/**
 * QubitDecoded landing (blueprint) — uses design-system tokens only for colors.
 */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: var(--qd-font-size-base);
}

::selection {
  background: color-mix(in srgb, var(--qd-color-accent-success) 28%, transparent);
  color: var(--qd-color-text-primary);
}

::-webkit-scrollbar {
  width: 3px;
}

::-webkit-scrollbar-track {
  background: var(--qd-color-bg-base);
}

::-webkit-scrollbar-thumb {
  background: var(--qd-color-border-default);
  border-radius: var(--qd-radius-xs);
}

/* ─── Reading progress + grain (parity with index.html) ─── */
#rp {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  z-index: 5000;
  background: linear-gradient(
    90deg,
    var(--qd-color-accent-success),
    var(--qd-color-accent-cyan),
    var(--qd-color-accent-violet)
  );
  transform-origin: left;
  transform: scaleX(0);
  transition: transform 0.08s linear;
}

body.ld-page::after {
  content: '';
  pointer-events: none;
  position: fixed;
  inset: -200%;
  z-index: 9999;
  width: 400%;
  height: 400%;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.035'/%3E%3C/svg%3E");
  opacity: 0.55;
  animation: ld-grain 0.3s steps(2) infinite;
}

[data-theme='light'] body.ld-page::after {
  opacity: 0.28;
}

@keyframes ld-grain {
  0% {
    transform: translate(0, 0);
  }
  25% {
    transform: translate(-5%, -5%);
  }
  50% {
    transform: translate(-10%, 5%);
  }
  75% {
    transform: translate(5%, -10%);
  }
  100% {
    transform: translate(-5%, 10%);
  }
}

/* ─── Page base ─── */
.ld-page {
  font-family: var(--qd-font-sans);
  background: var(--qd-color-bg-base);
  color: var(--qd-color-text-primary);
  line-height: var(--qd-line-height-body);
  overflow-x: hidden;
  transition: background 0.35s var(--qd-motion-easing-standard),
    color 0.35s var(--qd-motion-easing-standard);
}

.ld-page a {
  color: inherit;
  text-decoration: none;
}

/* ─── NAV — styles/ld-nav-shell.css (linked after this file on each page) ─── */

/* ─── HERO ─── */
.ld-hero {
  position: relative;
  z-index: 1;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: var(--qd-space-8) var(--qd-space-8) var(--qd-space-12);
  padding-top: calc(var(--qd-layout-nav-height) + var(--qd-space-10));
  overflow: hidden;
}

.ld-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(
      ellipse 800px 500px at 70% 40%,
      color-mix(in srgb, var(--qd-color-accent-cyan) 6%, transparent) 0%,
      transparent 70%
    ),
    radial-gradient(
      ellipse 600px 400px at 20% 60%,
      color-mix(in srgb, var(--qd-color-accent-success) 5%, transparent) 0%,
      transparent 70%
    );
}

.ld-hero-grid {
  position: relative;
  z-index: 1;
  max-width: var(--qd-layout-container-max);
  margin: 0 auto;
  width: 100%;
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: var(--qd-space-12);
  align-items: center;
}

.ld-hero-copy {
  position: relative;
  z-index: 1;
}

.ld-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--qd-space-2);
  font-family: var(--qd-font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--qd-color-accent-success);
  background: var(--qd-color-accent-success-muted);
  border: 1px solid var(--qd-color-accent-success-border);
  border-radius: var(--qd-radius-full);
  padding: 0.3rem 0.9rem;
  margin-bottom: var(--qd-space-6);
  animation: ld-fade-up 0.6s 0.1s var(--qd-motion-easing-standard) both;
}

.ld-eyebrow-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--qd-color-accent-success);
  animation: ld-pulse 2.4s ease-in-out infinite;
}

@keyframes ld-pulse {
  0%,
  100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.2;
    transform: scale(0.5);
  }
}

@keyframes ld-fade-up {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.ld-h1 {
  font-family: var(--qd-font-serif);
  font-size: clamp(3rem, 5.5vw, 4.8rem);
  font-weight: 300;
  line-height: 1.02;
  letter-spacing: -0.04em;
  color: var(--qd-color-text-primary);
  margin-bottom: var(--qd-space-6);
  animation: ld-fade-up 0.7s 0.18s var(--qd-motion-easing-standard) both;
}

