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

/* CSS Variables for Theme Colors */
:root[data-theme="dark"] {
    --primary-color: #5dade2;
    --primary-dark: #3498db;
    --primary-light: #85c1e9;
    --gradient-start: #5dade2;
    --gradient-end: #3498db;
    --bg-primary: #1a1a2e;
    --bg-secondary: #16213e;
    --card-bg: #0f3460;
    --text-primary: #e0e0e0;
    --text-secondary: #adb5bd;
    --border-color: #3a506b;
}

:root[data-theme="light"],
:root {
    --primary-color: #2196f3;
    --primary-dark: #1976d2;
    --primary-light: #64b5f6;
    --gradient-start: #42a5f5;
    --gradient-end: #1e88e5;
    --bg-primary: #f5f7fa;
    --bg-secondary: #ffffff;
    --card-bg: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --border-color: #e0e7ff;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.08);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.12);
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg-primary);
    min-height: 100vh;
    margin: 0;
    padding: 0;
    color: var(--text-primary);
    transition: background 0.3s, color 0.3s;
}

/* Light Theme - Now using CSS Variables */
body.light-theme,
[data-theme="light"] {
    background: var(--bg-primary);
    color: var(--text-primary);
}

body.light-theme .yt-header {
    background: #fff;
    border-bottom: 1px solid #e5e5e5;
}

body.light-theme .yt-icon-btn {
    color: #030303;
}

body.light-theme .yt-icon-btn:hover {
    background: rgba(0,0,0,0.1);
}

body.light-theme .yt-logo {
    color: #030303;
}

body.light-theme .yt-sidebar {
    background: #f9f9f9;
    border-right: 1px solid #e5e5e5;
}

body.light-theme .yt-sidebar-item {
    color: #030303;
}

body.light-theme .yt-sidebar-item:hover {
    background: rgba(0,0,0,0.05);
}

body.light-theme .yt-sidebar-item.active {
    background: rgba(0,0,0,0.1);
}

body.light-theme .yt-dropdown {
    background: #fff;
    border: 1px solid #e5e5e5;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

body.light-theme .yt-dropdown-header {
    border-bottom: 1px solid #e5e5e5;
}

body.light-theme .yt-username {
    color: #030303;
}

body.light-theme .yt-role {
    color: #606060;
}

body.light-theme .yt-dropdown-item {
    color: #030303;
}

body.light-theme .yt-dropdown-item:hover {
    background: #f2f2f2;
}

body.light-theme .yt-dropdown-divider {
    background: #e5e5e5;
}

body.light-theme .course-card {
    background: #fff;
    box-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

body.light-theme .course-card:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

body.light-theme .course-code {
    color: #606060;
}

body.light-theme .course-title {
    color: #030303;
}

body.light-theme .course-description {
    color: #606060;
}

body.light-theme .btn-course {
    background: #065fd4;
    color: #fff;
}

body.light-theme .btn-course:hover {
    background: #0556c1;
}

body.light-theme .section-title {
    color: #030303;
}

body.light-theme .no-data {
    color: #606060;
}

/* YouTube-style Header */
.yt-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 56px;
    background: var(--card-bg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 16px;
    z-index: 2000;
    box-shadow: 0 1px 4px rgba(0,0,0,0.08);
    border-bottom: 1px solid var(--border-color);
}

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

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

.yt-logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    text-decoration: none;
}

.yt-icon-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: transparent;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.2s;
}

.yt-icon-btn:hover {
    background: var(--bg-secondary);
}

/* User Menu */
.yt-user-menu {
    position: relative;
}

.yt-user-btn {
    background: transparent;
    border: none;
    cursor: pointer;
    padding: 0;
}

.yt-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 600;
    font-size: 14px;
}

.yt-avatar-large {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 600;
    font-size: 16px;
}

.yt-dropdown {
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    min-width: 300px;
    box-shadow: 0 8px 24px rgba(0,0,0,0.12);
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.2s;
}

