/* --- Google Fonts & CSS Variables --- */
@import url('https://fonts.googleapis.com/css2?family=Poppins:wght@400;500;600;700&display=swap');

:root {
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --secondary-color: #6c757d;
    --background-color: #f8f9fa;
    --sidebar-bg: #fff;
    --text-color: #212529;
    --card-bg: #fff;
    --card-border: #e9ecef;
    --heading-color: #343a40;
    --box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.05);
    --sidebar-width: 260px;
}

body.dark-mode {
    --primary-color: #0d6efd;
    --primary-hover: #3385fd;
    --background-color: #1a1a1a;
    --sidebar-bg: #212529;
    --text-color: #f8f9fa;
    --card-bg: #2c3034;
    --card-border: #343a40;
    --heading-color: #fff;
    --box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
}

/* --- Base Styles --- */
body {
    font-family: 'Poppins', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
}

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

/* --- Sidebar --- */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    box-shadow: var(--box-shadow);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s ease-in-out;
    position: fixed;
    height: 100%;
    z-index: 1000;
    overflow-y: auto;
    border-right: 1px solid var(--card-border);
}

.sidebar::-webkit-scrollbar { width: 5px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb { background-color: rgba(0, 0, 0, 0.2); border-radius: 10px; }
body.dark-mode .sidebar::-webkit-scrollbar-thumb { background-color: rgba(255, 255, 255, 0.2); }

.sidebar-header {
    padding: 1.25rem;
    border-bottom: 1px solid var(--card-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.sidebar-header h3 { color: var(--primary-color); margin: 0; font-weight: 600; font-size: 1.5rem; }

.sidebar .nav { flex-wrap: nowrap; padding: 0.5rem 0; }
.sidebar .nav-link {
    color: var(--text-color);
    padding: 0.85rem 1.5rem;
    font-weight: 500;
    border-left: 4px solid transparent;
    transition: all 0.2s ease-in-out;
    display: flex;
    align-items: center;
    border-radius: 0;
}
.sidebar .nav-link i { margin-right: 1rem; font-size: 1.1rem; width: 20px; text-align: center; }
.sidebar .nav-link:hover { background-color: var(--background-color); color: var(--primary-color); }
.sidebar .nav-link.active {
    background: linear-gradient(90deg, rgba(var(--bs-primary-rgb), 0.1), transparent);
    color: var(--primary-color);
    border-left-color: var(--primary-color);
    font-weight: 600;
}

.sidebar-footer { padding: 1rem; border-top: 1px solid var(--card-border); color: var(--secondary-color); }

/* --- Main Content & Header --- */
.main-content {
    flex-grow: 1;
    margin-left: var(--sidebar-width);
    padding: 0;
    transition: margin-left 0.3s ease-in-out;
}

.header {
    background-color: var(--card-bg);
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--card-border);
    box-shadow: var(--box-shadow);
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 999;
}
.header #module-title { margin: 0; font-weight: 600; color: var(--heading-color); }

.content-body { padding: 1.5rem; }

.module { display: none; animation: fadeIn 0.4s ease; }
.module.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(15px); } to { opacity: 1; transform: translateY(0); } }

/* --- Components --- */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 0.5rem;
    box-shadow: var(--box-shadow);
    transition: all 0.3s;
}
.card-header {
    background-color: transparent;
    border-bottom: 1px solid var(--card-border);
    font-weight: 600;
    color: var(--heading-color);
    padding: 1rem 1.25rem;
}
.card-header i { color: var(--primary-color); margin-right: 0.5rem; }

/* --- Printable Slip Styles --- */
.printable-slip { font-family: 'Arial', sans-serif; border: 1px solid #ccc; padding: 1.5rem; color: #000; }
.printable-slip * { color: #000 !important; }
.printable-slip .slip-header { text-align: center; border-bottom: 2px solid #000; padding-bottom: 1rem; margin-bottom: 1.5rem; }
.printable-slip .slip-header h4 { margin: 0; font-weight: bold; }
.printable-slip .slip-details-table { width: 100%; margin-bottom: 1.5rem; }
.printable-slip .slip-details-table td { padding: 5px; }
.printable-slip .slip-details-table td:first-child { font-weight: bold; }
.printable-slip .slip-footer { text-align: center; margin-top: 2rem; padding-top: 1rem; border-top: 1px solid #eee; font-size: 0.8rem; color: #555; }
.timetable-grid { display: grid; grid-template-columns: 100px repeat(6, 1fr); gap: 1px; background-color: var(--card-border); }
.timetable-grid > div { background-color: var(--card-bg); padding: 0.5rem; }
.timetable-grid .day-header { font-weight: bold; text-align: center; }

/* --- Print Media Query --- */
@media print {
    body * { visibility: hidden; }
    #printableModalBody, #printableModalBody * { visibility: visible; }
    #printableModalBody .printable-slip { position: absolute; left: 0; top: 0; width: 100%; border: none; box-shadow: none; padding: 0; }
    .modal-footer, .modal-header, #menu-toggle-btn, .sidebar, .header { display: none !important; }
}

/* --- Responsive Design --- */
@media (max-width: 992px) {
    .sidebar { transform: translateX(calc(-1 * var(--sidebar-width))); }
    .sidebar.active { transform: translateX(0); }
    .main-content { margin-left: 0; width: 100%; }
}
@media (min-width: 992px) {
    #sidebar-toggle-btn, #menu-toggle-btn { display: none; }
}