.ld-h1-accent {
  font-style: italic;
  font-weight: 600;
  background: linear-gradient(
    115deg,
    var(--qd-color-accent-success) 0%,
    var(--qd-color-accent-cyan) 55%,
    var(--qd-color-accent-violet) 100%
  );
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.ld-lede {
  font-size: 1.1rem;
  line-height: 1.8;
  color: var(--qd-color-text-secondary);
  max-width: 480px;
  margin-bottom: var(--qd-space-8);
  animation: ld-fade-up 0.7s 0.26s var(--qd-motion-easing-standard) both;
}

.ld-lede strong {
  color: var(--qd-color-text-primary);
  font-weight: 600;
}

.ld-hero-actions {
  display: flex;
  align-items: center;
  gap: var(--qd-space-4);
  flex-wrap: wrap;
  margin-bottom: var(--qd-space-6);
  animation: ld-fade-up 0.7s 0.38s var(--qd-motion-easing-standard) both;
}

.ld-btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.85rem 1.9rem;
  border-radius: var(--qd-radius-lg);
  background: var(--qd-color-accent-success);
  color: var(--qd-color-on-accent-dark);
  font-family: var(--qd-font-sans);
  font-size: 0.95rem;
  font-weight: 700;
  text-decoration: none;
  box-shadow: var(--qd-shadow-glow-success), var(--qd-shadow-control);
  transition: transform 0.2s var(--qd-motion-easing-standard),
    box-shadow 0.2s var(--qd-motion-easing-standard);
}

.ld-btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--qd-shadow-glow-success), var(--qd-shadow-control-hover);
}

.ld-btn-arrow {
  transition: transform 0.2s var(--qd-motion-easing-standard);
}

.ld-btn-primary:hover .ld-btn-arrow {
  transform: translateX(4px);
}

.ld-btn-ghost {
  display: inline-flex;
  align-items: center;
  padding: 0.85rem 1.5rem;
  border-radius: var(--qd-radius-lg);
  border: 1px solid var(--qd-color-border-default);
  color: var(--qd-color-text-secondary);
  font-size: 0.95rem;
  text-decoration: none;
  transition: border-color 0.2s var(--qd-motion-easing-standard),
    color 0.2s var(--qd-motion-easing-standard),
    background 0.2s var(--qd-motion-easing-standard);
}

.ld-btn-ghost:hover {
  border-color: var(--qd-color-accent-cyan-border);
  color: var(--qd-color-accent-cyan);
  background: var(--qd-color-accent-cyan-muted);
}

.ld-proof {
  font-size: 0.78rem;
  color: var(--qd-color-text-tertiary);
  font-style: italic;
  animation: ld-fade-up 0.7s 0.5s var(--qd-motion-easing-standard) both;
}

/* Bloch column (class names aligned with index inline script) */
.sphere-col {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.1rem;
}

.sphere-wrap {
  position: relative;
  width: 420px;
  height: 420px;
  flex-shrink: 0;
}

#bloch3d {
  position: absolute;
  inset: 0;
  width: 100% !important;
  height: 100% !important;
  display: block;
  cursor: grab;
  touch-action: none;
  border-radius: 50%;
}

#bloch3d:active {
  cursor: grabbing;
}

.sphere-aura {
  position: absolute;
  inset: -32px;
  border-radius: 50%;
  pointer-events: none;
  background: radial-gradient(
    circle,
    color-mix(in srgb, var(--qd-color-accent-cyan) 13%, transparent) 0%,
    transparent 66%
  );
  animation: ld-breathe 3.8s ease-in-out infinite;
}

@keyframes ld-breathe {
  0%,
  100% {
    opacity: 0.6;
    transform: scale(1);
  }
  50% {
    opacity: 1;
    transform: scale(1.06);
  }
}

.drag-hint {
  position: absolute;
  inset: 0;
  z-index: 5;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  pointer-events: none;
  transition: opacity 0.5s ease;
}

.drag-hint.hidden {
  opacity: 0;
}

.drag-hint-icon {
  font-size: 1.6rem;
  animation: ld-drag-nudge 1.8s ease-in-out infinite;
}

