/* ===========================
   Horizon-Style Clean UI
   =========================== */

/* --- Root Variables --- */
:root {
  --md-primary-fg-color: #ffffff;
  --md-primary-bg-color: #0a1628;
  --md-accent-fg-color: #4361ee;
  --horizon-navy: #0a1628;
  --horizon-blue: #4361ee;
  --horizon-gray: #f5f7fa;
  --horizon-border: #e8ecf1;
  --horizon-text: #4a5568;
  --horizon-text-light: #718096;
  --horizon-card-shadow: 0 1px 3px rgba(0, 0, 0, 0.06), 0 1px 2px rgba(0, 0, 0, 0.04);
  --horizon-card-shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.08), 0 4px 10px rgba(0, 0, 0, 0.04);
  --logo-pink: #FF1B6B;
  --logo-blue: #45CAFF;
  --logo-pink-light: #FFE0EC;
  --logo-blue-light: #E0F4FF;
}

/* --- Global Overrides --- */
[data-md-color-scheme="default"] {
  --md-default-bg-color: #ffffff;
  --md-primary-fg-color: #ffffff;
  --md-primary-fg-color--light: #ffffff;
  --md-primary-fg-color--dark: #0a1628;
  --md-primary-bg-color: #0a1628;
  --md-typeset-color: #2d3748;
}

/* Code blocks should always be LTR */
code, pre {
  direction: ltr;
  text-align: left;
}

/* --- Header / Navigation Bar --- */
[data-md-color-scheme="default"] .md-header {
  background: #ffffff;
  color: var(--horizon-navy);
  box-shadow: 0 1px 0 var(--horizon-border);
}

[data-md-color-scheme="default"] .md-header .md-header__title {
  color: var(--horizon-navy);
  font-weight: 700;
}

[data-md-color-scheme="default"] .md-header .md-header__topic {
  color: var(--horizon-navy);
  font-weight: 700;
}

[data-md-color-scheme="default"] .md-header .md-header__button {
  color: var(--horizon-navy);
}

[data-md-color-scheme="default"] .md-header[data-md-state="shadow"] {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

/* --- Navigation Tabs --- */
[data-md-color-scheme="default"] .md-tabs {
  background: #ffffff;
  border-bottom: 1px solid var(--horizon-border);
}

[data-md-color-scheme="default"] .md-tabs__link {
  color: var(--horizon-text);
  font-weight: 500;
  opacity: 1;
  font-size: 0.82rem;
  transition: color 0.2s ease;
}

[data-md-color-scheme="default"] .md-tabs__link:hover {
  color: var(--logo-pink);
}

[data-md-color-scheme="default"] .md-tabs__link--active {
  color: var(--horizon-navy);
  font-weight: 600;
}

/* --- Search Bar --- */
[data-md-color-scheme="default"] .md-search__input {
  background: var(--horizon-gray);
  border-radius: 12px;
}

[data-md-color-scheme="default"] .md-search__input::placeholder {
  color: var(--horizon-text-light);
}

/* --- Typography --- */
.md-typeset h1 {
  font-weight: 800;
  color: var(--horizon-navy);
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.md-typeset h2 {
  font-weight: 700;
  color: var(--horizon-navy);
  letter-spacing: -0.01em;
  margin-top: 2em;
}

.md-typeset h3 {
  font-weight: 600;
  color: var(--horizon-navy);
}

/* --- Homepage Styles --- */

/* Hero Section */
.homepage-hero {
  text-align: center;
  padding: 3rem 0 1.5rem 0;
  max-width: 800px;
  margin: 0 auto;
}

.homepage-hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 900;
  background: linear-gradient(135deg, var(--logo-blue), #6366F1, var(--logo-pink));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 0.5rem;
  letter-spacing: -0.03em;
  line-height: 1.1;
}

.md-typeset a.discord-btn,
a.discord-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1.5rem;
  padding: 0.65rem 1.5rem;
  background: #5865F2;
  color: #ffffff;
  border-radius: 12px;
  font-size: 0.92rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
  box-shadow: 0 2px 8px rgba(88, 101, 242, 0.3);
}

a.discord-btn:hover {
  background: #4752c4;
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(88, 101, 242, 0.4);
}

.homepage-hero .hero-subtitle {
  font-size: 1.1rem;
  color: var(--horizon-text-light);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.6;
}

