/* ==========================================================================
   ALPTUGAN PRESENTATIONS — MONOCHROMATIC MINIMALISM DESIGN SYSTEM
   Custom-built for Slidev Presentations Hub & Course Pages
   
   Palette:
     Background:       #121212 (charcoal black)
     Primary Text:     #E0E0E0 (light gray)
     Secondary Text:   #B0B0B0 (medium gray)
     Borders/Dividers: #444444 (dark gray)
     Accent:           #888888 (soft gray)
   ========================================================================== */

/* --- Font Declarations --- */
@import url('https://fonts.googleapis.com/css2?family=Archivo:ital,wght@0,400..700;1,400..700&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* --- Design Tokens & Color Palettes --- */
:root {
  /* Default: Monochromatic Minimalism (Dark Charcoal Theme) */
  --bg-canvas: #121212;
  --bg-surface: #181818;
  --bg-subtle: #222222;
  --bg-muted: #2a2a2a;
  
  --border-color: #444444;
  --border-subtle: #2d2d2d;
  --border-hover: #888888;
  
  --text-primary: #E0E0E0;
  --text-secondary: #B0B0B0;
  --text-muted: #888888;
  --text-faint: #787878;
  
  --accent-color: #888888;
  --accent-hover: #FFFFFF;
  --accent-subtle: rgba(224, 224, 224, 0.08);
  --accent-contrast: #121212;
  
  --btn-primary-bg: #E0E0E0;
  --btn-primary-text: #121212;
  --btn-primary-hover: #FFFFFF;
  
  --status-ready-bg: #1e1e1e;
  --status-ready-text: #E0E0E0;
  --status-ready-border: #444444;
  
  --status-upcoming-bg: #151515;
  --status-upcoming-text: #969696;
  --status-upcoming-border: #2a2a2a;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.65), 0 2px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 40px -6px rgba(0, 0, 0, 0.8);

  /* Typography */
  --font-sans: 'Archivo', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Sizing & Radius */
  --radius-xs: 4px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  --radius-xl: 20px;
  --radius-full: 9999px;

  --container-max: 1200px;
  --header-height: 68px;
  
  --transition-fast: 0.15s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Explicit Dark Mode matches root monochromatic values */
[data-theme="dark"] {
  --bg-canvas: #121212;
  --bg-surface: #181818;
  --bg-subtle: #222222;
  --bg-muted: #2a2a2a;
  
  --border-color: #444444;
  --border-subtle: #2d2d2d;
  --border-hover: #888888;
  
  --text-primary: #E0E0E0;
  --text-secondary: #B0B0B0;
  --text-muted: #888888;
  --text-faint: #787878;
  
  --accent-color: #888888;
  --accent-hover: #FFFFFF;
  --accent-subtle: rgba(224, 224, 224, 0.08);
  --accent-contrast: #121212;
  
  --btn-primary-bg: #E0E0E0;
  --btn-primary-text: #121212;
  --btn-primary-hover: #FFFFFF;
  
  --status-ready-bg: #1e1e1e;
  --status-ready-text: #E0E0E0;
  --status-ready-border: #444444;
  
  --status-upcoming-bg: #151515;
  --status-upcoming-text: #969696;
  --status-upcoming-border: #2a2a2a;
  
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 8px 24px -4px rgba(0, 0, 0, 0.65), 0 2px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 40px -6px rgba(0, 0, 0, 0.8);
}

/* Monochromatic Minimalism - Light Mode Alternate (Zero Blues) */
[data-theme="light"] {
  --bg-canvas: #f6f6f6;
  --bg-surface: #ffffff;
  --bg-subtle: #ececec;
  --bg-muted: #e0e0e0;
  
  --border-color: #d0d0d0;
  --border-subtle: #e4e4e4;
  --border-hover: #666666;
  
  --text-primary: #121212;
  --text-secondary: #444444;
  --text-muted: #5e5e5e;
  --text-faint: #6c6c6c;
  
