/* Duke-branded pydata-sphinx-theme styling with CoLab layout conventions. */
@import url("https://fonts.googleapis.com/css2?family=Open+Sans:wght@400;600;700&display=swap");

:root {
  --pst-font-family-base: "Open Sans", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --pst-font-family-heading: "Open Sans", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  --duke-navy: #012169;
  --duke-royal-blue: #00539b;
  --duke-prussian-blue: #005587;
  --duke-shale-blue: #0577b1;
  --duke-copper: #c84e00;
  --duke-cast-iron: #262626;
  --duke-graphite: #666666;
  --duke-hatteras: #e2e6ed;
  --duke-whisper-gray: #f3f2f1;
  --duke-ginger-beer: #fcf7e5;

  --brand-ink: var(--duke-cast-iron);
  --brand-navy: var(--duke-navy);
  --brand-slate: var(--duke-royal-blue);
  --brand-wave: var(--duke-prussian-blue);
  --brand-sky: var(--duke-shale-blue);
  --brand-foam: var(--duke-whisper-gray);
  --brand-border: var(--duke-hatteras);
  --brand-shadow: rgba(1, 33, 105, 0.14);

  --pst-color-primary: var(--brand-navy);
  --pst-color-secondary: var(--brand-slate);
  --pst-color-info: var(--brand-sky);
  --pst-color-success: #1d6363;
  --pst-color-warning: var(--duke-copper);
  --pst-color-danger: #c14953;
  --pst-color-text-base: var(--brand-ink);
  --pst-color-link: var(--brand-slate);
  --pst-color-link-visited: var(--brand-slate);
  --pst-color-link-hover: var(--brand-wave);
}

html[data-theme="light"] {
  --pst-color-link: var(--brand-slate);
  --pst-color-link-visited: var(--brand-slate);
  --pst-color-link-hover: var(--brand-wave);
}

body {
  font-family: "Open Sans", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  color: var(--pst-color-text-base);
  background: linear-gradient(180deg, #ffffff 0%, var(--duke-whisper-gray) 34%, #ffffff 100%);
}

h1,
h2,
h3,
h4,
h5,
h6,
.bd-content h1,
.bd-content h2,
.bd-content h3,
.bd-content h4,
.bd-content h5,
.bd-content h6,
.bd-sidebar .bd-links,
.bd-sidebar .toctree-l1 > a,
.bd-sidebar .toctree-l2 > a {
  font-family: "Open Sans", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
}

.bd-header {
  background: linear-gradient(120deg, var(--duke-navy) 0%, var(--duke-royal-blue) 65%, var(--duke-prussian-blue) 100%);
  box-shadow: 0 8px 30px var(--brand-shadow);
  border: none;
}

.bd-header .navbar-header-items__start {
  flex: 1 1 auto;
  max-width: none;
  min-width: 0;
  width: auto;
}

.bd-header .navbar-header-items {
  flex: 0 0 auto;
  min-width: 0;
  width: auto;
  max-width: none;
  margin-left: auto;
}

.bd-header .navbar-header-items__end {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.bd-header .navbar-brand {
  margin: 0.7rem 0;
  padding-right: 0.85rem;
  border-right: none;
}

.bd-header .navbar-brand,
.bd-header .navbar-brand:visited,
.bd-header .navbar-brand:hover,
.bd-header .navbar-brand:focus,
.bd-header .navbar-brand .title,
.bd-header .navbar-brand .title:visited {
  color: #ffffff !important;
}

.bd-header .navbar-brand .logo__title {
  margin-left: 1rem;
  overflow-wrap: anywhere;
}

.bd-header .navbar-brand img {
  height: 44px;
  width: auto;
  max-height: 44px;
  object-fit: contain;
  padding: 2px 0;
  border-radius: 0;
  background: transparent;
  border: none;
}

.bd-header .navbar-nav .nav-link,
.bd-header .navbar-nav .nav-link:visited {
  color: #ffffff !important;
  letter-spacing: 0.01em;
  text-transform: uppercase;
  font-weight: 600;
  text-shadow: 0 2px 6px rgba(0, 0, 0, 0.35);
}

.bd-header .navbar-nav .nav-link:hover,
.bd-header .navbar-nav .nav-link:focus,
.bd-header .navbar-nav .nav-link.active {
  color: #ffffff !important;
  text-decoration: none;
}

.bd-header a,
.bd-header a:visited,
.bd-header a:hover,
.bd-header a:focus {
  color: #ffffff !important;
}

.bd-header .search-button-field {
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.55);
  color: #ffffff;
}