/* About Banner - homepage link to about page */
.md-typeset a.about-banner,
a.about-banner {
  display: flex;
  align-items: center;
  gap: 1.2rem;
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 20px;
  padding: 1rem 1.5rem;
  max-width: 750px;
  margin: 2rem auto;
  box-shadow: var(--horizon-card-shadow);
  text-decoration: none;
  transition: all 0.25s ease;
  cursor: pointer;
}

a.about-banner:hover {
  box-shadow: var(--horizon-card-shadow-hover);
  transform: translateY(-2px);
  border-color: var(--logo-blue);
}

.about-banner-text {
  flex: 1;
}

.about-banner-text strong {
  display: block;
  color: var(--horizon-navy);
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

/* About Card - collapsible (legacy) */
.about-card {
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 20px;
  padding: 0;
  max-width: 750px;
  margin: 2rem auto;
  box-shadow: var(--horizon-card-shadow);
  overflow: hidden;
}

.about-toggle {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 2rem;
  cursor: pointer;
  user-select: none;
  color: var(--horizon-navy);
  font-weight: 600;
  font-size: 0.95rem;
  transition: background 0.2s ease;
}

.about-toggle:hover {
  background: var(--horizon-gray);
}

.about-toggle-icon {
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.about-card.open .about-toggle-icon {
  transform: rotate(180deg);
}

.about-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 2rem;
}

.about-card.open .about-content {
  max-height: 600px;
  padding: 0 2rem 1.5rem 2rem;
}

.about-card p {
  color: var(--horizon-text);
  font-size: 0.95rem;
  line-height: 1.7;
  margin: 0 0 0.8rem 0;
}

.about-card p:last-of-type {
  margin-bottom: 0;
}

.about-card .about-links {
  display: flex;
  gap: 0.75rem;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}

.about-card .about-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1.1rem;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
}

.about-card .about-links a.link-primary {
  background: var(--horizon-navy);
  color: #ffffff;
}

.about-card .about-links a.link-primary:hover {
  background: #162544;
  box-shadow: 0 4px 12px rgba(10, 22, 40, 0.2);
}

.about-card .about-links a.link-secondary {
  background: var(--horizon-gray);
  color: var(--horizon-navy);
  border: 1px solid var(--horizon-border);
}

.about-card .about-links a.link-secondary:hover {
  background: #edf0f5;
  border-color: #d0d5dd;
}

/* Section Headers */
.section-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 3rem;
  margin-bottom: 1.2rem;
  max-width: 750px;
  margin-left: auto;
  margin-right: auto;
}

.section-header h2 {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--horizon-navy);
  margin: 0;
  letter-spacing: 0;
  padding-bottom: 0.4rem;
  border-bottom: 3px solid transparent;
  border-image: linear-gradient(to left, var(--logo-blue), var(--logo-pink)) 1;
  display: inline-block;
}

/* Course Chip Grid (legacy) */
.course-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  max-width: 750px;
  margin: 0 auto 1rem auto;
}

.md-typeset a.course-chip {
  display: inline-flex;
  align-items: flex-start;
  gap: 0.6rem;
  padding: 0.9rem 1.3rem;
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 14px;
  font-size: 0.88rem;
  font-weight: 400;
  color: var(--horizon-text);
  text-decoration: none;
  transition: all 0.2s ease;
  cursor: pointer;
  line-height: 1.6;
  flex: 1 1 280px;
}

.course-chip strong {
  color: var(--horizon-navy);
  font-weight: 600;
}

.md-typeset a.course-chip:hover {
  background: var(--logo-blue-light);
  border-color: var(--logo-blue);
  box-shadow: var(--horizon-card-shadow);
  transform: translateY(-1px);
  color: var(--logo-blue);
}

.course-chip .chip-icon {
  font-size: 1rem;
  color: var(--logo-blue);
  opacity: 1;
  margin-top: 0.2rem;
  flex-shrink: 0;
}

/* Course Card Grid */
.course-cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 1rem;
  max-width: 750px;
  margin: 0 auto 1rem auto;
}

.md-typeset a.course-card {
  display: flex;
  flex-direction: column;
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 16px;
  overflow: hidden;
  text-decoration: none;
  transition: all 0.25s ease;
  box-shadow: var(--horizon-card-shadow);
}

.md-typeset a.course-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.12);
  border-color: transparent;
}

.course-card-img {
  height: 100px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.course-card-img svg {
  opacity: 0.9;
  transition: transform 0.25s ease;
}

.md-typeset a.course-card:hover .course-card-img svg {
  transform: scale(1.1);
  opacity: 1;
}

.course-card-body {
  padding: 0.9rem 1.1rem 1.1rem;
}

.course-card-body strong {
  color: var(--horizon-navy);
  font-size: 0.9rem;
  font-weight: 700;
  display: block;
  margin-bottom: 0.3rem;
  line-height: 1.4;
}

