ======== */
.app-wrapper {
    display: flex;
    min-height: 100vh;
}

/* ---- Sidebar ---- */
.sidebar {
    width: var(--sidebar-width);
    height: 100vh;
    position: fixed;
    left: 0;
    top: 0;
    background: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    z-index: 1000;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
    overflow-y: auto;
    overflow-x: hidden;
}

.sidebar-header {
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 12px;
    border-bottom: 1px solid var(--border-color);
    min-height: 64px;
}

.sidebar-header .logo-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-gradient);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    color: #fff;
    flex-shrink: 0;
}

.sidebar-header .logo-text {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-primary);
    white-space: nowrap;
}

.sidebar-menu {
    padding: 16px 12px;
    flex: 1;
}

.sidebar-menu .menu-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    padding: 8px 12px;
    margin-top: 8px;
}

.sidebar-menu .menu-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 11px 16px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 13.5px;
    transition: var(--transition);
    margin-bottom: 2px;
    white-space: nowrap;
}

.sidebar-menu .menu-item i {
    width: 20px;
    text-align: center;
    font-size: 15px;
    flex-shrink: 0;
}

.sidebar-menu .menu-item:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.sidebar-menu .menu-item.active {
    background: var(--primary-gradient);
    color: #fff;
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3);
}

.sidebar-user {
    padding: 16px 20px;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 12px;
}

.sidebar-user img {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    object-fit: cover;
}

.sidebar-user .user-info {
    flex: 1;
    min-width: 0;
}

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

.sidebar-user .user-info .user-role {
    font-size: 11px;
    color: var(--text-muted);
    text-transform: capitalize;
}

/* ---- Main Content ---- */
.main-content {
    margin-left: var(--sidebar-width);
    flex: 1;
    min-height: 100vh;
    transition: var(--transition);
}

/* ---- Navbar ---- */
.navbar-top {
    height: var(--navbar-height);
    background: var(--bg-navbar);
    backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 24px;
    position: sticky;
    top: 0;
    z-index: 900;
}

.navbar-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.sidebar-toggle {
    display: none;
    width: 38px;
    height: 38px;
    border: none;
    background: var(--bg-hover);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 18px;
    cursor: pointer;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.sidebar-toggle:hover {
    background: var(--primary-light);
    color: var(--primary);
}

.page-title {
    font-size: 18px;
    font-weight: 700;
    color: var(--text-primary);
}

.navbar-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-btn {
    width: 38px;
    height: 38px;
    border: none;
    background: var(--bg-hover);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    position: relative;
}

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

.nav-btn .badge {
    position: absolute;
    top: 4px;
    right: 4px;
    width: 8px;
    height: 8px;
    background: var(--danger);
    border-radius: 50%;
    border: 2px solid var(--bg-navbar);
}

.lang-btn {
    padding: 6px 12px;
    background: var(--bg-hover);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-transform: uppercase;
    font-family: inherit;
}

.lang-btn:hover {
    background: var(--primary-light);
    color: var(--primary);
    border-color: var(--primary);
}

.nav-dropdown {
    position: relative;
}

.nav-dropdown .dropdown-menu {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    background: var(--bg-dropdown);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 8px;
    min-width: 200px;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-5px);
    transition: var(--transition);
    z-index: 1000;
}

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

.dropdown-menu .dropdown-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 13px;
    transition: var(--transition);
}

.dropdown-menu .dropdown-item:hover {
    background: var(--bg-hover);
}

.dropdown-menu .dropdown-item i {
    width: 18px;
    color: var(--text-muted);
}

.dropdown-divider {
    border-top: 1px solid var(--border-color);
    margin: 4px 0;
}

/* ---- Page Content ---- */
.page-content {
    padding: 24px;
}

/* ======== COMPONENTS ======== */

/* ---- Stats Cards ---- */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 24px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 24px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
}

.stat-card.purple::before { background: var(--primary-gradient); }
.stat-card.blue::before { background: linear-gradient(135deg, #3b82f6, #06b6d4); }
.stat-card.green::before { background: linear-gradient(135deg, #10b981, #34d399); }
.stat-card.orange::before { background: linear-gradient(135deg, #f59e0b, #fb923c); }
.stat-card.pink::before { background: linear-gradient(135deg, #ec4899, #f472b6); }
.stat-card.cyan::before { background: linear-gradient(135deg, #06b6d4, #67e8f9); }

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.stat-card .stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    margin-bottom: 16px;
}

.stat-card.purple .stat-icon { background: rgba(99, 102, 241, 0.1); color: var(--primary); }
.stat-card.blue .stat-icon { background: rgba(59, 130, 246, 0.1); color: var(--info); }
.stat-card.green .stat-icon { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.stat-card.orange .stat-icon { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.stat-card.pink .stat-icon { background: rgba(236, 72, 153, 0.1); color: #ec4899; }
.stat-card.cyan .stat-icon { background: rgba(6, 182, 212, 0.1); color: var(--secondary); }