.bd-header .search-button-field:hover,
.bd-header .search-button-field:focus {
  background: rgba(255, 255, 255, 0.24);
  border-color: #ffffff;
  color: #ffffff;
}

.bd-header .search-button-field .search-button__default-text,
.bd-header .search-button-field .fa-magnifying-glass {
  color: #ffffff;
}

.bd-header .search-button-field kbd {
  background: rgba(255, 255, 255, 0.22);
  color: #ffffff;
}

.bd-header .theme-switch-button {
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 8px;
  color: #ffffff !important;
}

.bd-header .theme-switch-button:hover,
.bd-header .theme-switch-button:focus {
  background: rgba(255, 255, 255, 0.24);
  border-color: #ffffff;
  color: #ffffff !important;
}

.bd-header .theme-switch-button i {
  color: #ffffff !important;
}

.bd-header .navbar-toggler {
  border: 1px solid rgba(145, 192, 221, 0.55);
  background: rgba(255, 255, 255, 0.06);
  color: #f7fbff;
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.25);
}

.bd-header .navbar-toggler-icon {
  background-image: none;
  position: relative;
  width: 1.25rem;
  height: 0.9rem;
}

.bd-header .navbar-toggler-icon::before,
.bd-header .navbar-toggler-icon::after,
.bd-header .navbar-toggler-icon span {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 2px;
  background: #f7fbff;
  box-shadow: 0 0 6px rgba(0, 0, 0, 0.2);
}

.bd-header .navbar-toggler-icon::before {
  top: 0;
}

.bd-header .navbar-toggler-icon span {
  top: 50%;
  transform: translateY(-50%);
}

.bd-header .navbar-toggler-icon::after {
  bottom: 0;
}

.bd-header .pst-navbar-icon.sidebar-toggle {
  background: rgba(255, 255, 255, 0.14);
  border: 1px solid rgba(255, 255, 255, 0.55);
  border-radius: 8px;
  color: #ffffff;
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.22);
}

.bd-header .pst-navbar-icon.sidebar-toggle:hover,
.bd-header .pst-navbar-icon.sidebar-toggle:focus {
  background: rgba(255, 255, 255, 0.24);
  border-color: #ffffff;
  color: #ffffff;
}

.bd-header .pst-navbar-icon.sidebar-toggle span,
.bd-header .pst-navbar-icon.sidebar-toggle svg,
.bd-header .pst-navbar-icon.sidebar-toggle i {
  color: #ffffff;
}

.bd-sidebar {
  background: linear-gradient(180deg, #ffffff 0%, var(--duke-whisper-gray) 100%);
  border-right: 1px solid var(--brand-border);
}

.bd-sidebar .sidebar-primary-items__item {
  padding: 0.1rem 0.4rem;
}

.bd-sidebar .nav-link {
  color: var(--pst-color-text-muted);
  border-left: none;
  padding-left: 0.75rem;
  border-radius: 0;
  background: transparent;
}

.bd-sidebar .nav-link:visited,
.bd-toc-nav .nav-link,
.bd-toc-nav .nav-link:visited {
  color: var(--pst-color-text-muted);
}

html[data-theme="light"] .bd-sidebar .nav-link,
html[data-theme="light"] .bd-sidebar .nav-link:visited,
html[data-theme="light"] .bd-toc-nav .nav-link,
html[data-theme="light"] .bd-toc-nav .nav-link:visited {
  color: var(--duke-cast-iron);
}

.bd-sidebar .nav-link:hover {
  background: transparent;
  color: var(--pst-color-link);
  font-weight: 600;
}

.bd-sidebar .nav-link.active {
  border-left: none;
  background: transparent;
  font-weight: 700;
  color: var(--pst-color-link);
}

nav.bd-links .current > a {
  background-color: transparent;
  box-shadow: none;
  color: var(--pst-color-link);
  font-weight: 600;
}

html[data-theme="light"] .bd-sidebar .nav-link.active,
html[data-theme="light"] nav.bd-links .current > a {
  color: var(--duke-navy);
}

.bd-content {
  background: #ffffff;
  border-radius: 14px;
  box-shadow: 0 15px 40px var(--brand-shadow);
  border: 1px solid var(--duke-hatteras);
}

.bd-article-container {
  padding-top: 1rem;
}

.bd-content .header-article {
  border-bottom: 1px solid var(--brand-border);
  padding-bottom: 1rem;
  margin-bottom: 1.5rem;
}