.course-card-body p {
  color: var(--horizon-text);
  font-size: 0.78rem;
  line-height: 1.5;
  margin: 0;
}

/* Course Badge */
.course-badge {
  display: inline-block;
  background: linear-gradient(135deg, #45CAFF, #6366F1);
  color: white;
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  margin-right: 0.4rem;
  vertical-align: middle;
  letter-spacing: 0.03em;
}

/* Game Card */
.md-typeset a.game-card {
  border: 2px dashed #F59E0B;
  position: relative;
}

.md-typeset a.game-card:hover {
  border-color: #EF4444;
}

.game-badge {
  display: inline-block;
  background: linear-gradient(135deg, #F59E0B, #EF4444);
  color: white;
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  margin-right: 0.4rem;
  vertical-align: middle;
  letter-spacing: 0.03em;
}

[data-md-color-scheme="slate"] .md-typeset a.game-card {
  border-color: #F59E0B;
}

[data-md-color-scheme="slate"] .md-typeset a.game-card:hover {
  border-color: #EF4444;
}

/* Remove top spacing on homepage so gradient touches tabs */
.md-main:has(.homepage-gradient-top) .md-main__inner {
  margin-top: 0 !important;
}

.md-content:has(.homepage-gradient-top) > .md-content__inner {
  padding-top: 0 !important;
  margin-top: 0 !important;
}

.md-content:has(.homepage-gradient-top) > .md-content__inner:before {
  display: none !important;
}

/* Gradient Top Effect */
.homepage-gradient-top {
  height: 200px;
  background: linear-gradient(180deg, var(--logo-pink) 0%, #a855f7 25%, var(--logo-blue) 50%, #e0f4ff 75%, transparent 100%);
  margin-left: -50vw;
  margin-right: -50vw;
  margin-top: 0;
  padding-top: 0;
  position: relative;
  left: 50%;
  right: 50%;
  width: 100vw;
}

/* Gradient Bottom-of-Hero Effect (soft mirror of top gradient) */
.homepage-gradient-hero-bottom {
  height: 200px;
  margin-top: 0;
  margin-bottom: 0;
  padding-bottom: 0;
  background: linear-gradient(180deg, transparent 0%, #e0f4ff 25%, var(--logo-blue) 50%, #a855f7 75%, var(--logo-pink) 100%);
  border-radius: 0;
  margin-left: -50vw;
  margin-right: -50vw;
  position: relative;
  left: 50%;
  right: 50%;
  width: 100vw;
}

/* Gradient Footer Effect */
.homepage-gradient {
  height: 200px;
  margin-top: 0;
  margin-bottom: 0;
  padding-bottom: 0;
  background: linear-gradient(180deg, transparent 0%, #e0f4ff 25%, var(--logo-blue) 50%, #a855f7 75%, var(--logo-pink) 100%);
  border-radius: 0;
  margin-left: -50vw;
  margin-right: -50vw;
  position: relative;
  left: 50%;
  right: 50%;
  width: 100vw;
}

/* --- Sidebar: hide sibling courses when inside a specific course --- */
.md-nav[data-md-level="1"] > ul:has(> .md-nav__item--active) > .md-nav__item--nested:not(.md-nav__item--active) {
  display: none !important;
}

/* --- Course Cards (for non-homepage pages) --- */
.md-typeset .grid.cards > ul {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1rem;
  padding: 0;
  list-style: none;
}

.md-typeset .grid.cards > ul > li {
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 16px;
  padding: 1.5rem;
  transition: all 0.25s ease;
  box-shadow: var(--horizon-card-shadow);
}

.md-typeset .grid.cards > ul > li:hover {
  box-shadow: var(--horizon-card-shadow-hover);
  transform: translateY(-2px);
  border-color: #d0d5dd;
}

.md-typeset .grid.cards > ul > li > hr {
  margin: 0.75em 0;
  border-color: var(--horizon-border);
}

.md-typeset .grid.cards > ul > li a {
  color: var(--horizon-blue);
  font-weight: 600;
  text-decoration: none;
}

.md-typeset .grid.cards > ul > li a:hover {
  text-decoration: underline;
}

/* --- Sidebar --- */
[data-md-color-scheme="default"] .md-sidebar--secondary {
  border-right: none;
  border-left: 1px solid var(--horizon-border);
}

[data-md-color-scheme="default"] .md-sidebar--primary {
  border-left: none;
  border-right: 1px solid var(--horizon-border);
}

[data-md-color-scheme="default"] .md-nav__link {
  color: var(--horizon-text);
  font-size: 0.82rem;
}

