/* ============================================================
   rs-core.css — Runestone's replacement for Bootstrap.

   Implements ONLY the Bootstrap classes actually used by the
   templates in components/rsptx/templates (plus the handful of
   classes that published book bundles expect on assignment
   pages: modal, nav-tabs/tab-pane).  Values match Bootstrap 4
   defaults so removing the CDN does not change the look.

   Loaded by _base.html, admin/auth/_auth_base.html, and the
   LTI 1.3 pages.  Page/site stylesheets (main.css, admin.css,
   …) load after this file and may override it.
   ============================================================ */

/* ---------- Reboot (minimal subset of Bootstrap's) ---------- */
*,
*::before,
*::after {
    box-sizing: border-box;
}

html {
    font-family: sans-serif;
    line-height: 1.15;
    -webkit-text-size-adjust: 100%;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
        "Helvetica Neue", Arial, sans-serif;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: #212529;
    text-align: left;
    background-color: #fff;
}

h1, h2, h3, h4, h5, h6 {
    margin-top: 0;
    margin-bottom: 0.5rem;
    font-weight: 500;
    line-height: 1.2;
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.75rem; }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
    margin-top: 0;
    margin-bottom: 1rem;
}

ol, ul, dl {
    margin-top: 0;
    margin-bottom: 1rem;
}

ol ol, ul ul, ol ul, ul ol {
    margin-bottom: 0;
}

dt {
    font-weight: 700;
}

dd {
    margin-bottom: 0.5rem;
    margin-left: 0;
}

hr {
    box-sizing: content-box;
    height: 0;
    overflow: visible;
    margin: 1rem 0;
    border: 0;
    border-top: 1px solid rgba(0, 0, 0, 0.1);
}

a {
    color: #007bff;
    text-decoration: none;
    background-color: transparent;
}

a:hover {
    color: #0056b3;
    text-decoration: underline;
}

pre {
    margin-top: 0;
    margin-bottom: 1rem;
    overflow: auto;
    font-family: SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono",
        "Courier New", monospace;
    font-size: 87.5%;
}

img {
    vertical-align: middle;
    border-style: none;
    max-width: 100%;
}

table {
    border-collapse: collapse;
}

th {
    text-align: inherit;
}

label {
    display: inline-block;
    margin-bottom: 0.5rem;
}

button {
    border-radius: 0;
}

input, button, select, optgroup, textarea {
    margin: 0;
    font-family: inherit;
    font-size: inherit;
    line-height: inherit;
}

button, select {
    text-transform: none;
}

button, [type="button"], [type="reset"], [type="submit"] {
    -webkit-appearance: button;
}

[hidden] {
    display: none !important;
}

/* ---------- Layout: containers and grid ---------- */
.container {
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
    margin-right: auto;
    margin-left: auto;
}

@media (min-width: 576px)  { .container { max-width: 540px; } }
@media (min-width: 768px)  { .container { max-width: 720px; } }
@media (min-width: 992px)  { .container { max-width: 960px; } }
@media (min-width: 1200px) { .container { max-width: 1140px; } }

.container-fluid {
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
    margin-right: auto;
    margin-left: auto;
}

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

.col,
[class*="col-md-"] {
    position: relative;
    width: 100%;
    padding-right: 15px;
    padding-left: 15px;
}

.col {
    flex-basis: 0;
    flex-grow: 1;
    max-width: 100%;
}

/* Below the md breakpoint every column is full width */
@media (min-width: 768px) {
    .col-md-4  { flex: 0 0 33.333333%; max-width: 33.333333%; }
    .col-md-5  { flex: 0 0 41.666667%; max-width: 41.666667%; }
    .col-md-6  { flex: 0 0 50%;        max-width: 50%; }
    .col-md-7  { flex: 0 0 58.333333%; max-width: 58.333333%; }
    .col-md-8  { flex: 0 0 66.666667%; max-width: 66.666667%; }
    .col-md-12 { flex: 0 0 100%;       max-width: 100%; }
}

.form-row {
    display: flex;
    flex-wrap: wrap;
    margin-right: -5px;
    margin-left: -5px;
}

.form-row > .col,
.form-row > [class*="col-"] {
    padding-right: 5px;
    padding-left: 5px;
}

/* ---------- Display / flex utilities ---------- */
.d-none  { display: none !important; }
.d-flex  { display: flex !important; }
.flex-column { flex-direction: column !important; }
.align-items-center { align-items: center !important; }