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

.yt-dropdown-header {
    padding: 16px;
    display: flex;
    gap: 12px;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.yt-username {
    color: var(--text-primary);
    font-weight: 600;
    font-size: 15px;
}

.yt-role {
    color: var(--text-secondary);
    font-size: 13px;
}

.yt-dropdown-divider {
    height: 1px;
    background: var(--border-color);
    margin: 0 16px;
}

.yt-dropdown-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 12px 16px;
    color: var(--text-primary);
    text-decoration: none;
    transition: background 0.2s;
    font-size: 14px;
}

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

.yt-dropdown-item:first-child {
    border-radius: 0 0 12px 12px;
}

/* YouTube-style Sidebar */
.yt-sidebar {
    position: fixed;
    top: 56px;
    left: 0;
    width: 240px;
    height: calc(100vh - 56px);
    background: var(--card-bg);
    padding: 12px 0;
    overflow-y: auto;
    transition: transform 0.3s, width 0.3s;
    z-index: 1000;
    border-right: 1px solid var(--border-color);
}

.yt-sidebar.collapsed {
    width: 72px;
}

.yt-sidebar.collapsed .yt-sidebar-item span {
    display: none;
}

.yt-sidebar-item {
    display: flex;
    align-items: center;
    gap: 24px;
    padding: 10px 24px;
    color: var(--text-primary);
    text-decoration: none;
    transition: background 0.2s;
    font-size: 14px;
    font-weight: 400;
}

.yt-sidebar-item:hover {
    background: var(--bg-secondary);
}

.yt-sidebar-item.active {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--primary-color);
}

.yt-sidebar.collapsed .yt-sidebar-item {
    justify-content: center;
    padding: 16px;
}

.yt-sidebar-divider {
    height: 1px;
    background: var(--border-color);
    margin: 12px 0;
}

/* Main Content */
.yt-main-content {
    margin-left: 240px;
    margin-top: 56px;
    padding: 24px;
    transition: margin-left 0.3s;
    min-height: calc(100vh - 56px);
    background: var(--bg-primary);
}

.yt-main-content.expanded {
    margin-left: 72px;
}

.yt-container {
    max-width: 1800px;
    margin: 0 auto;
}

.container {
    width: 100%;
    max-width: 1200px;
}

.form-box {
    background: #2d3142;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
}

.form-box h2 {
    text-align: center;
    color: #f0f0f0;
    margin-bottom: 30px;
    font-size: 28px;
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #b0b0b0;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #3a3f52;
    border-radius: 5px;
    font-size: 14px;
    transition: border-color 0.3s;
    background: #1f2229;
    color: #e0e0e0;
}

.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #3a3f52;
    border-radius: 5px;
    font-size: 14px;
    transition: border-color 0.3s;
    background-color: #1f2229;
    cursor: pointer;
    color: #e0e0e0;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--gradient-start);
}

.btn {
    width: 100%;
    padding: 12px;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: background-color 0.3s;
}

.btn-primary {
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: white;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #5568d3 0%, #653a8a 100%);
}

.form-footer {
    margin-top: 20px;
    text-align: center;
    color: #666;
}

.form-footer a {
    color: var(--gradient-start);
    text-decoration: none;
    font-weight: 500;
}

.form-footer a:hover {
    text-decoration: underline;
}

.dashboard {
    background: white;
    padding: 40px;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
    text-align: center;
}

.dashboard h2 {
    color: #333;
    margin-bottom: 20px;
}

.dashboard p {
    color: #666;
    margin-bottom: 20px;
    font-size: 18px;
}

.btn-logout {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
    display: inline-block;
    padding: 12px 30px;
    text-decoration: none;
    border-radius: 5px;
    font-weight: 600;
    transition: background-color 0.3s;
}

.btn-logout:hover {
    background: linear-gradient(135deg, #e082ea 0%, #e4465b 100%);
}

/* Header Bar - Hidden when using YouTube style */
.header-bar {
    display: none;
}

/* Cards Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 16px;
    margin-top: 24px;
}

.course-card {
    background: var(--card-bg);
    border-radius: 12px;
    overflow: hidden;
    transition: all 0.3s;
    cursor: pointer;
    border: 1px solid var(--border-color);
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}