.bd-content h1,
.bd-content h2,
.bd-content h3,
.bd-content h4 {
  color: var(--duke-navy);
  font-family: "Open Sans", "Segoe UI", "Helvetica Neue", Arial, sans-serif;
  letter-spacing: 0.02em;
}

a:link,
a:visited {
  color: var(--brand-slate);
}

a:hover,
a:focus {
  color: var(--brand-wave);
}

/* Prev/next navigation links */
.prev-next-area a,
.prev-next-area a:visited {
  color: var(--brand-ink);
  border: none;
  border-radius: 0;
  background: transparent;
  box-shadow: none;
  transition: color 0.2s ease, font-weight 0.2s ease;
  text-decoration: none;
}

.prev-next-area a:hover,
.prev-next-area a:focus {
  color: var(--brand-wave);
  font-weight: 600;
  text-decoration: underline;
}

.prev-next-area .prev-next-subtitle {
  color: var(--brand-slate);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.prev-next-area .prev-next-title {
  color: inherit;
  font-weight: 600;
}

.btn,
.bd-header button,
.bd-header .btn {
  border-radius: 10px;
  font-weight: 600;
  border: none;
  box-shadow: 0 10px 22px rgba(96, 151, 191, 0.35);
}

.btn-primary {
  background: linear-gradient(135deg, var(--duke-royal-blue), var(--duke-prussian-blue));
}

.btn-primary:hover {
  background: linear-gradient(135deg, var(--duke-navy), var(--duke-royal-blue));
}

.admonition,
.note,
.seealso,
.important,
.hint {
  border-radius: 10px;
  border: 1px solid var(--brand-border);
  box-shadow: 0 12px 28px var(--brand-shadow);
}

/**********************************************************************************/
/* Exercise and Solution Admonitions */

/* Exercise and Solution - title div background */
.admonition.exercise > .admonition-title,
div.admonition.exercise > .admonition-title,
.admonition.solution > .admonition-title,
div.admonition.solution > .admonition-title {
  position: relative;
  margin: 0 -0.6rem !important;
  padding: 0.4rem 0.6rem 0.4rem 2rem;
  font-weight: 700;
  background-color: #fd7e1433;
}

/* Exercise Admonition Icon */
.admonition.exercise > .admonition-title::before,
div.admonition.exercise > .admonition-title::before {
  position: absolute;
  left: 0.6rem;
  width: 1rem;
  height: 1rem;
  color: #fd7e14;
  background-color: #fd7e1400;
  font-family: "Font Awesome 7 Free", "Font Awesome 6 Free", "Font Awesome 5 Free";
  font-weight: 900;
  content: "\f303";
}

/* Solution Left Icon */
.admonition.solution > .admonition-title::before,
div.admonition.solution > .admonition-title::before {
  position: absolute;
  left: 0.6rem;
  width: 1rem;
  height: 1rem;
  color: #fd7e14;
  background-color: #fd7e1400;
  font-family: "Font Awesome 7 Free", "Font Awesome 6 Free", "Font Awesome 5 Free";
  font-weight: 900;
  content: "\f06e";
}

.admonition.exercise > .admonition-title::after,
div.admonition.exercise > .admonition-title::after,
.admonition.solution > .admonition-title::after,
div.admonition.solution > .admonition-title::after {
  content: none;
}

/* Exercise and Solution - Left Border */
.admonition.exercise,
div.admonition.exercise,
.admonition.solution,
div.admonition.solution {
  margin: 1.5625em auto;
  padding: 0 0.6rem 0.8rem !important;
  overflow: hidden;
  page-break-inside: avoid;
  border-left: 0.2rem solid #fd7e14;
  border-radius: 0.1rem;
  box-shadow: 0 0.2rem 0.5rem rgb(0 0 0 / 5%), 0 0 0.05rem rgb(0 0 0 / 10%);
  transition: color 0.25s, background-color 0.25s, border-color 0.25s;
}

/**********************************************************************************/

/**********************************************************************************/
/* Key Points Admonition */

/* Key Admonition Div Background */
.admonition.key > .admonition-title,
div.admonition.key > .admonition-title {
  position: relative;
  margin: 0 -0.6rem !important;
  padding: 0.4rem 0.6rem 0.4rem 2rem;
  font-weight: 700;
  background-color: #00a30033;
}

/* Key Admonition Icon */
.admonition.key > .admonition-title::before,
div.admonition.key > .admonition-title::before {
  position: absolute;
  left: 0.6rem;
  width: 1rem;
  height: 1rem;
  color: #00a300;
  background-color: #00a30000;
  font-family: "Font Awesome 7 Free", "Font Awesome 6 Free", "Font Awesome 5 Free";
  font-weight: 900;
  content: "\f084";
}