/* ---------- Spacing utilities (only the ones in use) ---------- */
.mt-0 { margin-top: 0 !important; }
.mt-3 { margin-top: 1rem !important; }
.mt-4 { margin-top: 1.5rem !important; }
.mt-5 { margin-top: 3rem !important; }
.mb-0 { margin-bottom: 0 !important; }
.mb-3 { margin-bottom: 1rem !important; }
.ml-auto { margin-left: auto !important; }
.mr-auto { margin-right: auto !important; }
.me-2, .mr-2 { margin-right: 0.5rem !important; }
.mr-lg-2 { margin-right: 0.5rem !important; }

/* ---------- Text utilities ---------- */
.text-muted { color: #6c757d !important; }
.text-center { text-align: center !important; }
.text-black { color: #000 !important; }
.small, small { font-size: 80%; font-weight: 400; }

.sr-only,
.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.sticky-top {
    position: sticky;
    top: 0;
    z-index: 1020;
}

.bg-light {
    background-color: #f8f9fa !important;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-block;
    font-weight: 400;
    color: #212529;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
    user-select: none;
    background-color: transparent;
    border: 1px solid transparent;
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    line-height: 1.5;
    border-radius: 0.25rem;
    transition: color 0.15s ease-in-out, background-color 0.15s ease-in-out,
        border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.btn:hover {
    text-decoration: none;
}

.btn:focus {
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.btn:disabled,
.btn.disabled {
    opacity: 0.65;
    cursor: not-allowed;
}

.btn-primary { color: #fff; background-color: #007bff; border-color: #007bff; }
.btn-primary:hover:not(:disabled) { color: #fff; background-color: #0069d9; border-color: #0062cc; }

.btn-secondary { color: #fff; background-color: #6c757d; border-color: #6c757d; }
.btn-secondary:hover:not(:disabled) { color: #fff; background-color: #5a6268; border-color: #545b62; }

.btn-success { color: #fff; background-color: #28a745; border-color: #28a745; }
.btn-success:hover:not(:disabled) { color: #fff; background-color: #218838; border-color: #1e7e34; }

.btn-danger { color: #fff; background-color: #dc3545; border-color: #dc3545; }
.btn-danger:hover:not(:disabled) { color: #fff; background-color: #c82333; border-color: #bd2130; }

.btn-warning { color: #212529; background-color: #ffc107; border-color: #ffc107; }
.btn-warning:hover:not(:disabled) { color: #212529; background-color: #e0a800; border-color: #d39e00; }

.btn-info { color: #fff; background-color: #17a2b8; border-color: #17a2b8; }
.btn-info:hover:not(:disabled) { color: #fff; background-color: #138496; border-color: #117a8b; }

.btn-outline-secondary { color: #6c757d; background-color: transparent; border-color: #6c757d; }
.btn-outline-secondary:hover:not(:disabled) { color: #fff; background-color: #6c757d; border-color: #6c757d; }

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

.btn-lg {
    padding: 0.5rem 1rem;
    font-size: 1.25rem;
    line-height: 1.5;
    border-radius: 0.3rem;
}

/* ---------- Forms ---------- */
.form-control {
    display: block;
    width: 100%;
    height: calc(1.5em + 0.75rem + 2px);
    padding: 0.375rem 0.75rem;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.5;
    color: #495057;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid #ced4da;
    border-radius: 0.25rem;
    transition: border-color 0.15s ease-in-out, box-shadow 0.15s ease-in-out;
}

.form-control:focus {
    color: #495057;
    background-color: #fff;
    border-color: #80bdff;
    outline: 0;
    box-shadow: 0 0 0 0.2rem rgba(0, 123, 255, 0.25);
}

.form-control:disabled {
    background-color: #e9ecef;
    opacity: 1;
}

/* selects with size/multiple, textareas and file inputs are not
   fixed-height */
select.form-control[size],
select.form-control[multiple],
textarea.form-control,
.form-control[type="file"] {
    height: auto;
}

.form-control-sm {
    height: calc(1.5em + 0.5rem + 2px);
    padding: 0.25rem 0.5rem;
    font-size: 0.875rem;
    border-radius: 0.2rem;
}

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

.form-label {
    margin-bottom: 0.5rem;
}

.form-text {
    display: block;
    margin-top: 0.25rem;
}

.form-check {
    position: relative;
    display: block;
    padding-left: 1.25rem;
}

.form-check-input {
    position: absolute;
    margin-top: 0.3rem;
    margin-left: -1.25rem;
}

.form-check-label {
    margin-bottom: 0;
}

/* ---------- Tables ---------- */
.table {
    width: 100%;
    margin-bottom: 1rem;
    color: #212529;
}

.table th,
.table td {
    padding: 0.75rem;
    vertical-align: top;
    border-top: 1px solid #dee2e6;
}

.table thead th {
    vertical-align: bottom;
    border-bottom: 2px solid #dee2e6;
}