[data-md-color-scheme="default"] .md-nav__link:hover {
  color: var(--logo-pink);
}

[data-md-color-scheme="default"] .md-nav__link--active {
  color: var(--horizon-navy);
  font-weight: 600;
}

/* --- Content Area --- */
.md-content {
  max-width: 100%;
}

[data-md-color-scheme="default"] .md-content {
  background: #ffffff;
}

/* --- Footer --- */
[data-md-color-scheme="default"] .md-footer {
  background: var(--horizon-navy);
}

.md-footer-meta {
  display: none;
}

/* --- Admonitions --- */
[data-md-color-scheme="default"] .md-typeset .admonition,
[data-md-color-scheme="default"] .md-typeset details {
  border-radius: 12px;
  box-shadow: var(--horizon-card-shadow);
  border: 1px solid var(--horizon-border);
}

/* --- Code Blocks --- */
[data-md-color-scheme="default"] .md-typeset code {
  border-radius: 6px;
}

[data-md-color-scheme="default"] .md-typeset pre > code {
  border-radius: 12px;
}

/* --- Roadmap Section --- */
.roadmaps {
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  max-width: 750px;
  margin: 0 auto 1rem auto;
}

.roadmap-card {
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-right: 3px solid var(--logo-blue);
  border-radius: 14px;
  padding: 1rem 1.3rem;
  transition: all 0.2s ease;
}

.roadmap-card:nth-child(even) {
  border-right-color: var(--logo-pink);
}

.roadmap-card:hover {
  box-shadow: var(--horizon-card-shadow);
}

.roadmap-title {
  font-weight: 600;
  color: var(--horizon-navy);
  font-size: 0.92rem;
  margin-bottom: 0.7rem;
}

.roadmap-steps {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
}

.md-typeset a.roadmap-step {
  display: inline-block;
  padding: 0.3rem 0.75rem;
  background: var(--horizon-gray);
  border: 1px solid var(--horizon-border);
  border-radius: 8px;
  font-size: 0.78rem;
  font-weight: 500;
  color: var(--horizon-navy);
  text-decoration: none;
  transition: all 0.2s ease;
  white-space: nowrap;
}

.md-typeset a.roadmap-step:hover {
  background: var(--logo-blue-light);
  border-color: var(--logo-blue);
  color: var(--logo-blue);
}

.roadmap-arrow {
  color: var(--horizon-text-light);
  font-size: 0.85rem;
  flex-shrink: 0;
}

.roadmap-parallel {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  padding: 0.45rem;
  border: 1.5px dashed var(--logo-blue);
  border-radius: 10px;
}

@media screen and (max-width: 76.25em) {
  .roadmaps {
    padding: 0 1rem;
  }
}

/* --- Tabs Dropdown --- */
.md-tabs__item[data-dropdown-init] > .md-tabs__link {
  cursor: default;
}

.md-tabs__item[data-dropdown-init] > .md-tabs__link::after {
  content: '\25BE';
  margin-right: 0.3rem;
  font-size: 0.7rem;
  opacity: 0.5;
}

.tabs-dropdown {
  flex-direction: column;
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 10px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  padding: 0.35rem;
  z-index: 10000;
  min-width: 170px;
}

.tabs-dropdown-item {
  display: block;
  padding: 0.5rem 1rem;
  color: var(--horizon-text) !important;
  text-decoration: none !important;
  font-size: 0.82rem;
  font-weight: 500;
  border-radius: 8px;
  white-space: nowrap;
  transition: background 0.15s ease, color 0.15s ease;
}

.tabs-dropdown-item:hover {
  background: var(--horizon-gray);
  color: var(--horizon-navy) !important;
}

/* --- Homepage: hide footer behind gradient --- */
.md-typeset .homepage-gradient ~ * {
  display: none;
}

/* Remove bottom padding on homepage so gradient touches footer */
.md-content:has(.homepage-gradient) .md-content__inner {
  padding-bottom: 0;
  margin-bottom: 0;
}

.md-main:has(.homepage-gradient) {
  padding-bottom: 0;
  margin-bottom: 0;
}

.md-main:has(.homepage-gradient) .md-main__inner {
  padding-bottom: 0;
  margin-bottom: 0;
}

/* --- Header Logo --- */
[data-md-color-scheme="default"] .md-header__button.md-logo img {
  filter: none;
}

/* --- Responsive --- */
@media screen and (max-width: 76.25em) {
  .homepage-hero h1 {
    font-size: 2rem;
  }

