/* =============================================================================
   MLSysBook Landing — Root hub for two volumes. Matches Vol 1 theme.
   Supports both Light and Dark mode via data-bs-theme.
   ============================================================================= */

:root {
  --mls-accent: #A51C30;
  --mls-accent-hover: #8b1728;
  --mls-text: #111111;
  --mls-text-muted: #555555;
  --mls-bg: #ffffff;
  --mls-card-bg: rgba(255, 255, 255, 0.95);
  --mls-card-border: rgba(0, 0, 0, 0.05);
  --mls-card-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  --mls-card-shadow-hover: 0 20px 40px rgba(0, 0, 0, 0.12);
  --mls-glass-bg: rgba(255, 255, 255, 0.85);
  --mls-glass-border: rgba(255, 255, 255, 0.6);
  --mls-terminal-bg: rgba(25, 25, 30, 0.95);
  --mls-terminal-border: rgba(255, 255, 255, 0.1);
  --mls-terminal-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
  --mls-terminal-text: #e6e6e6;
  --mls-slider-bg: rgba(255, 255, 255, 0.5);
  --mls-slider-track: rgba(0, 0, 0, 0.1);
  --mls-slider-thumb: #ffffff;
  --mls-link: #444444;
  --mls-footer-bg: rgba(255, 255, 255, 0.9);
  --mls-vol-sep: rgba(0, 0, 0, 0.08);
}

[data-bs-theme="dark"] {
  --mls-accent: #ff4d6d;
  --mls-accent-hover: #ff758f;
  --mls-text: #e0e0e0;
  --mls-text-muted: #aaaaaa;
  --mls-bg: #0a0a0c;
  --mls-card-bg: rgba(20, 20, 25, 0.95);
  --mls-card-border: rgba(255, 255, 255, 0.1);
  --mls-card-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
  --mls-card-shadow-hover: 0 20px 40px rgba(0, 0, 0, 0.7);
  --mls-glass-bg: rgba(15, 15, 20, 0.85);
  --mls-glass-border: rgba(255, 255, 255, 0.1);
  --mls-terminal-bg: rgba(10, 10, 12, 0.95);
  --mls-terminal-border: rgba(255, 255, 255, 0.1);
  --mls-terminal-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
  --mls-terminal-text: #e6e6e6;
  --mls-slider-bg: rgba(20, 20, 25, 0.8);
  --mls-slider-track: rgba(255, 255, 255, 0.1);
  --mls-slider-thumb: #222222;
  --mls-link: #cccccc;
  --mls-footer-bg: rgba(20, 20, 25, 0.9);
  --mls-vol-sep: rgba(255, 255, 255, 0.1);
}

/* Page background */
html {
  scroll-snap-type: y mandatory;
  scroll-behavior: smooth;
  scroll-padding-top: 60px;
}

body,
#quarto-content,
main.content,
.column-page {
  background: var(--mls-bg) !important;
  color: var(--mls-text) !important;
}

/* No Quarto title block; we use .mls-hero only */
#title-block-header,
#title-block-header .description,
.quarto-title-block {
  display: none !important;
}

#quarto-margin-sidebar,
.quarto-sidebar-toggle {
  display: none !important;
}
.page-columns .content-col { margin-left: 0 !important; }

/* Neural net background: fixed, behind content, non-interactive */
#mls-neural-bg {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
  pointer-events: none;
  overflow: hidden;
}
#mls-neural-bg canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* Main column: above background; translucent so canvas shows through */
.mls-landing {
  position: relative;
  z-index: 1;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  color: var(--mls-text);
  line-height: 1.6;
  background: transparent;
}

.mls-section {
  scroll-snap-align: start;
  min-height: calc(100vh - 60px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 4rem 2rem;
  position: relative;
}

.mls-landing-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 3rem;
  align-items: center;
  width: 100%;
}

.mls-landing-left {
  background: var(--mls-glass-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  padding: 3rem;
  border-radius: 24px;
  border: 1px solid var(--mls-glass-border);
  box-shadow: var(--mls-card-shadow);
}

@media (max-width: 900px) {
  .mls-landing-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }
  .mls-landing-left {
    padding: 2rem;
  }
}

.mls-hero-eyebrow {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--mls-accent);
  margin: 0 0 1.5rem;
}

.mls-hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  color: var(--mls-text);
  letter-spacing: -0.03em;
  margin: 0 0 1.5rem;
  line-height: 1.2;
}

.mls-hero-tagline {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--mls-text);
  opacity: 0.9;
  margin: 0 0 1rem;
  line-height: 1.4;
}