.table-striped tbody tr:nth-of-type(odd) {
    background-color: rgba(0, 0, 0, 0.05);
}

.table-bordered,
.table-bordered th,
.table-bordered td {
    border: 1px solid #dee2e6;
}

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

.alert-success { color: #155724; background-color: #d4edda; border-color: #c3e6cb; }
.alert-danger  { color: #721c24; background-color: #f8d7da; border-color: #f5c6cb; }
.alert-warning { color: #856404; background-color: #fff3cd; border-color: #ffeeba; }
.alert-info    { color: #0c5460; background-color: #d1ecf1; border-color: #bee5eb; }

.alert-dismissible {
    padding-right: 4rem;
}

.alert-dismissible .close {
    position: absolute;
    top: 0;
    right: 0;
    padding: 0.75rem 1.25rem;
}

.close {
    float: right;
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1;
    color: #000;
    text-shadow: 0 1px 0 #fff;
    opacity: 0.5;
    background-color: transparent;
    border: 0;
    cursor: pointer;
}

.close:hover {
    opacity: 0.75;
}

.fade {
    transition: opacity 0.15s linear;
}

.fade:not(.show) {
    opacity: 0;
}

/* ---------- Cards ---------- */
.card {
    position: relative;
    display: flex;
    flex-direction: column;
    min-width: 0;
    word-wrap: break-word;
    background-color: #fff;
    background-clip: border-box;
    border: 1px solid rgba(0, 0, 0, 0.125);
    border-radius: 0.25rem;
}

.card-body {
    flex: 1 1 auto;
    min-height: 1px;
    padding: 1.25rem;
}

.card-title {
    margin-bottom: 0.75rem;
}

.card-text:last-child {
    margin-bottom: 0;
}

.card-header {
    padding: 0.75rem 1.25rem;
    margin-bottom: 0;
    background-color: rgba(0, 0, 0, 0.03);
    border-bottom: 1px solid rgba(0, 0, 0, 0.125);
    border-radius: 0.25rem 0.25rem 0 0;
}

/* ---------- Nav / tabs ---------- */
.nav {
    display: flex;
    flex-wrap: wrap;
    padding-left: 0;
    margin-bottom: 0;
    list-style: none;
}

.nav-link {
    display: block;
    padding: 0.5rem 1rem;
}

.nav-link:hover {
    text-decoration: none;
}

/* Tabs — used by the tabbedStuff book component (BS3-style li.active
   markup) and driven by nav.js */
.nav-tabs {
    display: flex;
    flex-wrap: wrap;
    padding-left: 0;
    margin-bottom: 0;
    list-style: none;
    border-bottom: 1px solid #dee2e6;
}

.nav-tabs > li > a,
.nav-tabs .nav-link {
    display: block;
    padding: 0.5rem 1rem;
    margin-bottom: -1px;
    border: 1px solid transparent;
    border-top-left-radius: 0.25rem;
    border-top-right-radius: 0.25rem;
    cursor: pointer;
}

.nav-tabs > li > a:hover {
    border-color: #e9ecef #e9ecef #dee2e6;
    text-decoration: none;
}

.nav-tabs > li.active > a,
.nav-tabs .nav-link.active {
    color: #495057;
    background-color: #fff;
    border-color: #dee2e6 #dee2e6 #fff;
}

.tab-content > .tab-pane {
    display: none;
}

.tab-content > .active {
    display: block;
}

/* ---------- Navbar ---------- */
.navbar {
    position: relative;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
    padding: 0.5rem 1rem;
}

.navbar-brand {
    display: inline-block;
    padding-top: 0.3125rem;
    padding-bottom: 0.3125rem;
    margin-right: 1rem;
    font-size: 1.25rem;
    line-height: inherit;
    white-space: nowrap;
}

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

.navbar-nav .nav-link {
    padding-right: 0;
    padding-left: 0;
}

.navbar-collapse {
    flex-basis: 100%;
    flex-grow: 1;
    align-items: center;
}

.navbar-toggler {
    padding: 0.25rem 0.75rem;
    font-size: 1.25rem;
    line-height: 1;
    background-color: transparent;
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: 0.25rem;
    cursor: pointer;
}

.navbar-toggler-icon {
    display: inline-block;
    width: 1.5em;
    height: 1.5em;
    vertical-align: middle;
    content: "";
    background: no-repeat center center;
    background-size: 100% 100%;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba(0, 0, 0, 0.5)' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
}

.navbar-light .navbar-brand {
    color: rgba(0, 0, 0, 0.9);
}

.navbar-light .navbar-nav .nav-link,
.navbar-light .nav-link {
    color: rgba(0, 0, 0, 0.5);
}