  .about-card {
    margin: 1.5rem 1rem;
    padding: 1.5rem;
  }

  .about-banner {
    margin: 1.5rem 1rem;
  }

  .course-chips {
    padding: 0 1rem;
  }

  .course-cards {
    padding: 0 1rem;
  }

  .section-header {
    padding: 0 1rem;
  }
}

@media screen and (max-width: 600px) {
  .homepage-hero {
    padding: 2rem 1rem 1rem 1rem;
  }

  .homepage-hero h1 {
    font-size: 1.8rem;
  }

  .about-card .about-links {
    flex-direction: column;
  }

  .about-banner {
    flex-direction: column;
    text-align: center;
  }

  .course-chip {
    width: 100%;
    justify-content: center;
  }

  .course-cards {
    grid-template-columns: 1fr;
  }
}

/* ===========================
   Progress Tracking
   =========================== */

/* --- Complete Button --- */
.complete-btn-container {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  margin: 3rem 0 1rem 0;
  padding-top: 2rem;
  border-top: 1px solid var(--horizon-border);
}

.complete-btn {
  padding: 0.75rem 2.5rem;
  border: 2px solid var(--horizon-border);
  border-radius: 12px;
  background: #ffffff;
  color: var(--horizon-text);
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
  font-family: inherit;
}

.complete-btn:hover {
  border-color: var(--logo-blue);
  color: var(--logo-blue);
  background: var(--logo-blue-light);
}

.complete-btn.completed {
  background: #ecfdf5;
  border-color: #10b981;
  color: #059669;
}

.complete-btn.completed:hover {
  background: #fef2f2;
  border-color: #ef4444;
  color: #dc2626;
}

.complete-btn .complete-check {
  font-weight: 700;
}

/* --- Lecture Navigation Buttons --- */
.nav-btn {
  padding: 0.75rem 1.5rem;
  border: 2px solid var(--horizon-border);
  border-radius: 12px;
  background: #ffffff;
  color: var(--horizon-text-light);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  text-decoration: none !important;
  transition: all 0.2s ease;
  font-family: inherit;
  white-space: nowrap;
}

.nav-btn:hover {
  border-color: var(--horizon-blue);
  color: var(--horizon-blue);
  background: var(--logo-blue-light);
}

.nav-btn-disabled {
  opacity: 0.3;
  cursor: default;
  pointer-events: none;
}

/* --- Course Progress Bar --- */
.course-progress {
  background: var(--horizon-gray);
  border: 1px solid var(--horizon-border);
  border-radius: 12px;
  padding: 0.8rem 1.2rem;
  margin-bottom: 1.5rem;
}

.course-progress-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.5rem;
  font-size: 0.82rem;
  color: var(--horizon-text);
  font-weight: 500;
}

.course-progress-pct {
  font-weight: 700;
  color: var(--horizon-navy);
}

.course-progress-track {
  height: 6px;
  background: var(--horizon-border);
  border-radius: 3px;
  overflow: hidden;
}

.course-progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--logo-blue), var(--logo-pink));
  border-radius: 3px;
  transition: width 0.4s ease;
  width: 0%;
}

/* --- Nav Completed Checkmarks --- */
.md-sidebar--primary a.md-nav__link.nav-completed {
  color: #059669;
}

.md-sidebar--primary a.md-nav__link.nav-completed::before {
  content: '\2713 ';
  font-weight: 700;
}

/* --- Nav Section/Topic Completed --- */
.md-sidebar--primary .md-nav__link.nav-section-completed {
  color: #059669;
}

.md-sidebar--primary .md-nav__link.nav-section-completed::before {
  content: '\2713 ';
  font-weight: 700;
}

/* --- Celebration Toast --- */
.celebrate-toast {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0.8);
  background: var(--horizon-navy);
  color: #ffffff;
  padding: 1.5rem 3rem;
  border-radius: 16px;
  font-size: 1.3rem;
  font-weight: 700;
  z-index: 10000;
  opacity: 0;
  transition: opacity 0.4s ease, transform 0.4s ease;
  pointer-events: none;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.celebrate-toast.show {
  opacity: 1;
  transform: translate(-50%, -50%) scale(1);
}

/* ===========================
   About Page
   =========================== */

.about-page {
  max-width: 750px;
  margin: 0 auto;
  padding: 2rem 0;
}

.about-page-header {
  display: flex;
  align-items: center;
  gap: 2rem;
  margin-bottom: 2.5rem;
}

.about-page-photo {
  width: 160px;
  height: 160px;
  border-radius: 50%;
  object-fit: cover;
  border: 4px solid transparent;
  background: linear-gradient(white, white) padding-box, linear-gradient(135deg, var(--logo-blue), var(--logo-pink)) border-box;
  flex-shrink: 0;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
}