.mls-hero-intro {
  font-size: 1.1rem;
  color: var(--mls-text-muted);
  margin: 0 0 2.5rem;
  line-height: 1.5;
}

.mls-meta {
  margin-top: 1rem;
}

.mls-links {
  font-size: 0.95rem;
  margin: 0 0 0.75rem;
}

.mls-links a {
  color: var(--mls-link);
  text-decoration: none;
  font-weight: 600;
}

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

/* Volume cards: stacked or side-by-side */
.mls-volumes {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

@media (min-width: 600px) {
  .mls-volumes {
    flex-direction: row;
    gap: 1.5rem;
  }
}

.mls-vol-card {
  background: var(--mls-card-bg);
  border: 1px solid var(--mls-card-border);
  border-radius: 16px;
  box-shadow: var(--mls-card-shadow);
  padding: 1.25rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.mls-vol-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--mls-card-shadow-hover);
}

.mls-vol-card-link {
  display: block;
  text-decoration: none;
  color: inherit;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

.mls-vol-card-link:hover { color: inherit; }

/* Cover: larger so images aren’t blurry, fixed aspect */
.mls-vol-cover-wrap {
  display: block;
  width: 100%;
  max-width: 100%;
  margin: 0 auto 1.5rem;
  border-radius: 4px;
  overflow: hidden;
}

.mls-vol-cover {
  width: 100%;
  height: auto;
  display: block;
  box-shadow: 0 4px 16px rgba(0,0,0,0.15);
}

.mls-vol-title {
  font-size: 0.85rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--mls-accent);
  margin: 0 0 0.5rem;
}

.mls-vol-subtitle {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--mls-text);
  margin: 0 0 1.25rem;
  line-height: 1.3;
}

.mls-vol-downloads {
  font-size: 0.85rem;
  color: var(--mls-text-muted);
  margin: auto 0 0 0;
  padding-top: 1rem;
  border-top: 1px solid var(--mls-vol-sep);
  font-weight: 600;
  display: flex;
  justify-content: space-between;
}

.mls-vol-downloads a {
  color: var(--mls-text);
  text-decoration: none;
}

.mls-vol-downloads a:hover {
  color: var(--mls-accent);
}

.mls-vol-sep {
  display: none;
}

.mls-footer {
  margin-top: 4rem;
  text-align: center;
  font-size: 0.85rem;
  color: var(--mls-text-muted);
}

.mls-footer span {
  background: var(--mls-footer-bg);
  padding: 0.5rem 1rem;
  border-radius: 6px;
  display: inline-block;
}

.mls-scroll-indicator {
  position: absolute;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%);
  text-align: center;
  color: var(--mls-text-muted);
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  animation: bounce 2s infinite;
  pointer-events: none;
}
.mls-scroll-arrow {
  font-size: 1.5rem;
  margin-top: 0.25rem;
  color: var(--mls-accent);
}
@keyframes bounce {
  0%, 20%, 50%, 80%, 100% { transform: translateY(0); }
  40% { transform: translateY(-10px); }
  60% { transform: translateY(-5px); }
}

/* Feature Sections (TinyTorch, Hardware, Labs) */
.mls-feature-card {
  background: var(--mls-card-bg);
  border: 1px solid var(--mls-card-border);
  border-radius: 12px;
  box-shadow: var(--mls-card-shadow);
  padding: 4rem 2rem;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  min-height: 400px;
}

.mls-feature-header {
  position: relative;
  display: inline-block;
  padding-left: 1.5rem;
  padding-bottom: 0.75rem;
  margin-bottom: 1.5rem;
  border-bottom: 1px solid rgba(165, 28, 48, 0.3);
  text-align: left;
}

.mls-feature-header::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.25rem;
  bottom: 0.75rem;
  width: 6px;
  background-color: var(--mls-accent);
}

.mls-feature-title {
  font-size: clamp(2rem, 4vw, 2.75rem);
  font-weight: 800;
  color: var(--mls-text);
  margin: 0;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.mls-feature-desc {
  font-size: 1.25rem;
  color: var(--mls-text-muted);
  max-width: 420px;
  margin: 0 auto;
  line-height: 1.5;
}

