:root {
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --danger-color: #dc3545;
    --danger-hover: #a71d2a;
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --card-bg: #ffffff;
    --border-color: #dee2e6;
    --muted-text: #6c757d;
}

* {
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    line-height: 1.5;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Navbar */
.navbar {
    background-color: #343a40;
    color: white;
    padding: 1rem 0;
    margin-bottom: 2rem;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.navbar-brand {
    font-size: 1.25rem;
    font-weight: bold;
    color: white;
    text-decoration: none;
}

.navbar-nav {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
}

.nav-item {
    margin-left: 1rem;
}

.nav-link {
    color: rgba(255,255,255,0.75);
    text-decoration: none;
}

.nav-link:hover {
    color: white;
}

/* Layout */
.container {
    width: 100%;
    max-width: 960px;
    margin: 0 auto;
    padding: 0 15px;
}

.row {
    display: flex;
    flex-wrap: wrap;
    margin: 0 -15px;
}

.col-main {
    flex: 0 0 66.666667%;
    max-width: 66.666667%;
    padding: 0 15px;
}

.col-sidebar {
    flex: 0 0 33.333333%;
    max-width: 33.333333%;
    padding: 0 15px;
}

.col-full {
    flex: 0 0 100%;
    max-width: 100%;
    padding: 0 15px;
}

.centered-form {
    max-width: 500px;
    margin: 0 auto;
}

/* Components */
.card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 0.25rem;
    margin-bottom: 1.5rem;
}

.card-body {
    padding: 1.25rem;
}

.card-title {
    margin-bottom: 0.75rem;
    font-size: 1.25rem;
    font-weight: 500;
}

.card-subtitle {
    margin-top: -0.375rem;
    margin-bottom: 0.5rem;
    color: var(--muted-text);
}

.card-text {
    margin-bottom: 1rem;
}

.text-muted {
    color: var(--muted-text);
    font-size: 0.875em;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-control {
    display: block;
    width: 100%;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    border: 1px solid #ced4da;
    border-radius: 0.25rem;
    transition: border-color .15s ease-in-out,box-shadow .15s ease-in-out;
}

.form-control:focus {
    border-color: #80bdff;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0,123,255,.25);
}

.btn {
    display: inline-block;
    font-weight: 400;
    text-align: center;
    vertical-align: middle;
    user-select: none;
    border: 1px solid transparent;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 0.25rem;
    cursor: pointer;
    transition: color .15s ease-in-out,background-color .15s ease-in-out,border-color .15s ease-in-out,box-shadow .15s ease-in-out;
}

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

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

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

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

.btn-block {
    display: block;
    width: 100%;
}

.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }

/* Pagination */
.pagination {
    display: flex;
    padding-left: 0;
    list-style: none;
    border-radius: 0.25rem;
}

.page-item:first-child .page-link {
    border-top-left-radius: 0.25rem;
    border-bottom-left-radius: 0.25rem;
}

.page-item:last-child .page-link {
    border-top-right-radius: 0.25rem;
    border-bottom-right-radius: 0.25rem;
}

.page-link {
    position: relative;
    display: block;
    padding: 0.5rem 0.75rem;
    margin-left: -1px;
    line-height: 1.25;
    color: var(--primary-color);
    background-color: #fff;
    border: 1px solid var(--border-color);
    text-decoration: none;
}

.page-link:hover {
    background-color: #e9ecef;
    text-decoration: none;
}

.page-item.disabled .page-link {
    color: var(--muted-text);
    pointer-events: none;
    cursor: auto;
    background-color: #fff;
    border-color: var(--border-color);
}

/* Utilities */
.img-fluid {
    max-width: 100%;
    height: auto;
}

.rounded {
    border-radius: 0.25rem;
}

.w-100 { width: 100%; }

.alert {
    position: relative;
    padding: 0.75rem 1.25rem;
    margin-bottom: 1rem;
    border: 1px solid transparent;
    border-radius: 0.25rem;
}

.alert-warning {
    color: #856404;
    background-color: #fff3cd;
    border-color: #ffeeba;
}

.input-group {
    display: flex;
    flex-wrap: wrap;
    align-items: stretch;
    width: 100%;
}

.input-group .form-control {
    flex: 1 1 auto;
    width: 1%;
    border-top-right-radius: 0;
    border-bottom-right-radius: 0;
}

.input-group .btn {
    border-top-left-radius: 0;
    border-bottom-left-radius: 0;
    margin-left: -1px;
}
.justify-center { justify-content: center; }
.float-right { float: right; }

.btn-outline-primary {
    color: var(--primary-color);
    background-color: transparent;
    border-color: var(--primary-color);
}
.btn-outline-primary:hover {
    color: #fff;
    background-color: var(--primary-color);
}

.btn-sm {
    padding: 0.25rem 0.5rem;
    font-size: 0.875rem;
    line-height: 1.5;
    border-radius: 0.2rem;
}

.card-header {
    padding: 0.75rem 1.25rem;
    margin-bottom: 0;
    background-color: rgba(0,0,0,.03);
    border-bottom: 1px solid rgba(0,0,0,.125);
}

.card-link + .card-link {
    margin-left: 1.25rem;
}
.card-link {
    color: var(--primary-color);
}
.card-link:hover {
    text-decoration: underline;
}