.admonition.key > .admonition-title::after,
div.admonition.key > .admonition-title::after {
  content: none;
}

/* Key Admonition left border */
.admonition.key,
div.admonition.key {
  margin: 1.5625em auto;
  padding: 0 0.6rem 0.8rem !important;
  overflow: hidden;
  page-break-inside: avoid;
  border-left: 0.2rem solid #00a300;
  border-radius: 0.1rem;
  box-shadow: 0 0.2rem 0.5rem rgb(0 0 0 / 5%), 0 0 0.05rem rgb(0 0 0 / 10%);
  transition: color 0.25s, background-color 0.25s, border-color 0.25s;
}

/**********************************************************************************/

code,
.rst-content tt {
  background: #f4f8fd;
  color: var(--brand-ink);
  border: 1px solid var(--brand-border);
  border-radius: 6px;
  padding: 0.15rem 0.4rem;
  font-weight: 600;
}

.highlight pre {
  background: #f6f9fd;
  color: #1c2c3f;
  border-radius: 12px;
  border: 1px solid rgba(48, 80, 115, 0.18);
  box-shadow: 0 18px 32px rgba(37, 53, 76, 0.18);
}

table.docutils {
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid var(--brand-border);
}

table.docutils thead {
  background: linear-gradient(135deg, var(--brand-slate), var(--brand-wave));
  color: #f7fbff;
}

table.docutils td,
table.docutils th {
  border-color: var(--brand-border);
}

footer.bd-footer {
  background: linear-gradient(120deg, var(--brand-navy) 0%, var(--brand-ink) 45%, var(--brand-slate) 100%);
  color: #e7f1f8;
}

footer.bd-footer a {
  color: #ffffff;
}

footer.bd-footer a:visited,
footer.bd-footer a:hover,
footer.bd-footer a:focus {
  color: #ffffff;
}

footer.bd-footer .footer-items__start,
footer.bd-footer .footer-item {
  width: 100%;
}

.site-footer {
  width: 100%;
  margin: 0;
  row-gap: 0.75rem;
}

.site-footer p {
  margin: 0 0 0.35rem;
  font-size: 0.82rem;
  line-height: 1.35;
}

.site-footer p:last-child {
  margin-bottom: 0;
}

.site-footer__duke {
  display: flex;
  align-items: center;
  justify-content: flex-end;
}

.site-footer__duke a {
  display: block;
  width: min(100%, 105px);
}

.site-footer__wordmark {
  display: block;
  max-width: 105px;
  max-height: 37px;
  width: 100%;
  height: auto;
}

.site-footer__content {
  text-align: left;
}

@media (max-width: 767.98px) {
  .site-footer__duke,
  .site-footer__content {
    justify-content: center;
    text-align: center;
  }
}

/* Back to top overrides */
#pst-back-to-top,
button.pst-back-to-top {
  background: linear-gradient(135deg, var(--brand-wave), var(--brand-sky));
  color: #ffffff;
  border: 1px solid rgba(48, 80, 115, 0.25);
  box-shadow: 0 12px 24px rgba(37, 53, 76, 0.22);
}

#pst-back-to-top:hover,
button.pst-back-to-top:hover {
  background: linear-gradient(135deg, var(--brand-slate), var(--brand-wave));
  color: #ffffff;
}

/* Dark mode adjustments, based on the cpp_lesson CoLab stylesheet. */
html[data-theme="dark"] {
  --brand-foam: #0f1826;
  --pst-color-text-base: #e6eef6;
  --pst-color-primary: #a8d8ff;
  --pst-color-link: #a8d8ff;
  --pst-color-link-hover: #a8d8ff;
  --pst-color-link-visited: #a8d8ff;
}

html[data-theme="dark"] body {
  background: radial-gradient(circle at 15% 15%, rgba(96, 151, 191, 0.18), transparent 35%),
    radial-gradient(circle at 80% 10%, rgba(48, 80, 115, 0.15), transparent 35%), #0b1220;
  color: var(--pst-color-text-base);
}

html[data-theme="dark"] .bd-container,
html[data-theme="dark"] .bd-container__inner,
html[data-theme="dark"] .bd-main {
  background: transparent;
}

html[data-theme="dark"] .bd-header {
  background: linear-gradient(135deg, #012169, #003a7a 60%, #00539b 100%);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
}

html[data-theme="dark"] .bd-header .navbar-brand img {
  background: transparent;
  border: none;
  filter: none;
}