  --accent-color: #444444;
  --accent-hover: #121212;
  --accent-subtle: rgba(18, 18, 18, 0.06);
  --accent-contrast: #ffffff;
  
  --btn-primary-bg: #121212;
  --btn-primary-text: #ffffff;
  --btn-primary-hover: #333333;
  
  --status-ready-bg: #f0f0f0;
  --status-ready-text: #121212;
  --status-ready-border: #cccccc;
  
  --status-upcoming-bg: #f9f9f9;
  --status-upcoming-text: #545454;
  --status-upcoming-border: #e0e0e0;
  
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 6px 18px -2px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 30px -4px rgba(0, 0, 0, 0.12);
}

/* --- Base & Reset --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Browser Surfaces Theming --- */
::selection {
  background-color: var(--text-primary);
  color: var(--bg-canvas);
}

input, textarea {
  caret-color: var(--text-primary);
}

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-canvas);
}

::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border-hover);
}

* {
  scrollbar-width: thin;
  scrollbar-color: var(--border-color) var(--bg-canvas);
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration: none;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* Accessibility Focus States */
:focus-visible {
  outline: 2px solid var(--accent-hover);
  outline-offset: 2px;
}

/* --- Layout Containers --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: clamp(1rem, 4vw, 2rem);
  padding-right: clamp(1rem, 4vw, 2rem);
}

.main-content {
  flex: 1 0 auto;
  padding-top: clamp(2rem, 5vw, 3.5rem);
  padding-bottom: clamp(3rem, 7vw, 5rem);
}

/* --- Header & Navigation --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: rgba(18, 18, 18, 0.92);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

[data-theme="light"] .site-header {
  background-color: rgba(246, 246, 246, 0.92);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  gap: 1.5rem;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  flex-shrink: 0;
}

.brand-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background-color: var(--border-color);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  overflow: hidden;
  border: 1px solid var(--border-color);
}

.brand-icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(1);
}

.brand-title {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-size: 0.95rem;
  font-weight: 700;
  line-height: 1.2;
  color: var(--text-primary);
}

.brand-sub {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  font-family: var(--font-mono);
}

/* Nav Links */
.nav-links {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.nav-link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 0.45rem 0.75rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-link:hover {
  color: var(--text-primary);
  background-color: var(--bg-subtle);
}

.nav-link.active {
  color: var(--text-primary);
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  font-weight: 600;
}

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.theme-toggle,
.mobile-nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  background-color: var(--bg-surface);
  transition: all var(--transition-fast);
}

.theme-toggle:hover,
.mobile-nav-toggle:hover {
  color: var(--text-primary);
  border-color: var(--border-hover);
  background-color: var(--bg-subtle);
}

.theme-toggle svg,
.mobile-nav-toggle svg {
  width: 18px;
  height: 18px;
}

.mobile-nav-toggle {
  display: none;
}

/* --- Hero Banner (Index) --- */
.hero {
  margin-bottom: clamp(2rem, 5vw, 3rem);
  padding-top: 0.5rem;
}

.hero-meta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  background-color: var(--bg-canvas);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-full);
  font-family: var(--font-mono);
  font-size: 0.775rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 1.25rem;
}

.hero-meta .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--text-primary);
  box-shadow: 0 0 8px rgba(255, 255, 255, 0.6);
}

[data-theme="light"] .hero-meta .dot {
  box-shadow: 0 0 6px rgba(0, 0, 0, 0.3);
}

.hero-title {
  font-size: clamp(2.2rem, 4.5vw, 3.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--text-primary);
  max-width: 24ch;
  margin-bottom: 1.25rem;
}

.hero-desc {
  font-size: clamp(1rem, 1.8vw, 1.15rem);
  color: var(--text-secondary);
  max-width: 68ch;
  line-height: 1.65;
  margin-bottom: 1.75rem;
}