.course-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(33, 150, 243, 0.15);
}

.course-image {
    height: 180px;
    background-size: cover;
    background-position: center;
    position: relative;
}

.course-badge {
    position: absolute;
    top: 8px;
    right: 8px;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

.course-content {
    padding: 12px;
}

.course-code {
    color: var(--primary-color);
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 4px;
}

.course-title {
    font-size: 16px;
    color: var(--text-primary);
    margin-bottom: 8px;
    font-weight: 600;
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-description {
    color: var(--text-secondary);
    font-size: 13px;
    line-height: 1.5;
    margin-bottom: 12px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.btn-course {
    display: inline-block;
    background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
    color: white;
    padding: 8px 20px;
    border-radius: 20px;
    text-decoration: none;
    font-weight: 600;
    font-size: 13px;
    transition: all 0.2s;
    box-shadow: 0 2px 6px rgba(33, 150, 243, 0.3);
}

.btn-course:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(33, 150, 243, 0.4);
}

.section-title {
    font-size: 20px;
    color: #fff;
    margin-bottom: 16px;
    font-weight: 500;
}

.no-data {
    text-align: center;
    color: #aaa;
    font-size: 14px;
    padding: 60px 20px;
}



.section-title {
    font-size: 28px;
    color: #f0f0f0;
    margin-bottom: 30px;
    text-align: center;
}

/* Cards Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
    margin-top: 30px;
}

.course-card {
    background: #2d3142;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
    transition: transform 0.3s, box-shadow 0.3s;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.4);
}

.course-image {
    height: 200px;
    background-size: cover;
    background-position: center;
    position: relative;
}

.course-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: white;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.course-content {
    padding: 20px;
}

.course-code {
    color: var(--primary-color);
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    margin-bottom: 8px;
}

.course-title {
    font-size: 20px;
    color: #f0f0f0;
    margin-bottom: 12px;
    font-weight: 600;
}

.course-description {
    color: #b0b0b0;
    font-size: 14px;
    line-height: 1.6;
    margin-bottom: 20px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.btn-course {
    display: inline-block;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: white;
    padding: 10px 20px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: background 0.3s;
}

.btn-course:hover {
    background: linear-gradient(135deg, #5568d3 0%, #653a8a 100%);
}

.no-data {
    text-align: center;
    color: #999;
    font-size: 16px;
    padding: 40px;
}

/* Login/Register Pages */
.login-page,
.register-page {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #2d3748 0%, #1a202c 100%);
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.login-page::before,
.register-page::before {
    content: '';
    position: absolute;
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 70%);
    border-radius: 50%;
    top: -200px;
    right: -200px;
    animation: float 6s ease-in-out infinite;
}

.login-page::after,
.register-page::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
    border-radius: 50%;
    bottom: -150px;
    left: -150px;
    animation: float 8s ease-in-out infinite reverse;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(20px); }
}

.auth-container {
    width: 100%;
    max-width: 480px;
    position: relative;
    z-index: 1;
}

.auth-box {
    background: #2d3142;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5);
    animation: slideUp 0.5s ease-out;
}

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

.auth-header {
    text-align: center;
    margin-bottom: 35px;
}

.auth-logo {
    margin: 0 auto 20px;
    width: 60px;
    height: 60px;
}

.auth-header h2 {
    font-size: 28px;
    color: #f0f0f0;
    margin: 0 0 8px 0;
    font-weight: 700;
}

.auth-subtitle {
    color: #a0a0a0;
    font-size: 14px;
    margin: 0;
}

.auth-form {
    margin-bottom: 25px;
}

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

.auth-form label {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 8px;
    color: #b0b0b0;
    font-weight: 500;
    font-size: 14px;
}

.auth-form label svg {
    color: var(--primary-color);
}

.auth-form input,
.auth-form select {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid #3a3f52;
    border-radius: 10px;
    font-size: 15px;
    transition: all 0.3s ease;
    background: #1f2229;
    color: #e0e0e0;
}