.about-page-info h1 {
  font-size: 2rem;
  font-weight: 900;
  color: var(--horizon-navy);
  margin: 0 0 0.3rem 0;
}

.about-page-tagline {
  font-size: 1.1rem;
  color: var(--horizon-text-light);
  margin: 0 0 1rem 0;
}

.about-page-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.about-page-links .link-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.5rem 1.2rem;
  border-radius: 10px;
  font-size: 0.85rem;
  font-weight: 600;
  text-decoration: none;
  transition: all 0.2s ease;
}

.about-page-links .link-btn-primary {
  background: linear-gradient(135deg, var(--logo-blue), var(--logo-pink));
  color: #ffffff;
}

.about-page-links .link-btn-primary:hover {
  box-shadow: 0 4px 16px rgba(69, 202, 255, 0.3);
  transform: translateY(-1px);
}

.about-page-links .link-btn-secondary {
  background: var(--horizon-gray);
  color: var(--horizon-navy);
  border: 1px solid var(--horizon-border);
}

.about-page-links .link-btn-secondary:hover {
  background: #edf0f5;
  border-color: var(--logo-blue);
}

.about-page-body {
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 20px;
  padding: 2rem;
  box-shadow: var(--horizon-card-shadow);
}

.about-page-body p {
  color: var(--horizon-text);
  font-size: 1rem;
  line-height: 1.8;
  margin: 0 0 1rem 0;
}

.about-page-body p:last-child {
  margin-bottom: 0;
}

@media screen and (max-width: 600px) {
  .about-page {
    padding: 1rem;
  }

  .about-page-header {
    flex-direction: column;
    text-align: center;
  }

  .about-page-photo {
    width: 120px;
    height: 120px;
  }

  .about-page-links {
    justify-content: center;
  }

  .about-page-body {
    padding: 1.5rem;
  }
}

/* ===========================
   Dark Mode (slate scheme)
   =========================== */

[data-md-color-scheme="slate"] {
  /* Horizon variable overrides */
  --horizon-navy: #e2e8f0;
  --horizon-blue: #60a5fa;
  --horizon-gray: #1e293b;
  --horizon-border: #334155;
  --horizon-text: #cbd5e1;
  --horizon-text-light: #94a3b8;
  --horizon-card-shadow: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
  --horizon-card-shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.5), 0 4px 10px rgba(0, 0, 0, 0.35);
  --logo-pink-light: rgba(255, 27, 107, 0.15);
  --logo-blue-light: rgba(69, 202, 255, 0.12);
  /* MkDocs Material core overrides */
  --md-default-bg-color: #0f172a;
  --md-default-fg-color: #e2e8f0;
  --md-default-fg-color--light: #94a3b8;
  --md-default-fg-color--lighter: #64748b;
  --md-default-fg-color--lightest: #334155;
  --md-typeset-color: #cbd5e1;
  --md-code-bg-color: #1e293b;
  --md-code-fg-color: #e2e8f0;
  --md-accent-fg-color: #60a5fa;
}

/* --- Header / Navigation Bar --- */
[data-md-color-scheme="slate"] .md-header {
  background: #0f172a;
  color: #e2e8f0;
  box-shadow: 0 1px 0 #334155;
}

[data-md-color-scheme="slate"] .md-header .md-header__title,
[data-md-color-scheme="slate"] .md-header .md-header__topic {
  color: #e2e8f0;
  font-weight: 700;
}

[data-md-color-scheme="slate"] .md-header .md-header__button {
  color: #e2e8f0;
}

[data-md-color-scheme="slate"] .md-header[data-md-state="shadow"] {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.5);
}

/* --- Navigation Tabs --- */
[data-md-color-scheme="slate"] .md-tabs {
  background: #0f172a;
  border-bottom: 1px solid #334155;
}

[data-md-color-scheme="slate"] .md-tabs__link {
  color: #94a3b8;
  font-weight: 500;
  opacity: 1;
  font-size: 0.82rem;
  transition: color 0.2s ease;
}

[data-md-color-scheme="slate"] .md-tabs__link:hover {
  color: var(--logo-pink);
}

[data-md-color-scheme="slate"] .md-tabs__link--active {
  color: #e2e8f0;
  font-weight: 600;
}

/* --- Search Bar --- */
[data-md-color-scheme="slate"] .md-search__input {
  background: #1e293b;
  border-radius: 12px;
  color: #e2e8f0;
}

[data-md-color-scheme="slate"] .md-search__input::placeholder {
  color: #64748b;
}