.hero-desc a {
  color: var(--text-primary);
  font-weight: 600;
  text-decoration: underline;
  text-decoration-thickness: 1.5px;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-hover);
}

.hero-desc a:hover {
  color: var(--accent-hover);
  text-decoration-color: var(--accent-hover);
}

/* --- Section Heading --- */
.section-header {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  margin-bottom: 1.75rem;
  gap: 1rem;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  line-height: 1.25;
}

.section-subtitle {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-top: 0.35rem;
}

/* --- Course Tiles Grid (Index) --- */
.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 1.5rem;
}

.course-card {
  display: flex;
  flex-direction: column;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all var(--transition-normal);
  position: relative;
}

.course-card:hover {
  transform: translateY(-3px);
  border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}

.course-cover {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  background-color: var(--bg-subtle);
  overflow: hidden;
  border-bottom: 1px solid var(--border-subtle);
}

.course-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), filter 0.4s ease;
  filter: contrast(1.05);
}

.course-card:hover .course-cover img {
  transform: scale(1.03);
}

.course-body {
  padding: 1.4rem;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.course-badges {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.8rem;
  flex-wrap: wrap;
}

.badge {
  display: inline-flex;
  align-items: center;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-xs);
  font-size: 0.725rem;
  font-weight: 600;
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
  font-variant-numeric: tabular-nums;
}

.badge-code {
  background-color: var(--bg-subtle);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.badge-term {
  background-color: var(--bg-canvas);
  color: var(--text-secondary);
  border: 1px solid var(--border-subtle);
}

.badge-status {
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-full);
}

.badge-status.ready {
  background-color: var(--status-ready-bg);
  color: var(--status-ready-text);
  border: 1px solid var(--status-ready-border);
}

.badge-status.upcoming {
  background-color: var(--status-upcoming-bg);
  color: var(--status-upcoming-text);
  border: 1px solid var(--status-upcoming-border);
}

.course-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  line-height: 1.35;
}

.course-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.25rem;
  flex: 1;
}

.course-footer {
  padding-top: 1rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.course-meta-text {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  color: var(--text-muted);
}

.course-action {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: gap var(--transition-fast), color var(--transition-fast);
}

.course-card:hover .course-action {
  color: var(--accent-hover);
  gap: 0.55rem;
}



/* --- Subpage / Course Detail Hero --- */
.subpage-hero {
  margin-bottom: clamp(2rem, 4vw, 3rem);
}

.breadcrumb-nav {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

.breadcrumb-nav a {
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  transition: color var(--transition-fast);
}

.breadcrumb-nav a:hover {
  color: var(--text-primary);
}

.subpage-header-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  display: grid;
  grid-template-columns: 1fr 340px;
  gap: clamp(1.25rem, 2.5vw, 2rem);
  padding: 1.25rem;
  align-items: stretch;
}

@media (max-width: 900px) {
  .subpage-header-card {
    grid-template-columns: 1fr;
    padding: 1.25rem;
    gap: 1.25rem;
  }
}

.subpage-header-info {
  padding: clamp(0.5rem, 1.5vw, 1.25rem);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.subpage-header-cover {
  position: relative;
  background-color: var(--bg-subtle);
  min-height: 240px;
  height: 100%;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-subtle);
  overflow: hidden;
}

@media (max-width: 900px) {
  .subpage-header-cover {
    min-height: 200px;
    max-height: 240px;
  }
}

.subpage-header-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: contrast(1.05);
}

.subpage-title {
  font-size: clamp(1.75rem, 3.2vw, 2.35rem);
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  line-height: 1.2;
}

.subpage-lead {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 65ch;
  margin-bottom: 1.5rem;
}

.subpage-meta-list {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 2rem;
  font-size: 0.85rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border-subtle);
}

.subpage-meta-item {
  display: flex;
  flex-direction: column;
}

.subpage-meta-item .label {
  font-size: 0.7rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 0.25rem;
}