html[data-theme="dark"] .bd-header .navbar-nav .nav-link {
  color: #ffffff !important;
  text-shadow: 0 2px 6px rgba(0, 0, 0, 0.45);
}

html[data-theme="dark"] .bd-header .navbar-toggler {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(145, 192, 221, 0.5);
  box-shadow: 0 8px 18px rgba(0, 0, 0, 0.35);
}

html[data-theme="dark"] .bd-header .navbar-toggler-icon::before,
html[data-theme="dark"] .bd-header .navbar-toggler-icon::after,
html[data-theme="dark"] .bd-header .navbar-toggler-icon span {
  background: #f7fbff;
}

html[data-theme="dark"] .bd-sidebar,
html[data-theme="dark"] .bd-sidebar-primary {
  background: linear-gradient(180deg, #0f1826 0%, #0d1421 100%);
  border-right-color: rgba(145, 192, 221, 0.25);
}

html[data-theme="dark"] .bd-sidebar .nav-link:hover {
  background: transparent;
  color: var(--pst-color-link);
  font-weight: 600;
}

html[data-theme="dark"] .bd-sidebar .nav-link.active {
  background: transparent;
  color: var(--pst-color-link);
  font-weight: 700;
}

html[data-theme="dark"] .bd-content {
  background: #0f1826;
  border-color: rgba(145, 192, 221, 0.25);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.45);
  color: #e9f2ff;
}

html[data-theme="dark"] .bd-content .header-article {
  border-bottom-color: rgba(145, 192, 221, 0.35);
}

html[data-theme="dark"] .bd-content h1,
html[data-theme="dark"] .bd-content h2,
html[data-theme="dark"] .bd-content h3,
html[data-theme="dark"] .bd-content h4 {
  color: #f5f7fb;
  text-shadow: 0 4px 14px rgba(0, 0, 0, 0.35);
}

html[data-theme="dark"] a:link,
html[data-theme="dark"] a:visited {
  color: #a8d8ff;
}

html[data-theme="dark"] a:hover,
html[data-theme="dark"] a:focus {
  color: #a8d8ff;
  font-weight: 600;
}

html[data-theme="dark"] .prev-next-area a,
html[data-theme="dark"] .prev-next-area a:visited {
  color: #a8d8ff;
  background: transparent;
  border: none;
  box-shadow: none;
}

html[data-theme="dark"] .prev-next-area a:hover,
html[data-theme="dark"] .prev-next-area a:focus {
  color: #a8d8ff;
}

html[data-theme="dark"] .prev-next-area .prev-next-subtitle {
  color: #96c3ec;
}

html[data-theme="dark"] .highlight pre {
  background: #0a111d;
  color: #e7f1f8;
  border-color: rgba(96, 151, 191, 0.35);
}

html[data-theme="dark"] code,
html[data-theme="dark"] .rst-content tt {
  background: #111b2a;
  color: #e7f1f8;
  border-color: rgba(145, 192, 221, 0.35);
}

html[data-theme="dark"] #pst-back-to-top,
html[data-theme="dark"] button.pst-back-to-top {
  background: linear-gradient(135deg, #2d4b6b, #6097bf);
  color: #ffffff;
  border-color: rgba(145, 192, 221, 0.25);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.4);
}

html[data-theme="dark"] #pst-back-to-top:hover,
html[data-theme="dark"] button.pst-back-to-top:hover {
  background: linear-gradient(135deg, #1f324a, #4b759b);
}

html[data-theme="dark"] .pst-navbar-icon.sidebar-toggle.primary-toggle,
html[data-theme="dark"] .pst-navbar-icon.sidebar-toggle.secondary-toggle,
html[data-theme="dark"] .pst-navbar-icon button.sidebar-toggle.primary-toggle,
html[data-theme="dark"] .pst-navbar-icon button.sidebar-toggle.secondary-toggle {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(145, 192, 221, 0.55);
  color: #f7fbff;
  box-shadow: 0 10px 22px rgba(0, 0, 0, 0.4);
}

html[data-theme="dark"] .pst-navbar-icon.sidebar-toggle.primary-toggle:hover,
html[data-theme="dark"] .pst-navbar-icon.sidebar-toggle.primary-toggle:focus,
html[data-theme="dark"] .pst-navbar-icon.sidebar-toggle.secondary-toggle:hover,
html[data-theme="dark"] .pst-navbar-icon.sidebar-toggle.secondary-toggle:focus {
  background: rgba(255, 255, 255, 0.16);
}