.stat-card .stat-value {
    font-size: 28px;
    font-weight: 800;
    color: var(--text-primary);
    line-height: 1;
    margin-bottom: 4px;
}

.stat-card .stat-label {
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* ---- Cards ---- */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.card-header {
    padding: 20px 24px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.card-header h3, .card-header h2 {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
}

.card-body {
    padding: 24px;
}

.card-footer {
    padding: 16px 24px;
    border-top: 1px solid var(--border-color);
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: var(--transition);
    font-family: inherit;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary-gradient);
    color: #fff;
}
.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 20px rgba(99, 102, 241, 0.3);
    color: #fff;
}

.btn-secondary {
    background: var(--bg-hover);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}
.btn-secondary:hover {
    background: var(--primary-light);
    color: var(--primary);
    border-color: var(--primary);
}

.btn-success { background: var(--success); color: #fff; }
.btn-success:hover { background: #059669; color: #fff; }
.btn-warning { background: var(--warning); color: #000; }
.btn-danger { background: var(--danger); color: #fff; }
.btn-danger:hover { background: #dc2626; color: #fff; }
.btn-info { background: var(--info); color: #fff; }
.btn-info:hover { color: #fff; }

.btn-sm { padding: 6px 14px; font-size: 12px; }
.btn-lg { padding: 14px 28px; font-size: 15px; }
.btn-icon { width: 36px; height: 36px; padding: 0; justify-content: center; }

/* ---- Tables ---- */
.table-container {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
}

.table th, .table td {
    padding: 14px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
    font-size: 13px;
}

.table th {
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 11px;
    letter-spacing: 0.5px;
    background: var(--bg-hover);
}

.table td { color: var(--text-primary); }
.table tbody tr:hover { background: var(--bg-hover); }
.table tbody tr { transition: var(--transition); }

/* ---- Badges ---- */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    text-transform: capitalize;
}

.badge-primary { background: rgba(99, 102, 241, 0.1); color: var(--primary); }
.badge-success { background: rgba(16, 185, 129, 0.1); color: var(--success); }
.badge-warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); }
.badge-danger { background: rgba(239, 68, 68, 0.1); color: var(--danger); }
.badge-info { background: rgba(59, 130, 246, 0.1); color: var(--info); }
.badge-secondary { background: var(--bg-hover); color: var(--text-secondary); }

/* ---- Forms ---- */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 13px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 6px;
}

.form-control {
    width: 100%;
    padding: 10px 14px;
    background: var(--bg-input);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 14px;
    font-family: inherit;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    background: var(--bg-card);
}

.form-control::placeholder { color: var(--text-muted); }
textarea.form-control { min-height: 100px; resize: vertical; }
select.form-control { cursor: pointer; appearance: auto; }

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}

.invalid-feedback {
    color: var(--danger);
    font-size: 12px;
    margin-top: 4px;
}

/* ---- Alert ---- */
.alert {
    padding: 14px 20px;
    border-radius: var(--radius-sm);
    margin-bottom: 20px;
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 10px;
    animation: slideUp 0.3s ease;
}

.alert-success { background: rgba(16, 185, 129, 0.1); color: var(--success); border: 1px solid rgba(16, 185, 129, 0.2); }
.alert-danger, .alert-error { background: rgba(239, 68, 68, 0.1); color: var(--danger); border: 1px solid rgba(239, 68, 68, 0.2); }
.alert-warning { background: rgba(245, 158, 11, 0.1); color: var(--warning); border: 1px solid rgba(245, 158, 11, 0.2); }
.alert-info { background: rgba(59, 130, 246, 0.1); color: var(--info); border: 1px solid rgba(59, 130, 246, 0.2); }

/* ---- Pagination ---- */
.pagination { display: flex; gap: 4px; list-style: none; }
.pagination .page-item .page-link {
    display: flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    padding: 0 10px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 13px;
    color: var(--text-secondary);
    background: var(--bg-card);
    transition: var(--transition);
}
.pagination .page-item .page-link:hover {
    background: var(--primary-light);
    color: var(--primary);
    border-color: var(--primary);
}
.pagination .page-item.active .page-link {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}
.pagination .page-item.disabled .page-link {
    opacity: 0.4;
    pointer-events: none;
}

/* ---- Course Cards ---- */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.course-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    overflow: hidden;
    transition: var(--transition);
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.course-card .card-thumbnail {
    width: 100%;
    height: 180px;
    object-fit: cover;
    border-bottom: 1px solid var(--border-color);
}