@keyframes ld-drag-nudge {
  0%,
  100% {
    transform: translate(0, 0);
  }
  25% {
    transform: translate(8px, -5px);
  }
  75% {
    transform: translate(-8px, 5px);
  }
}

.drag-hint-text {
  font-family: var(--qd-font-mono);
  font-size: 0.68rem;
  color: var(--qd-color-accent-cyan);
  letter-spacing: 0.06em;
  background: color-mix(in srgb, var(--qd-color-bg-base) 55%, transparent);
  backdrop-filter: blur(4px);
  border: 1px solid var(--qd-color-accent-cyan-border);
  border-radius: var(--qd-radius-sm);
  padding: 0.25rem 0.65rem;
}

[data-theme='light'] .drag-hint-text {
  background: color-mix(in srgb, var(--qd-color-bg-surface-1) 80%, transparent);
}

.q-label {
  position: absolute;
  z-index: 2;
  font-family: var(--qd-font-mono);
  font-size: 0.72rem;
  color: var(--qd-color-accent-cyan);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.7s ease;
  text-shadow: 0 0 10px color-mix(in srgb, var(--qd-color-accent-cyan) 45%, transparent);
  white-space: nowrap;
  background: color-mix(in srgb, var(--qd-color-bg-base) 45%, transparent);
  backdrop-filter: blur(4px);
  border: 1px solid color-mix(in srgb, var(--qd-color-accent-cyan) 12%, transparent);
  border-radius: var(--qd-radius-sm);
  padding: 0.2rem 0.5rem;
}

[data-theme='light'] .q-label {
  background: color-mix(in srgb, var(--qd-color-bg-surface-1) 75%, transparent);
}

.q-label.show {
  opacity: 1;
}

.ql-top-center {
  top: 6%;
  left: 50%;
  transform: translateX(-50%);
}

.ql-top-left {
  top: 30%;
  left: -2%;
}

.ql-bottom-left {
  bottom: 30%;
  left: -2%;
}

.ql-bottom-center {
  bottom: 6%;
  left: 50%;
  transform: translateX(-50%);
}

.sphere-readout {
  font-family: var(--qd-font-mono);
  font-size: 0.78rem;
  color: var(--qd-color-accent-cyan);
  text-align: center;
  animation: ld-fade-up 0.8s 0.6s ease both;
}

.sr-state {
  margin-bottom: 0.18rem;
}

.sr-hint {
  font-size: 0.66rem;
  color: var(--qd-color-text-tertiary);
  font-style: italic;
}

/* ─── MARQUEE ─── */
.ld-marquee {
  overflow: hidden;
  border-top: 1px solid var(--qd-color-border-subtle);
  border-bottom: 1px solid var(--qd-color-border-subtle);
  padding: 0.9rem 0;
  background: linear-gradient(
    90deg,
    var(--qd-color-accent-cyan-muted) 0%,
    var(--qd-color-accent-success-muted) 50%,
    color-mix(in srgb, var(--qd-color-accent-violet) 8%, transparent) 100%
  );
}

.ld-marquee-track {
  display: flex;
  gap: 2.5rem;
  width: max-content;
  animation: ld-scroll 40s linear infinite;
}

.ld-marquee-track:hover {
  animation-play-state: paused;
}

@keyframes ld-scroll {
  from {
    transform: translateX(0);
  }
  to {
    transform: translateX(-50%);
  }
}

.ld-marquee-item {
  font-family: var(--qd-font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  white-space: nowrap;
  color: var(--qd-color-text-tertiary);
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.ld-marquee-item::before {
  content: '·';
  color: var(--qd-color-accent-cyan);
  font-size: 1.1rem;
  opacity: 0.4;
}

.ld-marquee-item.accent-green {
  color: var(--qd-color-accent-success);
}

.ld-marquee-item.accent-cyan {
  color: var(--qd-color-accent-cyan);
}

.ld-marquee-item.accent-violet {
  color: var(--qd-color-accent-violet);
}

.ld-marquee-item.accent-amber {
  color: var(--qd-color-accent-amber);
}

/* ─── ABOUT ─── */
.ld-about {
  padding: var(--qd-space-16) var(--qd-space-8);
  max-width: var(--qd-layout-container-max);
  margin: 0 auto;
}

.ld-about-grid {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 6rem;
  align-items: start;
}

