:root {
    --primary-color: #007bff;
    --sidebar-bg: #1e293b;
    --sidebar-hover: #334155;
    --bg-light: #f4f6f9;
}

body {
    background-color: var(--bg-light);
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    font-size: 0.9rem;
    overflow-x: hidden;
}

/* --- Login Page --- */
.login-container {
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #007bff 0%, #0056b3 100%);
}

.login-card {
    width: 100%;
    max-width: 400px;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    border: none;
}

/* --- Layout --- */
.wrapper {
    display: flex;
    width: 100%;
    align-items: stretch;
}

/* Sidebar */
#sidebar {
    min-width: 250px;
    max-width: 250px;
    background: var(--sidebar-bg);
    color: #fff;
    transition: all 0.3s;
    min-height: 100vh;
}

#sidebar.active {
    margin-left: -250px;
}

#sidebar .sidebar-header {
    padding: 20px;
    background: #0f172a;
    border-bottom: 1px solid #334155;
}

#sidebar ul.components {
    padding: 20px 0;
}

#sidebar ul li a {
    padding: 12px 20px;
    font-size: 1rem;
    display: block;
    color: #cbd5e1;
    text-decoration: none;
    transition: 0.2s;
    border-left: 4px solid transparent;
}

#sidebar ul li a:hover, #sidebar ul li a.active {
    color: #fff;
    background: var(--sidebar-hover);
    border-left: 4px solid var(--primary-color);
}

#sidebar ul li a i {
    margin-right: 10px;
    width: 20px;
    text-align: center;
}

/* Content */
#content {
    width: 100%;
    min-height: 100vh;
    transition: all 0.3s;
}

/* Navbar */
.navbar {
    padding: 10px 20px;
    background: #fff;
    border-bottom: 1px solid #dee2e6;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.btn-sidebar-toggle {
    background: transparent;
    border: 1px solid #dee2e6;
    color: #555;
}

/* Cards */
.card-stat {
    border: none;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: transform 0.2s;
}

.card-stat:hover {
    transform: translateY(-5px);
}

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

/* Tables */
.table-responsive {
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    padding: 15px;
}

.table thead th {
    border-top: none;
    background-color: #f8f9fa;
    color: #495057;
    font-weight: 600;
}

.school-logo-thumb {
    width: 40px;
    height: 40px;
    object-fit: cover;
    border-radius: 50%;
}

.student-photo-thumb {
    width: 35px;
    height: 35px;
    object-fit: cover;
    border-radius: 4px;
}

/* Badges & Utilities */
.badge-default-session {
    background-color: #d1e7dd;
    color: #0f5132;
    padding: 5px 10px;
    border-radius: 20px;
    font-size: 0.8rem;
}

/* Responsive */
@media (max-width: 768px) {
    #sidebar {
        margin-left: -250px;
    }
    #sidebar.active {
        margin-left: 0;
    }
}