/* Animations */
/* Terminal Animation */
.css-terminal-wrapper {
  position: relative;
  width: 280px;
  margin: 0 auto 2rem auto;
  animation: floatTerminal 6s ease-in-out infinite;
}
.css-terminal {
  background: var(--mls-terminal-bg);
  border-radius: 8px;
  border: 1px solid var(--mls-terminal-border);
  box-shadow: var(--mls-terminal-shadow), inset 0 1px 0 rgba(255,255,255,0.1);
  overflow: hidden;
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
}
.css-terminal-header {
  background: rgba(0, 0, 0, 0.2);
  padding: 10px 12px;
  display: flex;
  gap: 8px;
  border-bottom: 1px solid rgba(0,0,0,0.2);
}
.term-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
}
.term-dot.close { background: #ff5f56; }
.term-dot.min { background: #ffbd2e; }
.term-dot.max { background: #27c93f; }
.css-terminal-body {
  padding: 16px;
  font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
  font-size: 0.75rem;
  color: var(--mls-terminal-text);
  text-align: left;
  min-height: 100px;
  line-height: 1.4;
}
.term-line {
  display: flex;
  gap: 10px;
  white-space: nowrap;
}
/* Syntax highlighting */
.term-kw { color: #ff7b72; }
.term-def { color: #d2a8ff; }
.term-var { color: #79c0ff; }
.term-num { color: #79c0ff; }

.term-prompt {
  color: #4285F4;
  font-weight: 600;
}
.term-cursor {
  display: inline-block;
  width: 8px;
  height: 16px;
  background: var(--mls-terminal-text);
  animation: blink 1s step-end infinite;
}
.term-shadow {
  position: absolute;
  bottom: -20px;
  left: 10%;
  width: 80%;
  height: 15px;
  background: rgba(0,0,0,0.1);
  border-radius: 50%;
  filter: blur(5px);
  animation: shadowTerminal 6s ease-in-out infinite;
}
[data-bs-theme="dark"] .term-shadow {
  background: rgba(0,0,0,0.5);
}
@keyframes floatTerminal {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}
@keyframes shadowTerminal {
  0%, 100% { transform: scale(1); opacity: 0.5; }
  50% { transform: scale(0.85); opacity: 0.2; }
}
@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

/* Hexagon/Cube Taxonomy Animation */
.hex-wrapper {
  position: relative;
  width: 320px;
  height: 240px;
  margin: 0 auto 2rem auto;
}
.hex-lines {
  position: absolute;
  top: 20px;
  left: 60px;
  width: 200px;
  height: 200px;
  overflow: visible;
  color: var(--mls-text-muted);
  opacity: 0.7;
}
.hex-polygon, .hex-line {
  stroke-dasharray: 6 6;
  animation: hexDash 20s linear infinite;
}
@keyframes hexDash {
  to { stroke-dashoffset: 200; }
}
.hex-dot {
  filter: drop-shadow(0 0 4px currentColor);
}
.dot-dam { color: var(--mls-accent); fill: var(--mls-accent); }
.dot-c3 { color: #4285F4; fill: #4285F4; }

.hex-node {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 8px;
  z-index: 2;
}
/* Center is at (160, 120). Radius is 80. */
.node-alg { top: 40px; left: 160px; transform: translate(-50%, -100%); flex-direction: column; padding-bottom: 8px;}
.node-comp { top: 80px; left: 229px; transform: translate(0, -50%); padding-left: 8px;}
.node-coord { top: 160px; left: 229px; transform: translate(0, -50%); padding-left: 8px;}
.node-mach { top: 200px; left: 160px; transform: translate(-50%, 0); flex-direction: column; padding-top: 8px;}
.node-comm { top: 160px; left: 91px; transform: translate(-100%, -50%); flex-direction: row-reverse; padding-right: 8px;}
.node-data { top: 80px; left: 91px; transform: translate(-100%, -50%); flex-direction: row-reverse; padding-right: 8px;}

.node-circle {
  width: 12px;
  height: 12px;
  background: var(--mls-card-bg);
  border: 2px solid var(--mls-text);
  border-radius: 50%;
  flex-shrink: 0;
  position: relative;
}
.node-circle::after {
  content: '';
  position: absolute;
  top: 2px; left: 2px; right: 2px; bottom: 2px;
  border-radius: 50%;
  background: currentColor;
  opacity: 0.5;
}
.dam-color { border-color: var(--mls-accent); color: var(--mls-accent); box-shadow: 0 0 10px rgba(165,28,48,0.2); }
[data-bs-theme="dark"] .dam-color { box-shadow: 0 0 10px rgba(255,77,109,0.3); }
.c3-color { border-color: #4285F4; color: #4285F4; box-shadow: 0 0 10px rgba(66,133,244,0.2); }

.node-label {
  font-size: 0.7rem;
  font-weight: 800;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--mls-text);
  white-space: nowrap;
}

.mls-feature-image {

.mls-feature-image {
  max-width: 140px;
  height: auto;
  margin-bottom: 2rem;
}