.ld-section-label {
  font-family: var(--qd-font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--qd-color-accent-cyan);
  margin-bottom: var(--qd-space-4);
}

.ld-section-h2 {
  font-family: var(--qd-font-serif);
  font-size: clamp(2rem, 3.5vw, 2.8rem);
  font-weight: 300;
  line-height: 1.15;
  letter-spacing: -0.025em;
  color: var(--qd-color-text-primary);
  margin-bottom: var(--qd-space-8);
}

.ld-section-h2 em {
  font-style: italic;
  font-weight: 600;
  color: var(--qd-color-accent-cyan);
}

.ld-body-text {
  font-size: 1.05rem;
  line-height: 1.82;
  color: var(--qd-color-text-secondary);
  margin-bottom: var(--qd-space-6);
  max-width: 56ch;
}

.ld-about-aside {
  display: flex;
  flex-direction: column;
  gap: var(--qd-space-8);
  padding-top: 3.5rem;
}

.ld-stat-block {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding-bottom: var(--qd-space-8);
  border-bottom: 1px solid var(--qd-color-border-subtle);
}

.ld-stat-block:last-child {
  border-bottom: none;
}

.ld-stat-num {
  font-family: var(--qd-font-mono);
  font-size: 3rem;
  font-weight: 700;
  line-height: 1;
  color: var(--qd-color-text-primary);
  letter-spacing: -0.04em;
}

[data-theme='light'] .ld-stat-num {
  color: var(--qd-color-accent-success);
}

.ld-stat-label {
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--qd-color-text-secondary);
}

/* ─── TRACKS ─── */
.ld-tracks {
  padding: var(--qd-space-16) var(--qd-space-8);
  max-width: var(--qd-layout-container-max);
  margin: 0 auto;
}

.ld-section-header {
  margin-bottom: var(--qd-space-12);
}

.ld-track-shelf {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: start;
  padding: 2.5rem;
  border: 1px solid var(--qd-color-border-subtle);
  border-radius: var(--qd-radius-lg);
  background: var(--qd-color-bg-surface-1);
  margin-bottom: var(--qd-space-6);
  transition: border-color 0.25s var(--qd-motion-easing-standard),
    background 0.25s var(--qd-motion-easing-standard);
  position: relative;
  overflow: hidden;
}

.ld-track-shelf::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  border-radius: 3px 0 0 3px;
}

.ld-track-shelf--green::before {
  background: var(--qd-color-accent-success);
}

.ld-track-shelf--blue::before {
  background: var(--qd-color-accent-blue);
}

.ld-track-shelf:hover {
  background: var(--qd-color-bg-surface-2);
}

.ld-track-shelf--green:hover {
  border-color: var(--qd-color-accent-success-border);
}

.ld-track-shelf--blue:hover {
  border-color: color-mix(in srgb, var(--qd-color-accent-blue) 28%, var(--qd-color-border-default));
}

.ld-track-meta {
  display: flex;
  align-items: center;
  gap: var(--qd-space-4);
  margin-bottom: var(--qd-space-4);
}

.ld-track-badge {
  font-family: var(--qd-font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  padding: 0.2rem 0.7rem;
  border-radius: var(--qd-radius-full);
}

.ld-track-badge--green {
  background: var(--qd-color-accent-success-muted);
  border: 1px solid var(--qd-color-accent-success-border);
  color: var(--qd-color-accent-success);
}

.ld-track-badge--blue {
  background: color-mix(in srgb, var(--qd-color-accent-blue) 10%, transparent);
  border: 1px solid color-mix(in srgb, var(--qd-color-accent-blue) 25%, transparent);
  color: var(--qd-color-accent-blue);
}

.ld-track-count {
  font-size: 0.8rem;
  color: var(--qd-color-text-tertiary);
  font-family: var(--qd-font-mono);
}

.ld-track-name {
  font-family: var(--qd-font-serif);
  font-size: 1.9rem;
  font-weight: 400;
  letter-spacing: -0.02em;
  color: var(--qd-color-text-primary);
  margin-bottom: var(--qd-space-4);
  line-height: 1.15;
}

.ld-track-desc {
  font-size: 0.97rem;
  line-height: 1.78;
  color: var(--qd-color-text-secondary);
  margin-bottom: var(--qd-space-8);
  max-width: 44ch;
}