.subpage-meta-item .value {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.875rem;
}

.subpage-meta-item a.value {
  color: var(--text-primary);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
  text-decoration-color: var(--border-hover);
}

.subpage-meta-item a.value:hover {
  color: var(--accent-hover);
  text-decoration-color: var(--accent-hover);
}

/* Quick Jump & Filter Toolbar */
.toolbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
  padding: 0.75rem 1.25rem;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
}

.toolbar-title {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  letter-spacing: 0.02em;
}

.toolbar-title svg {
  color: var(--text-muted);
  flex-shrink: 0;
}

.toolbar-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.search-input-wrapper {
  position: relative;
  display: flex;
  align-items: center;
}

.search-input-wrapper svg {
  position: absolute;
  left: 10px;
  width: 15px;
  height: 15px;
  color: var(--text-muted);
  pointer-events: none;
}

.search-input {
  font-family: inherit;
  font-size: 0.85rem;
  padding: 0.45rem 2rem 0.45rem 2rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  width: 220px;
  transition: all var(--transition-fast);
}

.search-input:focus {
  outline: none;
  border-color: var(--border-hover);
  background-color: var(--bg-subtle);
  width: 260px;
}

.search-kbd {
  position: absolute;
  right: 8px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 18px;
  min-width: 18px;
  padding: 0 4px;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xs);
  pointer-events: none;
  user-select: none;
}

.search-input:focus ~ .search-kbd {
  display: none;
}

/* Empty State component */
.empty-state {
  padding: 3.5rem 1.5rem;
  text-align: center;
  background-color: var(--bg-surface);
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-lg);
  margin-top: 1.5rem;
}

.empty-state-icon {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
}

.empty-state-icon svg {
  width: 28px;
  height: 28px;
  stroke-width: 1.5;
}

.empty-state-title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.4rem;
}

.empty-state-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  max-width: 48ch;
  margin: 0 auto;
  line-height: 1.5;
}

.empty-state-btn {
  margin-top: 1rem;
  font-size: 0.8rem;
  padding: 0.35rem 0.85rem;
}

/* --- Weekly Session Cards --- */
.sessions-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.session-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem 1.75rem;
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal), transform var(--transition-normal);
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr) auto;
  gap: 1.75rem;
  align-items: start;
}

.session-card:hover {
  border-color: var(--border-hover);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
}

[data-theme="light"] .session-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
}

.session-card.upcoming {
  background-color: var(--bg-canvas);
  border-style: dashed;
}

.session-card.upcoming:hover {
  background-color: var(--bg-surface);
  border-color: var(--border-hover);
}

.session-week-col {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.6rem;
  padding-right: 1.5rem;
  border-right: 1px solid var(--border-subtle);
  height: 100%;
}

.session-week-tag {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  display: inline-flex;
  align-items: center;
  font-variant-numeric: tabular-nums;
}

.session-card.upcoming .session-week-tag {
  color: var(--text-secondary);
}

.session-content-col {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-width: 0;
}

.session-heading {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  line-height: 1.35;
}

.session-card.upcoming .session-heading {
  color: var(--text-primary);
}

.session-topics {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  max-width: 68ch;
}

.session-topics li {
  font-size: 0.8875rem;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.25rem;
  line-height: 1.55;
}

.session-topics li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 5px;
  height: 1.5px;
  background-color: var(--text-muted);
  border-radius: 1px;
}

.session-actions-col {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  align-items: flex-end;
  justify-content: flex-start;
  padding-top: 0.1rem;
}

.session-card.upcoming .session-actions-col .btn-secondary {
  cursor: default;
  background-color: var(--bg-subtle);
  border-color: var(--border-subtle);
  color: var(--text-secondary);
  font-weight: 500;
  font-family: var(--font-mono);
  font-size: 0.775rem;
  letter-spacing: 0.02em;
  padding: 0.45rem 0.85rem;
}