/* --- Content Area --- */
[data-md-color-scheme="slate"] .md-content {
  background: #0f172a;
}

/* --- Sidebar --- */
[data-md-color-scheme="slate"] .md-sidebar--secondary {
  border-right: none;
  border-left: 1px solid #334155;
}

[data-md-color-scheme="slate"] .md-sidebar--primary {
  border-left: none;
  border-right: 1px solid #334155;
}

[data-md-color-scheme="slate"] .md-nav__link {
  color: #94a3b8;
  font-size: 0.82rem;
}

[data-md-color-scheme="slate"] .md-nav__link:hover {
  color: var(--logo-pink);
}

[data-md-color-scheme="slate"] .md-nav__link--active {
  color: #e2e8f0;
  font-weight: 600;
}

/* --- Footer --- */
[data-md-color-scheme="slate"] .md-footer {
  background: #060d18;
}

/* --- Admonitions --- */
[data-md-color-scheme="slate"] .md-typeset .admonition,
[data-md-color-scheme="slate"] .md-typeset details {
  background: #1e293b;
  border-color: #334155;
  border-radius: 12px;
  box-shadow: var(--horizon-card-shadow);
}

/* --- Code Blocks --- */
[data-md-color-scheme="slate"] .md-typeset code {
  border-radius: 6px;
}

[data-md-color-scheme="slate"] .md-typeset pre > code {
  border-radius: 12px;
}

/* --- About Banner --- */
[data-md-color-scheme="slate"] .md-typeset a.about-banner,
[data-md-color-scheme="slate"] a.about-banner {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] a.about-banner:hover {
  border-color: var(--logo-blue);
}

/* --- About Card (collapsible) --- */
[data-md-color-scheme="slate"] .about-card {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .about-toggle:hover {
  background: #243147;
}

[data-md-color-scheme="slate"] .about-card .about-links a.link-primary {
  background: #e2e8f0;
  color: #0f172a;
}

[data-md-color-scheme="slate"] .about-card .about-links a.link-secondary {
  background: #243147;
  color: #e2e8f0;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .about-card .about-links a.link-secondary:hover {
  background: #2d3f5a;
  border-color: #60a5fa;
}

/* --- Course Chips --- */
[data-md-color-scheme="slate"] .md-typeset a.course-chip {
  background: #1e293b;
  border-color: #334155;
  color: #cbd5e1;
}

[data-md-color-scheme="slate"] .md-typeset a.course-chip:hover {
  background: rgba(69, 202, 255, 0.12);
  border-color: var(--logo-blue);
  color: var(--logo-blue);
}

/* --- Course Cards --- */
[data-md-color-scheme="slate"] .md-typeset a.course-card {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .md-typeset a.course-card:hover {
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.5);
  border-color: transparent;
}

/* --- Grid Cards (non-homepage) --- */
[data-md-color-scheme="slate"] .md-typeset .grid.cards > ul > li {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .md-typeset .grid.cards > ul > li:hover {
  border-color: #4a5f7a;
}

[data-md-color-scheme="slate"] .md-typeset .grid.cards > ul > li > hr {
  border-color: #334155;
}

/* --- Roadmap Cards --- */
[data-md-color-scheme="slate"] .roadmap-card {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .md-typeset a.roadmap-step {
  background: #243147;
  border-color: #334155;
  color: #e2e8f0;
}

[data-md-color-scheme="slate"] .md-typeset a.roadmap-step:hover {
  background: rgba(69, 202, 255, 0.12);
  border-color: var(--logo-blue);
  color: var(--logo-blue);
}

/* --- Tabs Dropdown --- */
[data-md-color-scheme="slate"] .tabs-dropdown {
  background: #1e293b;
  border-color: #334155;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
}

[data-md-color-scheme="slate"] .tabs-dropdown-item {
  color: #cbd5e1 !important;
}

[data-md-color-scheme="slate"] .tabs-dropdown-item:hover {
  background: #243147;
  color: #e2e8f0 !important;
}

/* --- Progress Tracking --- */
[data-md-color-scheme="slate"] .complete-btn-container {
  border-top-color: #334155;
}

[data-md-color-scheme="slate"] .nav-btn {
  background: #1e293b;
  border-color: #334155;
  color: #64748b;
}

[data-md-color-scheme="slate"] .nav-btn:hover {
  border-color: var(--logo-blue);
  color: var(--logo-blue);
  background: rgba(69, 202, 255, 0.12);
}

[data-md-color-scheme="slate"] .complete-btn {
  background: #1e293b;
  border-color: #334155;
  color: #cbd5e1;
}