.ld-btn-primary--blue {
  background: var(--qd-color-accent-blue);
  color: var(--qd-color-on-accent-light);
  box-shadow: var(--qd-shadow-accent-blue-soft), var(--qd-shadow-control);
}

.ld-btn-primary--blue:hover {
  box-shadow: var(--qd-shadow-accent-blue-soft), var(--qd-shadow-control-hover);
}

.ld-lesson-preview {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0;
  padding: 0;
  border: 1px solid var(--qd-color-border-subtle);
  border-radius: var(--qd-radius-md);
  overflow: hidden;
}

.ld-lp-item {
  font-size: 0.88rem;
  color: var(--qd-color-text-secondary);
  padding: 0.7rem 1rem;
  border-bottom: 1px solid var(--qd-color-border-subtle);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  transition: background 0.15s;
}

.ld-lp-item::before {
  content: '';
  width: 5px;
  height: 5px;
  border-radius: 50%;
  flex-shrink: 0;
  background: var(--qd-color-text-tertiary);
  opacity: 0.4;
}

.ld-lp-item:hover {
  background: color-mix(in srgb, var(--qd-color-text-primary) 3%, transparent);
}

.ld-lp-fade {
  opacity: 0.4;
}

.ld-lp-more {
  font-size: 0.8rem;
  color: var(--qd-color-text-tertiary);
  padding: 0.6rem 1rem;
  font-family: var(--qd-font-mono);
  font-style: italic;
}

/* ─── SIMULATORS ─── */
.ld-simulators {
  background: var(--qd-color-bg-surface-1);
  border-top: 1px solid var(--qd-color-border-subtle);
  border-bottom: 1px solid var(--qd-color-border-subtle);
  padding: var(--qd-space-16) var(--qd-space-8);
}

.ld-sim-inner {
  max-width: var(--qd-layout-container-max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5rem;
  align-items: center;
}

.ld-sim-h2-tight {
  max-width: 14ch;
}

.ld-sim-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin-top: var(--qd-space-6);
  counter-reset: sim-counter;
}

.ld-sim-list li {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-size: 0.93rem;
  color: var(--qd-color-text-secondary);
  padding: 0.5rem 0;
  border-bottom: 1px solid var(--qd-color-border-subtle);
  counter-increment: sim-counter;
}

.ld-sim-list li::before {
  content: counter(sim-counter, decimal-leading-zero);
  font-family: var(--qd-font-mono);
  font-size: 0.7rem;
  color: var(--qd-color-accent-cyan);
  opacity: 0.6;
  min-width: 2ch;
}

.ld-sim-list li:last-child {
  border-bottom: none;
}

.ld-sim-frame-wrap {
  position: relative;
  background: var(--qd-color-bg-surface-2);
  border: 1px solid var(--qd-color-border-default);
  border-radius: var(--qd-radius-lg);
  overflow: hidden;
  aspect-ratio: 4 / 3;
  box-shadow: var(--qd-shadow-elevated),
    0 0 0 1px var(--qd-color-border-subtle);
}

.ld-sim-frame-wrap::after {
  content: '';
  position: absolute;
  inset: 36px 0 0 0;
  pointer-events: none;
  background-image:
    linear-gradient(var(--qd-color-border-subtle) 1px, transparent 1px),
    linear-gradient(90deg, var(--qd-color-border-subtle) 1px, transparent 1px);
  background-size: 32px 32px;
  opacity: 0.5;
  z-index: 0;
}

.ld-window-chrome {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 36px;
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 0 14px;
  background: var(--qd-color-bg-surface-1);
  border-bottom: 1px solid var(--qd-color-border-subtle);
}

.ld-chrome-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}

.ld-dot-red {
  background: var(--qd-color-accent-rose);
}

.ld-dot-yellow {
  background: var(--qd-color-accent-amber);
}

.ld-dot-green {
  background: var(--qd-color-accent-success);
}

.ld-sim-frame {
  position: absolute;
  inset: 36px 0 0 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background:
    radial-gradient(
      ellipse 60% 60% at 50% 50%,
      color-mix(in srgb, var(--qd-color-accent-cyan) 8%, transparent) 0%,
      transparent 70%
    );
}