.auth-form input:focus,
.auth-form select:focus {
    outline: none;
    border-color: var(--primary-color);
    background: #252933;
    box-shadow: 0 0 0 4px rgba(124, 138, 219, 0.1);
}

.auth-form select {
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='8' viewBox='0 0 12 8' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1L6 6L11 1' stroke='%23667eea' stroke-width='2' stroke-linecap='round'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    padding-right: 45px;
}

.btn.btn-primary {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, var(--gradient-start) 0%, var(--gradient-end) 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    margin-top: 25px;
}

.btn.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.4);
}

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

.auth-divider {
    position: relative;
    text-align: center;
    margin: 25px 0;
}

.auth-divider::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    height: 1px;
    background: #3a3f52;
}

.auth-divider span {
    position: relative;
    background: #2d3142;
    padding: 0 15px;
    color: #999;
    font-size: 13px;
}

.auth-footer {
    text-align: center;
}

.auth-footer p {
    color: #a0a0a0;
    font-size: 14px;
    margin-bottom: 12px;
}

.btn-secondary {
    display: inline-block;
    padding: 12px 30px;
    background: transparent;
    color: var(--primary-color);
    border: 2px solid var(--primary-color);
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    transition: all 0.3s ease;
}

.btn-secondary:hover {
    background: var(--primary-color);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(124, 138, 219, 0.3);
}

.alert {
    padding: 14px 16px;
    border-radius: 10px;
    margin-bottom: 20px;
    font-size: 14px;
    display: flex;
    align-items: center;
    gap: 10px;
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.alert-error {
    background-color: #fee;
    border: 1px solid #fcc;
    color: #c33;
}

.alert-success {
    background-color: #efe;
    border: 1px solid #cfc;
    color: #3c3;
}

.alert svg {
    flex-shrink: 0;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 15px;
        text-align: center;
    }
    
    .user-info {
        flex-direction: column;
        gap: 10px;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
    }
    
    .auth-box {
        padding: 30px 25px;
    }
    
    .auth-header h2 {
        font-size: 24px;
    }
    
    .admin-table {
        font-size: 13px;
    }
    
    .form-row {
        flex-direction: column;
    }
}

/* Admin Styles */
.admin-section {
    margin-bottom: 40px;
}

.admin-form-box {
    background: #2d3142;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.admin-form {
    max-width: 100%;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}

.admin-form textarea {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #3a3f52;
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    resize: vertical;
    transition: border-color 0.3s;
    background: #1f2229;
    color: #e0e0e0;
}

.admin-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.table-responsive {
    overflow-x: auto;
    background: #2d3142;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

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

.admin-table thead {
    background: linear-gradient(135deg, #4a5568 0%, #2d3748 100%);
    color: white;
}

.admin-table th,
.admin-table td {
    padding: 15px;
    text-align: left;
}

.admin-table th {
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
}

.admin-table tbody tr {
    border-bottom: 1px solid #3a3f52;
    transition: background 0.2s;
}

.admin-table tbody tr:hover {
    background: #353847;
}

.admin-table td {
    color: #b0b0b0;
    font-size: 14px;
}

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

.badge {
    display: inline-block;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    background: #e3f2fd;
    color: #1976d2;
}

.badge-admin {
    background: #ffebee;
    color: #c62828;
}

.badge-giao_vien {
    background: #e8f5e9;
    color: #2e7d32;
}

.badge-hoc_sinh {
    background: #fff3e0;
    color: #ef6c00;
}

.btn-small {
    display: inline-block;
    padding: 6px 12px;
    font-size: 13px;
    border-radius: 5px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    border: none;
    cursor: pointer;
    margin-right: 5px;
}

.btn-info {
    background: #2196f3;
    color: white;
}

.btn-info:hover {
    background: #1976d2;
}

.btn-success {
    background: #4caf50;
    color: white;
}

.btn-success:hover {
    background: #388e3c;
}

.btn-danger {
    background: #f44336;
    color: white;
}

.btn-danger:hover {
    background: #d32f2f;
}

.btn-warning {
    background: #ff9800;
    color: white;
}

.btn-warning:hover {
    background: #f57c00;
}

/* Version History Styles */
.version-timeline {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.version-card {
    background: #212121;
    border-radius: 12px;
    padding: 20px;
    border-left: 4px solid #666;
    transition: all 0.3s;
}

