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

:root {
    --sidebar-width: 280px;
    --sidebar-collapsed-width: 70px;
    --primary-color: #2563eb;
    --hover-color: #1e40af;
    --bg-dark: #1f2937;
    --bg-darker: #111827;
    --text-light: #f9fafb;
    --text-gray: #9ca3af;
    --border-color: #374151;
    --submenu-bg: #374151;
    --transition-speed: 0.3s;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f3f4f6;
    overflow-x: hidden;
}

/* Sidebar - HIDDEN */
.nav-sidebar {
    display: none !important;
}

/* When main sidebar is collapsed */
.main-sidebar.collapsed~.main-content-wrapper .nav-sidebar {
    left: 0;
}

.nav-sidebar::-webkit-scrollbar {
    width: 6px;
}

.nav-sidebar::-webkit-scrollbar-track {
    background: var(--bg-darker);
}

.nav-sidebar::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: 3px;
}

.nav-sidebar.collapsed {
    width: var(--sidebar-collapsed-width);
}

/* Sidebar Header */
.nav-sidebar-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px;
    background: var(--bg-darker);
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    white-space: nowrap;
}

.logo-icon {
    font-size: 24px;
    min-width: 30px;
}

.logo-text {
    font-size: 18px;
    font-weight: 600;
    transition: opacity var(--transition-speed);
}

.nav-sidebar.collapsed .logo-text {
    opacity: 0;
    width: 0;
}

.toggle-btn {
    background: none;
    border: none;
    color: var(--text-light);
    font-size: 20px;
    cursor: pointer;
    padding: 5px;
    border-radius: 4px;
    transition: background var(--transition-speed);
}

.toggle-btn:hover {
    background: var(--border-color);
}

.nav-sidebar.collapsed .toggle-btn {
    margin-left: -10px;
}

/* Navigation */
.nav-sidebar-nav {
    padding: 10px 0;
}

.nav-item {
    position: relative;
    margin: 2px 10px;
    border-radius: 8px;
    transition: all var(--transition-speed);
}

.nav-item.active>.nav-link,
.nav-item.active {
    background: var(--primary-color);
    color: white;
}

.nav-link,
.nav-item>a {
    display: flex;
    align-items: center;
    padding: 12px 15px;
    color: var(--text-gray);
    text-decoration: none;
    border-radius: 8px;
    transition: all var(--transition-speed);
    cursor: pointer;
    white-space: nowrap;
}

.nav-link:hover,
.nav-item>a:hover {
    background: var(--border-color);
    color: var(--text-light);
}

.nav-icon {
    font-size: 20px;
    min-width: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.nav-text {
    flex: 1;
    margin-left: 10px;
    transition: opacity var(--transition-speed);
}

.nav-sidebar.collapsed .nav-text {
    opacity: 0;
    width: 0;
}

.arrow {
    margin-left: auto;
    transition: transform var(--transition-speed);
    font-size: 18px;
}

.nav-item.active .arrow,
.nav-item.open .arrow {
    transform: rotate(90deg);
}

.nav-sidebar.collapsed .arrow {
    opacity: 0;
}

/* Submenu */
.submenu {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-speed) ease;
    background: var(--submenu-bg);
    border-radius: 8px;
    margin: 5px 0;
}

.submenu.show {
    max-height: 500px;
}

.submenu-item {
    display: block;
    padding: 10px 20px 10px 60px;
    color: var(--text-gray);
    text-decoration: none;
    transition: all var(--transition-speed);
    font-size: 14px;
}

.submenu-item:hover {
    background: var(--border-color);
    color: var(--text-light);
}

.submenu-item.active {
    background: var(--primary-color);
    color: white;
}

.nav-sidebar.collapsed .submenu {
    display: none;
}

/* Sidebar Footer */
.nav-sidebar-footer {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 15px;
    background: var(--bg-darker);
    border-top: 1px solid var(--border-color);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
    white-space: nowrap;
}

.user-icon {
    font-size: 24px;
    min-width: 30px;
}

.user-name {
    font-size: 14px;
    font-weight: 500;
    transition: opacity var(--transition-speed);
}

.nav-sidebar.collapsed .user-name {
    opacity: 0;
    width: 0;
}

/* Main Content */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 30px;
    transition: margin-left var(--transition-speed) ease;
    min-height: 100vh;
}

.nav-sidebar.collapsed+.main-content {
    margin-left: var(--sidebar-collapsed-width);
}

.content-wrapper {
    max-width: 1200px;
    margin: 0 auto;
}

.content-wrapper h1 {
    color: var(--bg-dark);
    margin-bottom: 10px;
}

.content-wrapper p {
    color: var(--text-gray);
    font-size: 16px;
}

/* Mobile Toggle Button */
.mobile-toggle {
    display: none;
    position: fixed;
    top: 20px;
    left: 20px;
    z-index: 999;
    background: var(--primary-color);
    color: white;
    border: none;
    padding: 10px 15px;
    border-radius: 8px;
    font-size: 20px;
    cursor: pointer;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

/* Mobile Responsive */
@media (max-width: 768px) {
    .nav-sidebar {
        transform: translateX(-100%);
        width: var(--sidebar-width);
    }

    .nav-sidebar.mobile-open {
        transform: translateX(0);
    }

    .nav-sidebar.collapsed {
        transform: translateX(-100%);
    }

    .main-content {
        margin-left: 0;
    }

    .mobile-toggle {
        display: block;
    }

    .nav-sidebar.mobile-open+.main-content .mobile-toggle {
        left: calc(var(--sidebar-width) + 20px);
    }
}

/* Animations */
@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.nav-item {
    animation: slideIn 0.3s ease forwards;
}

.nav-item:nth-child(1) {
    animation-delay: 0.05s;
}

.nav-item:nth-child(2) {
    animation-delay: 0.1s;
}

.nav-item:nth-child(3) {
    animation-delay: 0.15s;
}

.nav-item:nth-child(4) {
    animation-delay: 0.2s;
}

.nav-item:nth-child(5) {
    animation-delay: 0.25s;
}