.ld-sim-preview-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1rem;
  text-decoration: none;
  color: inherit;
  position: relative;
  z-index: 1;
}

.ld-sim-play-btn {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  background: var(--qd-color-accent-cyan-muted);
  border: 2px solid var(--qd-color-accent-cyan-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  color: var(--qd-color-accent-cyan);
  transition: transform 0.2s var(--qd-motion-easing-standard),
    background 0.2s var(--qd-motion-easing-standard);
}

.ld-sim-preview-link:hover .ld-sim-play-btn {
  background: color-mix(in srgb, var(--qd-color-accent-cyan) 20%, transparent);
  transform: scale(1.08);
}

.ld-sim-preview-label {
  font-family: var(--qd-font-mono);
  font-size: 0.72rem;
  color: var(--qd-color-text-tertiary);
  letter-spacing: 0.08em;
}

/* ─── QUANTUM LAB (homepage) ─── */
.ld-quantum-lab {
  padding: var(--qd-space-16) var(--qd-space-8);
  border-top: 1px solid var(--qd-color-border-subtle);
  background: var(--qd-color-bg-base);
}

.ld-quantum-lab .ld-body-text a {
  color: var(--qd-color-accent-cyan);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.ld-quantum-lab .ld-body-text a:hover {
  color: var(--qd-color-text-primary);
}

.ld-lab-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--qd-space-3);
  align-items: center;
  margin-top: var(--qd-space-6);
}

.ld-lab-promo {
  width: min(94%, 520px);
  margin-left: auto;
  margin-right: auto;
  display: grid;
  gap: 0.75rem;
  border: 1px solid color-mix(in srgb, var(--qd-color-accent-blue) 38%, transparent);
  border-radius: 16px;
  padding: 1.15rem 1.1rem 1.25rem;
  background: linear-gradient(145deg, rgba(15, 23, 42, 0.96), rgba(30, 58, 138, 0.42));
  box-shadow: 0 14px 40px rgba(2, 10, 23, 0.38), inset 0 0 0 1px rgba(148, 163, 184, 0.08);
}

.ld-lab-promo-badge {
  justify-self: start;
  font-family: var(--qd-font-mono);
  font-size: 0.64rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #93c5fd;
  border: 1px solid color-mix(in srgb, var(--qd-color-accent-blue) 45%, transparent);
  border-radius: 999px;
  padding: 0.28rem 0.64rem;
}

.ld-lab-promo-title {
  margin: 0;
  font-family: var(--qd-font-serif);
  font-size: clamp(1.05rem, 2vw, 1.35rem);
  color: #e8f0ff;
  letter-spacing: -0.02em;
}

.ld-lab-promo ul {
  margin: 0;
  padding-left: 1.15rem;
  font-size: 0.86rem;
  color: #b6c9e8;
  line-height: 1.55;
}

.ld-lab-promo-cta {
  justify-self: start;
  margin-top: 0.15rem;
}

/* ─── FOOTER ─── */
.ld-footer {
  padding: var(--qd-space-10) var(--qd-space-8);
  border-top: 1px solid var(--qd-color-border-subtle);
}

.ld-footer-inner {
  max-width: var(--qd-layout-container-max);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--qd-space-6);
  flex-wrap: wrap;
}

.ld-footer-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--qd-font-mono);
  font-size: 0.88rem;
  color: var(--qd-color-text-secondary);
}

.ld-footer-links {
  display: flex;
  gap: 2rem;
}

.ld-footer-links a {
  font-size: 0.88rem;
  color: var(--qd-color-text-tertiary);
  text-decoration: none;
  transition: color 0.2s;
}

.ld-footer-links a:hover {
  color: var(--qd-color-text-primary);
}

.ld-footer-copy {
  font-size: 0.78rem;
  color: var(--qd-color-text-tertiary);
  font-style: italic;
}

.ld-footer-mark {
  width: 28px;
  height: 28px;
  border-radius: var(--qd-radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--qd-font-mono);
  font-size: 0.65rem;
  font-weight: 700;
  color: var(--qd-color-on-accent-dark);
  background: linear-gradient(
    135deg,
    var(--qd-color-accent-success),
    var(--qd-color-accent-cyan)
  );
  box-shadow: var(--qd-shadow-accent-success-soft);
}