.version-card:hover {
    border-left-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
}

.version-current {
    border-left-color: #4caf50;
    background: #1a2a1a;
}

body.light-theme .version-card {
    background: #fff;
    border-left-color: #ddd;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}

body.light-theme .version-card:hover {
    border-left-color: var(--primary-color);
    box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

body.light-theme .version-current {
    border-left-color: #4caf50;
    background: #f1f8f4;
}

.version-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

body.light-theme .version-header {
    border-bottom-color: #e5e5e5;
}

.version-number {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 18px;
    font-weight: 600;
    color: #fff;
}

body.light-theme .version-number {
    color: #030303;
}

.version-number svg {
    color: var(--primary-color);
}

.badge-current {
    background: #4caf50;
    color: white;
    padding: 4px 10px;
    border-radius: 12px;
    font-size: 11px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.version-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #aaa;
    font-size: 13px;
}

body.light-theme .version-meta {
    color: #606060;
}

.version-body {
    color: #e0e0e0;
}

body.light-theme .version-body {
    color: #030303;
}

.version-change-desc {
    background: rgba(124, 138, 219, 0.1);
    padding: 12px;
    border-radius: 8px;
    margin-bottom: 16px;
    color: #e0e0e0;
}

body.light-theme .version-change-desc {
    background: rgba(124, 138, 219, 0.08);
    color: #030303;
}

.version-details {
    display: grid;
    gap: 12px;
}

.detail-item {
    color: #e0e0e0;
}

.detail-item strong {
    color: var(--primary-color);
}

body.light-theme .detail-item {
    color: #030303;
}

body.light-theme .detail-item strong {
    color: #5a6cc3;
}

.btn-rollback {
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
}

.btn-rollback:hover {
    background: #6a7bc9;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(124, 138, 219, 0.3);
}

body.light-theme .btn-rollback {
    background: #065fd4;
}

body.light-theme .btn-rollback:hover {
    background: #0556c1;
}

/* Role Select Dropdown */
.role-select {
    padding: 6px 12px;
    border-radius: 6px;
    border: 1px solid #444;
    background: #2d2d2d;
    color: #e0e0e0;
    font-size: 13px;
    cursor: pointer;
    transition: all 0.3s;
}

.role-select:hover {
    border-color: var(--primary-color);
}

.role-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(124, 138, 219, 0.2);
}

body.light-theme .role-select {
    background: #fff;
    border-color: #ddd;
    color: #030303;
}

body.light-theme .role-select:hover {
    border-color: var(--primary-color);
}

body.light-theme .role-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 2px rgba(124, 138, 219, 0.1);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 2000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.3s;
    overflow-y: auto;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background-color: #2d3142;
    margin: 10% auto;
    padding: 30px;
    border-radius: 12px;
    width: 90%;
    max-width: 500px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
    animation: slideDown 0.3s;
}

@keyframes slideDown {
    from {
        transform: translateY(-50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-content h3 {
    color: #f0f0f0;
    margin-bottom: 10px;
}

.modal-large {
    max-width: 700px;
}

.modal-subtitle {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 25px;
}

.modal-close {
    color: #aaa;
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: color 0.3s;
}

.modal-close:hover,
.modal-close:focus {
    color: #000;
}

.modal-buttons {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 25px;
}

.modal-buttons .btn,
.modal-buttons .btn-secondary {
    width: auto;
    padding: 10px 24px;
}

.course-info-box {
    background: #2d3142;
    padding: 25px;
    border-radius: 12px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
    margin-bottom: 30px;
}

.course-info-box h2 {
    color: #f0f0f0;
    margin-bottom: 15px;
}

.course-info-box p {
    color: #b0b0b0;
    margin-bottom: 8px;
}