:root {
    --primary-color: #4f46e5;
    --primary-light: #e0e7ff;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --info-color: #3b82f6;
    
    --bg-body: #f1f5f9;
    --bg-card: #ffffff;
    --bg-sidebar: #ffffff;
    
    --text-main: #1e293b;
    --text-muted: #64748b;
    --text-light: #94a3b8;
    
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-premium: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    --sidebar-width: 260px;
    --header-height: 70px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--bg-body);
    color: var(--text-main);
    line-height: 1.6;
    overflow-x: hidden;
}

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

ul {
    list-style: none;
}

/* Layout */
.app-container {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    height: 100vh;
    z-index: 100;
    transition: var(--transition);
}

.sidebar-header {
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.sidebar-toggle {
    background: none;
    border: none;
    font-size: 1.2rem;
    color: var(--text-muted);
    cursor: pointer;
    display: none; /* Hidden on desktop by default */
}

.sidebar-nav {
    flex: 1;
    padding: 1.5rem 1rem;
    overflow-y: auto;
}

.sidebar-nav ul li {
    margin-bottom: 0.5rem;
}

.sidebar-nav a {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem 1rem;
    border-radius: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
    transition: var(--transition);
}

.sidebar-nav a:hover, .sidebar-nav li.active a {
    background-color: var(--primary-light);
    color: var(--primary-color);
}

.sidebar-nav a i {
    font-size: 1.2rem;
    width: 24px;
    text-align: center;
}

.sidebar-footer {
    padding: 1.5rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.user-profile {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.user-profile img {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
}

.user-info h4 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-main);
}

.user-info p {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.logout-btn {
    color: var(--text-light);
    transition: var(--transition);
}

.logout-btn:hover {
    color: var(--danger-color);
}

/* Main Content */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    display: flex;
    flex-direction: column;
    transition: var(--transition);
}

/* Header */
.top-header {
    height: var(--header-height);
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 2rem;
    position: sticky;
    top: 0;
    z-index: 90;
}

.header-search {
    display: flex;
    align-items: center;
    background-color: var(--bg-body);
    padding: 0.6rem 1rem;
    border-radius: 2rem;
    width: 350px;
    gap: 0.75rem;
    color: var(--text-light);
}

.header-search input {
    border: none;
    background: none;
    outline: none;
    width: 100%;
    font-family: inherit;
    color: var(--text-main);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 1rem;
}

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

.icon-btn:hover {
    background-color: var(--bg-body);
    color: var(--primary-color);
}

.badge {
    position: absolute;
    top: 5px;
    right: 5px;
    background-color: var(--danger-color);
    color: white;
    font-size: 0.65rem;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    border: 2px solid var(--bg-card);
}

.add-new-btn {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 0.6rem 1.2rem;
    border-radius: 2rem;
    font-family: inherit;
    font-weight: 500;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
    box-shadow: 0 4px 10px rgba(79, 70, 229, 0.3);
}

.add-new-btn:hover {
    background-color: #4338ca;
    transform: translateY(-1px);
}

/* Dashboard Content */
.dashboard-content {
    padding: 2rem;
}

.welcome-banner {
    background: linear-gradient(135deg, var(--primary-color), #818cf8);
    border-radius: 1.5rem;
    padding: 2rem;
    color: white;
    margin-bottom: 2rem;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.banner-text h1 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.banner-text p {
    opacity: 0.9;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background-color: var(--bg-card);
    padding: 1.5rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    transition: var(--transition);
}

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

.stat-icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.stat-icon.students { background-color: #e0e7ff; color: var(--primary-color); }
.stat-icon.teachers { background-color: #dcfce7; color: var(--success-color); }
.stat-icon.revenue { background-color: #fef3c7; color: var(--warning-color); }
.stat-icon.attendance { background-color: #fee2e2; color: var(--danger-color); }

.stat-info h3 {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.stat-info .number {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-main);
    margin-bottom: 0.25rem;
}

.trend {
    font-size: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.trend.up { color: var(--success-color); }
.trend.down { color: var(--danger-color); }

/* Content Grid */
.content-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.card {
    background-color: var(--bg-card);
    border-radius: 1rem;
    box-shadow: var(--shadow-md);
    padding: 1.5rem;
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1.5rem;
}

.card-header h2 {
    font-size: 1.25rem;
    font-weight: 600;
}

.period-select {
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 0.5rem;
    color: var(--text-muted);
    font-family: inherit;
    outline: none;
}

.view-all {
    font-size: 0.85rem;
    color: var(--primary-color);
    font-weight: 500;
}

.chart-container {
    height: 300px;
    width: 100%;
}

/* Activity List */
.activity-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.activity-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
}

.activity-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.activity-icon.warning { background-color: #fffbeb; color: var(--warning-color); }
.activity-icon.success { background-color: #ecfdf5; color: var(--success-color); }
.activity-icon.info { background-color: #eff6ff; color: var(--info-color); }
.activity-icon.danger { background-color: #fef2f2; color: var(--danger-color); }

.activity-details h4 {
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 0.1rem;
}

.activity-details p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.time {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-left: auto;
    white-space: nowrap;
}

/* Table */
.table-card {
    margin-bottom: 2rem;
}

.card-actions {
    display: flex;
    gap: 0.75rem;
}

.card-actions button {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border-color);
    background-color: white;
    border-radius: 0.5rem;
    color: var(--text-muted);
    cursor: pointer;
    font-family: inherit;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.card-actions button:hover {
    background-color: var(--bg-body);
}

.table-responsive {
    overflow-x: auto;
}

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

th {
    text-align: left;
    padding: 1rem;
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: 500;
    border-bottom: 1px solid var(--border-color);
}

td {
    padding: 1rem;
    font-size: 0.9rem;
    color: var(--text-main);
    border-bottom: 1px solid var(--border-color);
}

tr:last-child td {
    border-bottom: none;
}

.student-cell {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.student-cell img {
    width: 32px;
    height: 32px;
    border-radius: 50%;
}

.status {
    padding: 0.25rem 0.75rem;
    border-radius: 1rem;
    font-size: 0.75rem;
    font-weight: 500;
}

.status.active {
    background-color: #ecfdf5;
    color: var(--success-color);
}

.status.pending {
    background-color: #fffbeb;
    color: var(--warning-color);
}

.action-btn {
    background: none;
    border: none;
    color: var(--text-light);
    cursor: pointer;
    padding: 0.25rem;
    transition: var(--transition);
}

.action-btn:hover {
    color: var(--primary-color);
}

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

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.active {
        transform: translateX(0);
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .sidebar-toggle {
        display: block;
    }
    
    .header-search {
        display: none;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}