/* ─── Scroll reveal (landing.js) ─── */
.ld-revealed {
  opacity: 1 !important;
  transform: none !important;
}

/* ─── Responsive ─── */
@media (max-width: 1060px) {
  .ld-hero-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .sphere-col {
    flex-direction: row;
    justify-content: flex-start;
    gap: 2rem;
  }

  .sphere-wrap {
    width: 320px;
    height: 320px;
  }
}

@media (max-width: 900px) {
  .ld-about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  .ld-about-aside {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 2rem;
    padding-top: 0;
  }

  .ld-track-shelf {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .ld-sim-inner {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

}

@media (max-width: 640px) {
  .ld-tracks,
  .ld-about,
  .ld-quantum-lab,
  .ld-simulators {
    padding: 3rem var(--qd-space-4);
  }

  .ld-hero {
    padding-left: var(--qd-space-4);
    padding-right: var(--qd-space-4);
  }

  .ld-h1 {
    font-size: clamp(2.2rem, 8vw, 3rem);
  }

  .ld-section-h2 {
    font-size: 1.75rem;
  }

  .ld-hero-actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .ld-about-aside {
    flex-direction: column;
  }

  .ld-footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: 1.5rem;
  }

  .sphere-col {
    flex-direction: column;
    align-items: center;
  }

  .sphere-wrap {
    width: 280px;
    height: 280px;
  }

}

@media (prefers-reduced-motion: reduce) {
  .ld-marquee-track {
    animation: none;
  }

  .ld-eyebrow,
  .ld-h1,
  .ld-lede,
  .ld-hero-actions,
  .ld-proof,
  .sphere-readout,
  .sphere-aura,
  .drag-hint-icon,
  .ld-eyebrow-dot {
    animation: none !important;
  }

  #bloch3d {
    display: none !important;
  }

  .ld-track-shelf,
  .ld-stat-block,
  .ld-sim-frame-wrap,
  .ld-lab-promo,
  .ld-section-header {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .ld-revealed {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }
}

/* ═══════════════════════════════════════════════════════════
   LIGHT THEME OVERRIDES
   All light-mode adjustments in one place.
   Dark theme is unaffected — these only activate under
   [data-theme="light"].
═══════════════════════════════════════════════════════════ */

/* ── Nav (light) — styles/ld-nav-shell.css ── */

/* ── Hero ── */
[data-theme='light'] .ld-hero {
  background:
    radial-gradient(ellipse 900px 600px at 65% 30%, rgba(5, 150, 105, 0.06) 0%, transparent 65%),
    radial-gradient(ellipse 700px 500px at 15% 70%, rgba(0, 143, 136, 0.05) 0%, transparent 65%);
}

[data-theme='light'] .ld-hero::before {
  /* Override the dark glow — lighter, more subtle */
  background:
    radial-gradient(ellipse 700px 450px at 68% 38%, rgba(5, 150, 105, 0.07) 0%, transparent 70%),
    radial-gradient(ellipse 500px 350px at 18% 62%, rgba(0, 143, 136, 0.05) 0%, transparent 70%);
}

[data-theme='light'] .ld-eyebrow,
[data-theme='light'] .ld-section-label {
  color: var(--qd-color-accent-success);
}

[data-theme='light'] .ld-lede {
  color: #4a5568;
}

[data-theme='light'] .ld-hero-h1 em,
[data-theme='light'] .ld-hero h1 em {
  background: linear-gradient(115deg, #059669 0%, #008f88 50%, #7c3aed 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ── Proof / social strip ── */
[data-theme='light'] .ld-proof {
  color: #4a5568;
}

/* ── Marquee strip ── */
[data-theme='light'] .ld-marquee {
  background: linear-gradient(
    90deg,
    rgba(5, 150, 105, 0.05) 0%,
    rgba(0, 143, 136, 0.04) 50%,
    rgba(124, 58, 237, 0.04) 100%
  );
  border-top-color: rgba(0, 0, 0, 0.07);
  border-bottom-color: rgba(0, 0, 0, 0.07);
}