.course-card .card-content {
    padding: 20px;
}

.course-card .card-category {
    font-size: 11px;
    font-weight: 600;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.course-card .card-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-card .card-desc {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-card .card-meta {
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-muted);
}

.course-card .card-meta .meta-item {
    display: flex;
    align-items: center;
    gap: 4px;
}

.course-card .card-footer {
    padding: 14px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-top: 1px solid var(--border-color);
}

.course-card .card-instructor {
    display: flex;
    align-items: center;
    gap: 8px;
}

.course-card .card-instructor img {
    width: 28px;
    height: 28px;
    border-radius: 50%;
    object-fit: cover;
}

.course-card .card-instructor span {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

.course-card .card-price {
    font-weight: 700;
    color: var(--primary);
    font-size: 14px;
}

/* ---- Progress Bar ---- */
.progress {
    width: 100%;
    height: 8px;
    background: var(--bg-hover);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: 4px;
    transition: width 0.6s ease;
}

.progress-sm { height: 6px; }
.progress-sm .progress-bar { height: 100%; }

/* ---- Course Player ---- */
.player-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 0;
    min-height: calc(100vh - var(--navbar-height));
}

.player-content {
    padding: 24px;
    overflow-y: auto;
}

.player-sidebar {
    background: var(--bg-card);
    border-left: 1px solid var(--border-color);
    overflow-y: auto;
    max-height: calc(100vh - var(--navbar-height));
    position: sticky;
    top: var(--navbar-height);
}

.player-sidebar .sidebar-header-player {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    font-weight: 700;
    color: var(--text-primary);
}

.module-accordion {
    border-bottom: 1px solid var(--border-color);
}

.module-title {
    padding: 14px 20px;
    background: var(--bg-hover);
    font-weight: 600;
    font-size: 13px;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.module-title:hover { background: var(--primary-light); }

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

.lesson-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 20px;
    font-size: 13px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    border-left: 3px solid transparent;
}

.lesson-item:hover { background: var(--bg-hover); }
.lesson-item.active { background: var(--primary-light); color: var(--primary); border-left-color: var(--primary); font-weight: 600; }
.lesson-item.completed { color: var(--success); }
.lesson-item .lesson-icon { font-size: 14px; width: 20px; text-align: center; }

/* ---- Content Viewer ---- */
.content-viewer {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 32px;
    min-height: 400px;
    line-height: 1.8;
    font-size: 15px;
    color: var(--text-primary);
}

.content-viewer h2 { font-size: 24px; margin-bottom: 16px; }
.content-viewer h3 { font-size: 20px; margin: 20px 0 12px; }
.content-viewer p { margin-bottom: 16px; }
.content-viewer ul, .content-viewer ol { margin-bottom: 16px; padding-left: 24px; }
.content-viewer li { margin-bottom: 8px; }
.content-viewer pre { background: var(--bg-input); padding: 16px; border-radius: var(--radius-sm); margin-bottom: 16px; overflow-x: auto; }
.content-viewer code { font-family: 'JetBrains Mono', monospace; font-size: 13px; }

/* ---- Lesson Navigation ---- */
.lesson-nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
}

/* ---- Quiz ---- */
.quiz-container {
    max-width: 800px;
    margin: 0 auto;
}

.quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
}

.quiz-timer {
    font-size: 18px;
    font-weight: 700;
    color: var(--danger);
    display: flex;
    align-items: center;
    gap: 8px;
}

.question-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 20px;
}

.question-card .question-number {
    font-size: 12px;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    margin-bottom: 8px;
}

.question-card .question-text {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.option-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-sm);
    margin-bottom: 8px;
    cursor: pointer;
    transition: var(--transition);
}

.option-item:hover { border-color: var(--primary); background: var(--primary-light); }
.option-item input[type="radio"] { accent-color: var(--primary); }
.option-item.correct { border-color: var(--success); background: rgba(16, 185, 129, 0.1); }
.option-item.incorrect { border-color: var(--danger); background: rgba(239, 68, 68, 0.1); }

/* ---- Certificate ---- */
.certificate-container {
    max-width: 850px;
    margin: 0 auto;
    background: var(--bg-card);
    border: 3px solid var(--primary);
    border-radius: var(--radius-lg);
    padding: 60px;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.certificate-container::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 6px;
    background: var(--primary-gradient);
}

.certificate-container .cert-logo { font-size: 50px; color: var(--primary); margin-bottom: 20px; }
.certificate-container .cert-title { font-size: 32px; font-weight: 800; color: var(--primary); margin-bottom: 8px; }
.certificate-container .cert-subtitle { font-size: 14px; color: var(--text-secondary); margin-bottom: 30px; text-transform: uppercase; letter-spacing: 3px; }
.certificate-container .cert-name { font-size: 36px; font-weight: 700; color: var(--text-primary); margin-bottom: 12px; }
.certificate-container .cert-course { font-size: 18px; color: var(--text-secondary); margin-bottom: 30px; }
.certificate-container .cert-details { display: flex; justify-content: center; gap: 40px; color: var(--text-muted); font-size: 13px; }