@media (max-width: 820px) {
  .session-card {
    grid-template-columns: 1fr;
    gap: 1.25rem;
    padding: 1.25rem;
  }

  .session-week-col {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
    padding-right: 0;
    padding-bottom: 0.75rem;
    border-right: none;
    border-bottom: 1px solid var(--border-subtle);
    height: auto;
    width: 100%;
  }

  .session-actions-col {
    align-items: stretch;
    padding-top: 0.85rem;
    border-top: 1px solid var(--border-subtle);
    width: 100%;
  }

  .session-actions-col .btn {
    width: 100%;
    justify-content: center;
  }
}

/* Button Component */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.55rem 1rem;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

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

.btn-primary:hover {
  background-color: var(--btn-primary-hover);
  color: var(--btn-primary-text);
  border-color: var(--btn-primary-hover);
  transform: translateY(-1px);
}

.btn-secondary {
  background-color: var(--bg-surface);
  color: var(--text-primary);
  border-color: var(--border-color);
}

.btn-secondary:hover {
  background-color: var(--bg-subtle);
  border-color: var(--border-hover);
  color: var(--text-primary);
}

.btn-sm {
  font-size: 0.8rem;
  padding: 0.4rem 0.75rem;
}

.btn svg {
  width: 14px;
  height: 14px;
  transition: transform var(--transition-fast);
}

.btn:hover svg {
  transform: translateX(2px) translateY(-1px);
}

/* --- Workshop Grid Specifics --- */
.workshop-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(330px, 1fr));
  gap: 1.5rem;
}

.workshop-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.6rem;
  display: flex;
  flex-direction: column;
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal), transform var(--transition-normal);
}

.workshop-card:hover {
  border-color: var(--border-hover);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
  transform: translateY(-2px);
}

[data-theme="light"] .workshop-card:hover {
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.05);
}

.workshop-card .badge {
  align-self: flex-start;
  margin-bottom: 0.85rem;
}

.workshop-title {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.015em;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
  line-height: 1.35;
}

.workshop-topics {
  flex: 1;
  list-style: none;
  margin-bottom: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
}

.workshop-topics li {
  font-size: 0.8875rem;
  color: var(--text-secondary);
  position: relative;
  padding-left: 1.25rem;
  line-height: 1.55;
}

.workshop-topics li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 5px;
  height: 1.5px;
  background-color: var(--text-muted);
  border-radius: 1px;
}

/* --- Site Footer --- */
.site-footer {
  background-color: #101010;
  border-top: 1px solid var(--border-color);
  padding: clamp(3rem, 6vw, 4.5rem) 0 2rem 0;
  margin-top: auto;
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

[data-theme="light"] .site-footer {
  background-color: #f0f0f0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

@media (max-width: 768px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.footer-brand .brand-name {
  font-size: 1.1rem;
  color: var(--text-primary);
}

.footer-brand-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  max-width: 40ch;
  line-height: 1.6;
}

.footer-col-title {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.footer-links-list {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links-list a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: color var(--transition-fast);
}

.footer-links-list a:hover {
  color: var(--accent-hover);
}

.footer-bottom {
  padding-top: 2rem;
  border-top: 1px solid var(--border-subtle);
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer-bottom a {
  color: var(--text-secondary);
}

.footer-bottom a:hover {
  color: var(--accent-hover);
}

/* --- Mobile Navigation Drawer / Menu --- */
@media (max-width: 900px) {
  .nav-links {
    display: none;
    position: absolute;
    top: var(--header-height);
    left: 0;
    right: 0;
    background-color: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    flex-direction: column;
    align-items: flex-start;
    gap: 0.5rem;
    box-shadow: var(--shadow-lg);
  }

  .nav-links.is-open {
    display: flex;
  }

  .nav-link {
    width: 100%;
    padding: 0.6rem 0.75rem;
  }

  .mobile-nav-toggle {
    display: inline-flex;
  }
}

/* Utilities */
.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;
}