.navbar-light .navbar-nav .nav-link:hover,
.navbar-light .nav-link:hover {
    color: rgba(0, 0, 0, 0.7);
    text-decoration: none;
}

/* collapse behavior (also used by profile.html's delete form) */
.collapse:not(.show) {
    display: none;
}

/* expand at the sm breakpoint, matching navbar-expand-sm */
@media (max-width: 575.98px) {
    .navbar-expand-sm .navbar-nav .dropdown-menu {
        position: static;
        float: none;
    }
}

@media (min-width: 576px) {
    .navbar-expand-sm {
        flex-flow: row nowrap;
        justify-content: flex-start;
    }

    .navbar-expand-sm .navbar-nav {
        flex-direction: row;
    }

    .navbar-expand-sm .navbar-nav .nav-link,
    .navbar-expand-sm .nav-link {
        padding-right: 0.5rem;
        padding-left: 0.5rem;
    }

    .navbar-expand-sm .navbar-collapse {
        display: flex !important;
        flex-basis: auto;
    }

    .navbar-expand-sm .navbar-toggler {
        display: none;
    }
}

/* ---------- Dropdowns (driven by nav.js) ---------- */
.dropdown {
    position: relative;
}

.dropdown-toggle::after {
    display: inline-block;
    margin-left: 0.255em;
    vertical-align: 0.255em;
    content: "";
    border-top: 0.3em solid;
    border-right: 0.3em solid transparent;
    border-bottom: 0;
    border-left: 0.3em solid transparent;
}

.dropdown-menu {
    position: absolute;
    top: 100%;
    left: 0;
    z-index: 1000;
    display: none;
    min-width: 10rem;
    padding: 0.5rem 0;
    margin: 0.125rem 0 0;
    font-size: 1rem;
    color: #212529;
    text-align: left;
    list-style: none;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid rgba(0, 0, 0, 0.15);
    border-radius: 0.25rem;
}

.dropdown-menu.show {
    display: block;
}

/* Book bundles ship a Bootstrap 3 dropdown plugin that hijacks the navbar
   toggles (bootstrap-sphinx.js calls $('.dropdown-toggle').dropdown()) and
   marks the open state with .open/.show on the PARENT instead of the menu.
   Honor that convention too so dropdowns work on pages that load a book
   bundle (doAssignment, peer pages, ...). */
.open > .dropdown-menu,
.show > .dropdown-menu {
    display: block;
}

.dropdown-menu-right {
    right: 0;
    left: auto;
}

.dropdown-item {
    display: block;
    width: 100%;
    padding: 0.25rem 1.5rem;
    clear: both;
    font-weight: 400;
    color: #212529;
    text-align: inherit;
    white-space: nowrap;
    background-color: transparent;
    border: 0;
}

.dropdown-item:hover,
.dropdown-item:focus {
    color: #16181b;
    text-decoration: none;
    background-color: #f8f9fa;
}

.dropdown-divider {
    height: 0;
    margin: 0.5rem 0;
    overflow: hidden;
    border-top: 1px solid #e9ecef;
}

/* ---------- Modal (for the activecode feedback shim in nav.js) ---------- */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1050;
    display: none;
    width: 100%;
    height: 100%;
    overflow: hidden auto;
    outline: 0;
}

.modal-dialog {
    position: relative;
    width: auto;
    margin: 0.5rem;
    pointer-events: auto;
}

@media (min-width: 576px) {
    .modal-dialog {
        max-width: 500px;
        margin: 1.75rem auto;
    }
}

.modal-content {
    position: relative;
    display: flex;
    flex-direction: column;
    width: 100%;
    background-color: #fff;
    background-clip: padding-box;
    border: 1px solid rgba(0, 0, 0, 0.2);
    border-radius: 0.3rem;
    outline: 0;
}

.modal-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    padding: 1rem;
    border-bottom: 1px solid #dee2e6;
    border-radius: 0.3rem 0.3rem 0 0;
}

.modal-title {
    margin-bottom: 0;
    line-height: 1.5;
}

.modal-body {
    position: relative;
    flex: 1 1 auto;
    padding: 1rem;
}

.modal-backdrop {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 1040;
    width: 100vw;
    height: 100vh;
    background-color: #000;
    opacity: 0.5;
}

body.modal-open {
    overflow: hidden;
}

/* ---------- Spinner ---------- */
@keyframes rs-spinner-border {
    to { transform: rotate(360deg); }
}

.spinner-border {
    display: inline-block;
    width: 2rem;
    height: 2rem;
    vertical-align: text-bottom;
    border: 0.25em solid currentColor;
    border-right-color: transparent;
    border-radius: 50%;
    animation: rs-spinner-border 0.75s linear infinite;
}

.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.2em;
}