/* ---- Discussion ---- */
.discussion-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 16px;
    transition: var(--transition);
}

.discussion-card:hover { box-shadow: var(--shadow-md); }

.discussion-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.discussion-header img {
    width: 36px;
    height: 36px;
    border-radius: 50%;
}

.reply-item {
    border-left: 3px solid var(--border-color);
    padding: 16px 20px;
    margin-left: 48px;
    margin-top: 12px;
    background: var(--bg-hover);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* ---- Grid Layouts ---- */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }

/* ---- Modal ---- */
.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.modal-backdrop.show { opacity: 1; visibility: visible; }

.modal {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 550px;
    max-height: 85vh;
    overflow-y: auto;
    box-shadow: var(--shadow-xl);
    transform: scale(0.95);
    transition: var(--transition);
}

.modal-backdrop.show .modal { transform: scale(1); }
.modal-header { padding: 24px; border-bottom: 1px solid var(--border-color); display: flex; align-items: center; justify-content: space-between; }
.modal-header h3 { font-size: 18px; font-weight: 700; }
.modal-body { padding: 24px; }
.modal-footer { padding: 16px 24px; border-top: 1px solid var(--border-color); display: flex; justify-content: flex-end; gap: 8px; }

/* ---- Empty State ---- */
.empty-state {
    text-align: center;
    padding: 60px 20px;
}

.empty-state .empty-icon {
    font-size: 56px;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.empty-state h3 {
    font-size: 18px;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.empty-state p {
    color: var(--text-secondary);
    max-width: 400px;
    margin: 0 auto 20px;
}

/* ---- Avatar ---- */
.avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
}
.avatar-sm { width: 28px; height: 28px; }
.avatar-lg { width: 48px; height: 48px; }
.avatar-xl { width: 80px; height: 80px; border-radius: 16px; }

/* ---- Utility ---- */
.text-primary { color: var(--primary) !important; }
.text-success { color: var(--success) !important; }
.text-danger { color: var(--danger) !important; }
.text-warning { color: var(--warning) !important; }
.text-muted { color: var(--text-muted) !important; }
.text-secondary { color: var(--text-secondary) !important; }
.fw-600 { font-weight: 600; }
.fw-700 { font-weight: 700; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.d-flex { display: flex; }
.align-center { align-items: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 8px; }
.gap-2 { gap: 16px; }
.gap-3 { gap: 24px; }
.flex-1 { flex: 1; }

/* ======== RESPONSIVE ======== */
@media (max-width: 1200px) {
    .stats-grid { grid-template-columns: repeat(2, 1fr); }
    .courses-grid { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 992px) {
    .sidebar {
        transform: translateX(-100%);
    }
    .sidebar.show {
        transform: translateX(0);
        box-shadow: var(--shadow-xl);
    }
    .main-content {
        margin-left: 0;
    }
    .sidebar-toggle {
        display: flex;
    }
    .sidebar-overlay {
        display: none;
        position: fixed;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
    }
    .sidebar-overlay.show {
        display: block;
    }
    .player-layout {
        grid-template-columns: 1fr;
    }
    .player-sidebar {
        position: relative;
        max-height: none;
        border-left: none;
        border-top: 1px solid var(--border-color);
    }
}

@media (max-width: 768px) {
    .stats-grid { grid-template-columns: 1fr 1fr; }
    .courses-grid { grid-template-columns: 1fr; }
    .grid-2, .grid-3 { grid-template-columns: 1fr; }
    .form-row { grid-template-columns: 1fr; }
    .page-content { padding: 16px; }
    .page-title { font-size: 16px; }
    .stat-card { padding: 16px; }
    .stat-card .stat-value { font-size: 22px; }
    .auth-card { padding: 24px; }
    .certificate-container { padding: 30px; }
    .certificate-container .cert-name { font-size: 24px; }
    .cert-details { flex-direction: column; gap: 12px !important; }
    .lesson-nav { flex-direction: column; gap: 12px; }
    .quiz-header { flex-direction: column; gap: 12px; }
    .reply-item { margin-left: 20px; }
}

@media (max-width: 576px) {
    .stats-grid { grid-template-columns: 1fr; }
    .navbar-right { gap: 4px; }
    .page-title { display: none; }
}

/* ---- Animations ---- */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in { animation: fadeIn 0.3s ease; }

/* ---- Chart Container ---- */
.chart-container {
    position: relative;
    height: 300px;
    width: 100%;
}