:root {
    --primary-color: #0d6efd;
    --success-color: #198754;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #0dcaf0;
    --transition-speed: 0.3s;
}

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

/* Body Layout */
body {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

main {
    flex: 1;
}

/* Navbar */
.navbar {
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid var(--bs-border-color);
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    letter-spacing: 0.5px;
}

.navbar-brand i {
    font-size: 1.75rem;
}

/* Navigation Links */
.nav-link {
    font-weight: 500;
    transition: all var(--transition-speed) ease;
    position: relative;
}

.nav-link:hover {
    color: var(--primary-color) !important;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-color);
    transition: width var(--transition-speed) ease;
}

.nav-link:hover::after {
    width: 100%;
}

/* User Avatar */
.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-color), var(--info-color));
    color: white;
    font-weight: 600;
    font-size: 1rem;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

/* Alerts */
.alert {
    border-radius: 8px;
    border: none;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    animation: slideDown var(--transition-speed) ease;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.alert-success {
    background-color: #d1e7dd;
    border-color: #badbcc;
    color: #0f5132;
}

.alert-error,
.alert-danger {
    background-color: #f8d7da;
    border-color: #f5c2c7;
    color: #842029;
}

.alert-warning {
    background-color: #fff3cd;
    border-color: #ffecb5;
    color: #664d03;
}

.alert-info {
    background-color: #cfe2ff;
    border-color: #b6d4fe;
    color: #084298;
}

/* Buttons */
.btn {
    border-radius: 6px;
    font-weight: 500;
    transition: all var(--transition-speed) ease;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-sm:hover {
    transform: translateY(-1px);
}

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

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

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

/* Form Controls */
.form-control,
.form-select {
    border-radius: 6px;
    border: 1px solid var(--bs-border-color);
    transition: all var(--transition-speed) ease;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
}

.form-control.is-invalid,
.form-select.is-invalid {
    border-color: var(--danger-color);
}

.form-control.is-invalid:focus,
.form-select.is-invalid:focus {
    border-color: var(--danger-color);
    box-shadow: 0 0 0 0.25rem rgba(220, 53, 69, 0.25);
}

/* Cards */
.card {
    border: 1px solid var(--bs-border-color);
    border-radius: 8px;
    transition: all var(--transition-speed) ease;
}

.card:hover {
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.1);
}

.card-header {
    border-bottom: 1px solid var(--bs-border-color);
    font-weight: 600;
}

/* Badges */
.badge {
    font-weight: 600;
    padding: 0.5rem 0.75rem;
    border-radius: 4px;
}

/* Tables */
.table {
    border-radius: 8px;
    overflow: hidden;
}

.table-hover tbody tr:hover {
    background-color: var(--bs-gray-100);
}

[data-bs-theme="dark"] .table-hover tbody tr:hover {
    background-color: var(--bs-gray-800);
}

/* Footer */
footer {
    background-color: var(--bs-gray-100);
    border-top: 1px solid var(--bs-border-color);
    margin-top: auto;
    padding: 2rem 0;
    text-align: center;
    color: var(--bs-gray-600);
}

[data-bs-theme="dark"] footer {
    background-color: var(--bs-gray-900);
    color: var(--bs-gray-400);
}

/* Main Container */
main.container-fluid {
    padding-bottom: 2rem;
}

/* Theme Colors Dark Mode */
[data-bs-theme="dark"] .navbar {
    background-color: var(--bs-gray-900);
}

[data-bs-theme="dark"] .card {
    background-color: var(--bs-gray-800);
    border-color: var(--bs-gray-700);
}

[data-bs-theme="dark"] .form-control,
[data-bs-theme="dark"] .form-select {
    background-color: var(--bs-gray-900);
    color: var(--bs-white);
    border-color: var(--bs-gray-700);
}

/* Responsive */
@media (max-width: 768px) {
    .navbar-brand {
        font-size: 1.25rem;
    }

    .user-avatar {
        width: 32px;
        height: 32px;
        font-size: 0.875rem;
    }

    main.container-fluid {
        padding: 1rem 0.5rem 2rem 0.5rem;
    }
}

/* Utility Classes */
.hover-card {
    transition: transform var(--transition-speed) ease, box-shadow var(--transition-speed) ease;
}

.hover-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15) !important;
}

.min-vh-75 {
    min-height: 75vh;
}

.shadow-lg {
    box-shadow: 0 1rem 3rem rgba(0, 0, 0, 0.175) !important;
}

/* Animations */
@keyframes spin {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

.spinner {
    animation: spin 1s linear infinite;
}

/* Loading State */
.loading {
    opacity: 0.6;
    pointer-events: none;
}