[data-md-color-scheme="slate"] .complete-btn:hover {
  border-color: var(--logo-blue);
  color: var(--logo-blue);
  background: rgba(69, 202, 255, 0.12);
}

[data-md-color-scheme="slate"] .complete-btn.completed {
  background: rgba(16, 185, 129, 0.15);
  border-color: #10b981;
  color: #34d399;
}

[data-md-color-scheme="slate"] .complete-btn.completed:hover {
  background: rgba(239, 68, 68, 0.15);
  border-color: #ef4444;
  color: #f87171;
}

[data-md-color-scheme="slate"] .course-progress {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .course-progress-track {
  background: #334155;
}

/* --- About Page --- */
[data-md-color-scheme="slate"] .about-page-photo {
  background: linear-gradient(#1e293b, #1e293b) padding-box,
              linear-gradient(135deg, var(--logo-blue), var(--logo-pink)) border-box;
}

[data-md-color-scheme="slate"] .about-page-body {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .about-page-links .link-btn-secondary {
  background: #243147;
  color: #e2e8f0;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .about-page-links .link-btn-secondary:hover {
  background: #2d3f5a;
  border-color: var(--logo-blue);
}

/* --- Homepage Gradients in dark mode --- */
[data-md-color-scheme="slate"] .homepage-gradient-top {
  background: linear-gradient(180deg, var(--logo-pink) 0%, #a855f7 25%, var(--logo-blue) 55%, #0f172a 85%, #0f172a 100%);
}

[data-md-color-scheme="slate"] .homepage-gradient-hero-bottom {
  background: linear-gradient(180deg, #0f172a 0%, #0f172a 15%, var(--logo-blue) 50%, #a855f7 75%, var(--logo-pink) 100%);
}

[data-md-color-scheme="slate"] .homepage-gradient {
  background: linear-gradient(180deg, #0f172a 0%, #0f172a 15%, var(--logo-blue) 50%, #a855f7 75%, var(--logo-pink) 100%);
}

/* --- Logo --- */
[data-md-color-scheme="slate"] .md-header__button.md-logo img {
  filter: brightness(1.1);
}

/* --- Blog Cards --- */
.blog-card-article {
  margin-bottom: 1rem;
}

.blog-card {
  display: block;
  background: #ffffff;
  border: 1px solid var(--horizon-border);
  border-radius: 12px;
  padding: 1.5rem 1.75rem;
  text-decoration: none !important;
  color: inherit;
  transition: box-shadow 0.2s ease, transform 0.2s ease, border-color 0.2s ease;
  box-shadow: var(--horizon-card-shadow);
}

.blog-card:hover {
  box-shadow: var(--horizon-card-shadow-hover);
  transform: translateY(-2px);
  border-color: var(--logo-pink);
}

.blog-card-top {
  margin-bottom: 0.4rem;
}

.blog-card-date {
  font-size: 0.78rem;
  color: var(--horizon-text-light);
  font-weight: 500;
}

.blog-card-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--horizon-navy);
  margin: 0 0 0.5rem 0 !important;
  line-height: 1.4;
  border: none !important;
  padding: 0 !important;
  transition: color 0.2s ease;
}

.blog-card:hover .blog-card-title {
  color: var(--logo-pink);
}

.blog-card-description {
  font-size: 0.88rem;
  color: var(--horizon-text);
  margin: 0 0 1rem 0;
  line-height: 1.65;
}

.blog-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.blog-tag {
  background: var(--logo-blue-light);
  color: #0e7fa8;
  font-size: 0.72rem;
  font-weight: 600;
  padding: 0.2rem 0.65rem;
  border-radius: 20px;
  border: 1px solid rgba(69, 202, 255, 0.35);
  letter-spacing: 0.01em;
}

/* Blog index: remove built-in Material post styles that conflict */
.md-post.md-post--excerpt {
  display: none;
}

/* Dark mode */
[data-md-color-scheme="slate"] .blog-card {
  background: #1e293b;
  border-color: #334155;
}

[data-md-color-scheme="slate"] .blog-card:hover {
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.35);
  border-color: var(--logo-pink);
}

[data-md-color-scheme="slate"] .blog-card-title {
  color: #e2e8f0;
}

[data-md-color-scheme="slate"] .blog-card-description {
  color: #94a3b8;
}

[data-md-color-scheme="slate"] .blog-card-date {
  color: #64748b;
}

[data-md-color-scheme="slate"] .blog-tag {
  background: rgba(69, 202, 255, 0.1);
  color: var(--logo-blue);
  border-color: rgba(69, 202, 255, 0.25);
}