[data-theme='light'] .ld-marquee-item {
  color: #4a5568;
}

[data-theme='light'] .ld-marquee-item.accent-green {
  color: #059669;
}
[data-theme='light'] .ld-marquee-item.accent-cyan {
  color: #008f88;
}
[data-theme='light'] .ld-marquee-item.accent-violet {
  color: #7c3aed;
}
[data-theme='light'] .ld-marquee-item.accent-amber {
  color: #d97706;
}

/* ── About / stat blocks ── */
[data-theme='light'] .ld-about-grid {
  background: #ffffff;
  border: 1px solid rgba(0, 0, 0, 0.08);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.06);
}

[data-theme='light'] .ld-stat-block {
  border-right-color: rgba(0, 0, 0, 0.07);
}

[data-theme='light'] .ld-stat-num {
  color: var(--qd-color-accent-success);
}

[data-theme='light'] .ld-stat-label {
  color: #6b7280;
}

/* ── Track shelf cards ── */
[data-theme='light'] .ld-track-shelf {
  background: #ffffff;
  border-color: rgba(0, 0, 0, 0.1);
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.07);
}

[data-theme='light'] .ld-track-shelf:hover {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.11);
  border-color: rgba(0, 0, 0, 0.15);
}

[data-theme='light'] .ld-track-tag {
  background: rgba(5, 150, 105, 0.08);
  border-color: rgba(5, 150, 105, 0.22);
}

/* ── Simulators section ── */
[data-theme='light'] .ld-sim-frame-wrap {
  background: #ffffff;
  border-color: rgba(0, 0, 0, 0.1);
  box-shadow: 0 2px 16px rgba(0, 0, 0, 0.07);
}

[data-theme='light'] .ld-sim-frame {
  background: radial-gradient(ellipse 60% 60% at 50% 50%, rgba(5, 150, 105, 0.07) 0%, transparent 70%);
}

[data-theme='light'] .ld-sim-frame-wrap::after {
  background-image:
    linear-gradient(rgba(0, 0, 0, 0.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(0, 0, 0, 0.06) 1px, transparent 1px);
  opacity: 0.6;
}

/* macOS chrome dots in light mode */
[data-theme='light'] .ld-sim-chrome {
  background: #f0f3f8;
  border-bottom-color: rgba(0, 0, 0, 0.08);
}

[data-theme='light'] .ld-quantum-lab {
  background: #f8fafc;
  border-top-color: rgba(0, 0, 0, 0.08);
}

[data-theme='light'] .ld-lab-promo {
  background: linear-gradient(145deg, #ffffff, #f1f5f9);
  border-color: color-mix(in srgb, var(--qd-color-accent-blue) 28%, rgba(0, 0, 0, 0.1));
  box-shadow: 0 8px 28px rgba(15, 23, 42, 0.08);
}

[data-theme='light'] .ld-lab-promo-badge {
  color: #2563eb;
  border-color: rgba(37, 99, 235, 0.35);
}

[data-theme='light'] .ld-lab-promo-title {
  color: #0f172a;
}

[data-theme='light'] .ld-lab-promo ul {
  color: #475569;
}

/* ── Section header labels ── */
[data-theme='light'] .ld-section-header .ld-section-label {
  color: var(--qd-color-accent-success);
}

/* ── Footer ── */
[data-theme='light'] .ld-footer {
  background: #f0f3f8;
  border-top-color: rgba(0, 0, 0, 0.09);
}

[data-theme='light'] .ld-footer-logo {
  color: #0c1117;
}

[data-theme='light'] .ld-footer-links a {
  color: #6b7280;
}

[data-theme='light'] .ld-footer-links a:hover {
  color: #0c1117;
}

[data-theme='light'] .ld-footer-copy {
  color: #94a3b8;
}

/* ── Sphere labels and readout ── */
[data-theme='light'] .q-label {
  background: rgba(255, 255, 255, 0.82);
  border-color: rgba(0, 143, 136, 0.18);
  color: #008f88;
  text-shadow: none;
}

[data-theme='light'] .sphere-readout {
  color: #008f88;
}

[data-theme='light'] .drag-hint-text {
  background: rgba(255, 255, 255, 0.88);
  border-color: rgba(0, 143, 136, 0.2);
  color: #008f88;
}

/* ── Sphere aura — lighter glow ── */
[data-theme='light'] .sphere-aura {
  background: radial-gradient(circle, rgba(5, 150, 105, 0.1) 0%, transparent 66%);
}